Stroke: clinical signs may help to diagnose severe carotid stenosis, but were not very helpful.

Clinical bottom line (level 1b)

  1. About a seventh of patients suspected of having severe carotid stenosis have it.
  2. Patients with ipsilateral bruit, diabetes or prior TIA were more likely to have severe carotid stenosis, and those without any were slightly less likely to have it.
  3. Patients who suffered a lacunar event were slightly more likely to have carotid stenosis, and those with another form were slightly less likely to have it.
  4. Increasing combinations of these factors made carotid artery stenosis more likely (1/4: (LR+1.3) 2/4: (LR+3.3) 3 or 4/4: (LR+5.7) )
Mead et al: Journal of Neurological Neurosurgery and Psychiatry 1999; 66: 16-19
Expires November 2002

The study

Setting: general hospital, UK

726 patients (aged ?, ?% male) acute stroke, transient ischaemic attack or retinal stroke admitted to the hospital or referred to neurovascular clinics

Excluded if
  • primary intracerebral haemorrhage
  • total anterior circulation stroke
  • uncertain Oxfordshire Community Stroke Project stroke types with midline lesions on computed tomography
  • posterior circulation events



    • Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
    Reference standard:
    • Doppler ultrasound
    Diagnostic test: clinical features- ipsilateral bruit, diabetes, previous transient ischaemic attack, not a lacunar event, or a combination of the above.
    • Although angiography is usually the reference standard test, in this particular hospital only patients in whom the ultrasonographer thinks that the artery is poorly visualised go for angiography.

    The evidence

    pre-test probability of severe (>70%) carotid stenosis: 13.2%, (95% CI: 10.8% to 15.9%)

    diagnostic test severe carotid stenosis (>70%) no severe carotid stenosis (<70%) LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    ipsilateral bruit 55 41 5.73
    (4.28 to 7.66)     		47.0% 0.47
    (0.38 to 0.60)     		7.00%
    diabetes 15 81 1.73
    (1.02 to 2.92)     		21.0% 0.93
    (0.85 to 1.01)     		12.0%
    previous TIA 23 73 1.84
    (1.22 to 2.77)     		22.0% 0.78
    (0.78 to 0.98)     		12.0%
    not lacunar event 81 15 1.12
    (1.12 to 1.37)     		16.0% 0.49
    (0.30 to 0.79)     		7.00%
    total 96 630


    diagnostic test number of patients sensitivity for
    severe carotid stenosis (>70%)
    (95% CI)    		 specificity for
    severe carotid stenosis (>70%)
    (95% CI)    		 LR+ LR-
    any one of ipsilateral bruit, diabetes, prior TIA or not lacunar event 45 99%
    (% to %)     		22%
    (% to %)     		1.3 0.05
    any two of ipsilateral bruit, diabetes, prior TIA or not lacunar event 27 65%
    (% to %)     		80%
    (% to %)     		3.3 0.44
    any three of ipsilateral bruit, diabetes, prior TIA or not lacunar event 3 17%
    (% to %)     		97%
    (% to %)     		5.7 0.86
    total 96

    Citation

    1. Mead GE, Wardlaw JM, Lewis SC, et al: Can simple clinical features be used to identify patients with severe carotid stenosis on Doppler ultrasound?. Journal of Neurological Neurosurgery and Psychiatry 1999; 66: 16-19
    Contributor: Clare Wotton and Musab Hayatli, November 1999
    Reviewer: Rowan Harwood

    Clinical Question.
    Patient severe carotid stenosis
    Intervention or Exposure clinical features
    Comparison ultrasound
    Outcome diagnosis