[Crossed cerebellar atrophy following hemispheric lesions occurring in adulthood]

Crossed cerebellar atrophy generally results from a large contralateral hemispheric lesion involving the cortico-spinal tract in neonates or infants. Two cases of crossed cerebellar atrophy which were particular from two points of view are reported: 1) the cerebellar alterations resulted from cerebral lesions which had occurred in adult life, after complete maturation of the central nervous system. One was observed in a 78 years old hypertensive woman who had presented 24 years before a right lenticular haemorrage, the other in a 73 years old woman who when aged 18 had presented a left cortical frontal traumatic lesion. The clinical and pathological data are compared to 13 similar cases reported in the literature. The retrograde or anterograde route of this transneuronal degeneration is discussed. The pathological features of those 2 cases lead the authors to favor the anterograde route; 2) the cerebral lesion was small and strictly limited to F2 in 1 case, the secondary lesions involving then, only the medial pontine nuclei and the quadrangular cerebellar lobule. This allows a clear demonstration, in man, of a systematisation of the cortico-pontine and ponto-cerebellar fibers similar to what has been described in the animal (Brodal, 1980).