Article

Complete or subtotal absence of one cerebellar hemisphere is exceptional;
only single cases have been described. We aimed to assess the long-term outcome
in children with severe unilateral cerebellar hypoplasia (UCH). METHOD: As part
of a retrospective study we describe neuroimaging features, clinical findings,
and cognitive outcomes of seven children with UCH (five males, two females; age
at first magnetic resonance imaging [MRI]: median 1y 3mo, range 9d-8y 10mo; age
at latest follow-up: median 6y 6mo, range 2y 3mo-14y 11mo). RESULTS: One child
had abnormalities on prenatal MRI at 21 weeks' gestation. The left cerebellar
hemisphere was affected in five children, and the right hemisphere in two
children. The vermis was involved in five children. The volume of the posterior
fossa was variable. At the latest follow-up, neurological findings included
truncal ataxia and muscular hypotonia in five children, limb ataxia in three
patients, and head nodding in two patients. Three children had learning
disability*, five had speech and language disorders, and one had a severe
behavioural disorder. INTERPRETATION: Severe UCH is a residual change after a
disruptive prenatal cerebellar insult, most likely haemorrhagic. The outcome is
variable, ranging from almost normal development to marked developmental
impairment. Ataxia is a frequent but not a leading sign. It seems that
involvement of the cerebellar vermis is often, but not consistently, associated
with a poorer cognitive outcome, whereas an intact vermis is associated with
normal outcome and no truncal ataxia.

Langue : ANGLAIS