Akinori Kondo

Follow-up results of microvascular decompression in trigeminal neuralgia and hemifacial spasm.

OBJECTIVE : We evaluated the follow-up results of microvascular decompression in 1032 patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS), who underwent operations between 1976 and 1991 and were followed for more than 5 years. METHOD : Patients were divided into two groups, and their follow-up results were compared and studied. The early series, Group A (1976-1986), comprised 588 patients (127 with TN and 461 with HFS) followed from 10 to 20 years (mean, 12.6 ± 2.1 yr), and the recent series, Group B (1987-1991), comprised 444 patients (154 with TN and 290 with HFS) followed from 5 to 9 years (mean, 7.0 ± 1.4 yr). RESULTS : The immediate postoperative cure rates were 92.9% in Group A and 96.7% in Group B for TN and 97.4% in Group A and 98.3% in Group B for HFS. Satisfactory results obtained by the follow-up study were 80.3% in Group A and 82.5% in Group B for TN and 84.2% in Group A and 89.0% in Group B for HFS. Incomplete cure rates were 7.1% in Group A and 3.3% in Group B for TN and 2.6% in Group A and 1.7% in Group B for HFS. Recurrence rates were 10.2% in Group A and 6.5% in Group B for TN and 8.9% in Group A and 6.9% in Group B for HFS. Postoperative hearing dysfunction occurred in 7.1% of patients with TN in Group A and 4.5% in Group B and 9.1% of patients with HFS in Group A and 3.7% in Group B. CONCLUSION : Improved methods of repositioning the affected vessels and of straightening the axis of the trigeminal nerve are important to obtain satisfactory follow-up results after microvascular decompression.

Cerebellopontine angle epidermoids presenting with cranial nerve hyperactive dysfunction: pathogenesis and long-term surgical results in 30 patients.

OBJECTIVE To provide the characteristics and long-term surgical results of patients who present with cerebellopontine angle epidermoids and trigeminal neuralgia (TN) or hemifacial spasm. METHODS A total of 30 patients (23 women, 7 men) who presented with cerebellopontine angle epidermoids and TN (28 patients) or hemifacial spasm (2 patients) between 1982 and 1995 were reviewed, with emphasis being placed on the clinical manifestations, the mechanisms of symptom development, the long-term follow-up results, and the anatomic relationship between the tumor and the surrounding neurovascular structures. RESULTS The average age of the patients was 37.8 years at symptom onset and 49.3 years at the time of the operation. The tumor-nerve relationships were classified into four types: complete encasement of the nerve by the tumor, compression and distortion of the nerve by the tumor, compression of the nerve by an artery located on the opposite side of the unilateral tumor, and compression of the nerve by an artery on the same side of the tumor. Total resection was achieved in 17 patients (56.7%). Microvascular decompression of the respective cranial nerve was achieved in nine cases of direct arterial compression in addition to tumor removal. The symptom was relieved completely in all cases. In an average follow-up period of 11.5 years, three patients developed recurrent symptoms: two experienced tumor regrowth, and one had arachnoid adhesion. CONCLUSION Hyperactive dysfunction of the cranial nerves, especially TN, may be the initial and only symptom that patients with cerebellopontine angle epidermoids experience. The occurrence of TN at a younger age was characteristic of TN patients with epidermoids, in contrast to patients with TN due to a vascular cause. The symptom is elicited by compression of the nerve by the tumor per se, by an artery that is displaced to the nerve, or by both. Careful resection of the tumor, whose capsule occasionally is strongly adherent to the neurovascular structures, is necessary, and microvascular decompression to straighten the neuraxis should be performed in some cases to achieve a complete, permanent cure of symptoms with a low rate of recurrence.

Serious complications of microvascular decompression operations for trigeminal neuralgia and hemifacial spasm

Serious complications of microvascular decompression operations for trigeminal neuralgia or hemifacial spasm are reported. Among 278 patients who underwent microvascular decompression, 9 serious complications were observed: 1 intracerebellar hematoma with acute hydrocephalus, 1 cerebellar swelling with acute hydrocephalus, 1 supratentorial acute subdural hematoma, 2 status epilepticus, 1 infarction of the brain stem, 1 subarachnoid hemorrhage due to traumatic aneurysm, and 1 infarction in the territory of the posterior cerebral artery. Of the 9 patients with such complications, 2 died. The possible causes of such serious complications are discussed.

Combined Hyperactive Dysfunction Syndrome of the Cranial Nerves: Trigeminal Neuralgia, Hemifacial Spasm, and Glossopharyngeal Neuralgia: 11-Year Experience and Review

