Dr Sofia Khan

Clinical Senior Lecturer in Neurology & Sleep Disorders / Honorary Consultant Neurologist

Qualifications: MRCP, MD (Res)

Phone: Work: 01483 68 3365
Room no: 09 PGM 00

Further information


We are setting up a local service for patients with sleep disorders to investigate and manage patients with excessive sleepiness, periodic limb movements, unusual behaviours at night and circadian rhythm disorders. For further information on this service please email: sleepservice@surrey.ac.uk

Research Interests

Sleep disorders in patients with neurological conditions.


Journal articles

  • Billows IJ, Khan S, Sterr A. (2013) 'Exploring sleep, sleepiness and fatigue in chronic stroke: A mixed methods study'. INTERNATIONAL JOURNAL OF STROKE, 8, pp. 73-73.
  • Bhandari M, Ingle M, Khan S, Pereira AC. (2013) 'SMART: a Reversible Stroke Mimic'. CEREBROVASCULAR DISEASES, 35, pp. 608-608.
  • Qu S-B, Khan S, Liu H. (2009) 'Primary central nervous system vasculitis mimicking brain tumour: case report and literature review'. RHEUMATOLOGY INTERNATIONAL, 30 (1), pp. 127-134.
  • Khan S, Rich P, Clifton A, Markus HS. (2009) 'Noninvasive detection of vertebral artery stenosis: a comparison of contrast-enhanced MR angiography, CT angiography, and ultrasound.'. Stroke, United States: 40 (11), pp. 3499-3503.


    Vertebral stenosis is associated with a high risk of recurrent stroke, but noninvasive imaging techniques to identify it have lacked sensitivity. Contrast-enhanced MR angiography and CT angiography have been recently developed and appear to have better sensitivity. However, no prospective studies have compared both of these techniques with ultrasound against the gold standard of intra-arterial angiography in the same group of patients.

  • Gulli G, Khan S, Markus HS. (2009) 'Vertebrobasilar stenosis predicts high early recurrent stroke risk in posterior circulation stroke and TIA.'. Stroke, United States: 40 (8), pp. 2732-2737.


    20% of ischemic stroke is in the posterior circulation, but there is little prospective data on early recurrent stroke risk and whether vertebrobasilar stenosis predicts a high recurrence risk. This natural history data are important as it is technically possible to stent such lesions. Contrast enhanced MRA (CE-MRA) and CT angiography (CTA) now allow noninvasive identification of vertebrobasilar stenosis.

  • Khan S, Cloud GC, Kerry S, Markus HS. (2007) 'Imaging of vertebral artery stenosis: a systematic review.'. J Neurol Neurosurg Psychiatry, England: 78 (11), pp. 1218-1225.


    BACKGROUND AND PURPOSE: Posterior circulation stroke accounts for 20% of ischaemic strokes. Recent data suggest that the early stroke recurrence risk is high and comparable with carotid artery disease. Vertebral artery stenosis accounts for approximately 20% of posterior circulation stroke, and with endovascular treatment available accurate diagnostic imaging is important. We performed a systematic literature review to validate the accuracy of the non-invasive imaging techniques Duplex ultrasound (DUS), magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) in detecting severe vertebral artery stenosis, with intra-arterial angiography (IAA) as the reference standard. METHODS: We identified studies that used non-invasive imaging and IAA as the reference standard to determine vertebral artery stenosis and provided adequate data to calculate sensitivity and specificity. We analysed the quality of these studies, looked for evidence of heterogeneity and performed subgroup analysis for different degrees of stenosis. RESULTS: 11 studies categorised stenosis into 50-99%. The sensitivity of CTA (single study) and pooled sensitivities of contrast enhanced MRA (CE-MRA) and colour duplex were 100% (95% CI 15.8 to 100), 93.9% (79.8 to 99.3) and 70.2% (54.2 to 83.3), respectively. The specificities for CTA, CE-MRA and colour duplex were 95.2% (83.8 to 99.4), 94.8% (91.1 to 97.3) and 97.7% (95.2 to 99.1). However, specificities for CE-MRA and colour duplex demonstrated significant heterogeneity (p = 0.003 and p = 0.002, respectively). CONCLUSIONS: CE-MRA and possibly CTA may be more sensitive in diagnosing vertebral artery stenosis than DUS. However, data are limited and further high quality studies comparing DUS, MRA and CTA with IAA are required.

Conference papers

  • Khan S. (2014) 'What do UK junior doctors' know about sleep disorders? A systematic literature review'. WILEY-BLACKWELL JOURNAL OF SLEEP RESEARCH, Tallinn, ESTONIA: 22nd Congress of the European-Sleep-Research-Society 23, pp. 248-248.
  • Khan S, Cloud GC, Kerry S, Markus HS. (2007) 'A systematic review of the diagnostic accuracy of Doppler, MR angiography and CT angiography compared with intra-arterial angiography in vertebral artery stenosis'. B M J PUBLISHING GROUP JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY, London, ENGLAND: Fall Meeting of the Association-of-British-Neurologists 78 (2), pp. 209-209.

Departmental Duties

Clinical Sleep Lead

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Page Created: Thursday 21 November 2013 15:15:17 by ha0009
Last Modified: Wednesday 11 November 2015 17:00:26 by kj0008
Expiry Date: Saturday 21 February 2015 15:11:41
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