Impairment of the ability to coordinate the movements required for normal ambulation (WALKING) which may result from impairments of motor function or sensory feedback. This condition may be associated with BRAIN DISEASES (including CEREBELLAR DISEASES and BASAL GANGLIA DISEASES); SPINAL CORD DISEASES; or PERIPHERAL NERVOUS SYSTEM DISEASES.
Incoordination of voluntary movements that occur as a manifestation of CEREBELLAR DISEASES. Characteristic features include a tendency for limb movements to overshoot or undershoot a target (dysmetria), a tremor that occurs during attempted movements (intention TREMOR), impaired force and rhythm of diadochokinesis (rapidly alternating movements), and GAIT ATAXIA. (From Adams et al., Principles of Neurology, 6th ed, p90)
The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.
Myoclonic Cerebellar Dyssynergia
A condition marked by progressive CEREBELLAR ATAXIA combined with MYOCLONUS usually presenting in the third decade of life or later. Additional clinical features may include generalized and focal SEIZURES, spasticity, and DYSKINESIAS. Autosomal recessive and autosomal dominant patterns of inheritance have been reported. Pathologically, the dentate nucleus and brachium conjunctivum of the CEREBELLUM are atrophic, with variable involvement of the spinal cord, cerebellar cortex, and basal ganglia. (From Joynt, Clinical Neurology, 1991, Ch37, pp60-1)
A group of recessively inherited diseases characterized by the intralysosomal accumulation of G(M2) GANGLIOSIDE in the neuronal cells. Subtypes include mutations of enzymes in the BETA-N-ACETYLHEXOSAMINIDASES system or G(M2) ACTIVATOR PROTEIN leading to disruption of normal degradation of GANGLIOSIDES, a subclass of ACIDIC GLYCOSPHINGOLIPIDS.
A clinically diverse group of epilepsy syndromes characterized either by myoclonic seizures or by myoclonus in association with other seizure types. Myoclonic epilepsy syndromes are divided into three subtypes based on etiology: familial, cryptogenic, and symptomatic (i.e., occurring secondary to known disease processes such as infections, hypoxic-ischemic injuries, trauma, etc.).
Myoclonic Epilepsy, Juvenile
A disorder characterized by the onset of myoclonus in adolescence, a marked increase in the incidence of absence seizures (see EPILEPSY, ABSENCE), and generalized major motor seizures (see EPILEPSY, TONIC-CLONIC). The myoclonic episodes tend to occur shortly after awakening. Seizures tend to be aggravated by sleep deprivation and alcohol consumption. Hereditary and sporadic forms have been identified. (From Adams et al., Principles of Neurology, 6th ed, p323)
A specified list of terms with a fixed and unalterable meaning, and from which a selection is made when CATALOGING; ABSTRACTING AND INDEXING; or searching BOOKS; JOURNALS AS TOPIC; and other documents. The control is intended to avoid the scattering of related subjects under different headings (SUBJECT HEADINGS). The list may be altered or extended only by the publisher or issuing agency. (From Harrod's Librarians' Glossary, 7th ed, p163)
Urinary Bladder, Neurogenic
Paraneoplastic Cerebellar Degeneration
Cerebellar degeneration associated with a remote neoplasm. Clinical manifestations include progressive limb and GAIT ATAXIA; DYSARTHRIA; and NYSTAGMUS, PATHOLOGIC. The histologic type of the associated neoplasm is usually carcinoma or lymphoma. Pathologically the cerebellar cortex and subcortical nuclei demonstrate diffuse degenerative changes. Anti-Purkinje cell antibodies (anti-Yo) are found in the serum of approximately 50% of affected individuals. (Adams et al., Principles of Neurology, 6th ed, p686)
Directories as Topic
Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or PERIPHERAL NERVE DISEASES. Motor ataxia may be associated with CEREBELLAR DISEASES; CEREBRAL CORTEX diseases; THALAMIC DISEASES; BASAL GANGLIA DISEASES; injury to the RED NUCLEUS; and other conditions.
Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual has an intellectual disability. IQ scores between 70 and 79 are in the borderline range. Scores below 67 are in the disabled range. (from Joynt, Clinical Neurology, 1992, Ch55, p28)
Mental Retardation, X-Linked
A class of genetic disorders resulting in INTELLECTUAL DISABILITY that is associated either with mutations of GENES located on the X CHROMOSOME or aberrations in the structure of the X chromosome (SEX CHROMOSOME ABERRATIONS).
