Alternating hemiplegia of childhood
From Wikipedia, the free encyclopedia
| Alternating hemiplegia of childhood Classification and external resources |
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| OMIM | 104290 |
|---|---|
| DiseasesDB | 33595 |
| eMedicine | neuro/219 |
Alternating hemiplegia of childhood (AHC) is a rare genetic disease which causes intermittent paralysis and progressive mental retardation starting in childhood.
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[edit] Symptoms
AHC usually occurs before four years of age and can present in either a severe or a less severe form.
- The less severe form has a good prognosis and is indicated by episodes occurring primarily at night, and can often be related to migraines. There is no neurological impairment in this form of AH.
- The severe form is indicated by the usual paralysis, mental impairment, gait and balance impairment, excessive sweating, and changes in body temperature. Seizures and movement disorders can also be present.
[edit] Etiology
Some cases of AHC are thought to be the result of a channelopathy - the gene ATP1A2 (an isoform of the sodium-potassium ATPase) has been implicated in at least one family. There is overlap with the syndrome of familial hemiplegic migraine in which the ATP1A2 gene undergoes a different mutation.
[edit] Treatment
Drug therapy includes flunarizine, a calcium channel blocker. It may help to reduce the severity and duration of attacks of paralysis associated with the more serious form of alternating hemiplegia.
[edit] Prognosis
Children with the benign form of alternating hemiplegia have a good prognosis. However, those who experience the more severe form have a poor prognosis because intellectual and mental capacity do not respond to drug therapy, and balance and gait problems continue. Over time, walking unassisted becomes difficult or impossible.
