Kernohan–woltman notch phenomenon:Case report and Review of literature

BACKGROUND: Subdural hematoma (SDH) is usually secondary to mechanical trauma. Spontaneous subdural hematoma is still rare with unclear pathophysiology. The classic findings of subdural hematoma is sudden drop in mental status, an ipsilateralmydriasis with contralateral hemiparesis. However SDH can sometimes compress the contralaterl corticospinal tract resulting in ipsilateral motor weakness, this phenomenon is known as Kernohan-Woltman Notch Phenomenon. CASE DESCRIPTION: We describe here a case of young lady presented to emergency department with brief history of drowsiness followed by right sided weakness. On arrival her Glasgow Coma Scale was 9/15, asymmetrical pupils with right sided weakness. Urgent CT scan was done and Neurosurgery was involved. CT scan showed right sided acute on chronic subdural hematoma. She underwent urgent mini-craniotomy and evacuation of hematoma. Post operatively she recovered well with full recovery of hemiplegia. In our case there was no history of any mechanical trauma and her findings were consistent with KWNP. CONCLUSION: It is critical to recognize this false-localizing examination finding, particularly in the emergency setting. Emergency physician should also keep high suspicion of SDH even in the absence of any trauma. There should be no delay for neuro-imaging and every patient should have early CT scan and neurosurgery involvement for prompt management and better outcome.