Intraocular extension of optic nerve meningioma in a case of neurofibromatosis.

A case of intraocular extension of primary optic nerve meningioma occurred in a 13-year-old girl with neurofibromatosis. An anomalous disc in the involved blind eye was diagnosed as optic nerve glioma at 2 1/2 years of age. The aggressive nature of meningiomas in the young and the long time period involved account for this rare occurrence of direct intraocular extension.

Recurrent acoustic tumor after a suboccipital removal.

Surgery for acoustic tumors has several priorities. First and foremost is the preservation of life with the total removal of the tumor; second is the preservation of the facial nerve; and last, when applicable, is the preservation of hearing. During the suboccipital (retrosigmoid) removal of a tumor, the surgeon unknowingly may leave tumor remnants leading to regrowth. We present five cases of recurrent acoustic tumors after a suboccipital removal. Inadequate drilling exposure of the internal auditory canal was the probable direct cause for tumor recurrence. A translabyrinthine removal is the best approach for total exposure of the entire internal auditory canal. The consequences of small tumor remnants will be discussed as well as their clinical relevance. Current radiological imaging and surgical techniques that avoid residual tumor will be presented.

Cerebellar astrocytomas in elderly patients with very long preoperative histories: report of three cases.

Three patients, ages 69, 67, and 74 years, respectively, underwent surgical removal of cystic cerebellar astrocytomas. All three had past histories pointing to the existence of a cerebellar lesion for many decades prior to surgery: Patient 1 had had nystagmus on lateral gaze on the side of the tumor since early childhood; Patient 2 had had sensorineural hearing loss on the side of her neoplasm for 38 years preceding the operation; and Patient 3 was diagnosed as having a brain tumor 51 years before the operation. (He has been blind because of pressure hydrocephalus for half a century, but otherwise managed to live a productive farming and family life until he sustained a head injury in a car accident, which forced him to undergo removal of his cerebellar tumor.) The neoplasms in all three instances were found by histological examination to be low-grade astrocytomas. These cases indicate that low-grade cerebellar astrocytomas, which are well known for their characteristically long postoperative courses, may at times manifest a slow growth potential with an exceptionally long preoperative course.

Cerebellar stimulation for cerebral palsy.

Eight children with cerebral palsy, who had implanted cerebellar stimulators, were evaluated by a panel of six experienced physicians in a double-blind cross-over experiment with 3-week periods of real and sham stimulation. Neither the panel of physicians nor the patients could tell whether the stimulators were operating or not.

The benefits of VII-VII neuroanastomosis in acoustic tumor surgery.

Division of the seventh nerve during acoustic tumor removal cannot always be avoided. Direct VII-VII neuroanastomosis is superior to any other neuroanastomosis for facial reanimation. Rerouting of the seventh nerve from the mastoid and neuroanastomosis can be accomplished primarily at the initial surgery. This study reviews 19 patients with a follow-up of greater than 18 months who underwent the procedure at the time of tumor removal because of seventh nerve involvement by tumor, intentional sacrifice or, rarely, unintentional division. A House class IV result or better, without the twelfth nerve neurological deficit produced by a VII-XII neuroanastomosis, was achieved in 16 of 19 patients. Although the technique is not new, surgeons unprepared to manage this surgical complication at primary tumor removal should either learn the technique, work with an associate who can do so, or be prepared to call in someone else to do it.

Histological acoustic tumor involvement of the VIIth nerve and multicentric origin in the VIIIth nerve.

The surgical plane between the VIIth nerve and acoustic tumor is often elusive. This histological relationship was reviewed in three patients who underwent VII-VII neuroanastomosis at tumor removal disclosing an inseparable surgical plane in two. In the third patient, tissue sections did not accurately show the relationship. In all three, surgical planes were not apparent at tumor removal. Another patient had a second, isolated tumor in the same VIIIth nerve proximally at the brain stem root entry zone. This was seen only on permanent section. In considering "total" tumor removal by microsurgical standards, these histological findings should be kept in mind. We advocate removal of the entire VIIIth nerve to the brain stem root entry zone along with smaller tumors.

Feasibility of multichannel human cochlear nucleus stimulation.

