by ROBERT G. OJEMANN, M.D.
© Congress of Neurological Surgeons Honored Guest Presentation
Originally Published Clinical Neurosurgery, Volume 40, Chapter 17, Pages 321-383, 1992
Used with permission of the Congress of Neurological Surgeons.
HTML Editor: Stephen B. Tatter, M.D., Ph.D.

FIG. 17.27. Tentorial meningioma. This 63-year-old woman presented with facial pain. At operation through a subtemporal approach the tumor was totally removed. There was dense adherence and partial encasement of the fourth nerve. A postoperative fourth nerve palsy gradually resolved. (A and B) CT scans show a small left medial tentorial meningioma.

Contents

• Introduction to the therapy of Meningiomas (File 1)
• General Considerations in Management of Meningiomas (File 1)
  • Surgery of Meningiomas (File 1)
  • Radiation Therapy of Meningiomas (File 1)
  • Observation of Meningiomas (File 1)
• Summary of Dr. Ojemann's Meningioma Series (File 1)
  • TENTORIAL MENINGIOMAS (This File)
    • Management (This File)
    • Results (This File)
• References (File 22)

FIG. 17.28. Tentorial meningioma. This 73-year-old woman had gradual onset of unsteady gait and slurred speech. A right frontal meningioma had been removed 7 years previously. Total removal of the tentorial meningioma was followed by full recovery. (A-D) CT scans after contrast show a large tentorw meningioma with both supratentorial and infratentorial extension. (E-H) Angiography defines the arterial blood supply from both Vertebra and external carotid artery branches and the relationship to the transverse sinuses.

TENTORIAL MENINGIOMAS

(Meningioma Management, File 16)

Management

MRI usually gives most of the information that is needed. In larger meningiomas involving the tentoiial edge, angiography should be done to define the location of the arterial branches and determine the status of the transverse sinus (FIG. 17.28, E-H).

The indications for operation are increasing neurological disability due to cerebellar or brainstem compression and cranial nerve deficits in younger patients. Radiation therapy has not been used. Some older patients with only cranial nerve deficits have been observed.

Key considerations in the operation include the following.

1. A subtemporal approach is used for tumors involving the medial edge, with preservation of the vein of Labbe and avoidance of excessive retraction on the temporal lobe.
2. A combined supratentorial and infratentorial approach is used for posterior lateral tentorial meningiomas (Fig. 17.29). In smaller tumors it is possible to remove the lesion by carefully elevating the occipital lobe and making a circumferential cut around the tumor.
3. In some patients it may be necessary to occlude the petrosal sinus.
4. If the transverse sinus is involved, it may be resected if it is known from angiography that the opposite sinus is open.

FIG. 17.29. Tentorial meningioma. A combined supratentorial and infratentoiial approach is used for posterior lateral tumors.

Results

In this series there were 20 patients, 19 women and one man, ranging in age from 32 to 79 years, with five over 70 years of age (Table 17.15). In six

the tumor involved the medial edge and adjacent tentorium. A total removal was done in four and a subtotal removal in two because of arteiial and cranial nerve involvement. Five of the six patients had a good result. Transient diplopia was noted in two. Two had hemorrhagic infarction in the temporal lobe. One required reoperation and, while that patient is fully functional, she has an unsteady gait. There has been no regrowth of tumor over 1-10 years. In two other patients the tumor involved the falx and medial edge of the tentorium. In one a subtotal removal and shunt were performed with a good result and no change on follow-up scans over 12 years. The other patient had a good result with subtotal removal and has been stable for eight years.

In 12 patients the meningioma involved the posterior and/or lateral tentorium and in some cases the transverse sinus and/or petrous dura. All had a total removal, including an occluded transverse sinus in six. There were no postoperative complications. All made a good recovery.

TABLE 17.15 Tentorial Meningiomas
aRemoval			bOutcome			Complications		Recurrence
	Medial	Posterior Lateral		Medial	Posterior Lateral
T	4	12	Good	7	12	Temporal lobe hematoma	2	None
RST	0	0	Fair	1	0
ST	4	0	Poor	0	0
aT, total removal RST, radical subtotal removal ST, subtotal removal bGood, free of major neurological deficit and able to return to previous activity level Fair, independent but not able to return to full activity because of new neurological deficit or significant preoperative deficit that did not fully recover Poor, dependent.

Sugita and Suzuki (73) reported on 49 patients operated upon for tentorial meningiomas, with 88% excellent or good results. The operative mortality was 4%. In the last several years of the series reported by Cantore and Ciappetta (10) there was no operative mortality.

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