Olivary degeneration after intracranial haemorrhage or trauma: follow-up MRI.

We studied serial MRI appearances of transneuronal degeneration in the inferior olives, retrospectively analysing follow-up images of five patients, three with head injury and two with brain stem haemorrhage. We performed 13 MRI studies 4 days to 2 years 7 months after the accident. All but one of the patients exhibited bilateral olivary high signal on T2-weighted images. The interval between causal event and appearance of olivary changes was 2-4 months, images 4 days to 1.5 months after the accidents revealing no changes. Olivary enlargement was observed in four patients 2-4 months after ictus.