Stimulus Sensitive Constant Micro Macro Square-Wave Jerks in a Comatose Patient.

Saccades are generally thought of as being cortically generated and not seen in comatose patients. We describe a patient, comatose secondary to a large intracerebral hemorrhage, who developed constant rhythmic small amplitude square-wave jerks with an intersaccadic interval of 130 ms. Despite the patient's comatose state the eye movements would stop transiently in response to auditory or tactile stimulation and then quickly regain their previous amplitude. The case suggests that the presence of repetitive saccades in the form of square-wave jerks does not indicate consciousness.