OBJECTIVE A pathological condition caused by vascular compression at the root entry/exit zone of the cranial nerves is designated hyperactive dysfunction syndrome (HDS) of the cranial nerves. Patients with HDS who exhibited a combination of trigeminal neuralgia (TN), hemifacial spasm (HFS), and/or glossopharyngeal neuralgia were retrospectively reviewed, to study the incidence, etiological factors, and demographic characteristics for this combined HDS group. METHODS Medical and surgical records were analyzed for 41 patients with combined HDS, of 1472 consecutive patients with HDS who were treated between 1984 and 1994. RESULTS The combined HDS group accounted for 2.8% of all patients with HDS; 19 patients (1.3%) exhibited bilateral symptoms, i.e., 14 cases of TN, 3 of combined TN and HFS, and 2 of HFS. Twenty-two patients (1.5%) exhibited ipsilateral symptoms, i.e., 19 cases of TN and HFS and 3 of TN and glossopharyngeal neuralgia. Excluding three patients whose symptoms were associated with brain tumors or arteriovenous malformations, this patient group was older (63.2 versus 55.3 yr, P = 0.0009) and exhibited an increased percentage of associated hypertension (47.4 versus 17.5%, P = 0.000008), with a female predominance (86.8 versus 71.3%, P = 0.07), compared with the single HDS group. Thirty-six of these patients underwent a total of 61 microvascular decompression procedures, with favorable outcomes. The offending vessels were similar to those in single HDS, which were usually conventional and multiple. CONCLUSION The associated etiological factors for vascular compression syndromes were more evident in the combined HDS group than in the single HDS group. Progressive arteriosclerotic vasculoarchitectural changes of the vertebrobasilar system, accelerated by aging and hypertension, bring about the development of combined HDS, with a remarkable female predominance.

Choroid Plexus Papilloma in the Posterior Third Ventricle: Case Report

OBJECTIVE AND IMPORTANCE The case of a 42-year-old woman with a choroid plexus papilloma (CPP) arising from the posterior wall of the third ventricle is described. This case is very unusual because the tumor did not have any connection with the choroid plexus but was attached to the normal brain parenchyma. CLINICAL PRESENTATION The patient presented with the symptoms of increasing intracranial pressure. Magnetic resonance imaging revealed hydrocephalus related to a small mass in the posterior third ventricle, occluding the aqueduct. INTERVENTION Surgery confirmed that the tumor was located at the surface of the posterior commissure without having any connection to the normal choroid plexus. A histopathological examination revealed a CPP with no attachment to the choroidal tissue. CONCLUSION A review of the literature demonstrates that CPPs without any connection to the choroid plexus are very unusual. To our knowledge, this is the first reported case of such a CPP that developed on the posterior wall of the third ventricle in which no choroid plexus was present. Furthermore, this tumor, to our knowledge, is also the smallest intraventricular CPP to be verified at surgery.

Intraventricular craniopharyngioma: Report of two cases and review of the literature

Two unusual cases of purely intraventricular craniopharyngioma are presented. Both patients complained of headache as a sign of increasing intracranial pressure, but neither other neurological deficits nor hormonal disorders were present. Magnetic resonance images showed a mass lesion located within the third ventricle. Surgery confirmed that these two tumors were completely confined within the third ventricle, and histologically they proved to be squamous papillary craniopharyngiomas. Review of the literature demonstrates that craniopharyngiomas at this location have many common features and would appear to form a distinct entity.

Painful tic convulsif caused by a brain tumor: case report and review of the literature.

Patient with painful tic convulsif caused by a brain tumor is presented. The patient was admitted with right trigeminal neuralgia and ipsilateral facial spasm, i.e., painful tic convulsif. Preoperative computed tomography scans showed no apparent abnormalities; however, surgery revealed that these symptoms were associated with a pearly tumor located in the cerebellopontine angle. Subtotal resection for the decompression of the right trigeminal and facial nerves was performed and resulted in complete relief of the symptoms. Histological examination demonstrated the tumor to be an epidermoid cyst.

Hemifacial Spasm in Childhood and Adolescence

Hemifacial spasm (HFS), a hyperactive dysfunction of the facial nerve, is rarely seen in young people. Between 1984 and 1994, we treated 924 patients with HFS by microvascular decompression at our institution. Of these, 8 (0.9%) were younger than 30 years. In most of the older patients with HFS, the offending artery which compresses the root exit zone was elongated, redundant, and focally arteriosclerotic as a result of hemodynamic effects due to aging or hypertension. On the other hand, the offending artery did not exhibit such characteristic changes of the vasculature in children and adolescents with HFS. In all of the young patients who underwent initial microvascular decompression at our clinic, the arachnoid membrane around the facial nerve was thickened and encased the artery, resulting in compression of the root exit zone of the facial nerve. Such thickening of the arachnoid surrounding the offending vessel may play an important role in the pathogenesis of HFS by trapping and encasing the artery to compress the root exit zone, particularly in the young patients.

Accessory nerve neurinoma manifesting with typical jugular foramen syndrome

A case of neurinoma arising from the accessory nerve is reported. The tumor was small and located entirely within the jugular foramen; the patient sought treatment for a jugular foramen syndrome. The lesion was visualized only on magnetic resonance imaging, and surgery confirmed that it originated from a cranial root of the accessory nerve. There have been no previous reports of a small, accessory neurinoma that is confined entirely to the jugular foramen, appearing with a typical jugular foramen syndrome.

Ruptured aneurysm of an azygos anterior cerebral artery

SummaryA ruptured saccular aneurysm of the azygos pericallosal artery was found and clipped successfully in a woman of 47 years. Aneurysm of an azygos pericallosal artery is extremely rare.