• After a 65-year-old man had received anticoagulation therapy for brain-stem ischemia, a large, bilateral pontomesencephalic hemorrhage developed in the ischemic region. He survived a period of being "locked in" to attain a limited functional recovery. When he first became alert, brain-stem auditory evoked potentials and short-latency somatosensory evoked potentials (SEPs) demonstrated bilateral brain-stem damage; computed tomography revealed a bilateral tegmental hematoma. Results of repeated studies changed little as clinical improvement occurred. Recovery from brain-stem hemorrhage is rare, and return of consciousness with bilateral tegmental involvement is even more rare. The shortlatency SEPs are useful in defining the extent of brain-stem damage, but they evaluate structures distinct from those regulating consciousness and cannot predict a return to alertness.
Portenoy RK, Kurtzberg D, Arezzo JC, Sands GH, Miller A, Vaughan HG. Return to Alertness After Brain-Stem HemorrhageA Case With Evoked Potential and Roentgenographic Evidence of Bilateral Tegmental Damage. Arch Neurol. 1985;42(1):85–88. doi:10.1001/archneur.1985.04060010095025