N. de Tribolet

Early surgery for brainstem cavernomas

SummaryBackground. The purpose was to review our experience with the surgical management of brainstem cavernomas (BSCs) and especially the impact of the surgical timing on the clinical outcome.Method. We retrospectively reviewed 22 patients harboring a BSC, who underwent 23 procedures.Findings. Surgery was carried out during the early stage after the last haemorrhage, with a mean delay of 21.6 days (range 4–90 days). Sixteen procedures were performed after a first bleeding event while seven after multiple bleedings. Complete resection was achieved in 19 patients (86.4%). Early after surgery, 12 patients (52.2%) improved neurologically, 5 (21.7%) were stable and 6 (26.1%) worsened. New postoperative deficits were noted after 9 procedures (39.1%). Statistically significant factors for postoperative aggravation were: late surgery (P = 0.046) and multiple bleedings (P = 0.043). No patient operated on within the first 19 days after bleeding did worsen (n = 11), as opposed to 6 out of 12 who did when operated on later. After a mean follow-up of 44.9 months, 20 patients (90.9%) were improved, 1 patient (4.6%) was worse and 1 patient was lost to follow-up (4.6%), after reoperation for rebleeding of a previously completely resected cavernoma. Late morbidity was reduced to 8.6%. The mean Glasgow Outcome Scale (GOS) at the end of the follow-up period was 4.24, compared to a mean preoperative GOS of 3.22 (P<0.001). Complete neurological recovery of motor deficits, sensory disturbances, cranial nerves (CNs), internuclear ophtalmoplegia and cerebellar dysfunction were respectively 41.7%, 38.5%, 52.6%, 60.0% and 58.3%. Among the most affected CNs: CN 3, CN 5 and CN 7 were more prone to completely recover, respectively in 60.0%, 70.0% and 69.2%.Conclusions. Surgical removal of BSCs is feasible in experienced hands with acceptable morbidity and good outcome. Early surgery and single bleeding were associated with better surgical results.

Hyponatremia hypo-osmolarity in neurosurgical patients. “Appropriate secretion of ADH” and “Cerebral salt wasting syndrome”

SummaryThis prospective study is based on 256 patients with severe brain injury. Six patients (2.3%) developed the clinical picture of inappropriate secretion of antidiuretic hormone (SIADH): 3 in the first 3 days following the injury, 3 after more than a week. Their ADH plasmatic level were measured by radio-immunoassay. In the former, many factors, largely iatrogenic, can explain the increased secretion of ADH we found and which is then definitely “appropriate”. It should be prevented by fluid restriction. In the latter, we found adequately low ADH levels, when the hypo-osmolarity is taken into account. Here, the aetiology seems to be a renal salt loss, eventually in relation to a natriuric factor (e.g. atrial natriuretic factor), justifying the term: “Cerebral salt wasting syndrome”. With the resistance to fluid restriction, the treatment still remains a problem.

Sellar and Parasellar Extra-Axial Cavernous Hemangiomas

SummaryCavernous hemangiomas can grow extra-axially within dural sinuses, particularly the cavernous sinus and present like tumours. Five cases of cavernous hemangiomas arising within or from the wall of the cavernous sinus are reported. Three of them had an “endophytic” growth within the cavernous sinus with a lateral extension into the middle cranial fossa, a medial extension into the sella and an anterior extension into the superior orbital fissure. Two cases presented with an “exophytic” extension from the sinus wall at the point of entry of the third and fourth cranial nerves respectively. These patterns of growths are best appreciated by MRI. Keeping in mind that these lesions are contained within a pseudocapsule will help in planing surgical strategy. Characteristic MRI findings of cavernous hemangiomas in this location include hypo-intensity on T 1-weighted images, marked hyperintensity on T 2-weighted images and Gadolinium enhancement.

Extreme lateral lumbar disc herniation: clinical presentation in 178 patients.

SummaryA retrospective analysis of clinical characteristics of 178 consecutive patients with extreme lateral lumbar disk herniation, amongst 3047 patients operated on for herniated lumbar disc, is presented. The level specific incidence of extreme lateral disc herniation (ELLDH) ranged from a low of 4.5% at L 4–5 to peak of 17.4% at L 3–4 although the largest number of ELLDH occurred at L 4–5 and L5-S1 for a total number of 139 cases (78.1%). 43.6% of all L3 radiculopathies were caused by an L 3–4 ELLDH, whereas only 4.4% of all L 5 radiculopathies were caused by an L 5-S 1 ELLDH.Leg pain, either of the sciatic or the femoral type, was the first and dominant clinical symptom of radiculopathy, but pain radiation occurred not always in the appropriate dermatomal segment. ELLDH at upper levels (L 2–3 and L 3–4) caused usually none or only minor low back signs (76.2%), whereas ELLDH at lower levels more often caused moderate or major lumbar symptoms and signs (59.6%). Positive femoral nerve traction test with upper ELLDH showed a high frequency (84.4%) and reliability and is therefore an important clinical parameter in this situation. Motor deficits occurred more often (78.8%) than sensory deficits (46.6%), were usually of the monoradicular type and were therefore a more reliable clinical sign than sensory disturbances.

Cellular and tumoural heterogeneity of EGFR gene amplification in human malignant gliomas

SummaryIt has been demonstrated that the epidermal growth factor receptor (EGFR) gene, the normal human counterpart of the viral erb-B oncogene, is amplified and overexpressed in over 50% of human malignant gliomas (HMGs). In the present study, analysis of the immunohistological staining characteristics of 57 HMGs using an anti-EGFR monoclonal antibody (mab) showed positive staining in 65% of the tumours with large cellular and regional differences in staining pattern and intensity. Screening a smaller number of HMGs with molecular hybridization techniques revealed 10/21 glioblastomas (48%) amplified for the gene; of 11 glioblastomas studied by Northern blot hybridization, 7 tumours with gene amplification showed RNA overexpression, the remaining 4 without amplification did not. Regional differences in DNA levels were observed by Southern blot in 2 tumours; in one particular case, amplification and overexpression were found to be localized to one half of a single HMG, the other half showing neither EFGR gene amplification nor overexpression.

