Huntington's Disease (Huntington's Chorea).docx

**Huntington\'s Disease (Huntington\'s Chorea)** **Huntington\'s Disease (HD) Overview:** - **Genetics and Inheritance:** - Inherited as an autosomal dominant disorder. - Caused by trinucleotide repeat expansion (CAG repeats) in the huntingtin gene. - Protein affecte...

**Huntington\'s Disease (Huntington\'s Chorea)** **Huntington\'s Disease (HD) Overview:** - **Genetics and Inheritance:** - Inherited as an autosomal dominant disorder. - Caused by trinucleotide repeat expansion (CAG repeats) in the huntingtin gene. - Protein affected: Huntingtin (Htt). - **Clinical Features:** - Typically manifests in the fourth or fifth decade, but onset can vary. - Anticipation phenomenon may lead to earlier onset in subsequent generations. - Initial symptoms may include involuntary choreiform movements (jerking, flowing from one body part to another). - Personality changes and behavioral disturbances are common. - Progressive dementia develops as the disease progresses. - Some individuals may later develop parkinsonism characterized by bradykinesia and rigidity. - **Psychosocial Impact and Prognosis:** - High rate of suicide, even in asymptomatic individuals, due to cognitive and emotional challenges. - Life expectancy reduced, with death typically occurring 10 to 20 years after symptom onset. - **Pathophysiology:** - Involves loss of inhibitory output from the striatum to the basal ganglia. - Results in hyperkinetic movements due to excess neural activity. - Neuronal apoptosis (cell death) occurs, contributing to disease progression. A close-up of a white background Description automatically generated - **Diagnostic Imaging and Pathological Findings:** - Gross examination of the brain reveals atrophy, particularly in the basal ganglia, including the caudate nucleus and putamen. - Coronal MRI may show a characteristic \"box-car\" ventricle appearance due to basal ganglia atrophy. - Microscopic examination shows severe loss of striatal neurons. - **Treatment Approaches:** - **Chorea Management:** - Tetrabenazine is the treatment of choice. - Side effects may include depression and increased suicide risk. - **Dementia Treatment:** - Acetylcholinesterase inhibitors may provide partial efficacy in managing cognitive decline. - **Psychosocial Support:** - Neuroleptics and GABA agonists may help manage behavioral symptoms.  \_\_\_\_\_\_ A 55-year-old man comes to the physician\'s office complaining of involuntary movements for the last three weeks. He has a known history of Huntington disease, and his daughter says he has also started acting strangely recently. Which of the following is this patient most likely going to develop? - Parkinsonism (Explanation: A term used to describe a group of movement symptoms seen in Parkinson\'s disease.) Huntington disease is an autosomal dominant disease that involves a loss of striatal inhibitory output to the basal ganglia. Which of the following is true about this condition? - CAG trinucleotide repeats on chromosome 4.Top of Form - Bottom of Form