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The following list includes brain disorders where much is known of the cause, neuropathology and associated clinical manifestations, and brain disorders for which much (cause, specific neuropathology) remains a mystery and the diagnosis reflects more of a behavioral description of symptoms.

Summary information on prevalence, incidence, and other demographics were extracted from August, 2006 through the present from the web site links provided.  Please go to suggested web sites for more detailed information on the brain disorder or disability of interest.  Please contact us if a brain disorder or disability is not on the list or if information is otherwise inaccurate or incomplete or if the link is broken.



An estimated 14.8 million Americans have used illicit drugs (sedative-hypnotics, barbiturates, opiates, hallucinogens or stimulants) within the past 30 days. Alcohol addiction (alcoholism) is a progressive disorder that affects approximately 8.2 million adults and youth in the U.S. An estimated 3.6 million people meet the diagnostic criteria for drug dependence.

Adrenoleukodystrophy (see also Leukodystrophy)

The prevalence of the most common form,
X-linked adrenoleukodystrophy, is approximately 1 in 20,000 individuals worldwide.

Agenesis of the Corpus Callosum

A rare disorder present at birth affecting the structure of the brain connecting the two hemispheres, and one that can have mild to severe effects depending upon the extent of brain abnormalities.  Gender-specific characteristics may be present, as well as other related malformations of the body.


Alzheimer’s Disease

Four million people in the U.S. are estimated to have Alzheimer’s disease, which usually begins after age 65.  About 3% of men and women ages 65-74 have Alzheimer’s, and approximately half of the elderly over age 85 may have the disease.

Amyotrophic Lateral Sclerosis (ALS/Lou Gehrig's Disease)

Approximately 5,600 people in the U.S. are diagnosed with amyotrophic lateral sclerosis (ALS) each year. The incidence of ALS is 2 per 100,000 people, and as many as 30,000 Americans may have the disease at any given time.


Anxiety Disorders

Anxiety disorders, the most common mental illness in America, affect more than 19 million people each year, and cost the U.S. $46.6 billion in 1990 in direct and indirect costs, nearly one-third of the nation's total mental health bill of $148 billion.

Arachnoid Cyst

Arachnoid cysts are rare.  They are cerebrospinal fluid-filled sacs that are located between the brain or spinal cord and the arachnoid membrane, one of the three membranes that cover the brain and spinal cord.

Arnold-Chiari Malformation

Chiari malformation was thought to occur in about 1 per 1,000 births. However, increased use of diagnostic imaging demonstrates the disorder may be much more common.


Asperger Syndrome

Asperger syndrome is conservatively estimated to occur in as many as 2 per 10,000 children, with boys 3 to 4 times more likely to have the syndrome.



Ataxia Telangiectasia
Ataxia telangiectasia is estimated to occur in about 1 in 40,000 to 100,000 births.

Attention Deficit Disorder

Attention-deficit/hyperactivity disorder occurs  in as many as 1 in 20 children, with a boy to girl ratio of 3 to 1.



By recent estimates, as many as 14 out of 10,000 children may have autism spectrum disorders.  In the U.S., about 125,000 individuals have these disorders, and nearly 4,000 families across the country have two or more children with autism. Approximately, 3 times as many boys as girls have autism.


Bipolar Disorder

At least 2 million Americans have bipolar disorder which typically begins in adolescence or early adulthood and continues throughout life. Although not common, bipolar disorder has been diagnosed in children under age 12.

Borderline Personality Disorder

Borderline personality disorder affects approximately 2% of adults, mostly young women. There is a high rate of self-injury, suicide attempts and completed suicide in severe cases. Patients often need extensive mental health services, and account for 20 percent of psychiatric hospitalizations.


Brain Injury

Each year in the U.S., 1.4 million individuals sustain traumatic brain injury (TBI): 50,000 die; 235,000 are hospitalized; and 1.1 million are treated and released. Among children ages 0 to 14 years, TBI results in an estimated: 2,685 deaths; 37,000 hospitalizations; and 435,000 emergency department visits annually.

