Frequent loss of 1p32 region but no mutation of the p18 tumor suppressor gene in meningiomas

After chromosome 22 and NF2 inactivation, the loss of chromosome 1p is one of the most frequent abnormalities encountered in meningiomas. However the putative tumor suppressor gene located on 1p inactivated in meningiomas has still to be identified. We screened 68 meningiomas for LOH on chromosome 22 and 1. We found 34 LOH on the NF2 region on chromosome 22 (50%) and 19 LOH on 1p (28%), 16 being associated with loss of chromosome 22. Partial deletions delimited a candidate region located between D1S234 and D1S2797. The p18INK4C tumor suppressor gene, a member of the genes family coding for inhibitors of cyclin-dependent kinases, is located in this region. To determine whether p18 is involved in development of meningiomas, we performed a mutation analysis of the p18 gene and a search for homozygous deletion in the 19 meningiomas with 1p loss. Sequencing analysis of the p18 gene revealed one polymorphism, but no somatic mutations and no homozygous deletions were found. These results confirm that the loss of chromosome 1p32 is a frequent feature in meningiomas, however the p18 tumor suppressor gene which is located in this region, does not seem to be involved.

Failure of long-term pallidal stimulation corrected by subthalamic stimulation in PD

Bilateral high-frequency continuous stimulation of the internal globus pallidus or subthalamic nucleus constitutes a new therapeutic approach for the treatment of patients with severe PD. The authors report two patients in whom stimulation of the globus pallidus failed to give long-term relief and was successfully replaced by bilateral subthalamic stimulation. The results emphasize the reversibility of deep brain stimulation therapy and suggest that the subthalamic target is preferable to the pallidal target.

Prediction of malignant middle cerebral artery infarction by diffusion-weighted imaging

BACKGROUND AND PURPOSE

This study was designed to analyze whether early diffusion-weighted imaging (DWI) provides reliable quantitative information for the prediction of stroke patients at risk of malignant brain infarct.

METHODS

We selected 28 patients with a middle cerebral artery (MCA) infarct and proven MCA or carotid T occlusion on DWI and MRI angiography performed within 14 hours after onset (mean 6.5+/-3.5 hours, median 5.2 hours). Of these, 10 patients developed malignant MCA infarct, whereas 18 did not. For the 2 groups, we compared the National Institutes of Health Stroke Scale (NIHSS) score at admission, site of arterial occlusion, standardized visual analysis of DWI abnormalities, quantitative volume measurement of DWI abnormalities (volume(DWI)), and apparent diffusion coefficient values. Univariate and multivariate discriminant analysis was used to determine the most accurate predictors of malignant MCA infarct.

RESULTS

Univariate analysis showed that an admission NIHSS score >20, total versus partial MCA infarct, and volume(DWI) >145 cm(3) were highly significant predictors of malignant infarct. The best predictor was volume(DWI) >145 cm(3), which achieved 100% sensitivity and 94% specificity. Prediction was further improved by bivariate models combining volume(DWI) and apparent diffusion coefficient measurements, which reached 100% sensitivity and specificity in this series of patients.

CONCLUSIONS

Quantitative measurement of infarct volume on DWI is an accurate method for the prediction of malignant MCA infarct in patients with persistent arterial occlusion imaged within 14 hours of onset. This may be of importance for early management of severe stroke patients.

Irregular jerky tremor, myoclonus, and thalamus: a study using low-frequency stimulation

