One-stage combined lumbo-sacral fusion, by anterior then posterior approach: clinical and radiological results.

INTRODUCTION: We intended to prospectively evaluate the clinical and radiological results of lumbo-sacral fusion achieved by a combined approach, anterior then posterior. MATERIAL AND METHODS: 62 patients were consecutively treated at L5-S1, L4-L5 or L4-S1 for degenerative disc disease or low-grade isthmic spondylolisthesis by combined surgery. RESULTS: Mean operative time and blood loss were 209 min and 308 ml, respectively, including the two approaches. VAS, ODI and Roland-Morris scores significantly improved postoperatively at 1 year (p < 0.005) and fusion was obtained in all cases on the CT scan at 1-year follow-up. Segmental lordosis significantly improved postoperatively (p < 0.05) with a mean gain of 10.2° at L5-S1 and 5.5° at L4-L5. CONCLUSION: The combined procedure meets the requested criteria for a lumbar fusion in terms of clinical results, functional outcomes, fusion rates while restoring segmental lordosis and disc height. It cumulates the advantages of the anterior and posterior approach performed alone, especially for L5-S1.

Intraoperative electrical stimulation mapping as an aid for surgery of intracranial lesions involving motor areas in children.

OBJECTIVE: We analysed the usefulness of intraoperative electrical stimulation mapping (ESM) for locating motor pathways in pediatric patients harboring cerebral lesions closely related to motor areas. METHODS: We applied ESM in 17 consecutive pediatric patients operated on under general anesthesia. It was possible to locate motor function in 15 patients and in all children 5 years old and younger, as well as in all patients presenting with severe motor deficits, using relatively high current intensities. Intraoperative seizures occurred in 20% of our patients. A macroscopically complete removal of the lesion was carried out in 12 cases out of 17 with no definitive postoperative aggravation. Motor function improved for all patients presenting preoperatively with a severe paresis. CONCLUSION: In our experience ESM revealed to be an useful tool for allowing us to push the resection of any lesion infringing on eloquent cortex up to the limit of functional areas, even in cases in very young and severely paretic children.

Malignant intracerebellar schwannoma.

The authors report an exceptional case of malignant cerebellar schwannoma in a 29-year-old woman, explored by computed tomography and angiography; a solid and vascular vermian tumor was removed at operation. The histological diagnosis of malignant schwannoma with epithelioid areas was confirmed by immunohistological staining (positive S-100 protein, Leu 7 and vimentin, negative glial fibrillary acid protein, cytokeratin, desmin and HMB45). The patient died 8 months after surgery for tumor recurrence. The literature review has shown 44 cases of schwannomas occurring in the cerebral hemispheres, 9 within the brain stem and 14 in the cerebellum. All but one reported cerebellar schwannomas were benign, with prevalence of young patients and vermian localization. The present case is the second reported malignant intracerebellar schwannoma.

Giant intradiploic epidermoid cyst of the occipital bone.

A rare case of giant intradiploic epidermoid cyst of the occipital bone with large intracranial extension in the posterior fossa is described. The lesion was discovered when the patient presented with headache and subcutaneous swelling in the occipital region, in the absence of signs of neurological involvement. CT scan showed extensive destruction of the occipital bone, mainly of the inner table, up to the foramen magnum. On MRI the lesion was hypointense in T(1) and hyperintense in T(2)-weighted images; signal inhomogeneity was due to cellular debris and cholesterol crystals. The enhancing rim due to the thickened dura confirmed the extradural location. Complete removal of the cyst was easily accomplished despite its large size. We found only 3 documented cases in the literature of giant intradiploic infratentorial epidermoid cysts, none of which was studied by MRI. The radiological features and differential diagnosis are discussed.

Meningiomas associated with brain metastases.

The authors report a series of 6 patients with simultaneous occurrence of meningioma and single brain metastasis, who underwent surgical removal with histological verification of both lesions. The site of the primary tumor was the breast in 3 cases, the ovary in one, the lung in one, and was unknown in one. Among the six patients, two had a carcinomatous metastasis accidentally found into a meningioma after histological examination of the meningiomatous mass. Two others had a brain metastasis in the cerebral parenchyma surrounding the meningioma; both lesions were removed in an one-stage operation. Finally, two patients, whose lesions were distant, first underwent removal of the brain metastasis, whereas the meningioma was excised 10 and 13 months later. The pathogenetic relationships between meningiomas and tumors of the female reproductive system are discussed. The occurrence of a metastasis into a meningioma is a rather unusual event, which has been described in 50 previously reported cases. The correct differential diagnosis between meningioma and metastasis is very important in these patients. An intracranial mass lesion occurring in patients with known malignant tumors elsewhere in the body (mainly females with breast cancers) has a small but real chance of being a meningioma.