A practical approach to coma diagnosis in the unresponsive patient.

Diagnosis of coma in the unresponsive patient can be done in a relatively short time by making key observations that will confirm disease of either the brain stem or the hemispheres, the two locations in which coma originates. Determining the location of the lesion is the primary goal in early assessment of the unresponsive patient. Examination of the patient's eyes is the single most important step in understanding coma.