hemiplegia alterans (alternating hemiplegia)

Etiology

idiopathic

Epidemiology

• develops in childhood, generally in 1st 4 years of age

Genetics

• associated with defects in ATP1A2

Clinical manifestations

• recurrent episodes of hemiplegia
• paralysis can affect eye movements, limbs, or facial muscles
• mental retardation
• balance & gait difficulties
• hyperhidrosis
• changes in body temperature
• sleep helps in the recovery from the periods of paralysis but the paralysis can recur upon waking
• variant form
  • occurs primarily at night, when a child awakens
  • related to migraine
  • no other mental or neurological impairments
• shares features with familial hemiplegic migraine 2
• typically distinguished from familial hemiplegic migraine by
  • infantile onset of symptoms
  • high prevalence of associated neurological deficits that become increasingly obvious with age

Management

• flunarizine may reduce the severity & duration of attacks of paralysis
• prognosis
  • good prognosis with variant form
  • more severe form associated with poor prognosis
    • mental retardation not responsive to drug therapy
    • balance and gait problems persist
    • over time, walking unassisted becomes difficult or impossible

More general terms

• developmental disorder
• genetic disease of the central nervous system

Additional terms

• hemiplegia (HP)

Database

• OMIM: https://mirror.omim.org/entry/104290