$Unique_ID{BRK03836} $Pretitle{} $Title{Hydrocephalus} $Subject{Hydrocephaly Water on the Brain Communicating Hydrocephalus Non-Communicating Hydrocephalus Obstructive Hydrocephalus Internal Hydrocephalus Normal Pressure Hydrocephalus Spina Bifida Meningitis Epilepsy Arnold-Chiari Syndrome Encephalocele Cardio-Facio-Cutaneous Syndrome Walker-Warburg Syndrome} $Volume{} $Log{} Copyright (C) 1984, 1985, 1987, 1988, 1989, 1992 National Organization for Rare Disorders, Inc. 10: Hydrocephalus ** IMPORTANT ** It is possible that the main title of the article (Hydrocephalus) is not the name you expected. Please check the SYNONYMS listing to find the alternate name and disorder subdivisions covered by this article. Synonyms Hydrocephaly Water on the Brain Disorder Subdivisions: Communicating Hydrocephalus Non-Communicating Hydrocephalus Obstructive Hydrocephalus Internal Hydrocephalus Normal Pressure Hydrocephalus Benign Hydrocephalus Information on the following diseases can be found in the Related Disorders section of this report: Spina Bifida Meningitis Epilepsy Arnold-Chiari Syndrome Encephalocele Cardio-Facio-Cutaneous Syndrome Walker-Warburg Syndrome General Discussion ** REMINDER ** The Information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Hydrocephalus is a condition in which abnormally dilated (widened) ventricles (cerebral spaces in the brain) inhibit the normal flow of cerebrospinal fluid (CSF). The cerebrospinal fluid accumulates in the skull and puts pressure on the brain tissue. An enlarged head in infants and increased cerebrospinal fluid pressure are frequent findings but are not necessary for the diagnosis of Hydrocephalus. There are several different forms of Hydrocephalus: communicating hydrocephalus, non-communicating hydrocephalus or obstructive hydrocephalus, internal hydrocephalus, normal pressure hydrocephalus and benign hydrocephalus. Symptoms Hydrocephalus is characterized in children with an unusually large head (cephalomegaly), a thin, transparent scalp, a bulging forehead with prominent fontalelles (space between the bones of the skull) and a downward gaze. Other symptoms may include convulsions, abnormal reflexes, a slowed heartbeat and respiratory rate, headache, vomiting, irritability, weakness and problems with vision. Blindness and continuing mental deterioration may occur if treatment is not administered. When hydrocephalus begins as an adolescent or a young adult, the facial abnormalities (physiognomic) are less obvious than in children with congenital or early onset hydrocephalus. Many of the other mental and physiologic symptoms are the same, with the added loss of previously acquired coordinated movement (motor coordination). Acquired hydrocephalus in children and adolescents is often associated with symptoms of hypopituitarism (under-active pituitary gland) such as delayed growth and obesity, and general weakness. Hydrocephalus is subdivided according to the particular defect that exists in the brain and whether or not the cerebrospinal fluid pressure is high or normal. In "communicating hydrocephalus" there is no blockage (obstruction) in the cerebral spaces of the brain (ventricular system); the cerebrospinal fluid flows readily into the subarachnoid space (the space between the arachnoid and pia mater membranes in the brain), but the fluid is not absorbed readily, or perhaps produced in too great a quantity to be absorbed. In "noncommunicating (obstructive) hydrocephalus", the cerebrospinal fluid is blocked causing dilation (widening) of the pathways upstream of the block, leading to increased cerebrospinal fluid pressure in the skull. "Normal-pressure hydrocephalus", which affects middle-aged and older persons, is characterized by dilated ventricles but normal pressure within the spinal column (lumbar pressure). This type of hydrocephalus may be detected by a diagnostic test known as pneumoencephalography. A pneumoencephalography is a procedure in which air is injected into certain spaces in the brain (lumbar subarachnoid spaces) and X-ray (radiographic) studies are done. Other symptoms of normal-pressure hydrocephalus include loss of memory and intellectual capacity (dementia), loss of muscle coordination (ataxia) and loss of bladder control (urinary incontinence). Causes The cause of hydrocephalus is not known. Some cases are caused by a birth defect; others can follow hemorrhage, viral infection, or meningitis. A genetic predisposition has been proposed, with transmission through autosomal recessive or X-linked genes. Human traits, including the classic genetic diseases, are a product of the interaction of two genes, one received from the father and one from the mother. In recessive disorders, the condition does not appear unless a person inherits the same defective gene for the same trait from each parent. If a person receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will show no symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent, and will be genetically normal. X-linked recessive disorders are conditions which are coded on the X chromosome. Females have two X chromosomes, but males have one X chromosome and one Y chromosome. Therefore, in females, disease traits on the X chromosome can be masked by the normal gene on the other X chromosome. Since males only have one X chromosome, if they inherit a gene for a disease present on the X, it will be expressed. Men with X-linked disorders transmit the gene to all their daughters, who are carriers, but never to their sons. Women who are carriers of an X-linked disorder have a fifty percent risk of transmitting the carrier condition to their daughters, and a fifty percent risk of transmitting the disease to their sons. Affected Population Most cases of hydrocephalus are diagnosed in the first 2 years of life, but onset may occur at any age, depending on the cause. This disorder seems to affect males and females equally, except those inherited as an X-linked genetic traits which affects males. Related Disorders The following disorders can occur in conjunction with Hydrocephalus. Comparisons may