Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory vascular disease [1] , which has been observed in almost every artery throughout the body, however it is more typically associated with renal and carotid arteries [2] . The typical renal FMD presentation is hypertension whereas carotid/vertebral FMD has been associated with stroke and TIA. We present a case to illustrate how FMD, although not being an uncommon cause of stroke, is significantly under-recognised as a high index of suspicion required to diagnose it. The subsequent discussion will focus on the aetiology, diagnosis and management of carotid and vertebral FMD.

A female office worker in her early 60 s attended our emergency department (ED) having developed left facial asymmetry, left sided weakness, and left visual neglect. Our hospital is representative of a medium to large dis-

trict general hospital in England treating about 600 inpatient strokes per year. The onset time was not clear as she had assumed it would resolve and continued working until her family encouraged her to seek medical attention. On review it became apparent she had a paucity of risk factors for cerebrovascular disease. She had no relevant past medical or family history, was a life-long non-smoker, drank alcohol very occasionally and was generally very active with a normal body mass index (BMI). Examination revealed profound left visual neglect, left upper motor neurone facial palsy and dysarthric speech. She had a mild left hemiparaesis with grade 4/5 power on the left. Her cardiovascular examination was normal.

The working diagnosis was a right partial anterior circulation stroke. She had an initial CT (see Figure 1), which demonstrated an area of low attenuation in the right parietal lobe consistent with an infarct after her delayed presentation. She went on to have a MRI brain with diffusion weighted sequence (see Figure 2) to confirm an is chaemic stroke and exclude other pathology such as a tumour. She underwent extensive investigations to identify the underlying cause of her stroke. Her ECG and ambulatory monitor showed no evidence of atrial fibrillation and she had a normal echocardiogram. There was no evidence of hypertension, hyperlipidaemia or diabetes mellitus. Rarer causes such as lupus or thrombophilia were also excluded. No evidence of significant internal carotid artery stenosis was identified on carotid doppler ultrasound scanning.

A further magnetic-resonance angiogram (MRA) of her carotids was organised as a second imaging modality (see Figure 3). This demonstrated a “string of beads” appearance and she was diagnosed with fibromuscular dysplasia. (FMD).The patient was subsequently referred to a tertiary centre for a conventional angiogram of the cerebral vessels. After discussion in the neurosurgical centre’s multi-disciplinary team meeting she was not deemed appropriate for surgical or radiological intervention at present. Instead she was commenced on dual antiplatelet therapy (aspirin and clopidogrel). The patient made a good functional recovery and was left with only a mild visual field defect that was noted during her follow up appointments. Formal written consent for this case report was obtained from the patient.

Our case highlights the importance of considering FMD as a potential cause of ischaemic stroke, particularly in women, where traditional vascular and other relevant risk factors have been effectively excluded. Carotid Doppler, often used as a first line investigation, particularly in district general hospitals in England is not an ideal imaging modality to detect FMD. CTA and MRA have much higher sensitivity and specificity and should be considered in selected cases. Once identified, neurosurgical and neuroradiology colleagues should be involved as select cases may benefit from intervention.