High-frequency thalamic stimulation alleviates tremor in Parkinson's disease (PD) and essential tremor (ET). The origin of thalamic myoclonus is unexplained and the effects of low-frequency thalamic stimulation on movement control are still unknown. We studied the effects of stimulation at a low frequency of 15 Hz in five drug-free patients (3 PD, 2 ET) 6 months after thalamic implantation of quadripolar electrodes (unilateral in four patients, bilateral in one patient). Clinical, electrophysiological, and videotaped assessment, using a monopolar 15 Hz frequency (3 V, 90 micros) stimulation current applied simultaneously through two adjacent contacts of the electrode, was performed. We observed myoclonus and irregular jerky tremor in the upper limb contralateral to the site of stimulation. The jerks lasted less than 200 ms, were irregular and not synchronous with stimulation, were superimposed on rest or postural tremor, and increased in response to tactile, proprioceptive, or vibratory stimuli. The fact that this complex movement disorder can be induced by low-frequency stimulation in the ventral intermediate nucleus (Vim) of the thalamus suggests that it results, at least partly, from dysfunction of the Vim and possibly adjacent nuclei of the thalamus.

Treatment of supratentorial glioblastoma multiforme with radiotherapy and a combination of BCNU and tamoxifen: a phase II study

From May 1990 to November 1994, 70 consecutive patients suffering from glioblastoma multiforme were treated following surgery with conventional radiotherapy and adjuvant IV BCNU administered alone or in combination with tamoxifen. Twenty-five patients received BCNU alone (control group A) while 24 patients also received 40 mg of tamoxifen (TMX) PO daily (group B) and 21 received 100 mg of TMX PO daily (group C). There were no significant differences between the 3 groups concerning age, type of resection and median post-operative Karnofsky performance status (KPS). Blood toxicity over grade II occurred in 33.5% of patients receiving TMX versus 12% of patients treated with BCNU alone (p < 0.05). Deep venous thrombosis complications were observed in 4 patients of each TMX group, whereas they were not observed in the control group (p < 0.04). Median time to tumor progression (MTTP) was 35 weeks in the control group and 27 weeks in both TMX groups B and C. Median survival time (MST) was 56, 66 and 51 weeks, respectively. These results suggest that the addition of TMX to standard treatment of glioblastomas does not affect the time to tumor progression and overall survival but may increase the risk of deep venous thrombosis or nitrosourea-induced blood toxicity.

Magnetic resonance-guided stereotactic biopsies: results in 100 consecutive cases

BACKGROUND

We present the results of 100 consecutive magnetic resonance (MR)-guided biopsies in cases where computerised tomography (CT) guiding was considered dangerous or impossible.

METHOD

MR guiding was preferred to CT guiding for cases where lesions were located in the central area, or were not clearly visible on CT scan, or where the visualization of vessels was considered necessary. For most of the patients, calculation of target co-ordinates was performed using dedicated software enabling trajectory previsualization. There were 62 cases of contrast enhanced lesions, 32 cases of lesions without contrast enhancement, and 6 cases of very small lesions appearing hyperintense on T2-weighted images.

FINDINGS

Biopsies allowed a histological diagnosis in 92 cases. In 8 cases, the biopsy was negative (necrosis, gliosis or normal brain tissue). Three patients had a transient worsening of their neurological disturbances. Two patient had a non-regressive loss of motor function. No patient died.

INTERPRETATION

MR guiding for stereotactic biopsies was effective for CT-invisible or ill-defined lesions, lesions located in functional or densely vascularized areas and in the brain stem. The rate of postoperative complications was equivalent to or less than that reported in series of CT-guided biopsies.

Axial parkinsonian symptoms can be improved: the role of levodopa and bilateral subthalamic stimulation

OBJECTIVE

To assess the effects of high frequency stimulation of the subthalamic nucleus (STN) on axial symptoms occurring in advanced stages of Parkinson's disease (PD).

METHODS

The efficacy of STN stimulation on total motor disability score (unified Parkinson's disease rating scale (UPDRS) part III) were evaluated in 10 patients with severe Parkinson's disease. The subscores were then studied separately for limb akinesia, rigidity, and tremor, which are known to respond to levodopa, and axial signs, including speech, neck rigidity, rising from a chair, posture, gait, and postural stability, which are known to respond less well to levodopa. Patients were clinically assessed in the "off" and "on" drug condition during a levodopa challenge test performed before surgical implantation of stimulation electrodes and repeated 6 months after surgery under continuous STN stimulation. A complementary score for axial symptoms from the "activities of daily living" (ADL)-that is, speech, swallowing, turning in bed, falling, walking, and freezing-was obtained from each patient's questionnaire (UPDRS, part II).

