Cerebellar heterotopia of infancy in sudden infant death syndrome: an observational neuropathological study of four cases

Abstract

Sudden infant death syndrome (SIDS) is the sudden unexpected death of an infant < 1 year of age that remains unexplained after comprehensive workup including complete autopsy and investigation of the circumstances of death. The triple risk hypothesis posits that SIDS results as a combination of both intrinsic and extrinsic factors on the background of a predisposing vulnerability. Neuropathological examination in the past has focussed mainly on the brainstem as the major player in respiratory control, where subtle findings have been linked to the chain of events leading to death in SIDS. The cerebellum has received less attention, probably due to an assumed negligible role in central cardiorespiratory control. We report four cases of SIDS in which neuropathological investigation revealed cerebellar heterotopia of infancy, a distinct malformation of the cerebellum, and discuss the potential impact of this condition on the aetiology and pathogenesis of SIDS.

Keywords: Arousal circuits; Forensic neuropathology; Malformations of the central nervous system; SIDS.

Fig. 1

Loosely aggregated misplaced poorly organised cerebellar cell rests, heterotaxia-type in cases #1 and #4, hematoxilin and eosin stain (a, d); well-organised misplaced cerebellar cell rests composed of all physiological foliar components, heterotopia-type in cases #2 and #3, HE (b, c). Scale bar 100 μm in a–d