Question
Patient presents after a fall confused, not moving his right side, but moving his left side spontaneously. What's the diagnosis?
Answer
- The patient has a right subdural hematoma (SDH) with midline shift and right uncal herniation.
- The classic presentation of a cerebral lesion with uncal herniation is ipsilateral mydriasis, contralateral hemiparesis, and abnormal extensor posturing.
- In this patient’s case, there is compression of the contralateral cerebral peduncle of the midbrain by the edge of the tentorium cerebelli producing an ipsilateral hemiplegia (see attachment for Figure 2).
- This false localizing sign is named Kernohan’s notch syndrome, Kernohan’s notch phenomenon, or Kernohan’s sign.
References
Diagram modified from "Localised Neurological Disease and Its Management A Intracranial". clinicalgate.com/localised-neurological-disease-and-its-management-a-intracranial/. Accessed 10 Aug 2016.
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