Authors: Drs Linxin Li & Maria Tuna, Centre for Prevention of Stroke and Dementia, Level 6, West Wing, John Radcliffe Hospital, Oxford, UK.

A 58-year-old ex-smoker and migrainous man, with otherwise no vascular risk factors, presented with one episode of isolated transient vertical diplopia lasting for one and a half hours. What would be your differentials? Another “funny turn” that you will tell the paitent not to worry about? Would you do an imaging study just for the peace of mind?

Yes, you would probably request an imaging study. But, would you be surprised to see an acute right anterior medial thalamic infarct on DWI?  Indeed, this is also a rare presentation of a unilateral paramedian thalamic infarct, but there have been other case reports,1 and perhaps the short-lasting vertical diplopia is related to a transient disturbance in the vestibuloocular pathway traversing the thalamus. So the “funny turn” – a transient isolated brainstem symptom, turned out to be a serious transient ischaemic attack (TIA)!

Transient isolated brainstem symptoms (e.g. isolated diplopia or isolated vertigo) are not classical presentations of TIA. Are we right in just calling them “funny turn”? Emerging evidence now suggests these patients with “funny turns” might be at increased long-term risks of vascular events.2 Moreover, these isolated brainstem symptoms are common before a posterior circulation stroke.3 So next time, if you see a “funny turn” in your stroke clinic, take the history carefully and think of TIA!


  1. Blitshteyn S, Hentschel K, Czervionke LF, Eidelman BH. Transient vertical diplopia and nystagmus associated with acute thalamic infarction. Clin Imaging. 2006;30:54–56
  2. Bos MJ, van Rijn MJ, Witteman JC, Hofman A, Koudstaal PJ, Breteler MM. Incidence and prognosis of transient neurological attacks. JAMA 2007;298:2877-2885.
  3. Paul NL, Simoni M, Rothwell PM, Oxford Vascular S. Transient isolated brainstem symptoms preceding posterior circulation stroke: a population-based study. Lancet neurology 2013;12:65-71.
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