RESULTS

Improvements in total motor disability score (62%), limb signs (62%), and axial signs (72%) obtained with STN stimulation were statistically comparable with those obtained with levodopa during the preoperative challenge (68%, 69%, and 59%, respectively). When levodopa and STN stimulation were combined there was a further improvement in total motor disability (80%) compared with preoperative levodopa administration. This consisted largely of an additional improvement in axial signs (84%) mainly for posture and postural stability, no further improvement in levodopa responsive signs being found. Axial symptoms from the ADL showed similar additional improvement when levodopa and STN stimulation were combined.

CONCLUSION

These findings suggest that bilateral STN stimulation improves most axial features of Parkinson's disease and that a synergistic effect can be obtained when stimulation is used in conjunction with levodopa treatment.

Subthalamic stimulation in Parkinson disease: a multidisciplinary approach

BACKGROUND

High-frequency stimulation of the subthalamic nucleus constitutes a therapeutic advance for severely disabled patients with Parkinson disease.

OBJECTIVE

To evaluate the efficacy and safety of continuous bilateral high-frequency stimulation of the subthalamic nucleus in patients with Parkinson disease.

DESIGN

A prospective study of patients with Parkinson disease treated at a university hospital.

PATIENTS AND METHODS

Electrodes were implanted bilaterally in the subthalamic nucleus of 23 consecutive patients with Parkinson disease who responded well to levodopa but had severe motor complications. There were 16 men and 7 women (mean +/- SEM age, 53 +/- 2 years) who had a mean +/- SEM disease duration of 14.7 +/- 1.0 years. Targets were determined by 3-dimensional magnetic resonance imaging, combined with intraoperative electrophysiologic recordings and stimulation.

RESULTS

Six months after surgery, motor disability, levodopa-induced motor fluctuations, dyskinesias, and the daily dose of levodopa equivalent decreased significantly by 67%, 78%, 77%, and 61%, respectively, compared with the preoperative state. No significant morbidity was observed, except transient depression in 4 patients.

CONCLUSIONS

The beneficial effects of subthalamic stimulation depend on (1) the criteria used for patient selection, (2) the precision with which the subthalamic nucleus is targeted (dependent on the 3-dimensional magnetic resonance imaging and the intraoperative electrophysiologic and clinical assessments), and (3) the long-term postoperative adjustment of stimulation variables.

Bilateral subthalamic stimulation for Parkinson's disease by using three-dimensional stereotactic magnetic resonance imaging and electrophysiological guidance

OBJECT

Several methods are used for stereotactically guided implantation of electrodes into the subthalamic nucleus (STN) for continuous high-frequency stimulation in the treatment of Parkinson's disease (PD). The authors present a stereotactic magnetic resonance (MR) method relying on three-dimensional (3D) T1-weighted images for surgical planning and multiplanar T2-weighted images for direct visualization of the STN, coupled with electrophysiological recording and stimulation guidance.

METHODS

Twelve patients with advanced PD were enrolled in this study of bilateral STN implantation. Both STNs were visible as 3D ovoid biconvex hypointense structures located in the upper mesencephalon. The coordinates of the centers of the STNs were determined with reference to the patient's anterior commissure-posterior commissure line by using a new landmark, the anterior border of the red nucleus. Electrophysiological monitoring through five parallel tracks was performed simultaneously to define the functional target accurately. Microelectrode recording identified high-frequency, spontaneous, movement-related activity and tremor-related cells within the STNs. Acute STN macrostimulation improved contralateral rigidity and akinesia, suppressed tremor when present, and could induce dyskinesias. The central track, which was directed at the predetermined target by using MR imaging, was selected for implantation of 19 of 24 electrodes. No surgical complications were noted.

