Five-level one-piece laminoplasty for extensive tumors of the lumbar spine.

The authors describe the surgical method and results of nonexpansive one-piece multivel laminoplasty of the whole lumbar spine, for microsurgical resection of extensive spinal tumors. This technique allows a very comfortable approach to the dura and intradural content, as well as a perfect replacement of the posterior spinal arch with supporting elements and an optimal reconstruction of the spinal anatomy. A nonexpansive whole lumbar one-piece laminoplasty was performed for resection of extensive multilevel lumbar tumors. The authors report an illustrative case of a patient who initially presented with a three-year history of numbness on both legs and progressive difficulty in walking. Two months before admission, he complained of bilateral sciatica and rectourinary dysfunction. A spinal magnetic resonance imaging (MRI) documented an intradural tumor extending from L2 to S1. The patient underwent a nonexpansive whole lumbar one-piece laminoplasty and microsurgical removal of the intradural lesion. The postoperative course was uneventful, the sensory disturbances and bilateral sciatica early recovered while rectourinary disturbance gradually improved up to a complete resolution at one year follow-up. The authors believe that multilevel laminoplasty rather than laminectomy is the technique of choice as a posterior procedure for extensive lumbar spinal tumors. With this technique, it is possible to obtain a very confortable approach to the dura and intradural content, as well as a perfect replacement of the posterior spinal arch with supporting elements and an optimal reconstruction of the normal spine. Moreover, this method prevents postoperative instability and deformity and avoids the so called post-laminectomy epidural membrane.

Transsphenoidal microsurgical selective removal of multiple (triple) adenomas of the pituitary gland.

This is the first case of multiple (triple) pituitary micro-adenomas documented by magnetic resonance imaging (MRI) in a living patient and treated by a transsphenoidal microsurgical approach. The patient, a 37-year-old woman, complained of a long history of bifrontal headache, weight gain and oligomenorrhea. Physical examination revealed moderate hirsutism and a slight fat pad overlying the vertebrae. Routine laboratory studies and endocrinological biochemical investigations were normal. A gadolinium-enhanced MRI of the pituitary region revealed three intrapituitary micro-adenomas. A transsphenoidal microsurgical approach to the pituitary gland was carried out and micro-adenomas were completely removed one at a time. One year follow-up showed complete resolution of clinical symptoms and signs and normal biochemical parameters of pituitary function.

Radiation-induced blood-brain barrier changes: pathophysiological mechanisms and clinical implications.

The pathophysiology of whole-brain radiation (WBR) toxicity remains incompletely understood. The possibility of a primary change in blood-brain barrier (BBB) associated with microvascular damage was investigated. Rats were exposed to conventional fractionation in radiation (200 +/- cGy/d, 5d/wk; total dose, 4,000 cGy). BBB changes were assessed by means of the quantitative 14C-alpha-aminoisobutyric acid (AIB) technique coupled with standard electron microscopy (EM) and morphometric techniques as well as studies of the transcapillary passage of horseradish peroxidase (HRP). At 15 days after WBR, AIB transport across BBB increased significantly in cerebral cortex. EM disclosed vesicular transport of HRP across the intact endothelium without opening of the tight junctions. Ninety days after WBR, well-defined alterations of the microvasculature were observed. The main feature of cortical microvessels was their collapsed aspect, associated with perivascular edema containing cell debris. Data suggest a possible association between damage of the microvascular/glial unit of tissue injury and development of radiation-induced brain cerebral dysfunction. We hypothesize the following sequence of pathophysiological events: WBR causes an early increase in BBB permeability, which produces perivascular edema and microvascular collapse. The interference with microcirculation affects blood flow and energy supply to the tissue, resulting in structural damage on an ischemic/dysmetabolic basis.

Pallidotomy improves quality of life in selected parkinsonian patients: an Italian report.

Pallidotomy has recently been reconfirmed as effective for otherwise intractable symptoms of Parkinson's disease. Nonetheless almost every aspect of its performance requires choices which are not fully established and may vary between centers. These include: 1) patient selection; 2) choice of imaging modality, 3) choice of anatomic landmarks for targeting the lesion, 4) choice of method for physiologic confirmation of location, 5) choice of lesion size and shape. We present two cases of pallidotomy procedures in Parkinsonian patients that in our knowledge are the first reported in Italy. Our experience and a careful review of the literature led to the following choices: 1) selection of Parkinsonian patients with dominant L-Dopa induced dyskinesia, akinetic and rigidity symptoms, 2) use of CT due to the distortion effects of MRI, 3) use of standard (Laitinen) coordinates combined with an image fusion method using MRI, 4) use of stimulation to gauge distance to internal capsule and optic tract, 5) production of vertical lesion covering internal segment of pallidum. At a 1-year follow-up the results include a 45% drop in UPDRS (Unified Parkinson's Disease Rating Scale) motor score and almost complete resolution of contralateral dopa induced dyskinesias in both patients.

