Overview of Alzheimer’s Disease

Alzheimer’s disease (AD) is an irreversible, progressive disorder in which brain cells (neurons) deteriorate, resulting in the loss of cognitive functions, primarily memory, judgment and reasoning, movement coordination and pattern recognition. In advanced stages of the disease, all memory and mental functioning may be lost.

Brain Anatomy

The cerebral cortex is an extremely convoluted and complicated structure associated with the “higher” functions of the mind—thought, reasoning, sensation, and motion. Each hemisphere of the cerebral cortex contains areas that control certain types of activity. These areas are referred to as the frontal lobe, parietal lobe, temporal lobe, and occipital lobe.

• The frontal lobe, located behind the forehead, is involved with controlling responses to input from the rest of the central nervous system (brain and spinal cord). It is responsible for voluntary movement, emotion, planning and execution of behavior, intellect, memory, speech, and writing.
• The parietal lobe, located above the ear, receives and interprets sensations of pain pressure, temperature, touch, size, shape, and body part awareness.
• The temporal lobe, located behind the ear, is involved in understanding sounds and spoken words, as well as emotion and memory.
• The occipital lobe, located at the back of the head, is involved in understanding visual images and the meaning of the written word.

The hippocampus plays a crucial role in learning and in processing various forms of information as long-term memory. Damage to the hippocampus produces global amnesia.

Plaques and Tangles

The two most significant physical findings in the cells of brains affected by Alzheimer’s disease are neuritic plaques and neurofibrillary tangles. Another significant factor in AD is the greatly reduced presence of acetylcholine in the cerebral cortex. Acetylcholine is necessary for cognitive function.

While some neuritic plaques, or patches, are commonly found in brains of elderly people, they appear in excessive numbers in the cerebral cortex of Alzheimer’s disease patients. A protein called beta amyloid occupies the center of these plaques. Surrounding the protein are fragments of deteriorating neurons, especially those that produce acetylcholine (ACh), a neurotransmitter essential for processing memory and learning. Neurotransmitters are chemicals that transport information or signals between neurons.

Neurofibrillary tangles (NFTs) are twisted remnants of a protein called tau, which is found inside brain cells and is essential for maintaining proper cell structure and function. An abnormality in the tau protein disrupts normal cell activity.

According to the Alzheimer’s Association, about 5.2 million people in the United States suffer from Alzheimer’s disease—and two-thirds of those affected are women. The Association reports that about 3.2 million American women and 1.8 million American men over the age of 60 have Alzheimer’s. Approximately 10 percent of all people over the age of 65 and as many as 50 percent of those over the age of 85 are diagnosed with the condition, which is the sixth leading cause for death in the United States.

Routine blood tests help determine the cause of back problems in a few situations. Results may reflect the presence of inflammation and/or an infection. For example:

• Blood levels of alkaline phosphatase (an enzyme released by bone-forming cells called osteoblasts) are often extremely high in people with active Paget’s disease (which can cause vertebral compression fractures and spinal stenosis). • Blood calcium levels are elevated in people with hyperparathyroidism (which, along with osteoporosis, can lead to vertebral compression fractures). • Prostate-specific antigen (PSA), which is elevated in men with prostate cancer, can be measured by a blood test to determine whether back pain is due to the spread of prostate cancer. • Abnormal proteins in blood and urine are often present in people with multiple myeloma (cancer of the plasma cells, a type of white blood cell).

Imaging Tests of the Back

Diagnostic imaging studies of the back provide a view of the bones and the soft tissues, which comprise muscles, ligaments, cartilage, tendons, and blood vessels. These studies are usually done when surgery might be necessary, when the doctor suspects a serious condition may be responsible for the back pain, or when you are experiencing severe pain.

Experts advise against routine imaging studies when no particular cause of the pain is identified through the physical examination, patient history, and laboratory tests. When imaging is ordered, the study chosen depends, in large part, on what is suspected to be causing the pain

Overview of Bell’s Palsy

Bell’s palsy is a form of temporary facial paralysis resulting from damage or trauma to one of the two facial nerves that is known as the seventh cranial nerve. The paralysis causes distortion of facial features and interferes with normal facial function, such as closing the eyes, chewing, and eating.

Bell’s palsy is named for Sir Charles Bell, a Scottish surgeon who studied the nerve and its innervation of the facial muscles approximately 200 years ago.

Facial Nerve Anatomy

The facial nerve controls the muscles that move the eyebrows, close the eyes, and move the mouth and lips. It also controls the tear glands, one of the salivary glands, and the taste buds in the front of the tongue.

Electrochemical signals are relayed between the brain and many facial muscles by 7000 nerve fibers that comprise the facial nerve. When the facial nerve is damaged, as in Bell’s palsy, the action of each nerve fiber is disrupted. Because the facial nerve controls several functions, several symptoms occur.

Incidence & Prevalence of Bell’s Palsy

Bell’s palsy affects about 40,000 people in the United States every year. It affects approximately 1 person in 65 during a lifetime. Worldwide statistics indicate a frequency of about .02 percent of the population.

Overview of Carpal Tunnel

Carpal tunnel syndrome is a common condition caused by compression, or entrapment, of the motor and sensory nerve in the wrist (median nerve), resulting in pain, muscle weakness, impaired reflexes, numbness, and tingling in the hand. Nerve compression is often associated with repetitive activities (e.g., typing, painting, hammering) that cause stress injury, swelling, and inflammation.

Incidence & Prevalence of Carpal Tunnel Syndrome

Incidence of carpal tunnel syndrome is highest in women over the age of 30. The condition may be more prevalent in people who use their wrists in repetitive activity (e.g., typists, computer operators, house painters).