CONCLUSIONS

At evaluation 6 months after surgery, continuous STN stimulation was shown to have improved parkinsonian motor disability by 64% and 78% in the "off' and "on" medication states, respectively. Antiparkinsonian drug treatment was reduced by 70% in 10 patients and withdrawn in two patients. The severity of levodopa-induced dyskinesias was reduced by 83% and motor fluctuations by 88%. Continuous high-frequency stimulation of the STN applied through electrodes implanted with the aid of 3D MR imaging and electrophysiological guidance is a safe and effective therapy for patients suffering from severe, advanced levodopa-responsive PD.

Correspondence between functional magnetic resonance imaging somatotopy and individual brain anatomy of the central region: comparison with intraoperative stimulation in patients with brain tumors

OBJECT

The goal of this study was to determine the somatotopical structure-function relationships of the primary motor cortex in individual patients by using functional magnetic resonance (fMR) imaging. This was done to assess whether there is a displacement of functional areas compared with anatomical landmarks in patients harboring brain tumors close to the central region, and to validate these findings with intraoperative cortical stimulation.

METHODS

One hundred twenty hemispheres in 60 patients were studied by obtaining blood oxygen level-dependent fMR images in patients while they performed movements of the foot, hand, and face on both sides. There was a good correspondence between anatomical landmarks in the deep portion of the central sulcus on axial slices and the somatotopical organization of primary motor areas. Pixels activated during hand movements were centered on a small characteristic digitation; those activated during movements in the face and foot areas were located in the lower portion of the central sulcus (lateral to the hand area) and around the termination of the central sulcus, respectively. In diseased hemispheres, signal-intensity changes were still observed in the projection of the expected anatomical area. The fMR imaging data mapped intraoperative electrical stimulation in 92% of positive sites.

CONCLUSIONS

There was a high correspondence between the somatotopical anatomy and function in the central sulcus, which was similar in normal and diseased hemispheres. The fMR imaging and electrical stimulation data were highly concordant. These findings may enable the neurosurgeon to locate primary motor areas more easily during surgery.

Effect of low and high frequency thalamic stimulation on sleep in patients with Parkinson's disease and essential tremor

Continuous high frequency stimulation of the ventral intermediate nucleus of the thalamus (Vim), delivered through surgically implanted quadripolar electrodes, alleviates tremor in Parkinson's disease (PD) and essential tremor (ET). The Vim is adjacent to the thalamic reticular nuclei, where sleep spindles originate according to animal models. In order to determine whether Vim stimulation affects sleep spindles, six patients (4 PD, 2 ET), aged 60-69 years, were recorded on a control night and a stimulation night (130 Hz, 2-3 V; right stimulation in five patients and bilateral stimulation in one patient). Stimulation did not modify sleep quality or architecture. Sleep spindles were present and symmetrical in five out of six patients under stimulation. However, in one patient with a sustained 'thalamotomy-like effect' that abolished tremor, spindles were asymmetrical even without stimulation. In each patient, spindle density was similar on both nights (mean+/- SEM: 2.25+/-0. 61 spindles per min of stage 2 sleep vs. 1.84+/-0.31). In an attempt to promote sleep two different patterns of stimulation were applied in the region of ventrooralis posterior and reticularis nuclei in five patients in the awake state. Continuous low frequency stimulation (5 Hz, 0.1 V), and repeated trains of 15 Hz for 1 s every 15 s mimicking the pattern of physiological spindles, each failed to induce sleep or cortical synchronization. We conclude that Vim stimulation, unlike thalamotomy, selectively reduces tremor without altering sleep or sleep spindles. Our results also suggest that low frequency stimulation applied in the region of the reticular nuclei does not induce sleep.

