Gerard Plans

Intracranial retrograde dissemination in filum terminale myxopapillary ependymomas

SummaryMyxopapillary ependymomas (ME) are considered benign tumours (WHO grade I) of the central nervous system with long term survival rates and a tendency to local recurrence. However an aggressive course has occasionally been described, leading to CSF dissemination and even systemic metastases.We describe the case of a 23-year-old man diagnosed with intracranial subarachnoid dissemination of a filum terminale ME three years after the initial diagnosis.We have performed a careful review of the literature on CSF dissemination in ME and finally propose treatment of these cases.

Electrical stimulation mapping of nouns and verbs in Broca's area

Electric stimulation mapping (ESM) is frequently used during brain surgery to localise higher cognitive functions to avoid post-chirurgical disabilities. Experiments with brain imaging techniques and neuropsychological studies showed differences in the cortical representation and processing of nouns and verbs. The goal of the present study was to investigate whether electric stimulation in specific sites in the frontal cortex disrupted noun and verb production selectively. We found that most of the stimulated areas showed disruption of both verbs and nouns at the inferior frontal gyrus. However, when selective effects were obtained, verbs were more prone to disruption than nouns with important individual differences. The overall results indicate that selective impairments can be observed at inferior and middle frontal regions and the action naming task seems to be more suitable to avoid post-chirurgical language disabilities, as it shows a greater sensitivity to disruption with ESM than the classical object naming task.

Surgical versus conservative treatment in patients with cerebral cavernomas and non refractory epilepsy

PURPOSE The optimal therapy of patients with cerebral cavernoma (CCs) and new onset epilepsy, sporadic seizures, or non well established refractory epilepsy is still not clear. The aim of this study was to compare the incidence of seizures in patients with CCs both operated and non operated, in order to obtain more information on the correct management of these patients. MATERIALS AND METHODS We studied retrospectively 43 patients with non refractory epilepsy secondary to CCs. Twenty-six of them (60.5%) underwent surgery and made up the surgical group, and 17 patients were treated medically and constituted the medical group. Seizure frequency and other clinical variables were compared between both groups. RESULTS At two years, out of the 26 operated patients, 19 (73%) remained seizure free, 4 (15%) had less than a seizure per month, and one patient (4%) had more than one seizure per month. At five years, 15 patients of the surgical group remained for analysis. Of them, 11 (73.3%) were seizure free, and 4 (26.7%) had less than one seizure a month. In the medical group, 12 out of 17 patients were seizure free (70.6%). There were no significant differences between the two groups (p=0.2 and p=0.3, respectively). Seven patients had postoperative neurological sequelae. CONCLUSION Surgical treatment of patients with non refractory epilepsy due to CCs did not significantly reduce the likelihood of seizures when compared to medical treatment. It must also be considered that surgery carries serious risks. A prospective and randomized study must be carried out to further clarify our findings.

Intraoperative electrical stimulation of language switching in two bilingual patients.

BACKGROUND Language switching (LS) is an important phenomena usually observed in some bilingual communities. The ability to switch languages is a very fast, efficient and flexible process, being a fundamental aspect of bilingual efficient language communication. The aim of the present study was to characterize the specific role of non-language specific prefrontal regions in the neural network involved in LS in bilingual patients, during awake brain surgery and using electrical stimulation mapping (ESM). METHODS In order to identify the neural regions involved in LS we used, a new specific ESM protocol in two patients undergoing awake brain surgery. Besides, functional magnetic resonance imaging (fMRI), neuropsychological testing and the assessment of daily conversational LS patterns post-surgery were used as complementary imaging and behavioral assessments. RESULTS The outcome of the multimodal ESM-fMRI neuroimaging comparison in both patients pointed out to the crucial involvement of the inferior and middle frontal cortices in LS. CONCLUSIONS The present results add to previous findings highlighting the important role of non-language specific frontal structures in regulating LS. The new protocol developed here might allow neurosurgeons to plan ahead for surgical intervention in multilingual patients to ensure the preservation of regions involved in LS and therefore the prevention of pathological language mixing after intervention.

Intracranial dermoid cyst rupture with subarachnoid and intraventricular fat dissemination

A 53-year-old man presented with an abrupt onset of depressive syndrome with atypical features (depersonalization, derealization, and occasional disorientation). Neurologic examination revealed mild sensory loss in the first left trigeminal division and diminished swallowing reflex. Cranial MRI showed a ruptured left cerebello-pontine angle dermoid …

Contralateral hearing loss after vestibular schwannoma surgery : Case report

OBJECTIVETo describe a case of contralateral hearing loss (CHL) in vestibular schwannoma (VS) surgery and to discuss the factors potentially related with this complication. CLINICAL PRESENTATIONA 48-year-old man awakened with complete bilateral hearing loss after an uneventful retrosigmoid excision of a 20 mm left-sided VS. The patient had no complaints of vertigo or facial palsy on the contralateral side. The hearing loss proved to be endocochlear in origin and no improvement was observed after a 24-month follow-up period. DISCUSSIONCHL in VS surgery is not commonly reported but can occur frequently as a subclinical phenomenon if it is specially addressed. The cause is a compensatory endolymphatic hydrops generated by the loss of cerebrospinal fluid. In this circumstance, the hearing loss is usually reversible within 3 months, but irreversible cases have been described. Vascular damage to the cochlea can be another explanation in irreversible cases. The significance of other potential factors described in the literature as a cause of CHL in VS surgery is less clear. CONCLUSIONA case of CHL after VS surgery is presented. The hearing loss proved to be endochlear in origin and irreversible in nature. Irreversible damage to the cochlea resulting from loss of cerebrospinal fluid or vascular injury is probably related in this case reported.