Brain Tumor

More than 200,000 people in the U.S. are diagnosed with a primary or metastatic brain tumor each year. Brain tumors are the leading cause of solid tumor cancer death in children under 20 years, and are the second leading cause of cancer death in male adults 20 to 29 years, and the fifth leading cause of cancer death in female adults 20 to 39 years.


Central Pain Syndrome

A neurological condition caused by damage to or dysfunction of the central nervous system following stroke, multiple sclerosis, tumors, epilepsy, brain or spinal cord trauma, or Parkinson's disease resulting in chronic pain.

Cerebral Palsy

Approximately 500,000 children and adults of all ages in the U.S. have cerebral palsy; in children over 3, the statistic is 2 to 3 per 1,000.

Cephalic Disorders

Rare congenital disorders that stem from damage to or abnormal development of the budding nervous system.

Chronic Fatigue and Immune Dysfunction Syndrome

DePaul University researchers estimate chronic fatigue syndrome affects approximately 422 per 100,000 persons in the U.S. which translates into as many as 800,000 people nationwide affected by this syndrome. The majority (90%) have not been diagnosed and are not receiving proper medical care for their illness.



A rare congenital brain abnormality in which the occipital horns - the posterior or rear portion of the lateral ventricles of the brain - are larger than normal because white matter in the posterior cerebrum has failed to develop or thicken.


Creutzfeldt - Jakob Disease

The incidence of Creutzfeldt-Jakob disease in the U.S. is thought to be 1 in 9000 adults 55 years and older.  Approximately 85% of the cases are sporadic, which means there is no known cause at present.


Dandy-Walker Syndrome

Dandy-Walker Syndrome is a rare congenital malformation of the cerebellum and the fluid filled spaces around it.


The lifetime prevalence of major depression is 24% for women and 15% for men. Approximately, 1 in 4 women will experience clinical depression in her lifetime, and 1 in 10 mothers meets the criteria for depression postpartum. Although men are less likely to have depression, 3 to 4 million men in the U.S. are affected by the illness. Finally, as many as 1 in 33 children and 1 in 8 adolescents have depression.

Developmental Disabilities (see Learning and Developmental Disabilities)


Dystonia disorders affect about 30 of every 100,000 persons. Certain types of dystonia in specific populations may have a greater prevalence.  For instance, Ashkenazi Jews have a high prevalence of a specific type of dystonia, approximately 1 in 10,000, due to a mutation in the DYT1 gene.


Eating Disorders

An estimated 0.5 to 3.7% of females have anorexia nervosa and between 1.1% to 4.2% have bulimia nervosa in their lifetime. Anorexia and bulimia are far less common in males (only 5 to 15% of all cases); 2 to 5% of Americans experience binge-eating disorder, 35% of whom are male.


More than 2.7 million people in the U.S. of all ages are living with epilepsy, and each year 181,000 Americans will develop seizures and epilepsy for the first time.


Fetal Alcohol Syndrome Spectrum Disorders

The reported rates of fetal alcohol spectrum disorders (FASD) vary widely due to populations surveyed and methods used. CDC studies report a range of 0.2 to 1.5 per 1,000 live births for FAS in different areas of the U.S.. Other FASDs are believed to occur approximately 3 times as often as FAS.


Over 6 million Americans, 90% of them women in the prime of their life, have fibromyalgia syndrome (FMS) and sometimes struggle for years before being correctly diagnosed. Symptoms usually appear between 20 to 55 years of age, but children are also diagnosed with FMS.


Hemimegalencephaly (see Megalencephaly)

HIV-Induced Dementia

Between 7 and 27% of U.S. patients with advanced HIV develop dementia, and it is a common cause of death in late-stage AIDS. The life expectancy for patients who receive no treatment for HIV dementia is approximately six months.


Holoprosencephaly is a rare congenital disorder caused by the failure of the prosencephalon (the embryonic forebrain) to sufficiently divide into the double lobes of the cerebral hemispheres. 


Huntington's Disease

Huntington’s disease affects men and women equally and has a prevalence of about 1 in every 10,000 persons in most Western countries.