Germline mutations of p53 but not p16/CDKN2 or PTEN/MMAC1 tumor suppressor genes predispose to gliomas. The ANOCEF Group. Association des NeuroOncologues d'Expression Française

Constitutional DNA from 44 selected patients suspected of being genetically predisposed to develop astrocytic tumors was analyzed for germline mutations of the p53, p16, and PTEN genes. Six constitutional missense mutations of the p53 gene were identified (13.6%), but no mutations of the p16 and PTEN genes were found, suggesting that (1) germline p53 mutations contribute to a small portion of astrocytic tumors, (2) inherited mutations of the p16 and PTEN gene do not predispose to the development of gliomas, and (3) other genes are involved in glioma predisposition.

Treatment of meningeal gliomatosis

To evaluate whether vigorous treatment is beneficial for patients with meningeal gliomatosis (MG) we reviewed the case records of 20 consecutive patients treated for a symptomatic MG in our center. All received systemic or intrathecal chemotherapy and six received additional cranial or spinal radiotherapy. Six patients (30%) achieved a partial response (one low-grade astrocytoma, two anaplastic astrocytomas, one anaplastic oligodendroglioma and two glioblastomas). In these cases, clinical improvement was associated with radiological improvement on CT scan or MRI in five and with a major cerebrospinal fluid improvement in three. Three patients (15%) were stable for 3 months or more and 11 (55%) had progressive disease. Median survival was longer for the responding patients (10 months) than for the other patients (2 months). This study suggests that some patients with MG may benefit from a treatment combining radiotherapy to symptomatic areas and chemotherapy with agents that cross the blood-brain barrier or are delivered directly into the CSF.

[First treatment for brain metastases by stereotactic radiosurgery]

Local control of brain metastases is better with first treatment by stereotactic radiosurgery than with radiosurgery for recurrence. We reported a retrospective analysis of the influence of clinical and technical factors on local control and survival after radiosurgery realised in first intention. From January 1994 to December 1997, 26 patients presenting with 43 metastases underwent radiosurgery. The median age was 61 years and the median Karnofsky index 70. Primary sites included: lung (12 patients), kidney (7 patients), breast (2 patients), colon (1 patient), melanoma (2 patients), osteosarcoma (1 patient), it was unknown for one patient. Seven patients had extracranial metastases. Twenty-one sessions of radiosurgery have been realized for one metastase, and 9 for two, three or four lesions. The median diameter was 21 mm and the median volume 1.8 cm3. The median peripheral dose to the lesion was 14 Gy, and the median dose at the isocenter 20 Gy. Forty-two metastases were evaluable for response analysis. The overall local control rate was 90.5% and the 1-year, 2- and 3-year actuarial rates were 85% and 75%. In univariate analysis, theorical radioresistance was significantly associated with better local control (100% versus 77%, p < 0.05). All patients were evaluable for survival. The median survival rate was 15 months. Four patients had a symptomatic oedema (RTOG grade II). Two lesions have required a surgical excision. In conclusion, low dose radiosurgery (14 Gy delivered at the periphery of metastasis) can be proposed in first intention for brain metastases, in particularly for theorical radioresistant lesions.

Treatment of malignant gliomas in the elderly

The benefit of standard treatment of malignant glioma in older patients is debated. In order to assess the effect of a combination of surgery, radiotherapy and chemotherapy on survival of elderly patients with high grade gliomas, 30 consecutive patients older than 70 years with malignant supratentorial gliomas were studied between 9/93 and 9/96. Median age was 73 years (70-79). The mean Karnofsky performance status (KPS) was 66 (30-100). Patients underwent maximum possible surgery, followed by a course of radiotherapy (45 Gy/25 fractions/5 weeks) with 3 or 4 orthogonal beams and a 2 cm margin around the tumor bed. The administration of chemotherapy was left at the discretion of the responsible physician and 12 patients received reduced dose nitrosourea-based chemotherapy. The overall median survival was 36 weeks. The median time to progression was 26 weeks. Three months after surgery, 26 patients were alive, 5 were in complete response, 2 in partial response and 10 were stabilized. Preradiotherapy KPS was the only significant prognostic factor with a median survival of 40 weeks in patients with KPS > or = 70 and 25 weeks when KPS was < 70 (logrank test, p = 0.05). In responding and stable patients (57% of the group) the median KPS was 68 and 66 at 1 and 3 months after the completion of radiotherapy. There was no case of radiotherapy-induced dementia with this regimen. Four out of 12 patients who received chemotherapy, experienced WHO grade 3/4 hematotoxicity. This study suggest that some patients older than 70 years with KPS > or = 70 may benefit from the treatment of malignant gliomas with surgery followed by reduced dose of limited field radiotherapy. Further studies are needed to define the most appropriate dose of radiotherapy and to evaluate further the risk/benefit ratio of a reduced dose chemotherapy in this population.

