15. Abnormal pupillary responses in coma Metabolic encephalopathy, B/l thalamic, pontine lesions, hydrocephalus,narcotics,OP,barbiturates Midbrain damage or compression Seizure Thalamus, sympathetic efferents from posterior hypothalamus, tegmentum, descending to the cervical cord Bilateral small ,reactive b/l dilated and unreactive b/l dilation&reactive Unilateral miosis
16. Pupillary responses and coma Compression of ipsilateral III nerve -Fascicular lesion -Nuclear lesion -Extracranial defect T1-T2 to carotid bifurcation -Between hypothalamus and spinal cord -ICA vs cavernous sinus vs SOF vs orbit Unilateral, unreactive & enlarged -unilateral ptosis -bilateral ptosis Unilateral,small,reactive, ipsilateral ptosis -with face anhydrosis -anhydrosis entire side of body -without anhydrosis
19. Cerebral herniation :clinical syndromes Decrease consciousness, small & reactive pupils, normal eye movements. Fixed pupils, cheyne stroke respiration, opthalmoplegia, decorticate posturing Initial obstruction hydrocephalus, thalamus, hypothalamus displacement Supra tentorial diffuse brain edema, haemorrage, midline tumors Central herniation Dilated ipsilateral pupil with preserved or sluggish reaction to light. CnIII,ophthalmoplegia,ipsilateral hemipareis Ipsilateral III compression Hemispheric/lateral middle fossa Uncal herniation
20. Cerebral herniation clincal syndromes All brainstem reflexes are lost, flaccid paralysis, ataxic respiration, then ceasing Medulla-lower pons, cerebellar tonsils Infra tentorial lesions Foramen magnum herniation Decerebrate posturing, midposition pupils, sometimes irregular and loss of pupillary, oculocephalic and oculo vestibular reflexes Midbrain and upper pons Advanced stage of central herniation, upward infra tentorial lesions Midbrain compression