Hydranencephaly is a rare condition in which the brain's cerebral hemispheres are absent and replaced by sacs filled with cerebrospinal fluid.  Many born with hydranencephaly die within first year of life, but some children live for several or more years.



Hydrocephalus is believed to affect approximately 1 in every 500 children. However, incidence and prevalence data are difficult to establish since there is no national registry of people with hydrocephalus and closely associated disorders. Most cases are diagnosed prenatally, at the time of delivery, or in early childhood.

Learning and Developmental Disabilities

Learning and developmental disabilities are thought to occur in 1.4% of the world's population.


The leukodystrophies are rare, and involve progressive degeneration of the white matter of the brain due to imperfect growth or development of the myelin sheath.



The prognosis for children with lissencephaly is dependent upon on the degree of brain malformation; many will die before the age of 2, some will survive, but show no significant development beyond a 3- to 5-month-old level, and still others may have near-normal development and intelligence.

Macrancephaly (see Megalencephaly)

ega Cisterna Magna (see Dandy Walker Syndrome)

Megalencephaly (also called Macrancephaly)

Megalencephaly is a rare disorder thought to be related to a disturbance in the regulation of cell production in the brain. http://www.ninds.nih.gov/disorders/megalencephaly/megalencephaly.htm

Mental Retardation (see Learning and Developmental Disabilities)


Children with microcephaly may have mental retardation, delayed motor functions and speech, facial distortions, dwarfism or short stature, hyperactivity, seizures, difficulties with coordination and balance, and other brain or neurological abnormalities. Some will have only mild disability and others will have normal intelligence and continue to develop and meet regular age-appropriate milestones.


Multiple Sclerosiss

Today there are 350,000 to 500,000 people in the U.S. who have been diagnosed with multiple sclerosis, a disorder that is more common in women, and appears more frequently in whites than in Hispanics or African Americans, and is relatively rare among Asians and other groups.


Non-Verbal Learning Disorder

Nonverbal learning disorders, or right-hemisphere dysfunction, affect one of every ten children with a learning disability (Rourke, 1995; Torgeson, 1993).

Obsessive Compulsive Disorder

Approximately 3.3 million Americans between 18 to 54 years old or 2.3% of the U.S. population in that age group have obsessive-compulsive disorder (OCD) in a given year. Men and women are equally affected, and the disease typically begins during adolescence or early childhood.


Ohtahara Syndrome

A rare congenital brain disorder in which most infants show significant underdevelopment of part or all of the cerebral hemispheres, characterized by seizures from infancy.

Panic Disorder

Approximately 2.4 million Americans between 18 to 54 years of age or 1.7% of the U.S. population in that age group has panic disorder in a given year. Panic disorder is twice as likely in women as men and typically strikes in young adulthood.

Parkinson's Disease

At least 1 million people in the U.S. are estimated to have Parkinson's, and perhaps half are thought to be undiagnosed. In general, both men and women are affected equally and the appearance of first symptoms occurs on average after the age of 50.

Periventricular nodular heterotopia

The prevalence is unknown for periventricular nodular heterotopia (PNH), a brain malformation, caused by abnormal neuronal migration, in which a subset of neurons fails to migrate into the developing cerebral cortex and remains as nodules that line the ventricular surface.


Phobias occur in 7.8% of American adults. Phobias are the most common psychiatric illness among women of all ages and are the second most common psychiatric illness among men older than 25.

Post-partum Depression

Post-partum depression (PPD) is estimated to occur in approximately 10 to 20% of new mothers. It is a major form of depression and is less common than postpartum blues. PPD includes all the symptoms of depression but occurs only following childbirth, and can begin any time after delivery for up to a year after the birth.

Post-traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is estimated to occur in 7.8% of Americans at some point in their lives, with women (10.4%) twice as likely as men (5%) to develop the disorder. About 3.6% of U.S. adults aged 18 to 54 (5.2 million people) have PTSD during the course of a given year.

Progressive Supranuclear Palsy

Progressive supranuclear palsy affects approximately 20,000 Americans, or one in every 100,000 people over the age of 60. Patients suffer from serious and permanent problems with control of gait and balance, are usually middle-aged or elderly and more often male.