Analysis of the p21 gene in gliomas

The p21 gene encodes a cyclin dependent kinase inhibitor protein (p21) which has a tumor suppressive activity in a variety of tumor cell lines. Since, the p21 gene is up-regulated by the p53 tumor suppressor gene, which is frequently mutated in gliomas, acting therefore in the same control pathway, it constitutes a good candidate gene to be also inactivated in these tumors. To test this hypothesis, DNAs from 81 gliomas (48 glioblastomas, 11 anaplastic astrocytomas, 10 low-grade astrocytomas, 12 oligodendrogliomas and mixed gliomas), were investigated for mutations in the p21 coding sequence by denaturant gradient gel electrophoresis followed by sequencing. All these tumors have been previously screened for p53 mutations. Three different DNA variants were identified on codon 31 (17 cases), 27 (1 case) and 117 (1 case) and shown to be also present in matching constitutional DNA, suggesting they were polymorphisms. None of the tumors demonstrated a somatic mutation. No significant correlation between the presence of a p21 variant and the p53 mutation tumor status was observed. In conclusion, mutation in the p21 gene unlikely contributes to the development of gliomas.

A case of epidermoid cyst arising from the rostral neuropore: case report

OBJECTIVE AND IMPORTANCE

Supratentorial epidermoid cysts located on the midline are very rare. We describe the first case of such a cyst arising from the rostral neuropore.

CLINICAL PRESENTATION AND INTERVENTION

We report a patient suffering from seizures and progressive frontal syndrome and presenting with a huge cyst developed in the midline at the rostralmost part of the corpus callosum. The patient was operated on, and the cyst was found to be epidermoid.

CONCLUSION

Only six cases of supracallosal epidermoid cysts have been reported. In our case, the involved region was located at the exact limit between lamina terminalis and corpus callosum. This region corresponds to the place of the closing rostral neuropore during embryogenesis. We thus propose that the cyst arises from the rostral neuropore and that its eventual deep location is explained by the complex morphogenetic movements affecting the dorsal region of the telencephalic vesicle.

Are enemas given before abdominal operations useful? A prospective randomised trail

OBJECTIVE

To assess the effect of preoperative enemas on the recovery of peristalsis after non-colonic abdominal operations.

DESIGN

Prospective randomised trail.

SETTING

University hospital, Switzerland.

SUBJECTS

116 adult patients (> 16 year old) about to undergo elective non-colonic abdominal operations under general anaesthaesia were considered.

INTERVENTION

Two groups were randomised to receive a one litre water and glycerine enema the day before operation (n = 53) or no preoperative intestinal preparation (n = 53).

MAIN OUTCOME MEASURES

Return of peristalsis after operation, assessed by auscultation of bowel sounds and time of the first spontaneous faeces. All participants were followed daily for 10 days or until discharge by the same observer.

RESULTS

110 patients gave informed consent, 6 refused to participate, and 4 had to be withdrawn after randomisation, leaving 106 for analysis. The patients without an enema recovered bowel sounds activity sooner (p = 0.02) and passed their first spontaneous faeces significantly earlier (p = 0.01). No subgroup of patients benefited from an enema.

CONCLUSION

Preoperative enemas delay rather than improve the return of normal peristalsis after surgery. We recommend this practice should be abandoned.