Carpal Tunnel Syndrome Cause & Risk Factors

Carpal tunnel syndrome is caused by compression of the median nerve. The primary risk factor is a history of another musculoskeletal disorder. The condition develops most often in people who regularly use vibrating machinery and tools and those who use their wrists repetitively, such as:

• Accountants
• Artists–musicians, painters, writers
• Assembly line workers
• Bus, taxi, and truck drivers
• Carpenters
• Check-out clerks
• Computer operators and programmers

Hobbies such as rowing, knitting, needlepoint, and gardening may also increase the risk for carpal tunnel syndrome. Other risk factors include underlying medical conditions, such as the following:

• Arthritis
• Amyloidosis (metabolic disorder)
• Bone enlargement caused by overproduction of growth hormone (acromegaly)
• Diabetes mellitus
• Reduced thyroid gland function (hypothyroidism)
• Pregnancy (may cause swelling of the extremities)
• Tendon inflammation (tenosynovitis)
• Uremia (condition in which the kidneys do not filter the blood sufficiently)
• Wrist fracture

Signs & Symptoms of Carpal Tunnel Syndrome

The primary symptoms of carpal tunnel syndrome are pain and numbness in the thumb, index, and middle fingers that often worsen at night and may radiate to the upper arm. Symptoms usually occur near the palm of the hand. Other symptoms include muscle weakness in the hand and wrist, tingling, and impaired reflexes.

In advanced cases of carpal tunnel syndrome, shrinkage (atrophy) of the fleshy area at the base of the thumb may occur.

Overview of Cephalic Disorders

The term “cephalic disorders” refers to defects resulting from abnormal development of, or damage to, the brain and spinal cord. Cephalic disorders are present at or before birth.

Cephalic disorders may be caused by genetic conditions or by exposure of the mother and developing fetus to infections, toxic substances, medications, or radiation.

The severity of these disorders varies greatly. Some cause mild disabilities; others are profound, resulting in total lifelong disability, vastly reduced functional capacity, and sometimes death.

Anencephaly

Anencephaly is one of the most serious cephalic disorders and afflicts roughly 1,000 to 2,000 babies born in the United States annually. Female infants are affected more often than males. Infants born with this disorder have no forebrain—the main portion of the cerebrum, responsible for thinking and coordination. Brain tissue that does develop often is not covered by bone or skin.

Causes of Anencephaly

The cause of anencephaly remains unknown. A developmental failure occurs between the 23rd and 26th days of pregnancy. The cephalic (or head) end of the neural tube fails to close, and major portions of the brain, skull, and scalp do not develop. Recent studies suggest the addition of folic acid to the diet of women in their child-bearing years may reduce the incidence of neural tube defects, suggesting that factors associated with diet and vitamins may play a role.

Signs and Symptoms of Anencephaly

Anencephalic infants typically are born blind, deaf, unconscious, and insensitive to pain. Some may have a rudimentary brainstem that permits reflex actions such as breathing and, in some cases, responsiveness to sound or touch.

Anencephaly Diagnosis

Anencephaly often can be diagnosed before birth through an ultrasound examination.

Treatment for Anencephaly

The condition is untreatable and incurable.

Prognosis for Infants with Anencephaly

Without a functioning cerebrum, anencephalic infants cannot gain consciousness. Most anencephalic infants are stillborn or die within a few hours or days after birth.

Colpocephaly

In this disorder, there is abnormal enlargement of the occipital horns—the rear portion of the cavities or chambers of the brain. Colpocephaly results from underdevelopment or lack of thickening of the white matter in the posterior cerebrum.

Causes of Colpocephaly

The cause is unknown. Research suggests there may be a intrauterine disturbance between the 2nd and 6th months of pregnancy.

Signs and Symptoms of Colpocephaly

Infants with colpocephaly have abnormally small heads (microcephaly), profound mental retardation, motor abnormalities, muscle spasms, and seizures.

Diagnosis of Colpocephaly

Colpocephaly sometimes is discovered late in pregnancy but is often misdiagnosed as hydrocephalus—excessive cerebrospinal fluid in the brain. More often, colpocephaly is diagnosed after birth when symptoms appear.

Treatment for Colpocephaly

Treatment is symptomatic. Anti-convulsant drugs may prevent seizures and other medications may be prescribed to prevent muscle shrinkage or contractures.

Prognosis for Infants with Copocephaly

Prognosis depends on the severity of microcephaly and brain malformation. In some cases, children with colpocephaly are able to participate in special education.

Overview of Cerebral Palsy

In cerebral palsy, faulty development or damage to motor areas in the brain impair the body’s ability to control movement and posture. This results in a number of chronic neurological disorders. Cerebral palsy is usually associated with events that occur before or during birth, but may be acquired during the first few months or years of life as the result of head trauma or infection.

Some people with severe CP are completely disabled and require lifelong care, while others display only slight awkwardness and need no special assistance. Complications associated with CP include learning disabilities, gastrointestinal dysfunction, tooth decay (dental caries), sensory deficits, and seizures.

Types of Cerebral Palsy

Cerebral palsy (CP) is classified as spastic, athetoid, ataxic, or mixed. These classifications reflect the type of movement disturbance displayed by the patient.

• Spastic CP–stiff, permanently contracted muscles; 50 to 75 percent of cases
• Athetoid CP (also called dyskinetic cerebral palsy)–slow, uncontrolled, writhing movements; 10 to 20 percent of cases
• Ataxic CP–poor coordination, balance, and depth perception; 5 to 10 percent of cases
• Mixed CP–two or more types present; about 10 percent of cases (percentage may be higher)

Incidence of Cerebral Palsy

Approximately 1 million people in the United States have CP. Improvements in prenatal, pediatric, and intensive care over the past 30 years have enabled more critically premature and frail babies to survive infancy. Many of these surviving children suffer developmental disorders and neurological damage.

Overview of Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth (CMT) disease, also known as hereditary motor and sensory neuropathy (HMSN), is an inherited, degenerative nerve disorder that causes muscle weakness and atrophy in the feet, legs, hands, and forearms. CMT disease is characterized by progressive loss of use and sensation in the limbs.

In CMT, the myelin coating on motor and sensory nerves gradually deteriorates, resulting in poor transmission of nerve impulses. The feet and legs are the first to show the affects of myelin deterioration, or demyelination. Muscles fail to receive stimulation from the nerves and then begin to waste away (atrophy). Atrophy in the small muscles in the feet and hands causes the fingers and toes to curl.

Anatomy of the Nerves

Peripheral nerves extend from the spinal cord throughout the body. Nerve cells, or neurons, carry impulses to and from the brain via the spinal cord. Motor neurons signal muscles to move; sensory neurons transmit sensations, such as heat, pain, and surface texture to the brain.

Most neurons are made up of:

• a soma
• dendrites
• an axon, and
• synaptic terminals.

The soma contains a large nucleus and other structures responsible for proper maintenance and function of the neuron.

