Brain : a journal of neurology
-
Using a standard protocol including MRI and magnetic resonance angiography (MRA), we studied 28 consecutive patients, all with an acute infarct in the lower brainstem. MRI patterns above and below the inferior olivary nucleus enabled identification of six topographical types of infarct: small midlateral, dorsolateral, inferolateral, large inferodorsolateral, dorsal and paramedian infarcts. Small midlateral, dorsolateral, inferolateral and inferodorsolateral infarcts were the most common types and were associated with Wallenberg's syndrome, with specific clusters and severity of neurological features in each of the four groups. ⋯ Atheromatosis was by far the most frequent stroke aetiology (72%), with intracranial vertebral artery tight stenosis or occlusion in 28% of the cases and in 75% of the cases with large inferodorsolateral infarct. Vertebral artery dissection and cardioembolism accounted each for 14% of the cases, the latter being associated with dorsal infarct. Our study shows that differences in topographical patterns of infarction in the lower brainstem probably reflect differences in aetiopathogenic mechanisms.
-
The clinical differentiation of Parkinson's disease from the striatonigral degeneration (SND) type of multiple system atrophy (MSA) and Steele-Richardson-Olszewski syndrome (SRO) may be difficult. This is reflected by a 20-25% misdiagnosis rate in clinicopathological series of cases labelled as 'Parkinson's disease' in life. The caudate and putamen contain a high density of opioidergic neurons and receptors which have a close anatomical and physiological relationship with the dopaminergic system. ⋯ Corresponding figures for putamen opioid receptor binding were: none of the Parkinson's disease cases (0%); three of the SND cases (43%); and all of the SRO cases (100%). We conclude that there are differences in the pattern of opioid receptor binding in the striatum of Parkinson's disease, SND and SRO patients, as determined by [11C]diprenorphine PET. The different binding patterns may help to differentiate these akinetic-rigid syndromes in life.