Evaluation of the High-Frequency Monopolar Stimulation Technique for Mapping and Monitoring the Corticospinal Tract in Patients With Supratentorial Gliomas. A Proposal for Intraoperative Management Based on Neurophysiological Data Analysis in a Series of 92 Patients

BACKGROUND Intraoperative identification and preservation of the corticospinal tract is often necessary for glioma resection. OBJECTIVE To make a proposal for intraoperative management with the high-frequency monopolar stimulation technique for monitoring the corticospinal tract. METHODS Ninety-two patients operated on with the assistance of the high-frequency monopolar stimulation. Clinical and neurophysiological data have been related with the motor status at 3 months to establish prognostic factors of motor deterioration. RESULTS Twenty-one patients (22.8%) presented intraoperative alterations in motor-evoked potentials (MEPs). Twelve (13%) presented an increment in the MEP threshold ≥5 mA (no deficit at 3 months). Two (2.2%) presented an MEP amplitude reduction >50% (100% deficit at 3 months). Seven (7.6%) had an intraoperative MEP loss (80% deficit at 3 months). Subcortical stimulation was positive in 75 patients (81.5%). Eighty-five patients were available for the analysis at 3 months. Fourteen presented new deficits (16.5%). Among them, 5 presented a deficit in nonmonitored muscles (5.9%) and 1 presented a new deficit not detected intraoperatively. The combination of patients with preoperative motor deficits, MEP deterioration, or loss and intensity of subcortical stimulation ≤3 mA showed the highest sensitivity and specificity in the prediction of new deficits. CONCLUSIONS Persistent MEP loss or deterioration is associated with a high probability of new deficits. It seems recommendable to stop the subcortical resection before obtaining a subcortical MEP threshold at 3 mA especially in patients with preoperative motor deficits. A careful selection of muscles for the registration of MEPs is mandatory to avoid deficits in nonmonitored muscles.

An intrinsic DFF40/CAD endonuclease deficiency impairs oligonucleosomal DNA hydrolysis during caspase-dependent cell death: a common trait in human glioblastoma cells.

BACKGROUND Glioblastoma (GBM) or grade IV astrocytoma is one of the most devastating human cancers. The loss of DFF40/CAD, the key endonuclease that triggers oligonucleosomal DNA fragmentation during apoptosis, has been linked to genomic instability and cell survival after radiation. Despite the near inevitability of GBM tumor recurrence after treatment, the relationship between DFF40/CAD and GBM remains unexplored. METHODS We studied the apoptotic behavior of human GBM-derived cells after apoptotic insult. We analyzed caspase activation and the protein levels and subcellular localization of DFF40/CAD apoptotic endonuclease. DFF40/CAD was also evaluated in histological sections from astrocytic tumors and nontumoral human brain. RESULTS We showed that GBM cells undergo incomplete apoptosis without generating oligonucleosomal DNA degradation despite the correct activation of executioner caspases. The major defect of GBM cells relied on the improper accumulation of DFF40/CAD at the nucleoplasmic subcellular compartment. Supporting this finding, DFF40/CAD overexpression allowed GBM cells to display oligonucleosomal DNA degradation after apoptotic challenge. Moreover, the analysis of histological slices from astrocytic tumors showed that DFF40/CAD immunoreactivity in tumoral GFAP-positive cells was markedly reduced when compared with nontumoral samples. CONCLUSIONS Our data highlight the low expression levels of DFF40/CAD and the absence of DNA laddering as common molecular traits in GBM. These findings could be of major importance for understanding the malignant behavior of remaining tumor cells after radiochemotherapy.

Treatment of cavernous malformations in supratentorial eloquent areas: experience after 10 years of patient-tailored surgical protocol

BackgroundEloquent area surgery has become safer with the development of intraoperative neurophysiological monitoring and brain mapping techniques. However, the usefulness of intraoperative electric brain stimulation techniques applied to the management and surgical treatment of cavernous malformations in supratentorial eloquent areas is still not proven. With this study, we aim to describe our experience with the use of a tailored functional approach to treat cavernous malformations in supratentorial eloquent areas.MethodsTwenty patients harboring cavernous malformations located in supratentorial eloquent areas were surgically treated. Individualized functional approach, using intraoperative brain mapping and/or neurophysiological monitoring, was utilized in each case. Eleven patients underwent surgery under awake conditions; meanwhile, nine patients underwent asleep surgery.ResultsTotal resection was achieved in 19 cases (95%). In one patient, the resection was not possible due to high motor functional parenchyma surrounding the lesion tested by direct cortical stimulation. Ten (50%) patients presented transient neurological worsening. All of them achieved total neurological recovery within the first year of follow-up. Among the patients who presented seizures, 85% achieved seizure-free status during follow-up. No major complications occurred.ConclusionsIntraoperative electric brain stimulation techniques applied by a trained multidisciplinary team provide a valuable aid for the treatment of certain cavernous malformations. Our results suggest that tailored functional approach could help surgeons in adapting surgical strategies to prevent patients’ permanent neurological damage.

WO26 Multimodal intraoperative neurophysiological monitoring in intracranial aneurism surgery

this pilot study, we evaluate the potential applicability of this technique for cEEG monitoring in the ICU using 15 EEG recordings from ICU-patients who were monitored with cEEG for 24 to more than 80 hours. Results: Essentials of the raw EEG are well represented by the four proposed features. There is good agreement in the assessment of asymmetries, as may occur in focal seizures or unilateral ischaemia, and generalized background slowing. In addition, we illustrate its potential to detect abnormal increased synchronization, as present during focal or generalized epileptiform discharges. Conclusion: Visual transformation of the raw EEG assists in the interpretation and facilitates its use in the Intensive Care Unit