Dendrites are branching structures that extend from the soma. Dendrites may have hundreds or thousands of synapses that receive signals from other neurons and relay information to the soma.

The axon is an elongated structure that conducts signals from the soma to synaptic terminals. Each neuron has one axon, which is wrapped in multiple layers of a substance called myelin. Axons transmit signals at a constant speed, called nerve conduction velocity (NCV), which is determined by the diameter of the axon and by the thickness of its myelin sheath. Myelin is critical in nerve signal conduction.

Synaptic terminals are formed within the end of an axon. They contain chemicals (neurotransmitters) that relay signals from one neuron to other neurons or to tissues (i.e., muscles, glands).

Types of Charcot-Marie-Tooth Disease

There are two forms of CMT. One form involves degeneration of the myelin sheath that surrounds a nerve’s axon. The other involves impairment of the axon. There are several types of CMT within each form. The most commonly diagnosed type is CMT1. In patients with CMT1, there is axonal demyelination resulting in reduced motor and sensory nerve conduction. Loss of stimulation by the affected nerves causes muscle weakness and atrophy.

Incidence & Prevalence of Charcot-Marie-Tooth Disease

Approximately 125,000 people in the United States have Charcot-Marie-Tooth disease. CMT occurs slightly more often in men than in women and is not prevalent in any one race. Signs of the disease usually appear before the age of 30.

Cause of Charcot-Marie-Tooth Disease

CMT is caused by an inherited genetic mutation. There are rare cases in which the mutation occurs spontaneously within one egg or sperm.

Overview of Chronic Pain

Pain is an unpleasant sensation triggered by the nervous system. The ability to experience pain is critical for survival because it can make us immediately aware of injury to the body. Pain is an individual experience affected by environmental, emotional and cognitive factors.

Chronic pain may persist for weeks, months, or years and may not respond to treatment. It can be debilitating and often becomes the defining factor in patients’ lives. Without relief, or the hope for relief, many patients lose the ability to eat, sleep, work and function normally.

Chronic pain can cause patients to alienate those around them and often leads to drug addiction, irritability, and depression. Physical, psychological, and emotional stress may worsen chronic pain.

Incidence and Prevalence of Chronic Pain

According to the Centers for Disease Control and Prevention, chronic pain is the leading cause of disabilityin the United States. Chronic pain occurs in as many as 90 percent of cancer patients and often is under-treated.

Overview of Coma

A coma is a deep state of unconsciousness, during which an individual is not able to react to his or her environment. Someone in a coma cannot consciously respond to stimulation.

A coma usually does not last for more than a few weeks. Many people recover their full physical and mental functioning when they emerge from a coma. Others require various forms of therapy to recover as much functioning as possible. Some patients never recover anything but very basic body functions.

Sometimes, following a coma, a person may enter what is known as a persistent vegetative state; patients in persistent vegetative state have lost all cognitive neurological function but are still able to breathe and may exhibit various spontaneous movements. They may even be awake and appear to be normal but, because the cognitive part of their brain no longer functions, they are not able to respond to their environment. A vegetative state can last for years.

There are other terms, in addition to coma and vegetative state, that are used to describe varying levels of unconsciousness and a person’s ability to respond to stimuli. These include stupor, in which a person is unconscious but will eventually respond to repeated, vigorous stimulation; and obtundation and lethargy, which are used to describe a person who is not entirely unconscious but does not respond to stimuli.

Overview of Dementia

Dementia refers to a loss of cognitive function (cognition) due to changes in the brain caused by disease or trauma. The changes may occur gradually or quickly; and how they occur may determine whether dementia is reversible or irreversible.

• Decision making, judgment
• Memory
• Spatial orientation
• Thinking, reasoning
• Verbal communication

Dementia also may result in behavioral and personality changes, depending on the area(s) of the brain affected.

Types of Dementia

Some dementia is reversible and can be cured partially or completely with treatment. The degree of reversibility often depends on how quickly the underlying cause is treated.

Irreversible dementia is caused by an incurable condition (e.g., Alzheimer’s disease). Patients with irreversible dementia are eventually unable to care for themselves and may require round-the-clock care.

Incidence and Prevalence of Dementia

The prevalence of dementia has increased over the past few decades, either because of greater awareness and more accurate diagnosis, or because increased longevity has created a larger population of elderly, which is the age group most commonly affected. In September 2009, it was estimated that as many as 35 million people throughout the world have some type of dementia.

Overview of Encephalitis

Encephalitis is irritation and swelling (inflammation) of the brain. It often coexists with inflammation of the covering of the brain and spinal cord (meningitis) and most cases are caused by viral infection. Encephalitis ranges in severity from mild to severe. It may result in permanent neurological damage and death.

Types of Encephalitis

Primary Encephalitis—This type results from viral infection of the brain and spinal cord. Primary encephalitis may occur in isolated cases (sporadic) or occur in many people at the same time in the same area (epidemic).

The most common type of sporadic infection is herpes simplex encephalitis, which is caused by the herpesvirus. This type carries a high risk for serious neurological damage and death and can occur in newborns if the virus is passed from the mother to the infant during birth.

Arthropod-borne viruses (transmitted through the bite of insects and ticks) may cause arboviral encephalitis. Mosquitoes are the most common agents of transmission and most cases occur during warmer weather, when the insects are more active. Arboviral encephalitis and rabies encephalitis (usually transmitted through the bite of an infected animal) may be sporadic or epidemic.

In the United States, the most common types of arboviral encephalitis are St. Louis, La Crosse, western equine and eastern equine encephalitis (EEE). Recent outbreaks of West Nile encephalitis (transmitted by mosquitoes, commonly infects birds) have occurred in eastern, southeastern, and midwestern regions of the United States, following bird migration.

Other types of arboviral encephalitis include the following:

• Japanese (widespread in Asia)
• Murray Valley (endemic in Australia)
• Powassan (transmitted by ticks; occurs in Canada and the northern United States)
• Tick-borne (occurs throughout Europe; vaccine available)
• Venezuelan equine (common in Central and South America)

Secondary Encephalitis—This type develops as a complication of a viral infection or reactivation of a latent virus. Viruses can become reactive when the immune system is suppressed by other conditions (e.g., malnutrition, stress, disease). Infections that may cause secondary encephalitis include influenza, chickenpox (varicella-zoster), measles (rubeola), mumps, and German measles (rubella).

