Transient isolated diplopia – anything else on the checklist?
Author: Dr Linxin Li, Center for Prevention of Stroke and Dementia, John Radcliffe hospital, Oxford
You have received a referral from a family doctor asking you to see a 71-year old gentleman in the emergency TIA clinic. He presented with 5 episodes of transient diplopia in the last week. None of the episodes were associated with headache, vertigo, any other visual symptoms, facial or limb weakness, sensory disturbance or speech problem. There was no recognised trigger and the episodes could happen any time of the day and lasted from few seconds up to fifteen minutes. He had no vascular risk factors and was otherwise well.
Neurological exam was normal. Brain MRI was unremarkable and there was no abnormality identified on the MRA of the extracranial/intracranial vessels. He was in sinus rhythm in clinic and echocardiography was also normal.
What are the differentials on your checklist? Transient ischaemic attacks? Myasthenia gravis? Atypical migraine? Or, have we missed anything? If there is one additional test you could request, what might be helpful?
Given his age, Erythrocyte sedimentation rate (ESR) was requested, which came back to be elevated at 85mm/hr. He was immediately treated with steroids and a subsequent temporal artery biopsy confirmed the diagnosis of active giant cell arteritis. He had no more episodes within 24 hours after starting the treatment.
Giant cell arteritis (GCA) or temporal arteritis (TA) is a known medical emergency because failure to make a quick diagnosis may lead to irreversible visual loss and inappropriate treatment. Typical presentations of GCA include new onset of visual loss, amaurosis fugax, localized headache, tenderness in the temporal artery, and jaw claudication. Transient isolated diplopia is a less recognised but not uncommon ocular presentation, with a reported prevalence between 5.9% and 25% in different cohorts.1 It is thought to be related to ischaemia of extraocular muscles or their nerves or of the brainstem. Interestingly, the only two historical features that substantially increased the odds of GCA among patients referred for biopsy were jaw claudication and diplopia.2 ESR is very helpful and normal ESR indicated much less likelihood of the disease.2
So, next time when you see an elderly patient presenting with transient diplopia in the TIA clinic, consider requesting ESR and don’t forget giant cell arteritis on your checklist!
- Haering M, Holbro A, Todorova MG, et al. Incidence and prognostic implications of diplopia in patients with giant cell arteritis. J Rheumatol 2014; 41: 1562-1564
- Smetana GW, Shmerling RH. Does this patient have temporal arteritis? JAMA 2002; 287: 92-101.