Do spinal meningiomas penetrate the pial layer? Correlation between magnetic resonance imaging and microsurgical findings and intracranial tumor interfaces.

OBJECTIVE: To study the relationships between spinal dura-arachnoid and tumor-cord interfaces in spinal meningiomas and to investigate whether a disruption of the pial layer and penetration of the tumor in the spinal cord occurs. METHODS: Fifteen patients with histologically proven meningiomas underwent magnetic resonance imaging (MRI) preoperatively. All patients underwent microsurgery. The histological characteristics of the tumors were compared with MRI and microsurgical findings. RESULTS: At surgery, the peritumoral hypointense rim revealed by MRI in 10 of 15 patients corresponded to a well-defined cerebrospinal fluid-containing space confined between the outer arachnoidal layer and the inner leptomeningeal layer. In those patients in whom the hypointense peritumoral rim was absent, the inner layer was either difficult to identify or clearly absent, and the blood vessels were extremely adherent to the tumor, requiring a more cautious dissection. Penetration of the tumors through disruption of the pial surface was not documented. CONCLUSION: Previous anatomic and electron microscopy studies demonstrated, in human spinal meninges, the presence of an intermediate layer attached to the inner aspect of the arachnoid, extending laterally over the dorsal surface of the spinal cord and arborizing over the nerve roots and blood vessels. The intermediate layer is not present in human cerebral leptomeninges. The presence/absence of this layer might explain the hypointense rim detected by MRI and might also explain why no penetration and no peritumoral edema is observed in spinal meningiomas as compared with intracranial meningiomas.

Peritumoral edema in meningiomas: microsurgical observations of different brain tumor interfaces related to computed tomography.

Although generally benign tumors, meningiomas may be associated with extensive peritumoral brain edema as seen on computed tomographic scans. Fifty-two patients with intracranial meningiomas were studied, and the hypodense areas on computed tomographic scans were related to the intraoperative microsurgical findings and to the sizes of the tumors. We have identified three kinds of tumor-brain interfaces characterized by different difficulties in microsurgical dissection: smooth type, transitional type, and invasive type. These different microsurgical interfaces seem to correlate very precisely with computed tomographic images of halo-like and finger-like hypodense areas, allowing prediction of the microsurgical effort to be made in the surgery of meningiomas. The size of the tumor seems to be important in our subjects in determining the amount of edema produced. Indeed, a positive correlation (P < 0.001) was found between the sizes of the tumors and the extent of peritumoral hypodensity. A positive correlation (P < 0.002) also has been found between grade of edema and cortical penetration. Cerebral cortex disruption was systematically observed by us in invasive-type meningiomas and in 3 of 21 cases (14.3%) in transitional-type meningiomas. No penetration was observed in smooth-type meningiomas.

[Intra-orbital hydatid cyst. An uncommon site of hydatidosis. Discussion apropos of a recent case]. / Kyste hydatique intra-orbitaire. Une localisation exceptionnelle de l'hydatidose. Discussion à propos d'un cas récent.

The authors present an observation of intraorbital hydatid cyst. They review the literature and discuss the main data of such a rare lesion. Hydatid cyst should be systematically evoked in any case of tumoral exophthalmia developed in a young patient, particularly if he comes from an endemic country. The pre-operative diagnosis relies on the confrontation between clinical and echographical data, and C.T.-scan imaging. The only treatment is surgery. A puncture performed at the beginning of the surgical procedure will confirm the diagnosis. In fact, it should be indicated for every intra-orbital neoplasm observed in a country of endemicity, mostly when the preoperative diagnosis is difficult, that is when no C.T.-scan or echography are at disposal. The infectious prognosis is excellent; but the functional one depends on the precocity of surgery and remains reserved in most cases.

Computerized use of ICP data. Preliminary elements on the shunt patient.

An incorrect choice of valve may produce a delay in psychomotor development in shunted hydrocephalic children. The intracranial pressure was measured for 24 h in 20 subjects suffering from nontumoral hydrocephalus, obtaining a pressure/volume index with compliance and perfusion pressure data. Their data were entered into a computer and used to determine the correct valve to be chosen.