Snapshot A 20-year-old man presents with a two-year history of motor restlessness that has progressed to uncontrollable choreiform movements. He has moderate dementia with a severe gait disturbance as well as agitation and problems with his mood. CT scan of the brain shows atrophy of the cerebral cortex and caudate nucleus. Introduction An autosomal dominant disorder characterized by choreiform movements progressive intellectual deterioration exhibits genetic anticipation Epidemiology demographics symptoms usually begin to appear in the 3rd-5th decade of life both sexes are affected equally incidence 0.38 cases per 100,000 per year Genetic inheritance autosomal dominant mutation CAG triplet repeat expansion in huntingtin gene (chromosome 4) login to view 1 more bullet demonstrates anticipation mutation leads to atrophy of striatum (especially caudate nucleus) with neuronal loss and gliosis decrease in the levels of GABA and ACh Pathophysiology changes in neurotransmitters with Huntington's disease ↑ dopamine (in ventral tegmentum and substantia nigra) and ↓ GABA (in nucleus accumbens) and ACh (in basal nucleus of Meynert) login to view 2 more bullets Presentation Symptoms progressive choreiform movements of all limbs ataxic gait dementia depression grimacing Evaluation MRI shows atrophy of caudate Treatment Pharmacologic no known cure medications used to treat Huntington's disease include amine-depleting agents (inhibit VMAT, involved in monoamine transport) login to view 4 more bullets antipsychotics login to view 4 more bullets muscle relaxants login to view 1 more bullet Prognosis, Prevention, and Complications Death inevitable Suicide common cause of death