Huntington’s Disease

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Huntington’s disease is a movement disorder characterized by chorea and dementia. It is inherited in an autosomal dominant manner and occurs throughout the world, in all ethnic groups, with a prevalence rate of about 5 per 100,000. The gene responsible for the disease has been located on the short arm of chromosome No. 4. At 4p16.3 there is an expanded and unstable CAG trinucleotide repeat. Symptoms do not usually develop until after 30 years of age, by which time the patient has usually had children, and so the disease continues from one generation to the next. The cause of Huntington’s disease is unknown. Online Trusted Pharmacy

Clinical Findings

Clinical onset is usually between 30 and 50 years of age. The disease is progressive and usually leads to a fatal outcome within 15–20 years. The initial symptoms may consist of either abnormal movements or intellectual changes, but ultimately both occur. The earliest mental changes are often behavioral, with irritability, moodiness, antisocial behavior, or a psychiatric disturbance, but a more obvious dementia subsequently develops. The dyskinesia may initially be no more than an apparent fidgetiness or restlessness, but eventually choreiform movements and some dystonic posturing occur. Progressive rigidity and akinesia (rather than chorea) sometimes occur in association with dementia, especially in cases with childhood onset. CT scanning usually demonstrates cerebral atrophy and atrophy of the caudate nucleus in established cases. MRI and positron emission tomography (PET) have shown reduced glucose utilization in an anatomically normal caudate nucleus. Buy Cheap Antibiotics pills

Chorea developing with no family history of choreoathetosis should not be attributed to Huntington’s disease, at least not until other causes of chorea have been excluded clinically and by appropriate laboratory studies. In younger patients, self-limiting Sydenham’s chorea develops after group A streptococcal infections on rare occasions. If a patient presents solely with progressive intellectual failure, it may not be possible to distinguish Huntington’s disease from other causes of dementia unless there is a characteristic family history or a dyskinesia develops. Canadian Prescriptions Drugs

Treatment

There is no cure for Huntington’s disease, progression cannot be halted, and treatment is purely symptomatic. The reported biochemical changes suggest a relative underactivity of neurons containing gamma-aminobutyric acid (GABA) and acetylcholine or a relative overactivity of dopaminergic neurons. Treatment with drugs blocking dopamine receptors, such as phenothiazines or haloperidol, may control the dyskinesia and any behavioral disturbances. Haloperidol treatment is usually begun with a dose of 1 mg once or twice daily, which is then increased every 3 or 4 days depending on the response. Tetrabenazine, a drug that depletes central monoamines, is widely used in Europe to treat dyskinesia but is not available in the USA. Reserpine is similar in its actions to tetrabenazine and may be helpful; the daily dose is built up gradually to between 2 and 5 mg, depending on the response. Behavioral disturbances may respond to clozapine. Attempts to compensate for the relative GABA deficiency by enhancing central GABA activity or to compensate for the relative cholinergic underactivity by giving choline chloride have not been therapeutically helpful. High levels of somatostatin (a neuropeptide) have recently been reported in certain areas of the brain in patients with Huntington’s disease, and the therapeutic response to cysteamine (a selective depleter of somatostatin in the brain) is currently under study. Buy Discount Anti Depressants pills at XL-DrugStore

Offspring should be offered genetic counseling. Now that the gene responsible for the disorder has been isolated, an accurate and specific test for the presymptomatic detection and definitive diagnosis of Huntington’s disease has become more widely available. Human Growth Agent

10240:17:1 Furtado S, Suchowersky O: Huntington’s disease: Recent advances in diagnosis and management. Can J Neurol Sci 1995;22:5.