Epidermoid presenting as Trigeminal Neuralgia
Clinical Significance and Surgical Approach
1984 Volume 24 Issue 10 Pages 774-781
Details
1984 Volume 24 Issue 10 Pages 774-781
In the past 4 years, the authors operated on 120 cases of trigeminal neuralgia. It is noteworthy that among the series there were 13 cases (11 %) of cerebellopontine (CP) angle epidermoid. This report discusses the clinical significance of this tumor and the surgical approach. The age distribution ranged from 22 to 70 years, with a mean age of 45 years, which is considerably lower than the mean age of 59 years in the series. There were no characteristic findings regarding sex, laterality or distribution of pain. The patients were classified into 3 groups from the nature of the neuralgia and associated neurological findings; 8 patients were classified into Group I with genuine tic douloureux, 3 patients into Group II with atypical trigeminal neuralgia, 2 patients into Group III with trigeminal neuralgia and other neurological signs. The duration of the symptoms was from 6 months to 10 years, with a mean of 5 years. Previous treatments were varied. According to the extent of epidermoid, the posterior fossa approach was used in 11 cases and the subtemporal transtentorial approach in 2 cases. Computerized tomography (CT) and metrizamide CT cisternography were very useful and characteristic in the diagnostic procedure, but there were 4 cases in which the high resolution CT findings were negative and the diagnosis of CP angle epidermoid was made by craniectomy aimed for microvascular decompression. The epidermoid was extending from the lower cranial nerves up to the midbrain or the hypothalamus and to the middle fossa. In all 13 cases the tumor was totally removed microsurgically and postoperative follow-up disclosed complete disappearance of trigeminal neuralgia in all cases. The permanent postoperative deficit were decreased hearing in 1 case and hearing loss in 1 case.
The relatively high frequency of epidermoid in this series (11 %) should be kept in mind when treating trigeminal neuralgia even by some other procedure, particularly in younger patients.