A group of genetic, infectious, or sporadic degenerative human and animal nervous system disorders associated with abnormal PRIONS. These diseases are characterized by conversion of the normal prion protein to an abnormal configuration via a post-translational process. In humans, these conditions generally feature DEMENTIA; ATAXIA; and a fatal outcome. Pathologic features include a spongiform encephalopathy without evidence of inflammation. The older literature occasionally refers to these as unconventional SLOW VIRUS DISEASES. (From Proc Natl Acad Sci USA 1998 Nov 10;95(23):13363-83)
A rare transmissible encephalopathy most prevalent between the ages of 50 and 70 years. Affected individuals may present with sleep disturbances, personality changes, ATAXIA; APHASIA, visual loss, weakness, muscle atrophy, MYOCLONUS, progressive dementia, and death within one year of disease onset. A familial form exhibiting autosomal dominant inheritance and a new variant CJD (potentially associated with ENCEPHALOPATHY, BOVINE SPONGIFORM) have been described. Pathological features include prominent cerebellar and cerebral cortical spongiform degeneration and the presence of PRIONS. (From N Engl J Med, 1998 Dec 31;339(27))
Small proteinaceous infectious particles which resist inactivation by procedures that modify NUCLEIC ACIDS and contain an abnormal isoform of a cellular protein which is a major and necessary component. The abnormal (scrapie) isoform is PrPSc (PRPSC PROTEINS) and the cellular isoform PrPC (PRPC PROTEINS). The primary amino acid sequence of the two isoforms is identical. Human diseases caused by prions include CREUTZFELDT-JAKOB SYNDROME; GERSTMANN-STRAUSSLER SYNDROME; and INSOMNIA, FATAL FAMILIAL.
An autosomal dominant familial prion disease with a wide spectrum of clinical presentations including ATAXIA, spastic paraparesis, extrapyramidal signs, and DEMENTIA. Clinical onset is in the third to sixth decade of life and the mean duration of illness prior to death is five years. Several kindreds with variable clinical and pathologic features have been described. Pathologic features include cerebral prion protein amyloidosis, and spongiform or neurofibrillary degeneration. (From Brain Pathol 1998 Jul;8(3):499-513; Brain Pathol 1995 Jan;5(1):61-75)
A dominantly-inherited ATAXIA first described in people of Azorean and Portuguese descent, and subsequently identified in Brazil, Japan, China, and Australia. This disorder is classified as one of the SPINOCEREBELLAR ATAXIAS (Type 3) and has been associated with a mutation of the MJD1 gene on chromosome 14. Clinical features include progressive ataxia, DYSARTHRIA, postural instability, nystagmus, eyelid retraction, and facial FASCICULATIONS. DYSTONIA is prominent in younger patients (referred to as Type I Machado-Joseph Disease). Type II features ataxia and ocular signs; Type III features MUSCULAR ATROPHY and a sensorimotor neuropathy; and Type IV features extrapyramidal signs combined with a sensorimotor neuropathy. (From Clin Neurosci 1995;3(1):17-22; Ann Neurol 1998 Mar;43(3):288-96)
Magnetic Resonance Imaging
A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Image Processing, Computer-Assisted
A congenital condition where the greater portions of the cerebral hemispheres and CORPUS STRIATUM are replaced by CSF and glial tissue. The meninges and the skull are well formed, which is consistent with earlier normal embryogenesis of the telencephalon. Bilateral occlusions of the internal carotid arteries in utero is a potential mechanism. Clinical features include intact brainstem reflexes without evidence of higher cortical activity. (Menkes, Textbook of Child Neurology, 5th ed, p307)
National Health Planning Information Center (U.S.)
Poison Control Centers
A "smooth brain" malformation of the CEREBRAL CORTEX resulting from abnormal location of developing neurons during corticogenesis. It is characterized by an absence of normal convoluted indentations on the surface of the brain (agyria), or fewer and shallower indentations (pachygryia). There is a reduced number of cortical layers, typically 4 instead of 6, resulting in a thickened cortex, and reduced cerebral white matter that is a reversal of the normal ratio of cerebral white matter to cortex.
A nonspecific term referring both to the pathologic finding of swelling of distal portions of axons in the brain and to disorders which feature this finding. Neuroaxonal dystrophy is seen in various genetic diseases, vitamin deficiencies, and aging. Infantile neuroaxonal dystrophy is an autosomal recessive disease characterized by arrested psychomotor development at 6 months to 2 years of age, ataxia, brain stem dysfunction, and quadriparesis. Juvenile and adult forms also occur. Pathologic findings include brain atrophy and widespread accumulation of axonal spheroids throughout the neuroaxis, peripheral nerves, and dental pulp. (From Davis & Robertson, Textbook of Neuropathology, 2nd ed, p927)
Cyclical movement of a body part that can represent either a physiologic process or a manifestation of disease. Intention or action tremor, a common manifestation of CEREBELLAR DISEASES, is aggravated by movement. In contrast, resting tremor is maximal when there is no attempt at voluntary movement, and occurs as a relatively frequent manifestation of PARKINSON DISEASE.