Incidence and Prevalence of Encephalitis

Incidence of encephalitis throughout the world is difficult to determine because the disease is often underreported. Approximately 150 to 3000 cases, most of which are mild, may occur each year in the United States. Herpesvirus accounts for most cases of encephalitis in the United States.

Arboviral encephalitis is more prevalent in warm climates and incidence varies considerably from area to area and from year to year. St. Louis encephalitis is the most prevalent type of arboviral encephalitis in the United States, and Japanese encephalitis is the most prevalent type in other parts of the world.

Encephalitis is more common in children and young adults.

Overview of Fibromyalgia

Fibromyalgia is a chronic musculoskeletal syndrome characterized by pain, achiness, tenderness, and stiffness in the muscle tissue, ligaments, and tendons. Fibromyalgia most frequently affects the neck, shoulders, chest, legs, and lower back.

Fibromyalgia pain is generally accompanied by sleep disorders, fatigue, gastrointestinal disorders, and depression. Many fibromyalgia symptoms are similar to symptoms of chronic fatigue syndrome, myofascial pain syndrome, and temporomandibular joint syndrome (TMJ).

Incidence and Prevalence of Fibromyalgia

There have been reports of fibromyalgia in children. What may be considered “growing pains” might in fact be fibromyalgia, especially if the child also experiences difficulty sleeping.

Overview of GBS

Guillain-Barre syndrome (GBS) is an inflammatory disorder of the peripheral nerves. The peripheral nerves convey sensory information (e.g., pain, temperature) from the body to the brain and motor (i.e., movement) signals from the brain to the body. GBS is characterized by weakness and numbness or tingling in the legs and arms, and possible loss of movement and feeling in the legs, arms, upper body, and face.

Chronic inflammatory demyelinating polyradicalneuropathy (CIDP), is considered to be a related form of Guillain-Barre syndrome. It is much less common than GBS, evolves much more slowly, and usually is longer lasting. Some CIDP patients experience periods of worsening and improvement, and individual relapses can be confused with GBS.

Incidence of GBS

Headache Overview

Headache is a term used to describe aching or pain that occurs in one or more areas of the head, face, mouth or neck. Headaches can be chronic, recurrent or occasional. Headache pain can be mild or severe enough to disrupt daily activities. Headaches involve the network of nerve fibers in the tissues, muscles and blood vessels located in the head and at the base of the skull.

Types of Headaches

Primary headache accounts for about 90 percent of all headaches. There are three types of primary headache: tension headache, cluster headache, and migraine.

Tension headache is the most common type of primary headache. Episodes usually begin in middle age and are often associated with the stresses, anxiety, and depression that can develop during these years.

Cluster headaches occur daily over a period of weeks, sometimes months, and often cause severe pain. They may disappear and then recur during the same season in the following year.

Secondary headache is associated with an underlying condition such as cerebrovascular disease, head trauma, infection, tumor and metabolic disorders (e.g., diabetes, thyroid disease).

Head pain also can result from syndromes involving the eyes, ears, neck, teeth or sinuses. In these cases, the underlying condition must be diagnosed and treated. Also, certain types of medication produce headache as a side effect.

Severe, sudden, and debilitating secondary headache that develops after a blow to the head, that interferes with normal activity, or that accompanies other symptoms (e.g., convulsions, disorientation, dizziness, loss of consciousness, pain in the eye or ear, fever) should be evaluated by a physician as soon as possible.

Incidence and Prevalence of Headache

In the United States, over 45 million people—including the more than 33 million with conditions like asthma, diabetes, and heart disease—experience chronic, recurring headaches. Of these, 28 million people suffer migraine headaches every year.

Overview of Huntington’s Disease

Huntington’s disease (HD) is a fatal hereditary disease that destroys neurons in areas of the brain involved in movement, intellect, and emotions. The course of Huntington’s is characterized by jerking uncontrollable movement of the limbs, trunk, and face (chorea); progressive loss of mental abilities; and the development of psychiatric problems.

Juvenile HD (also called Westphal variant or akinetic-rigid HD) develops before the age of 20, progresses rapidly, and produces muscle rigidity in which the patient moves little, if at all (akinesia).

Autosomal Dominant Inheritance of Huntington’s Disease

In autosomal dominant inherited disease, a single abnormal allele is inherited from one parent. Alleles are the pairs of genes that determine individual characteristics.

Any child, male or female, with one affected parent has a 50% chance of inheriting Huntington’s disease. Unaffected children of parent with Huntington’s cannot transmit the disease to their children because they have not inherited the abnormal gene.

Incidence and Prevalence of Huntington’s Disease

Experts estimate that one in every 10,000 persons—nearly 30,000 in the United States—have Huntington’s disease. Juvenile Huntington’s occurs in approximately 16 percent of all cases.

Huntington’s disease is not prevalent within any particular population. All races and ethnic groups, and both sexes are affected.

Overview of Hydrocephalus

The word hydrocephalus is derived from two Greek words, hydro, meaning water, and cephalus, meaning head, and once was called “water on the brain.” Hydrocephalus is the condition caused by the accumulation of an abnormally large amount of cerebrospinal fluid (CSF) in the skull, or cranium. Normally, CSF flows continually from the interior cavities in the brain (ventricles) to the thin subarachnoid space that surrounds the brain and spinal cord.

CSF performs the following functions:

• Balances the amount of blood in the head.
• Bathes and protects the brain and spinal cord.
• Carries nutrients between the brain and spinal cord while removing waste.

Normal flow and absorption through the subarachnoid space is dependent on proper CSF pressure in the head (called intracranial pressure). A build up of CSF often causes a dangerous increase in pressure. The combination of CSF buildup and the subsequent increase in intracranial pressure can stress brain tissue and can cause the characteristic symptoms of hydrocephalus, though they also may occur with normal pressure.

Incidence and Prevalence of Hydrocephalus

Congenital hydrocephalus affects about one in every 1000 births. The overall prevalence in the United States is about 0.5 percent. Most cases are detected early, either at or soon after birth. The incidence of acquired hydrocephalus in adults is not known because it occurs as a result of injury, illness, or environmental factors.

Types of Hydrocephalus

The two main types of hydrocephalus are congenital (developed before birth) and acquired (developed during or after birth). Hydrocephalus is further classified as communicating and noncommunicating.

