Impact of Covid-19 pandemic on neuro-oncology multidisciplinary tumor board in the pre-vaccine era: the Normandy experience.

INTRODUCTION: The COVID19 pandemic had a strong impact on the healthcare system, particularly in oncology. Brain tumor are usually revealed by acute and life threatening symptoms. We wanted to evaluate the possible consequences of the COVID19 pandemic in 2020 on the activity of neuro-oncology multidisciplinary tumor board in a Normandy region (France). METHODS: A descriptive, retrospective, multicenter study was conducted in the four referent centers (two universitary hospitals and two cancer centers). The main objective was to compare the average number of neuro-oncology patients presented per multidisciplinary tumor board per week between a pre-COVID19 reference period (period 1 from December 2018 to December 2019) and the pre-vaccination period (period 2 from December 2019 to November 2020). RESULTS: Across Normandy, 1540 cases were presented in neuro-oncology multidisciplinary tumor board in 2019 and 2020. No difference was observed between period 1 and 2: respectively 9.8 per week versus 10.7, P=0.36. The number of cases per week also did not significantly differ during the lockdown periods: 9.1/week versus 10.4 during the non-lockdown periods, P=0.26. The only difference observed was a higher proportion of tumor resection during the lockdown periods: 81.4% (n=79/174) versus 64.5% (n=408/1366), P=0.001. CONCLUSION: The pre-vaccination era of the COVID19 pandemic did not impact the activity of neuro-oncology multidisciplinary tumor board in the Normandy region. The possible consequences in terms of public health (excess mortality) due to this tumor location should now be investigated.

Impact of EGFRA289T/V mutation on relapse pattern in glioblastoma.

BACKGROUND: Molecular factors influence relapse patterns in glioblastoma. The hotspot mutation located at position 289 of the extracellular domain of the epidermal growth factor receptor (EGFRA289mut) is associated with a more infiltrative phenotype. The primary objective of this study was to explore the impact of the EGFRA289 mutation on the pattern of relapse after chemoradiotherapy-based treatment of patients suffering from newly diagnosed glioblastoma. PATIENTS AND METHODS: An ancillary study from a prospective cohort of patients suffering from glioblastoma was conducted. All patients received radiotherapy and concomitant temozolomide. The population was divided into two groups according to EGFRA289 status (mutated versus wild-type). The primary endpoint was the overlap score (varying from 0 to 1) between the initial irradiated tumor volume (Vinit) and the relapse volume (Vr). Secondary endpoints explored the impact of EGFRA289mut on survival. RESULTS: One hundred twenty-eight patients were included and analyzed: 11% had EGFRA289mut glioblastoma (n = 14/128). EGFRA289mut glioblastomas had a relapse pattern that was more marginal than EGFRA289wt glioblastomas: a median overlap score Vinit/Vr of 0.96 was observed in the EGFRA289mut group versus 1 in the EGFRA289wt group (P = 0.05). Half of the population with EGFRA289mut tumor (n = 7/14) had a marginal relapse (i.e. overlap scoreVr/Vinit ≤ 0.95) compared to 23.7% (n = 27/114) in the EGFRA289wt group, P = 0.035. EGFRA289mut did not influence survival. CONCLUSION: We highlighted a link between the EGFRA289 mutation and the relapse pattern in glioblastoma. The independent role of EGFRA289mut and its clinical implication should now be explored in further studies.

Untreated unruptured aneurysm: Natural history at long-term.

BACKGROUND AND OBJECTIVES: Although the diagnosis of unruptured intracranial aneurysm (IA) has become more frequent, its natural history and management still remain controversial. A better comprehension of its evolution could optimize our therapeutic strategies. The aim of our study was to evaluate, in a cohort of patients with untreated unruptured IA based on the proposition of multidisciplinary staff meetings, the proportion of bleeding, death and cardiovascular events during a long-term prospective follow-up. PATIENTS AND METHODS: This longitudinal study concerned a series of patients with unruptured IA collected over a period of 8 years (2006-2014) identified from a prospectively collected database including all patients with unruptured IA discussed during multidisciplinary staff meetings in the neurosurgery department at Rouen University Hospital. Clinical endpoints were the rupture rate, incidence of death or occurrence of noticeable pathological event defined by any event leading to death, admission to the intensive care unit or challenging the vital prognosis. RESULTS: After a mean follow-up delay of 46.9±18.7 months, the IA remained stable in 73 patients (98.6%) out of 74. The rate of rupture per aneurysm year of follow-up was 0.3%, the rate of cardiovascular events was 2.1% and the death rate was 2.8% per year of follow-up. DISCUSSION: In this study, we emphasize the important incidence of adverse events in these patients, which has to be taken into account before proposing a prophylactic IA exclusion. The low incidence of IA rupture confirmed the decision of conservative treatment made during a multidisciplinary staff meeting.

