neurologic disorders
Huntington Disease
Treatment of Huntington Disease
Supportive measures Genetic counseling for relatives Because Huntington disease is progressive, The Dying Patient should be discussed early. Treatment of Huntington disease is supportive and symptomatic. However, researchers continue to look for ways to slow and stop disease progression. Antipsychoticsmay partially suppress chorea and agitation. Antipsychotics include Chlorpromazine25 to 300 mg orally 3 times a day Haloperidol5 to 45 mg orally 2 times a day Risperidone0.5 to 3 mg orally 2 times a day Olanzapine5 to 10 mg orally once a day Clozapine12.5 to 100 mg orally 1 or 2 times a day In patients takingclozapine, white blood cell (WBC) counts must be done frequently because agranulocytosis is a risk. The antipsychotic dose is increased until intolerable adverse effects (eg, lethargy, parkinsonism) develop or symptoms are controlled. Alternatively, a vesicular monoamine transporter type 2 (VMAT-2) inhibitor (tetrabenazine,deutetrabenazine) may be used. These drugs depletedopamineand aim to lessen chorea and dyskinesias. Tetrabenazineis started at 12.5 mg orally once a day and increased to 12.5 mg 2 times a day in the 2nd week, and 12.5 mg 3 times a day in the 3rd week. Dose can be increased by another 12.5 mg in the 4th week. Doses of > 12.5 mg are given orally 3 times a day (resulting in a total dose of 37.5 mg/day); the total dose is increased 12.5 mg/day weekly. The maximum dose is 33.3 mg orally 3 times a day (total dose of 100 mg/day). Doses are increased sequentially as needed to control symptoms or until intolerable adverse effects occur. Adverse effects can include excessive sedation, akathisia, parkinsonism, and depression. Depression is treated with antidepressants. Deutetrabenazineis now available for treatment of chorea in Huntington disease. The recommended dose is 6 to 48 mg/day, given orally in 2 doses. The starting dose is 6 mg once a day, then increased by 6 mg/day every week (eg, to 6 mg 2 times a day) to a maximum of 24 mg 2 times a day (48 mg/day). (Doses ≥ 12 mg are given in 2 divided doses.) Adverse effects are similar to those oftetrabenazinebut are better-tolerated. However, VMAT-2 inhibitors are costly. Therapies currently under study aim to reduce glutamatergic neurotransmission via theN-methyl-d-aspartate receptor and to bolster mitochondrial energy production. Treatments that aim to increase GABAergic function in the brain have been ineffective. Selective serotonin reuptake inhibitors may help patients with depression, anxiety, or obsessive-compulsive disorder associated with Huntington disease and lessen symptoms in patients with impulse behavioral disorder. People who have 1st-degree relatives with Huntington disease, particularly women of childbearing age and men considering having children, should be offered Prenatal Genetic Counseling . Genetic counseling should be offered before genetic testing because the ramifications of Huntington disease are so profound. 