This 24 year-old male patient presented with sudden onset diplopia, ataxia, and headache. Clinical examination yielded evidence of an internuclear ophthalmoplegia.
The axial T2-weighted MR image above shows flame-shaped areas of high signal in both cerebellar hemispheres. Most of these showed restricted diffusion. One actually showed increased diffusion and may have been an old infarct. There were also areas of restricted diffusion in posterior pons, tectum, and occipital lobe. There was a probable old lacunar infarct in the left thalamus.
The appearance of multiple infarcts of different ages suggests emboli as a cause. Head and neck MR angiography demonstrated no vascular cause, and there was no evidence of vertebral artery dissection. The apparent limitation of infarcts to the posterior circulation was unusual for a proximal source of emboli and led to differential diagnoses such as vasculitis or posterior circulation vasospasm being postulated. A transoesophageal echocardiogram later demonstrated an atrial myxoma, a well-known source of emboli.
Reference: Osborn A. Diagnostic Imaging: Brain Amirsys 2004
Credit: Dr Laughlin Dawes