(Huntington’s disease; Huntington’s disease, chronic progressive chorea, hereditary chorea)
M. Huntington is an autosomal dominant disease that is characterized by chorea, neuropsychiatric symptoms and progressive cognitive decline and usually begins in middle age. The diagnosis is made by a genetic test. first-degree relatives should be offered before genetic tests are performed genetic counseling. Treatment is supportive.
M. Huntington affects both sexes equally.
M. Huntington is an autosomal dominant disease that is characterized by chorea, neuropsychiatric symptoms and progressive cognitive decline and usually begins in middle age. The diagnosis is made by a genetic test. first-degree relatives should be offered before genetic tests are performed genetic counseling. Treatment is supportive. M. Huntington affects both sexes equally. Pathophysiology The caudate nucleus atrophies, the inhibitory neurons stachelzelligen (spiny neurons) degenerate in the corpus striatum, and the levels of the neurotransmitter ?-aminobutyric acid (GABA) and substance P decrease. M. Huntington is brought about by a mutation in the huntingtin (HTT) gene (on chromosome 4), causing the abnormal repeats of the DNA sequence CAG coding for the amino acid glutamine. The corresponding gene product, a large protein called huntingtin, is an expansion of Polyglutaminresten that accumulate in neurons and run through unknown mechanisms to the disease. The more CAG repeats are present, the earlier the disease begins and the more difficult is their expression (phenotype). The number of repeats can increase in subsequent generations within a family over time to increasingly severe diseased phenotypes result (so-called. Anticipation). Symptoms and signs The symptoms of chorea Huntington develop insidiously and start depending on the phenotypic expression to the 35th-40th Age. Before or simultaneously with the movement disorder is a dementia or psychiatric disorders (eg., Depression, apathy, irritability, anhedonia, antisocial behavior, fully trained bipolar or schizophreniform disorder) develop. Abnormal movements occur; these include chorea, myoclonic jerks, and Pseudotics (a cause of “Tourettismus”). Tourettismus refers to Tourette-like symptoms resulting from a neurological disease or use of a medicament. Typical features are a bizarre, puppet-like gait, grimacing, moving the eyes quickly arbitrarily and without blinking an inability, or spin head movements (oculomotor apraxia) and the inability to get a motor act like a tongue protrusion or grasping upright (motor instability ). The disease is progedient, walking makes impossible and swallowing difficult; it results in severe dementia. After all, most patients require institutionalization. Death usually occurs within 13 to 15 years after onset of symptoms. Diagnosis Clinical investigation, confirmed by genetic testing Neuroimaging The diagnosis of Huntington’s disease is due to the typical symptoms and a positive family history and confirmed by genetic testing, which measures the number of CAG repeats (interpretation of the results, see Table: Genetic Testing Neuroradiological on Huntington’s disease), imaging helps identify the caudate atrophy and often a predominant frontal cortical atrophy in. Genetic testing for Huntington’s disease the number of CAG repeats Interpretation ? 26 Normal 27-35 normal but (that children have Huntington’s disease increased risk) unstable 36-39 Abnormal variable penetrance; unstable (in some studies, most patients had symptoms and signs) ? 40 Abnormal with complete penetrance treatment Supportive Genetic counseling of relatives Because Huntington’s disease is progressive, should be discussed at an early stage about the medical and nursing procedures in the terminal stage (The Dying Patient ). The treatment of Huntington’s disease is supportive. Antipsychotics can partially suppress chorea and agitation. Among the antipsychotics include chlorpromazine 25 to 300 mg po three times a day haloperidol 5 to 45 mg p.o. twice daily risperidone 0.5 to 3 mg p.o. twice daily olanzapine 5-10 mg p.o. 1 times daily clozapine 12.5 mg to 100 p. o. once / day or twice / day in patients taking clozapine, the white blood cell count often has to be determined because of a potential for agranulocytosis is. The Antipsychotikadosis is so increased until nichttolerable side effects (eg. B. lethargy, parkinsonism) occur or the symptoms have been brought under control. Alternatively, tetrabenazine can be used. The initial dose is 12.5 mg p.o. once daily, increased to 12.5 mg 2 times / day in the second week, 12.5 mg 3 times / day in the third week and 12.5 mg p.o. 4 times / day in the fourth week. Doses of> 12.5 mg p.o. 4 times / day (total dose of 50 mg p.o./Tag) are placed in 3 doses / day; the total dose is increased to 12.5 mg / day weekly. The maximum dose is 33.3 mg p.o. 3 times daily (total dose of 100 mg / day). The doses to be increased sequentially as needed to control the symptoms or occur until intolerable side effects. Adverse effects may include excessive sedation, akathisia, parkinsonism and depression. The depression is treated with antidepressants. Currently examined therapies aim to reduce glutamatergic neurotransmission via the N-methyl-d-aspartate receptor and enhance mitochondrial energy production. Therapies with the goal to increase GABAergic function in the brain, have been shown to be not effective. People who fell ill 1st degree with Huntington’s disease have, especially women of childbearing age and men who are considering having children should be offered counseling and genetic testing (Prenatal genetic counseling and assessment). Genetic counseling should be offered genetic testing before, as the effects of Huntington’s disease are so profound. Conclusion M. Huntington, an autosomal dominant inherited disease that affects both sexes, usually caused in middle age dementia and chorea. If symptoms and family history speak for the diagnosis, perform in front of a genetic test first genetic counseling through and pull neuroradiological imaging into consideration. Treat the symptoms and discuss the care in the terminal stage as soon as possible. They offer 1st degree, v. a. potential parents, counseling and genetic testing.