Saccadic oscillations associated with the quick phases of caloric nystagmus in severe diffuse brain damage

Eye movement measurement in diagnostic assessment of disorders of consciousness

We review the literature to appraise the evidence supporting or disputing the use of eye movement measurement in disorders of consciousness (DOC) with low levels of arousal or awareness, such as minimally conscious state (MCS), vegetative state (VS), and coma for diagnostic and prognostic purposes. We will focus on the effectiveness of each technique in the diagnostic classification of these patients and the gradual trend in research from manual to computerized tracking methods. New tools have become available at clinicians' disposal to assess eye movements with high spatial and temporal fidelity. The close relationship between eye movement generation and organic dysfunction in the brain allows these tools to be applied to the assessment of severe DOC as a unique supplementary toolset. We posit that eye tracking can improve clinical diagnostic precision for DOC, a key component of assessment that often dictates the course of clinical care in DOC patients. We see the emergence of long-term eye-tracking studies with seamless integration of technology in the future to improve the performance of clinical assessment in DOC.

Biochemical parameters of recovery in acute severe head injury

Levels of urinary catecholamines (noradrenaline, adrenaline, dopamine), plasma acetylcholinesterase, serum serotonin and plasma 3-methoxy-4-hydroxyphenylglycol were recorded in 38 adult subjects during the first 21 days after severe head injury. Levels of acetylcholinesterase, serotonin and 3-methoxy-4-hydroxyphenylglycol differed significantly between survivors and those who died. For survivors, initially abnormal biochemical levels recovered toward the norm as time after injury progressed.

Caloric-induced nystagmus with isoelectric electroencephalogram

Caloric vestibular testing induced nystagmus in a patient with an isoelectric electroencephalogram after cardiopulmonary arrest. This has been demonstrated previously in patients in a chronic persistent vegetative state with intact brainstem reflexes, but never in a patient with an isoelectric electroencephalogram. Animal studies indicate that the quick phase of nystagmus and horizontal saccades are generated in the paramedian pontine reticular formation. The present case supports the conclusion that caloric-induced nystagmus originates in the brainstem in rudimentary form.