Twenty-five meningiomas located at the tentorial notch were surgically
treated between 1978 and 1993 at the Neurosurgical Department of Nord
stadt Hospital in Hannover, Germany. Nineteen meningiomas were classif
ied as originating from the lateral tentorial incisura (Group I) and s
ix were from the posteromedial tentorial incisura (Group II). Clinical
ly, the most common symptom was trigeminal neuralgia, followed by head
ache. Neuroradiologically, 64% of the meningiomas were larger than 30
x 30 mm. Further evaluation revealed signs of brainstem compression in
88% of the patients. Radical surgical removal (Simpson I and II) was
achieved in 88% of the cases. There was no mortality. Follow up reveal
ed that 80% of patients were able to return to their premorbid activit
y. Surgical approaches to the tentorial notch included the suboccipita
l retrosigmoidal or the combined subtemporal-presigmoidal approach for
Group I tentorial notch meningiomas; and the supracerebellar-infraten
torial or the suboccipital-transtentorial approaches for Group II meni
ngiomas. Because the best surgical approach to the tentorial incisura
is still a matter of debate, the anatomy of the tentorial incisura, th
e clinical presentation of the patients, diagnostic indications, surgi
cal findings, and follow up are discussed, with reference to the liter
ature.