Locked-in syndrome: a critical and time-dependent diagnosis.

Locked-in syndrome (LIS) is the combination of quadriplegia and anarthria (inability to speak), with the preservation of consciousness. The majority of cases are caused by basilar artery occlusion leading to brainstem infarction in the ventral pons, yet numerous other etiologies have been described. The diagnosis of LIS is completely dependent on the physician's ability to know that these manifestations originate in the brainstem and the posterior circulation that supplies it. This knowledge hinges on the ability of the examining physician to conduct a rapid, yet appropriately thorough neurologic examination. With recent advances in interventional neuroradiology leading to improved patient outcomes, LIS has evolved into a critical, time-dependent diagnosis. Herein, we present the case of a male patient who initially presented to the emergency department of a community hospital with coma of unknown cause. By presenting this case and focusing on the importance of the occulomotor exam, we hope to help in the rapid identification and treatment of patients with LIS in the emergency room and avoid outcomes similar to that of our patient.