Objective: We report an unusual case of the CT appearance of diffuse subara
chnoid hemorrhage in a patient with anoxic encephalopathy, a situation whic
h neurosurgeons, neurologists, and neuroradiologists should be aware of. Cl
inical presentation: A young man collapsed unconscious in jail after abusin
g an unknown quantity and variety of drugs. CT scan showed a picture compat
ible with diffuse subarachnoid hemorrhage. Intervention: As the patient had
a Glasgow Coma Score of 3 no heroic intervention was undertaken. An autops
y performed 40 hours after the initial ictus and 24 hours after death revea
led no evidence of subarachnoid hemorrhage but gross and microscopic eviden
ce of anoxic encephalopathy. Conclusion: Anoxic encephalopathy can mimic di
ffuse subarachnoid hemorrhage on CT.