All are true about Huntington's disease except: (DNB Dec 2010)
|C||Early onset of memory loss|
Early onset of memory loss
Huntington’s Disease (Ref. Hari-18th ed., pg- 3330)
1). Autosomal dominant, degenerative brain disorder Q
2). The HD gene called IT IS is located on chromosome 4
3). It contain CAG triple repeat expansion
4). Onset is 4 –5th decade. May be childhood to >75year
5). Clinical hallmarks are progressive chorea and emotional disturbance, dementia and death Q
6). Gait is poorly coordinated and has a dancing quality. Emotional disturbance manifest as irritability in behavior
7). With advancing disease, there may be a reduction in chorea and emergence of dystonia, rigidity, bradykinesia, myoclonus, and spasticity.
8). Attention, Judgment, awareness and executive functions are seriously deficient at an early stage.
9). Depression, social withdrawal, irritability and disinhibitions positive
10). Seizure are common which Juvenile HD & rare which Adult HD.
11). Pathologically there is atrophy of caudate nucleus
12). Neuro chemically there is marked decrease at GABA anergic and cholinergic neurons in corpus striatum.
13). Treatment – Phenothiazine, haloperidol, benzodiazepines, olanzapine.
Extra Edge: Other triple repeat genetic abnormality are dystrophica myotonia (CTG),fragile X syndrome(CGG), Freidrich’s ataxia(GAA)}