Analysis on clinical features and surgical outcome of primary and secondary trigeminal neuralgia

Abstract

Objective To explore clinical features and surgical outcome of primary and secondary trigeminal neuralgia (TN). Methods A total of 105 cases of TN, including 90 primary and 15 secondary TN cases, were treated with microvascular decompression (MVD) or primary lesion resection and trigeminal nerve detection followed by necessary MVD, respectively. The postoperative effect and neurological complications (including hearing loss, symptomatic ischemic stroke and facial nerve injury) were evaluated. Results Of all 90 cases of primary TN, 85 cases underwent MVD via suboccipital retrosigmoid approach (85 cases, 100%), offending vessels were detected in 81 cases (95.29%), neuralgia was relieved in 84 cases (98.82%) after surgery, and neurological complications were detected in one case (1.18%) manifested as hearing loss. Of 15 cases of secondary TN, primary lesions were resected with surrounding vessels exploration [12 cases (12/15) through suboccipital retrosigmoid approach and 3 cases (3/15) through infratemporal tentorial approach]. Primary lesion resection and trigeminal nerve detection were applied followed by necessary MVD. Offending vessels were detected in 3 cases (3/15), all 15 cases (15/15) had neuralgia relieved, and 7 cases (7/15) had neurological complications in secondary TN, including hearing loss in 5 cases, symptomatic ischemic stroke in one case, and facial nerve injury in 6 cases. Postoperative pathological examination showed acoustic neuroma in 5 cases (5/15), epidermoid cyst in 4 cases (4/15), endothelioid meningioma (WHOⅠ) in 2 cases (2/15), transitional meningioma (WHOⅠ) in 2 cases (2/15) and cerebellar arteriovenous malformation in one case (1/15). One case (1/15) with arachnoid cyst did not perform pathological examination. In the primary TN cases, the age at initial symptom onset was older [(51.61 ± 12.21) years vs. (44.87 ± 11.87) years; t = 1.988, P = 0.049], the ratio of cases with preoperative hearing loss was lower [0 (0/90) vs. 7/15; adjusted χ2 = 37.813, P = 0.000], the ratio of surgeries through suboccipital retrosigmoid approach was higher [100% (85/85) vs. 12/15; adjusted χ2 = 11.327, P = 0.001], the ratio of offending vessels detected during surgery was higher [95.29% (81/85) vs. 3/15; adjusted χ2 = 48.325, P = 0.000], the ratio of postoperative complications was lower [1.18% (1/85) vs. 7/15; adjusted χ2 = 29.934, P = 0.000] than those in secondary TN cases, respectively. Conclusions Differences are noted in clinical features between primary and secondary TN. Hearing loss considering as early symptom may suggest primary lesion in secondary TN. Appropriate surgical approach should be selected for surgery according to specific lesions. During surgery, all surrounding vessels of cisternal segment of trigeminal nerve should be explored to achieve sufficient decompression of trigeminal nerve. The rate of pain relief after operation is high in both primary and secondary TN, while neurological complications may occur in secondary TN after surgery.

Keywords

• Trigeminal neuralgia
• Microsurgery
• Postoperative complications