Microsurgical anatomy and operative technique for extreme lateral lumbar disc herniations

SummaryThe anatomy of the lateral aspect of the lumbar spine and our lateral microsurgical technique for extreme lateral lumbar disc herniations (ELLDH) is described. This study was based on the microdissection of 4 cadavers, on the morphometric evaluation of these as well as 6 dried cadaver spines and 8 lumbar CT scans, and on the use of this technique on over 200 cases.Level dependent changes in the posterior arch cause a shift of the disc space distally relative to the facet joint, an increasing amount of bone to overlie the intervertebral foramen, and a decreasing amount of working space within the exposure in the caudal direction. Therefore, more bone removal from the lateral aspect of the pars interarticularis and supero-lateral aspect of the facet joint is required in the lower lumbar spine. When the exposed ligamentum flavum is resected, the dorsal root ganglion is seen and access to the herniation and disc space is achieved. Level dependent changes in the pedicles and transverse processes lead to an alteration in the course and relationships of the nerves, thereby influencing the pathophysiology of and surgical technique for the ELLDH. The operative target is the lateral aspect of the pars interarticularis and not the intertransverse space as has been previously described.Our techniques allows for the early identification of the nerve with minimal risks of injury to it, to the adjacent vessels and to the structural integrity of the facet joint and pars interarticularis.

Hypotensive effect of nimodipine during treatment for aneurysmal subarachnoid haemorrhage

SummaryTo determine the incidence of induced systemic hypotension in patients after aneurysmal subarachnoid haemorrhage (SAH) and nimodipine treatment 87 consecutive cases were reviewed.The patients were managed according to the same Nimodipine treatment protocol. After confirmation of SAH the nimodipine treatment was started as a continuous intravenous perfusion at a dosage of 0.5 mg/h and gradually increased every 6 hours if haemodynamically tolerated until the maintenance dose of 2 mg/h was reached. Median systemic pressure was continuously measured and tolerated until a lowest limit of 75 mmHg. In 31 patients (36%) hypotension with values below 75 mmHg during at least 30 minutes was noted and needed Nimodipine reduction. Intravenous Nimodipine administration was responsible for hypotension in 26 cases as compared to 5 cases due to oral administration. 38% of all patients required support by vaso-active agents (Dopamine or Noradrenaline).There was no statistically significant difference of incidence of delayed ischaemic deterioration comparing the Nimodipine-reduction group with the normal dose group.This study demonstrates that a considerable risk exists of Nimodipine induced hypotension in intravenous administration despite gradually increasing the doses. Correction of hypotension through further induced hypervolaemia accompanied by vasoactive agents can lead to critical haemodynamic situations. We therefore recommend oral Nimodipine administration.

Expression and release of interleukin-1 by human glioblastoma cells in vitro and in vivo

SummaryThe present study demonstrates interleukin-1 (IL-1) production by human glioblastorna cells bothin vitro andin vivo. The presence of IL-1α and IL-1β transcripts was analyzed in 4 cell lines. IL-1α mRNA was expressed constitutively in one cell line whereas constitutive IL-1β mRNA could not be detected in any of the cell lines. IL-1α transcripts could be induced with phorbol myristate acetate (PMA) or PMA plus lipopolysaccharide (LPS) in 2 of 4 cell Unes and IL-1β mRNA in 2 of 4 cell lines. Culture fluid from these cell lines was tested for the presence of IL-1 using a specific radioimmuno-assay for either IL-1α or IL-1β. In agreement with the results on RNA, one of 4 cell lines was found to constitutively produce IL-1α but not IL-1β. After treatment with PMA and LPS, IL-1α was detected in the culture fluid from two other lines and IL-1β in the medium from three lines. That the IL-1 produced by these cell lines was biologically active was confirmed in a two step thymocyte proliferation assay. IL-1 like activity was detected in all samples that were positive in the radio-immuno-assay.Finally, immunohistological analysis on fresh frozen tumour sections provided evidence for IL-1 production by glioblastoma cellsin vivo. Fourteen out of 28 glioblastomas were stained with an anti-IL-1α monoclonal antibody while none of them was stained with an anti-IL-1β antibody.

Cerebellar Haematoma Due to a Cavernous Angioma in a Child

SummaryThe authors describe the case of a 12-year-old child with a right cerebellar haemorrhage due to a histologically proven cavernous angioma. The clinical course, radiological features, histology, and surgical treatment of such lesions are discussed.

Cavernous haemangioma of the pineal region

SummaryCavernous haemangiomas rarely occur in the pineal region, only eight histologically verified cases have been reported to date. Clincally and radiographically, they are often confused with other tumours of the pineal region, particularly germ cell tumours. When radiotherapy is performed without the benefit of biopsy, cavernous haemangiomas as well as other radioresistant neoplasms may be unnecessarily treated.We report two surgically treated cases of cavernous haemangioma of the pineal region, and comment upon one treated by shunt placement alone. Two cases were associated with an adjacent venous malformation. In all instances, magnetic resonance imaging (MRI) permitted a correct pre-operative diagnosis. We conclude that surgical exploration and total resection is the treatment of choice when the diagnosis of cavernous haemangioma is suspected on the basis of neuro-imaging. A conservative attitude is justifiable in the case of elderly patients with a higher surgical risk.