In communicating hydrocephalus, the obstruction occurs in the subarachnoid space.Noncommunicating hydrocephalus means the obstruction is located within the ventricles. Intracranial pressure is usually increased and significant neurological abnormalities may develop, including damage to brain tissue. This type is most commonly caused by stroke or traumatic brain injury.

Normal pressure hydrocephalus (NPH) is more common in patients over the age of 60. In NPH, obstruction develops over time, slowly enlarging the ventricles and increasing pressure in the brain. NPH usually affects areas of the brain that control the bladder, movement in the legs, and cognitive abilities (e.g., memory, reasoning, problem solving).

Overview of Lyme Disease

Lyme disease is a progressive, systemic illness that is caused by bacteria (Borrelia burgdorferi) and is usually transmitted by the bite of an infected deer tick. Infection may result in flu-like symptoms (e.g., malaise, fever, headache, fatigue, muscle pain) and the characteristic “bull’s eye” rash. If left untreated, it may cause arthritis and affect the heart and central nervous system. Lyme disease is treated with antibiotics.

Incidence and Prevalence of Lyme Disease

According to the Centers for Disease Control and Prevention (CDC), more than 30,000 confirmed cases of Lyme disease are reported each year in the United States. It is endemic (prevalent) throughout the wooded coastal regions of the Northeast, the upper Midwest and Great Lakes region, and the Pacific Northwest. In the Northeast and Great Lakes regions, the disease is more prevalent from May to August. In the Pacific Northwest, it is more prevalent from January to May.

In August 2015, the CDC reported that the number of people infected with Lyme each year in the United States actually may be about 10 times higher than thought—about 329,000. Studies are ongoing to determine how many people are infected annually and how to prevent infection.

As stated by the CDC, about 95 percent of new cases of Lyme disease in 2012 were reported in these 13 states:

• Connecticut
• Delaware
• Maine
• Maryland
• Massachusetts
• Minnesota
• New Hampshire
• New Jersey
• New York
• Pennsylvania
• Vermont
• Virginia
• Wisconsin

Overview of Meningitis

Meningitis is inflammation of the meninges that results in swelling of brain tissue and sometimes spinal tissue (spinal meningitis). Swelling inhibits the flow of blood and oxygen to brain tissue. The characteristic symptoms of meningitis are stiff neck, severe headache, and fever.

Overview of Movement Disorders

Movement disorders are neurological conditions that affect the speed, fluency, quality, and ease of movement. Abnormal fluency or speed of movement (called dyskinesia) may involve excessive or involuntary movement (hyperkinesia) or slowed or absent voluntary movement (hypokinesia).

• Ataxia (lack of coordination, often producing jerky movements)
• Dystonia (causes involuntary movement and prolonged muscle contraction)
• Huntington’s disease (also called chronic progressive chorea)
• Multiple system atrophies (e.g., Shy-Drager syndrome)
• Myoclonus (rapid, brief, irregular movement)
• Parkinson’s disease
• Progressive supranuclear palsy (rare disorder that affects purposeful movement)
• Restless legs syndrome (RLS) and reflex sympathetic dystrophy/periodic limb movement disorder (RSD/PLMD)
• Tics (involuntary muscle contractions)
• Tourette’s syndrome
• Tremor (e.g., essential tremor, resting tremor)
• Wilson disease (inherited disorder that causes neurological and psychiatric symptoms and liver disease)

Common dystonias include spasmodic torticollis, which affects muscles of the head, face, and neck, and blepharospasm, which causes involuntary closing of the eyelids.

Tourette’s syndrome is an inherited disorder characterized by multiple motor and vocal tics (repeated muscle contractions). Symptoms of Tourette’s usually develop during childhood or early adolescence. Patients with the disorder often develop behavioral problems such as hyperactivity, inattention, impulsivity, obsessions, and compulsions. In most cases, symptoms vary in frequency and in severity.

Tics are involuntary muscle contractions that interrupt normal activities. They often are preceded by a strong sensation or urge that is temporarily relieved following the muscle contraction. Examples of common tics include the following:

• Blinking
• Clearing the throat
• Facial twitching
• Grunting
• Shrugging the shoulders
• Sighing

Overview of Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory, chronic, degenerative disorder that affects nerves in the brain and spinal cord. Myelin, the fatty substance that surrounds and insulates nerves and facilitates the conduction of nerve impulses is the initial target of inflammatory destruction in multiple sclerosis.

Because different nerves are affected at different times, MS symptoms often worsen (exacerbate), improve, and develop in different areas of the body. Early symptoms of the disorder may include vision changes (e.g., blurred vision, blind spots), numbness, dizziness and muscle weakness.

MS can progress steadily or cause acute attacks (exacerbations) followed by partial or complete reduction in symptoms (remission). Most patients with the disease have a normal lifespan.

Incidence and Prevalence of Multiple Sclerosis

MS is the most common neurological cause of debilitation in young people. According to the National Institute of Neurological Disorders and Stroke, about 250,000–350,000 people in the United States have been diagnosed with multiple sclerosis. Worldwide, the incidence of MS is approximately 0.1 percent. Northern Europe, the northern United States, southern Australia, and New Zealand have the highest prevalence, with more than 30 cases per 100,000 people.

MS is more common in women and in Caucasians. The average age of onset is between 20 and 40, but the disorder may develop at any age. Children of parents with MS have a higher rate of incidence (30–50 percent).

Overview of Multisystem Atrophy

Multisystem atrophy (MSA) is a group of rare, multisystem degenerative diseases that have several clinical features of Parkinson’s disease and are sometimes referred to as the “Parkinsonism-plus syndromes.”

Multisystem atrophy has three cardinal features:

• Parkinsonism
• Autonomic failure (including orthostatic hypotension, erectile dysfunction [ED, impotence], and urinary incontinence or retention)
• Cerebellar ataxia (failure of muscular coordination)

All three characteristics occur in the majority of MSA cases, but with considerable variation with regards to specific attributes, and any one of the three may predominate. If autonomic failure predominates, MSA is known as Shy-Drager syndrome.

If parkinsonism predominates, it is known as striatonigral degeneration. Striatonigral degeneration is usually indistinguishable from Parkinson’s disease, except that it does not respond to Parkinson’s treatment.

