Friday, May 10, 2013

How does HUNTINGTON CHOREA present? How to treat the disease?



Definition
Its autosomal dominant disorder characterized pathologically by degeneration of GABA-nergic neurons of caudate nucleus and clinically by chorea and dementia.

Clinical presentation

  • Involuntary writhing motions (i.e., choreiform) when pre-senting in adults during the fourth or fifth decades; seizures
  • and rigidity when presenting at a younger age.
  • Depression and cognitive impairment (i.e., dementia).
  • Patients often commit suicide because of the prognosis.

Mutation

  •  Huntingtin gene on chromosome 4.
  •  Mutation is an increase in the number of CAG repeats in the huntingtin gene.
  • Transcription of the expanded CAG repeats results in the accumulation of excess numbers of polygluta-mine residues in the huntingtin protein. 
  • There is an inverse relationship between the number of CAG repeats and the age of onset of disease. 
  • The CAG repeats increase in number during spermatogenesis,which results in the disease presenting earlier in successive generations (referred to as anticipa-tion)



Clinical manifestation
i. The disease manifests between age 20-40 years.
ii.Chorea:sudden,unexpected and purposeless contractions of proximal muscles
iii. Changes in personality,marked tendency for suicide and dementia

Microscopic findings
Loss of medium spiny GABA-nergic neurons in the caudate and putamen,associated with gliosis

Diagnosis:
Genetic diagnosis possible but controversial

Treatment:
Antipsychotic drugs (e.g; haloperidol)


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