Bipolar electrical stimulation of the brainstem cochlear nucleus (CN) following acoustic tumor removal in an only-hearing ear can provide beneficial hearing. However, the benefits of multichannel stimulation have yet to be defined. Following removal of a second acoustic tumor in a patient with neurofibromatosis 2, a Nucleus mini-22 channel implant device was inserted with the electrode array tip from the foramen of Luschka cephalad along the root entry zone of the eighth nerve, secured by a single suture superficially in the brain stem. Initial stimulation on the sixth postoperative day indicated that electrodes 18 to 22 were capable of CN stimulation without seventh nerve stimulation. Presumed electrode migration precluded further CN stimulation 1 month later. This report illustrates the feasibility of brainstem CN stimulation with an existing multichannel system.

Genetic analysis in the diagnosis of familial paragangliomas.

OBJECTIVES: In the management of two related patients with multicentric glomus jugulare tumors, given the incidence of 1:30,000 with approximately 20% familial cases, our objective was to review the genetic characteristics and inheritance patterns of these tumors and to determine what molecular genetic screening possibilities exist for the phenotypically normal family members. In addition, our aim was to review the incidence of various multicentric paraganglioma (PGL) tumor location combinations. METHODS: Molecular genetic linkage analysis testing was performed on the 2 patients and 14 other unaffected family members. We report the results of this screening and review the literature on the incidence and genetics of paragangliomas. RESULTS: The inheritance pattern in the literature demonstrates autosomal dominant transmission with maternal imprinting (inactivation). The proclivity for multicentric origin increases to 26% in familial cases, as reflected in our patients. In addition to the two patients, four unaffected family members demonstrated the presence of the disease haplotype at chromosome band 11q23, which indicates a very high likelihood of developing a paraganglioma, given the highly penetrant nature of the disease. CONCLUSIONS: It is clear that the familial PGL gene locus is situated at chromosome 11q23. The gene itself and its exact degree of penetrance, however, still await identification. Since early detection of paragangliomas reduces the incidence of morbidity and mortality, genotypic analysis as a screening tool in families of affected patients should play a front-line diagnostic role, leading to more timely and cost-effective patient management.

Magnetic resonance imaging shows gadolinium enhancement of intradural herniated disc.

STUDY DESIGN: A patient with a herniated intradural disc at L2-L3 and an extradural herniated disc at L5-S1 had homogeneous enhancement of the intradural disc on magnetic resonance imaging. BACKGROUND DATA: The only prior report of intradural disc enhancement with contrast on magnetic resonance imaging showed nonhomogeneous peripheral or ring enhancement. RESULTS: Magnetic resonance and computed tomography images and myelogram films are presented, with an operative photograph. CONCLUSIONS: Enhancement likely depends on the age of the intradural disc herniation.

Acoustic tumors: preoperative measurement and correlation with postoperative facial nerve function.

The cases of 67 patients consecutively operated on for acoustic tumors are reported. Preoperative records consist of tumor size and the position of the fourth ventricle on computerized tomography (CT) scans. An analysis is made of the immediate postoperative and current function of the facial nerves. There is a statistically significant relationship between the number of weak or paralyzed seventh nerves and displacement of the fourth ventricle (P less than .05). It is now possible to accurately measure acoustic tumors on preoperative CT scans. The position of the fourth ventricle can also be clearly seen. The current standard of diagnosis and management of acoustic tumors should include a cursor measurement of tumor size on CT scan and a notation of the position of the fourth ventricle. Adoption of this method of reporting will permit meaningful evaluation of treatment for acoustic tumors. This analysis illustrates the importance of accurate measurements in reporting and evaluating surgical results.

To abandon or not abandon: antesigmoid craniotomy with retrolabyrinthine vestibular nerve section.

Increasing popularity of the retrosigmoid approach would have one believe this is the preferred posteriorfossa approach for a vestibular nerve section. The authors take issue with this. The antesigmoid posterior lateral retrolabyrinthine approach is a gentle craniotomy, easily performed and with low morbidity. A review of 70 consecutive cases revealed no procedural alteration because of surgical exposure, an absence of meningitis, no VIIth nerve weakness, minimal headache, average hospital stay of five days, and only one patient with a significant CSF leak. Hyperventilation anesthesia, patience during delicate VIIIth nerve exposure, incorporation of abdominal fat into dural closure sutures and prophylactic antibiotics have made this operation easy for the patient...and the surgeon. Don't abandon it!