If cerebellar ataxia predominates, MSA is known as olivopontocerebellar atrophy (OPCA).

Although cognitive dysfunction may appear minimal in people with multisystem atrophy, most patients do experience frontal system impairment and many develop dementia late in the course of the disease. MSA is generally more severe than Parkinson’s. More than 40 percent of MSA patients are confined to a wheelchair or otherwise severely disabled within 5 years of initial diagnosis. Except in a few cases, the drug of choice for Parkinson’s patients (levedopa) has no effect on MSA and may even worsen symptoms.

Incidence and Prevalence of Multisystem Atrophy

MSA affects men twice as often as women. The average age of onset is 50 years old, and the average survival time after initial diagnosis is 10 years. As many as 10 percent of Parkinson’s cases that are incorrectly diagnosed are later identified as MSA upon autopsy.

Overview of Myasthenia Gravis

Myasthenia gravis (MG) is a chronic autoimmune disorder that results in progressive skeletal muscle weakness. Skeletal muscles are primarily muscle fibers that contain bands or striations (striated muscles) that are connected to bone. MG causes rapid fatigue (fatigability) and loss of strength upon exertion that improves after rest.

Types of Myasthenia Gravis

pr> Myasthenia gravis can be classified according to which skeletal muscles are affected. Within a year of onset, approximately 85–90 percent of patients developgeneralized myasthenia gravis, which is characterized by weakness in the trunk, arms, and legs.

About 10–15 percent of patients have weakness only in muscles that control eye movement. This type is called ocular myasthenia gravis.

Other types of MG include congenital, which is an inherited condition caused by genetic defect, and transient neonatal, which occurs in infants born to mothers who have MG. Congenital MG develops at or shortly after birth and causes generalized symptoms.

Transient neonatal MG is a temporary condition that develops in 10–20 percent of infants born to mothers who have MG. Transient neonatal MG is caused by circulation of the mother’s antibodies through the placenta and it lasts as long as the mother’s antibodies remain in the infant (usually a few weeks after birth).

Incidence and Prevalence of Myasthenia Gravis

Myasthenia gravis affects approximately 2 out of every 100,000 people and can occur at any age. It is most common in women between the ages of 18 and 25. In men, the condition usually develops between 60 and 80 years of age.

Overview of Myopathy

Myopathies are diseases that affect muscles connected to bones (called skeletal muscles), such as the biceps in the upper arm and the quadriceps in the thigh. Myopathies can be caused by inherited genetic defects (e.g., muscular dystrophies), or by endocrine, inflammatory (e.g., polymyositis), and metabolic disorders.

Some myopathies, such as the muscular dystrophies, usually develop at an early age, and others develop later in life. Some conditions worsen over time and do not respond well to treatment and others are treatable and othe remain stable. When few treatments are available that address the root cause of the disease, the myopathy is labeled “nonspecific muscle myopathy.”

Incidence and Prevalence of Myopathy

Worldwide incidence of inheritable myopathies is about 14 percent. Of all inheritable myopathyies, central core disease accounts for 16 percent of cases; nemaline rod myopathy accounts for 20 percent; centronuclear myopathy accounts for 14 percent; and multicore myopathy accounts for 10 percent.

Prevalence of muscular dystrophy is higher in males. In the United States, Duchenne MD and Becker MD occur in approximately 1 in 3300 boys. Overall incidence of muscular dystrophy is about 63 per 1 million.

Worldwide incidence of inflammatory myopathies (e.g., dermatomyositis, polymyositis) is about 5–10 per 100,000 people. These disorders are more common in women.

Incidence and prevalence of endocrine and metabolic myopathies are unknown. Corticosteroid myopathy is the most common type of endocrine myopathy and endocrine disorders are more common in women than in men. Metabolic myopathies are rare, but diagnosis of these conditions is increasing in the United States.

Overview of Neurofibromatosis

Neurofibromatosis (NF) is a genetic neurological disorder that affects cell growth in nerve tissue. NF produces tumors of the skin, internal organs, and nerves that may become cancerous (malignant). It also can affect bones, causing severe pain and debilitation and may result in learning disabilities, behavioral dysfunction, and hearing and vision loss. There is no cure for neurofibromatosis.

Incidence and Prevalence of Neurofibromatosis

Neurofibromatosis is the most common genetic neurological disorder that is caused by a single gene. It affects more than 100,000 people in the United States. Type 1 NF affects 1 in 4000 people and is usually diagnosed during childhood. Type 2 affects 1 in 50,000 and is usually diagnosed in early adulthood. Schwannomatosis is rare.

NF occurs throughout the world and affects men and women of all races and ethnic groups.

Neurofibromatosis Types

Neurofibromatosis can be inherited as an autosomal dominant trait (a parent with the disorder has a 50 percent chance of passing it to an offspring) or can result from a spontaneous genetic mutation.

Type 1 neurofibromatosis, also called von Recklinghausen NF, is transmitted on chromosome 17 and is caused by mutation (or rarely, deletion) of the NF1 gene. This type causes multiple areas of hyperpigmentation (i.e., birthmarks) that appear shortly after birth. In late childhood, a few to thousands of tumors appear on the skin (called cutaneous lesions) and under the skin (called subcutaneous lesions). These tumors may become cancerous.

Type 2 neurofibromatosis results from mutation (or rarely, deletion) of the NF2 gene and is transmitted on chromosome 22. In this type, tumors form in the nervous system, usually within the skull (intracranial tumors) and spinal canal (intraspinal tumors). Tumors on the eighth cranial nerve (vestibulocochlear nerve), which are sometimes referred to as acoustic neuromas, are most common. This type causes hearing loss and loss of sense of balance (equilibrium), usually during the late teens or early 20s. These tumors may become cancerous.

Overview of Nerve Damage

Peripheral neuropathy is a general term referring to disorders of peripheral nerves. The peripheral nervous system is made up of the nerves that branch out of the spinal cord to all parts of the body.

Peripheral neuropathy can be associated with poor nutrition, a number of diseases (including diabetes), and pressure or trauma. Many people suffer from the disorder without ever identifying the cause.

Incidence and Prevalence of Neuropathy

Peripheral neuropathy affects at least 20 million people in the United States. Nearly 60 percent of all people with diabetes suffer from diabetic neuropathy.

