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Three Part Question

Can [CT scan] reliably rule out [cerebellar infarct] in [adults presenting to the emergency department with concerning features of vertigo]?

Clinical Scenario

74 year old man presents to emergency department with a 1 day history of dizziness, sensation of vertigo and imbalance. He has nystagmus on clinical exam. His head CT is negative for cerebellar infarct. Does he need an MRI to exclude cerebellar stroke?

Search Strategy

OVID Medline Epub Ahead of Print, In-Process & Other Non-Indexed Citations, OVID MEDLINE(R) Daily and Ovid MEDLINE(R) 1946 to Present:

exp. Cerebellar Infarction/ or exp Stroke/ or exp Cerebellum/ or cerebellar stroke.mp

AND

exp Magnetic Resonance Imaging/ or MRI.mp

AND

CT scan.mp or exp Tomography, X-Ray Computed/

AND

Sensitivity.mp or exp “sensitivity and specificity”/ or rule out.mp or safety.mp. or Safety/

AND

Emergency department.mp or exp Emergency Service, Hospital/ OR emergency room.mp

An additional search was done of the "grey literature" via Google Scholar, using same search terms as above.

Search Outcome

OVID search yielded 28 studies. 13 were excluded from title and abstract screening, and 15 moved to full text review. 1/15 papers from full text review was included in the final results.

Search of the grey literature yielded 5 studies. 4/5 were excluded by title and abstract screening, and 1/5 moved to full text review. This single paper from full text review was included in the final results.

Overall, there were 2 papers included in the final results.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Hwang et al. 2012 USA	Adults presenting to the ED with symptoms of infratentorial infarct with MRI evidence, between 2003-2009 (67 patients total)	Retrospective, observational	Sensitivity of CT for detecting stroke	Sensitivity posterior fossa infarcts =  41.8% (95% CI 30.1-54.4)  Sensitivity cerebellar infarcts = 54.8% (95% CI 36.0 – 72.7)  Sensitivity brainstem infarcts = 33.3% (95% CI 16.6-54.0)	Radiologists not blinded to CT results prior to reviewing MRI
Simmons et al. 1986 USA	Adults with MRI evidence of cerebellar infarction (14 patients total)	Retrospective,observational	Detection of cerebellar infarct with CT vs. MRI	6/14 (42%) of patients were diagnosed with cerebellar infarct using CT prior to MRI	Not all patients had clinical diagnosis of cerebellar infarct Unclear timing of scans with onset of symptoms Unclear indications for CT and MRI   No statistical reporting

Comment(s)

Surprisingly a very small amount of papers published on the subject.

Clinical Bottom Line

Currently, there is not enough evidence to state that CT scan can or cannot rule out cerebellar infarcts in adults presenting to the ED with concerning features of vertigo.

References

1. Hwang et al. Comparative Sensitivity of Computed Tomography vs. Magnetic Resonance Imaging for Detecting Acute Posterior Fossa Infarct The Journal of Emergency Medicine 2012;559-565
2. Simmons et al. Cerebellar Infarction: Comparison of Computed Tomography and Magnetic Resonance Imaging Annals of Neurology 1986; 291-293