Focal appearance of cerebellar torpedoes associated with discrete lesions in the cerebellar white matter.

Cerebellar torpedoes, unique fusiform swellings of Purkinje cell axons within the granular layer, have been known to occur sparsely associated with diffuse cerebellar changes. This report describes, in three human autopsy cases with focal necrotic lesions in the cerebellar white matter, torpedoes which were essentially confined to the cerebellar cortex overlying the lesions. Purkinje cells in the same region showed no recognizable change, but were obviously decreased in number. The location of the necrotic lesions was such that they may well have severed Purkinje cell axons projecting into the deeply located cerebellar nuclei from the torpedo-carrying cortex. These findings indicate that damage to Purkinje cell axons, even if it occurs far away from the cell bodies, may have a critical influence upon the metabolism of Purkinje cells and play an important role in the formation of torpedoes.