Overview of Parkinson’s Disease

Parkinson’s disease is a chronic, progressive neurodegenerative movement disorder. Tremors, rigidity, slow movement (bradykinesia), poor balance, and difficulty walking (called parkinsonian gait) are characteristic primary symptoms of Parkinson’s disease.

Idiopathic Parkinson’s disease is the most common form of parkinsonism, which is a group of movement disorders that have similar features and symptoms. Parkinson’s disease also is called idiopathic Parkinson’s because the cause for the condition is unknown. In the other forms of parkinsonism, a cause is known or suspected.

Parkinson’s results from the degeneration of nuclei in a number of dopamine-producing nerve cells in the brainstem. Dopamine is a neurotransmitter that stimulates motor neurons, which are nerve cells that control the muscles.

When dopamine production is depleted, the motor system nerves are unable to control movement and coordination. Parkinson’s disease patients have lost 80 percent or more of their dopamine-producing cells by the time symptoms appear. In searching for a cause for Parkinson’s disease, most of the attention has focused on areas of the brain called the substantia nigra and the locus coeruleus.

Overview of Reflex Sympathetic Dystrophy (RSD)/Complex Regional Pain Syndrome (CRPS)

Complex regional pain syndrome (CRPS), formerly called reflex sympathetic dystrophy (RSD) and causalgia, is a chronic, painful, and progressive neurological condition that affects the skin, muscles, joints and bones. The syndrome usually develops in an injured limb, such as a broken leg, or following surgery.

However, many cases of CRPS involve only a minor injury, such as a sprain or strain. And in some cases, no precipitating event can be identified.

RSD/CRPS is characterized by various degrees of burning pain, excessive sweating, swelling, and sensitivity to touch. Pain may begin in one area or limb and then spread to other limbs. In some cases, symptoms of RSD/CRPS diminish for a period of time and then reappear with a new injury.

RSD/CRPS Types

Two types of RSD/CRPS have been defined:

• Type 1 (CRPS I)—without nerve injury
• Type 2 (CRPS II)—with nerve injury

Both types of RSD/CRPS share the same signs and symptoms.

Incidence and Prevalence of RSD/CRPS

Millions of people in the United States may suffer from RSD/CRPS. This chronic pain syndrome affects both men and women, and also occurs in children. It can occur at any age, but usually affects people between the ages of 40 and 60 years. According to most experts, CRPS is more common in young women.

The National Institute of Neurological Disorders and Strokes (NINDS) reports that 2–5 percent of peripheral nerve injury patients and 12–21 percent of patients with paralysis on one side of the body (hemiplegia) develop reflex sympathetic dystrophy as a complication. The Reflex Sympathetic Dystrophy Syndrome Association of America (RSDSA) reports that the condition develops after 1–2 percent of bone fractures.

Overview of Epilepsy

Epilepsy is a chronic neurological condition characterized by recurrent seizures that are caused by abnormal cerebral nerve cell activity. There is a distinction between a patient who has one seizure and a patient who has epilepsy. Epilepsy can be classified as either idiopathic or symptomatic.

Incidence and Prevalence of Epilepsy

According to the Epilepsy Foundation®, more than 2 million people in the United States and about 65 million worldwide suffer from epilepsy. Epilepsy is the fourth most common neurological disorder in the United States—about 150,000 new cases are diagnosed each year.

Approximately 300,000 people with epilepsy are under the age of 14 and 500,000 are over the age of 65. One in ten people will have a seizure at some point during their life.

Overview of Sleep Disorders

Sleep is absolutely essential for normal, healthy function. Scientists and medical professionals still have much to learn about this complicated physiological phenomenon. According to the National Institute of Neurological Disorders and Stroke, about 40 million people in the United States suffer from chronic long-term sleep disorders each year and an additional 20 million people experience occasional sleep problems. In February 2016, results of a study released by the U.S. Centers for Disease Control and Prevention (CDC) indicate more than a third of American adults are not getting enough sleep on a regular basis.

• lack of sleep (e.g., insomnia),
• disturbed sleep (e.g., obstructive sleep apnea), and
• excessive sleep (e.g., narcolepsy).

In most cases, sleep disorders can be easily managed once they are properly diagnosed. Insomnia is the most common sleep disorder. It occurs more often in women and in the elderly.

The amount of sleep that a person needs to function in a normal manner depends on several factors, including age. Infants sleep most of the day (about 16 hours); teenagers usually need about 9 hours a day; and adults need an average of 7 to 8 hours a day.

Although older adults require about as much sleep as younger adults, they usually sleep for shorter periods and spend less time in deep stages of sleep. About 50 percent of adults over the age of 65 have some type of sleep disorder, although it is not clear whether this is a normal part of aging or a result of other factors, such as medications that are commonly used by older people.

Falling asleep and waking up are controlled by a number of chemical changes in the brain and the blood. Foods and medicines that alter the balance of these chemicals also can affect how well we sleep. For example, caffeine, which is found in coffee, tea, colas, and chocolate, can cause insomnia (lack of sleep) and antidepressants, alcohol, and smoking can cause a loss of REM (rapid eye movement) sleep. Smoking and alcohol also can result in a loss of deep sleep. Both REM and deep sleep are essential parts of the normal sleep cycle.

What Is Sleep?

Sleep is a dynamic process during which the brain is very active. There are recognized stages of sleep, each of which is characterized by a different type of brain wave activity.

Why Does the Body Need Sleep?

It is not clear exactly why the body requires sleep, although inadequate sleep can have severe detrimental effects on health. Studies have shown that sleep is essential for normal immune system function and to maintain the ability to fight disease and sickness. Sleep also is essential for normal nervous system function and the ability to function both physically and mentally. In addition, sleep is essential for learning and for normal, healthy cell growth.

Stroke Overview

Strokes, or brain attacks, are a major cause of death and permanent disability. They occur when blood flow to a region of the brain is obstructed and may result in death of brain tissue.

There are two main types of stroke: ischemic and hemorrhagic.Ischemic strokeis caused by blockage in an artery that supplies blood to the brain, resulting in a deficiency in blood flow (ischemia).Hemorrhagic stroke is caused by the bleeding of ruptured blood vessels (hemorrhage) in the brain.

