A 27-year-old man suffered from right hemiparesis after a closed head injury. Computed tomography (CT) revealed a right hemisphere subdural haematoma with midline structure shifted to the left. The CT finding was believed to be mislabeled because the site of haematoma did not correlate with an ipsilateral hemiparesis. Magnetic resonance imaging revealed a right transtentorial uncal herniation and a small lesion within left cerebral peduncle, suggesting Kernohan-Woltman notch phenomenon (KWNP). KWNP has been rarely seen in patients with acute traumatic subdural haemorrhage. Anatomical small maximum tentorial notch width is the possible anatomical factor predisposing our patient to this phenomenon. (Hong Kong j.emerg.med. 2014;21:116-119)
KernohanJ., WoltmanH.Incisura of the crus due to contralateral brain tumor. Arch Neurol1929; 21: 274–87.
2.
ZafonteR.D., LeeC.Y.Kernohan-Woltman notch phenomenon: an unusual cause of ipsilateral motor deficit. Arch Phys Med Rehabil1997; 78(5): 543–5.
3.
MastronardiL., PuzzilliF., RuggeriA., GuiducciA.Magnetic resonance imaging findings of Kernohan-Woltman notch in acute subdural haematoma. Clin Neurol Neurosurg1999; 101(2): 122–4.
4.
CarrascoR., PascualJ.M., NavasM., Martínez-FlórezP., Manzanares-SolerR., SolaR.G.Kernohan-Woltman notch phenomenon caused by an acute subdural haematoma. J Clin Neurosci2009; 16(12): 1628–31.
5.
YamasakiF., KodamaY., HottaT., YukiK., TaniguchiE., HashizumeA.[Magnetic resonance imaging of Kernohan's notch in chronic subdural haematoma][Article in Japanese]. No To Shinkei1997; 49(6): 563–6.
SunderlandS.The tentorial notch and complications produced by herniations of the brain through that aperture. Br J Surg1958; 45(193): 422–38.
9.
JonesK.M., SeegerJ.F., YoshinoM.T.Ipsilateral motor deficit resulting from a subdural hematoma and a Kernohan notch. AJNR Am J Neuroradiol1991; 12(6): 1238–9.
10.
WolfR.F., ter WeemeC.A., KrikkeA.P.Kernohan's notch and misdiagnosis. Lancet1995; 345(8944): 259–60.
BinderD.K., LyonR., ManleyG.T.Transcranial motor evoked potential recording in a case of Kernohan's notch syndrome: case report. Neurosurgery2004; 54(4): 999–1002.
13.
AdlerD.E., MilhoratT.H.The tentorial notch: anatomical variation, morphometric analysis, and classification in 100 human autopsy cases. J Neurosurg2002; 96(6): 1103–12.
