Unilateral Cerebellar Aplasia

Abstract

We describe three children with unilateral cerebellar aplasia (UCA). Deliveries at term and neonatal periods were uneventful. Pregnancy was normal in one and complicated by mild bleeding (in second and fourth month respectively) in two instances. Presenting signs were delayed motor development with marked contralateral torticollis (n = 1), hemiplegia (n = 1) and unusual head nodding (n = 1). Neuroradiological investigations revealed complete aplasia (n = 1) and subtotal aplasia (n = 2) of one cerebellar hemisphere with only a residual wing-like structure below the tentorium. There was contralateral underdevelopment of the brainstem. The infant with hemiplegic cerebral palsy had an additional supratentorial periventricular parenchymal defect, contralateral to the cerebellar hypoplasia. In view of literature reports, describing similar neuroradiological or neuropathological findings in asymptomatic individuals, it is doubtful whether UCA is responsible for our patient's problems. In our cases UCA has presumably resulted from a prenatal destructive lesion, possibly an infarct, but the timing and exact nature are unknown.

Outcome of severe unilateral cerebellar hypoplasia

“…29 Cognitive outcome was reported in only seven of the 18 previously reported cases (four patients were too young, two patients died in utero, and in five patients outcome was not described). [9][10][11][12][13] Normal cognitive development has been reported in three patients, although no IQ results were documented. [9][10][11] In two cases the vermis was normal; in one patient the involvement of the vermis was not described.…”

“…[9][10][11][12][13] Normal cognitive development has been reported in three patients, although no IQ results were documented. [9][10][11] In two cases the vermis was normal; in one patient the involvement of the vermis was not described. In other cases of UCH, learning disability of differing severity was reported, with IQ scores (if measured or documented) ranging between 60 and 74.…”

“…In other cases of UCH, learning disability of differing severity was reported, with IQ scores (if measured or documented) ranging between 60 and 74. 9,13 In one patient the vermis was hypoplastic; in the other patients the involvement of the vermis was not described. In our series four of the seven patients had a normal cognitive outcome.…”

“…Of the 18 cases described previously, follow-up data were reported for 11 patients (median age 3y, range 6mo-38y). 3,4,6,[8][9][10][11][12][13] At followup, three of the 11 patients had a squint, two patients had truncal ataxia and head nodding, and one patient had limb ataxia and muscular hypotonia. In our series typical symptoms are truncal or limb ataxia and muscular hypotonia: another finding may be head nodding.…”

“…1 In our experience, minor asymmetry of the cerebellar hemispheres is occasionally seen as an incidental finding without clinical significance whereas severe UCH is expected to be of clinical relevance. Previous descriptions of UCH have mostly been single case reports with a prenatal [3][4][5][6][7] or postnatal [8][9][10][11][12][13] diagnosis. The lack of outcome data available as a basis for well-founded prenatal counselling provided additional motivation for us to assess the prognosis of patients with UCH.…”