During ischemic stroke, diminished blood flow initiates a series of events (called ischemic cascade) that may result in additional, delayed damage to brain cells. Early medical intervention can halt this process and reduce the risk for irreversible complications.

Overview of TBI

Traumatic brain injury (TBI) is damage to the brain caused by a blow to the head. The severity of the injury may range from minor, with few or no lasting consequences, to major, resulting in profound disability or death.

Incidence and Prevalence of TBI

According to the Centers for Disease Control and Prevention (CDC), approximately 2.5 million TBIs occur either as an isolated injury or along with other injuries each year in the United States and more than 50,000 people die from the injury. Estimates of the number of people who have survived a TBI is broad—brain injury may go unreported—and ranges from 2.5 million to 6.5 million.

The cost of traumatic brain injuries in the United States is estimated at more than $48.3 billion annually: over $31.7 billion in hospitalization costs and another $16.6 billion+ in costs associated with fatalities.

The CDC estimates the total cost of acute care and rehabilitation for TBI victims in the United States is about $10 billion per year, not including indirect costs to families and society (e.g., lost earnings, work time, and productivity for family members, caregivers, and employers, or the costs associated with providing social services).

It is estimated that over a lifetime, it can cost between $600,000 and $1,875,000 to care for a survivor of severe TBI.

What Is Essential Tremor?

Essential tremor, also known as familial tremor, benign essential tremor or hereditary tremor is a rhythmic shaking movement caused by involuntary muscle contractions. This tremor, termed essential because it is not related to an underlying disorder, most frequently affects the hands and neck; it generally spares the muscles of the torso and lower limbs.

Symptoms appear gradually. The most common of the so-called shaking disorders, essential tremor is not a serious health risk. It responds well to treatment and in fact seems to be an indicator of an unusually long life.

What Causes Essential Tremor?

• The cause of essential tremor is unknown.
• Genetic factors play a role in about half of all cases (familial tremor).
• Other causes of essential tremor include alcohol withdrawal, hyperthyroidism, pheochromocytoma (type of tumor of the sympathoadrenal system), excessive caffeine intake, use of certain medications, cigarette smoking and Wilson’s disease.

Symptoms of Essential Tremor

• Rhythmic shaking of the hands and fingers and, less frequently, the head, tongue, larynx, eyelids, or other parts of the body. The speed of the shaking movements may be rapid or moderate.
• Worsening of the tremor under the following conditions: with emotional or physical stress; when voluntarily moving the hands, head, and other muscles; when voluntarily trying to hold the head or hands still
• Cessation of the tremor when at rest
• Shaky handwriting
• Quavering voice
• Difficulty holding or using small objects (e.g., silverware or a pen)
• Head nodding

Prevention of Essential Tremor

There is no known way to prevent essential tremor.

Diagnosis of Essential Tremor

• Patient history and physical examination are performed.
• Blood tests and imaging studies (head CT, brain MRI and x-rays) usually are normal but may be performed to rule out other conditions.

How to Treat Essential Tremor

• Beta-blocking drugs (commonly used to treat high blood pressure) such as Inderal (propranolol) and Mysoline (primidone) are generally the most effective medications for treating essential tremor.
• Other drugs, including anticonvulsants (such as primidone) and tranquilizers (such as clonazepam, lorazepam, or alprazolam), may be used to treat muscle tremors that do not respond to beta-blockers.
• Patients may be advised to drink one glass of wine or one ounce of 80-proof liquor a day, because alcohol has been shown to ease tremors in some cases. However, sometimes a rebound effect occurs, causing the tremor to worsen after the effect of the alcohol has worn off. In addition, some doctors fear the potential risk of alcohol abuse.
• Avoid the consumption of caffeine and other stimulants, which may exacerbate the tremor.
• In severe, disabling cases that do not respond satisfactorily to medications, controlled injections of botulinum toxin (which causes the muscle paralysis associated with botulism) into muscles of the forearm or neck may stop tremors.
• Surgical destruction of specific cells within the brain, or electrical stimulators implanted in certain regions of the brain, may provide relief from symptoms in severe cases that do not respond to other forms of treatment, but this is done only as a last resort.

When to Call a Doctor

Make an appointment with a doctor if involuntary trembling or shaking of the hands, head, or other muscles interferes with normal activities.

Source:

Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Overview of Nervous System Tumors

A tumor is the abnormal, spontaneous growth of new tissue. Tumors are either benign (do not spread to other tissues or parts of the body) or malignant (cancerous tumors that invade other tissues and parts of the body). Nervous system (NS) tumors can develop in either the brain or spinal cord, although spinal cord tumors are rare.

Benign tumors and cancerous tumors at the site of origin are referred to as primary tumors. Tumors that develop somewhere other than the site of origin are called a metastatic tumors.

More than 100,000 people in the United States are diagnosed with a brain tumor each year, and the numbers are increasing. In most cases, the cause for the brain tumor is unknown. Because of the incredible complexity of the human brain and its role in the normal function of the body, brain tumors often have incapacitating consequences.

Surgery and radiation are the most common treatments for brain tumors, although the effectiveness of these treatments may be limited by the risk for damage to healthy brain tissue.

About 44 percent of all primary brain tumors are benign. Although these tumors do not spread, they are serious, can recur after they have been removed, and can be fatal.

Malignant brain tumors are the second leading cause of cancer death in young adults under the age of 34, young children under the age of 15, and people over the age of 65.

Overview of Vertigo

Vertigo usually occurs as a result of a disorder in the vestibular system (i.e., structures of the inner ear, the vestibular nerve, brainstem and cerebellum). The vestibular system is responsible for integrating sensory stimuli and movement and for keeping objects in visual focus as the body moves. Benign paroxysmal position vertigo (BPPV) is a common cause for dizziness.

When the head moves, signals are transmitted to the labyrinth, which is an apparatus in the inner ear that is made up of three semicircular canals surrounded by fluid. The labyrinth then transmits movement information to the vestibular nerve and the vestibular nerve carries the information to the brainstem and cerebellum(areas of the brain that control balance, posture, and motor coordination). There are a number of different causes for dizzy spells.

Incidence and Prevalence of Vertigo

Vertigo is one of the most common health problems in adults. According to the National Institutes of Health (NIH), about 40 percent of people in the United States experience feeling dizzy at least once during their lifetime. Prevalence is slightly higher in women and increases with age.