ABSTRACT
Patients who are drowsy or comatose pose a particular problem, as so much of the routine neurological examination relies on the ability of the patient to cooperate and follow instructions. A different approach is therefore required. Often the patient is already intubated, ventilated, sedated and even paralysed by the time the readers get the opportunity to examine them, and some drugs may need to be temporarily withdrawn or reversed, under certain circumstances, to perform the neurological examination. Coma results from impaired function of the brainstem reticular formation. The most common cause is drug overdose, but other causes include severe head injury, hypoxic brain injury, infections (like bacterial meningitis or viral encephalitis) metabolic disturbance like diabetic coma or hepatic failure, subarachnoid haemorrhage, exposure to toxins (e.g. carbon monoxide), encephalitis and severe raised intracranial pressure.
