Background. Alternating hemiplegia of childhood (AHC) is a rare neurological disease of unknown aetiology
characterized by recurrent paroxysmal attacks of side - alternating hemiplegias of variable duration associated with
other paroxysmal dysfunctions. Paroxysmal attacks start in infants but neurological deficits become progressive with
Methods and Results. During the last 20 years 8 patients (5 boys, 3 girls) with AHC were followed. Mean age at the
time of diagnosis was 2.75 years, age range 2–5 years; mean follow up period 13.9 years (range 1 month-20 years)
The diagnosis was based on clinical history and neurological findings, completed by neurophysiological and
neuroimaging methods (SPECT, PET), and results of psychological and biochemical findings. Paroxysmal
phenomena (occulo-motor, tonic, choreo-athetotic, autonomic) appearing at the age of 4.1±2.2 months and followed
by repeated attacks of hemiplegia (age onset 16.3±13.0 months) were the first symptoms. Progressive neurological
impairment covering spasticity, dyskinetic syndrome, cerebellar ataxia and intellectual deficit was present in all cases,
epileptic seizures in 7 out of 8 patients. On ictal SPECT/PET examination hypoperfusion/glucose hypometabolism
were demonstrated above affected hemispheres including basal ganglia, both thalami and cerebellar hemispheres.
Improvement of hemiparesis was illustrated by nocturnal videomonitoring.
Conclusions. AHC is a chronic disease with progressive neurological deficit. A flunarizine therapy has a favorable
effect on frequency and severity of paroxysmal attacks, but does not prevent a progressive neurological impairment.
alternating hemiplegia, paroxysmal attacks, diagnosis, neuroimaging methods, video-polysomnography,
long-term follow-up, prognosis, therapy.