Rasmussen's Encephalitis

Rasmussen’s encephalitis is a rare, chronic inflammatory disease that usually affects only one hemisphere of the brain. Currently, it is thought to be an autoimmune disease.

Rett Syndrome

Rett Syndrome was thought to occur in approximately 1 in 15,000 female births until a recent gene discovery. Since that discovery, findings suggest a milder form of the Syndrome occurs in larger numbers.

Schizoaffective Disorder

Approximately 1 in every 200 people (0.5%) develops schizoaffective disorder at some point during his or her life. This disorder is one of the most serious psychiatric disorders.  More hospital beds are occupied by persons with schizoaffective disorder and schizophrenia than any other psychiatric disorder.


Approximately 1 in every 100 (1%) of Americans have schizophrenia which is usually diagnosed in the late teens and early 20s in men and in the mid-20s to early 30s in women. The illness seldom occurs after age 45, and only rarely before puberty (though cases of schizophrenia in children as young as 5 have been reported).  Men and women are affected equally, and similar rates of the illness occur around the world.

Sensory Processing Disorder

It is estimated that between 5—13 % of children entering school have SPD and that 3 of 4 are boys.
http://www.thespiralfoundation.org/pdfs/Fact Sheet for Educators.pdf

Septo Optic Dysplasia

Septo-optic dysplasia (SOD) is a rare disorder characterized by abnormal development of the optic disk, pituitary deficiencies, and often agenesis (absence) of the septum pellucidum (the part of the brain that separates the anterior horns or the lateral ventricles of the brain).


Sleep Disorders

Sleep disorders include sleep apnea (18 million Americans), narcolepsy (1 million Americans), chronic insomnia (approximately 10-15% of adults), and restless leg syndrome (10% of adults in North America and Europe, and lower prevalence in India, Japan, and Singapore).


Smith-Magenis Syndrome

Th exact incidence is unknown, but estimates indicate SMS occurs in 1 out of every 25,000 births, which may be an underestimate as many are thought to remain undiagosed due to lack of awareness of the syndrome.



More than 700,000 strokes occur each year in the U.S. It is the third leading cause of death in the U.S. Stroke causes more serious long-term disabilities than any other disease.  Almost 75% of all strokes occur in people over the age of 65, with the risk of a stroke doubling with each decade after the age of 55. Stroke is more common and more deadly in African Americans - occurring more frequently in this group even in young and middle-aged adults.



Stuttering is estimated to occur in over 1 million Americans, and affects individuals of all ages but most frequently occurs in young children between the ages of 2 and 6.  Boys are 3 times more likely to stutter than girls.  Most children outgrow their stuttering, with less than 1% of adults still stuttering.


Tourette Syndrome

An estimated 200,000 Americans have Tourette Syndrome (TS), and possibly as many as 1 in 100 people have a milder form of the disorder, such as chronic or transient tics in childhood. Tourette's affects people of all racial and ethnic groups and males are affected 3 to 4 times more often. It is believed that TS affects 3 to 5 in every 10,000 individuals, and about 10 in every 10,000 school-age children.  Onset of TS and tics typically occurs between the ages of 6 to 8 years old.


Transmissible Spongiform Encephalopathies

Transmissible spongiform encephalopathies (TSE), or prion diseases, are a group of rare degenerative brain disorders characterized by tiny holes that give the brain a "spongy" appearance when brain tissue is viewed under a microscope. Creutzfeldt-Jakob disease, kuru, fatal familial insomnia, and Gerstmann-Straussler-Scheinker disease are included among TSEs.

Tuberous Sclerosis

Tuberous sclerosis complex affects 25,000 to 40,000 Americans, and 1 to 2 million individuals worldwide. It is a rare multi-system genetic disorder that causes benign tumors to grow in the brain and other organ systems.

Williams Syndrome

Williams syndrome is a rare genetic condition estimated to occur in 1 of 20,000 births which causes medical and developmental problems, affects males and females equally, and has been identified worldwide in all ethnic groups.



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