ABSTRACT
Coma and reduced level of consciousness may result either from global cerebral dysfunction or from pathology affecting the reticular activating system located in the brainstem. Global cerebral dysfunction may be caused by systemic disease or by specific central nervous system disorders. Damage to the reticular activating system may result from pathology directly affecting the brainstem, or from indirect compression of this area due to raised intracranial pressure. In clinical practice, the causes of coma and reduced conscious level are most conveniently classified into systemic and central nervous system categories. Local central nervous system pathology may be further classified into infectious, inflammatory, vascular, neoplastic and miscellaneous categories. Confusion in the elderly may be precipitated by almost any acute illness. Conditions that commonly present with acute confusion in the elderly include urinary retention, constipation and myocardial infarction. Glasgow Coma Scale score, this is a standardised method of measuring a patient's level of consciousness.