be useful for differential diagnosis. Spina Bifida is a condition in which the spinal cord is not properly closed and part of the contents of the spinal canal may protrude through this opening. In its mildest form, this condition may go undetected. The lack of closure may affect a very small area of the spine. In the more severe form of Spina Bifida, a sac (meningocele) may be present on the back containing parts of the spinal canal. Fluid may then accumulate in the cavities in the brain, leading to hydrocephalus. (For more information on this disorder, choose "Spina Bifida" as your search term in the Rare Disease Database). Arnold-Chiari syndrome is a rare disorder that is characterized by the displacement of the brain stem (distal medulla). The brain stem becomes elongated and flattened and protrudes into the area of the upper spinal canal. In infants, Arnold-Chiari syndrome is associated with the presence of a sac or hernia (myelomeningocele) from the spinal cord which may contain the spinal cord and the membranes that surround the spinal cord (meninges). Hydrocephalus is commonly present. In infants, vomiting, mental impairment, head and facial muscle weakness, and difficulties in swallowing may be present. (For more information on this disorder, choose "Arnold-Chiari" as your search term in the Rare Disease Database). Epilepsy is a disorder of the central nervous system. It is characterized by recurrent electrical disturbances in the brain. Symptoms of this disorder may include loss of consciousness, convulsions, spasms, sensory confusion and disturbances in the autonomic nervous system. Attacks are frequently preceded by a feeling of uneasiness, discomfort or strange behavior. If the electrical disturbances or symptoms respond to medication, the patient can expect an otherwise normal life. Some types of epilepsy are characterized by absent staring and an apparent disinterest in the surrounding environment, which can happen repeatedly throughout the day. Hydrocephalus can occur with or possibly result in epilepsy. (For more information on this disorder, choose "Epilepsy" as your search term in the Rare Disease Database). Meningitis is an infection that causes inflammation of the membranes that surround the brain (meninges). In its milder form, the cause is thought to be viral. Bacterial meningitis is generally a more severe disease. Symptoms may include a general feeling of ill health (malaise), nausea, abdominal pain, and stiffness in the back and neck. Meningitis can occur in conjunction with hydrocephalus. (For more information on this disorder, choose "Meningitis" as your search term in the Rare Disease Database). Encephalocele is a rare disorder in which an infant is born with a gap in the skull. The membranes that cover the brain (meninges), and the brain tissue protrude through this gap. Infants with an encephalocele may develop hydrocephalus. (For more information on this disorder, choose "Encephalocele" as your search term in the Rare Disease Database). Cardio-Facio-Cutaneous Syndrome is a rare disorder in which an infant is born with multiple physical deformities and mental retardation. The common symptoms of this disorder include abnormal skin conditions (including patchy and unusually dry skin), an unusual face, sparse and curly hair and heart defects. Infants with Cardio-Facio-Cutaneous syndrome have a characteristic face in which the opening between the upper and lower eyelids slants downward. It is not uncommon for patients with this disorder to have an excess amount of spinal fluid in the head causing a widening of the ventricles of the brain (Hydrocephalus). (For more information on this disorder, choose "Cardio-Facio-Cutaneous Syndrome" as your search term in the Rare Disease Database). Walker-Warburg syndrome (WWS) is a very rare genetic disorder in which an infant is born with congenital hydrocephalus, "smooth" brain tissue (lissencephaly) that is greatly reduced in size, severe developmental retardation and multiple brain malformations. Developmental abnormalities if the Retina (retinal dysplasia) also occur. Walker-Warburg syndrome is also known as HARD Syndrome +/-E. Therapies: Standard Standard treatment for Hydrocephalus is the insertion of a shunt or tube into the head cavity which drains the excess cerebrospinal fluid into a part of the body that can absorb it. In growing children the shunt may have to be lengthened periodically. Complications may arise if the shunt becomes clogged or stops functioning. At times a new shunt may have to be reimplanted. Therapies: Investigational At the present time, there are several new surgical procedures being perfected for the treatment of Hydrocephalus. More research will be needed to determine the safety and effectiveness of these procedures. This disease entry is based upon medical information available through September 1992. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Hydrocephalus, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 Hydrocephalus Parent Support Group 225 Dickinson St., H-893 San Diego, CA 92103 National Hydrocephalus Foundation 400 N. Michigan Ave., Suite 1102 Chicago, IL 60611-4102 Hydrocephalus Association 870 Market St., Suite 955 San Francisco, CA 94102 (415) 776-4713 NIH/National Institute of Neurological Disorders & Stroke (NINDS) 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5751 (800) 352-9424 Association for Retarded Citizens of the U.S. P.O. Box 6109 Arlington, TX 76005 (817) 640-0204 (800) 433-5255 For information on genetics and genetic counseling referrals, please contact: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References MENDELIAN INHERITANCE IN MAN 9th Ed.: Victor McKusick; Johns Hopkins University Press, 1990. Pp. 1248-1250, 1635-1636. INTERNAL MEDICINE, 2nd Ed.: Jay H. Stein, ed.-in-chief; Little Brown and Co., 1987. P. 2213 CECIL TEXTBOOK OF MEDICINE, 19th Ed.: James B. Wyngaarden, and Lloyd H. Smith, Jr., Editors; W.B. Saunders Co., 1990. Pp. 2223-2224. HYDROCEPHALUS IN INFANCY AND CHILDHOOD, H.E. James; American Family Physician (Feb. 1992; 45(2)). Pp. 733-742.