. Any process interfering with the function of these structures may result in coma. Causes: 1. Structural brain damage - Infarction Hemorrhage Tumour

. ypoglycemia Wernicke's encephalopathy. Hypo/hypenatremia, Hypo/hypercalcemia.(b) Endocrine - Diabetic coma, myxoedema, Addison's disease, pituitary apoplexy. (c) Drug overdose and poisons - Barbiturates, organophosphorus poisoning, alcohol, carbon monoxide poisoning, etc. (d) Physical agents - Hypothermia, heat stroke. (e) Hypertensive encephalopathy. (f) Septicemia. 3. Psychogenic. iagnosis of Coma: I. Structural brain damage - A Supratentorial mass lesions: 1. Signs of causative lesion -e.g, hemiparesis, papilloedema. 2. Signs due to expanding mass lesion - causing downward displacement of the temporal lobe over the edge of the tentorium (uncal herniation), or midline compression of the upper brain-stem - (a) Uncal herniation - Signs of hemiparesis and papilloedema, and sequential loss of 3rd nerve function. Unilateral dilatation of the pupil with impaired response to light implies temporal lobe herniation. (b) Central herniation - Orderly progression of brain