<prompt> Lucid interval is most commonly seen in -Acute extradural hemorrhageChronic Subdural HemorrhageAcute Subdural HemorrhageSubarachnoid hemorrhage  <response>: Ans. is a i.e., Acute extradural hemorrhage Acute Extradural hematomao Accumulation of blood bw skull durao Bleeding is from a branch of middle meningeal artery in 90 of caseso Trauma is usually severe associated with concussion and skull fracture.o With arterial bleeding, the hematoma expands rapidly, and symptoms appear within hours after injuryo The clinical course is acute - After a head injury often associated with a variable period of concussion - the patient appears normal for several hours lucid interval. After this lucid interval, the pt. develops evidence of increased intracranial pressure with headache, vomitting, altered consciousness, and papilledema. Tentorial herniation rapidly follows, with occulomotor nerve palsy pupillary inequality appears first, followed by failure of reaction to light ka Hutchinsons sign and pyramidal tract compression. Compression of the brain stem follows, resulting in changes in heart rate, blood pressure and respiration. Coma and death rapidly ensue in untreated cases.o Its an emergency and requires prompt diagnosis surgical evacuation of the extradural blood collection. 