Lateral skull base chondroblastoma resected with facial nerve posterior transposition.

INTRODUCTION: Chondroblastoma is a rare tumor that can involve the temporal bone. Because it is a benign tumor, functional surgery must be proposed. We report a case of a patient with a massive chondroblastoma operated on with preservation of the facial nerve, and description of the surgical technique. CASE PRESENTATION: A 37-year-old man presented with a 9-month history of a growing left pre-auricular mass and hearing loss. Neuroimaging showed an osteolytic mass invading the temporal bone and temporomandibular joint. Excision was performed via a transpetrosal and transcochlear approach with posterior transposition of the facial nerve. EMG monitoring was effective in preventing facial palsy. Four years later, no sign of recurrence was observed. DISCUSSION: Chondroblastoma is a locally aggressive tumor, especially when located in the petrous bone and temporomandibular joint. The suggested treatment is a complete excision.

Growth of giant intracranial aneurysms: An aneurysmal wall disorder?

The enlargement of giant intracranial aneurysms (IA) can be observed in 30 % of cases resulting in a neurological deficit and epilepsy due to its mass effect. This growth process could be due to a morphological disorder of the IA wall. The authors report on 2 cases of giant IA growth responsible for intracranial hypertension. The treatment of these giant IA required a microsurgical excision combined with a series of cerebral revascularization procedures. The role of vasa vasorum on the inflammatory granuloma outside the vessel, which induced the enlargement, is discussed. These cases illustrate the abluminal vasculopathy as the main involvement of this unfavourable natural history.

Effects of melatonin in the treatment of asthenia in aneurysmal subarachnoid hemorrhage.

BACKGROUND AND OBJECTIVES: Survivors of aneurysmal subarachnoid hemorrhage (aSAH) commonly experience sleep disorders resulting in asthenia. The objective of this prospective study was to determine, in a cohort of patients with treated ruptured intracranial aneurysm (IA), the proportion of asthenia at 2months, in a cohort of patients treated with melatonin and in a control cohort. PATIENTS AND METHODS: Twenty consecutive patients admitted for the treatment of ruptured IA and able to answer a standardized questionnaire were included in the study. After evaluation for fatigue at discharge, we divided our population into 2 cohorts of 10 patients: the first cohort was treated with melatonin for a period of 2months; the second cohort had no specific treatment for fatigue. The primary endpoint was the proportion of asthenia at 2months in both groups. Confounding factors, such as depression, autonomy and apathy were evaluated at the same time. RESULTS: At discharge, there was no significant difference observed between both groups in terms of mean age and initial clinical status (WFNS, Rankin Scale and Fatigue Severity Scale). At 2months, the mean FSS score in the control group was of 4.7±1.0 versus 3.8±0.9 in the melatonin group (P=0.03). The mean MADRS score in the control group was of 1.1±1.45 versus 2.7±2.5 in the melatonin group (P=0.10). The mean LARS score in the control group was of -32.5±1.7 versus -31.7±1.9 in the melatonin group (P=0.24). DISCUSSION: In a prospective evaluation of post-aSAH fatigue, we suggest that melatonin could decrease fatigue. There is no significant impact on depression and apathy. Further studies would be necessary to improve our comprehension of fatigue physiopathology in a context of aSAH.

Pituitary metastasis: is there still a place for neurosurgical treatment?

Pituitary metastases are uncommon, ranging from 1 to 5 % of all metastases. Between 10 and 30 % of pituitary lesions are symptomatic responsible for diabetes insipidus, visual field defect or cranial nerve palsy. Primary sites are lung or breast in two-thirds of cases. There is no current reference concerning treatment of such lesions. Overall survival is poor and depends on primary site. Although the role of surgery is currently limited, discussion is warranted in several indications for diagnostic or symptomatic purposes. We report two cases of symptomatic pituitary metastases in a context of breast cancer and review the litterature concerning the role of surgery and other treatment modalities.

Brain metastasis from renal cell carcinoma.

BACKGROUND: Patients with brain metastasis (BM) from renal cell carcinoma (RCC) have a poorly known prognosis due to the rarity of this disease. The aim of our study was to assess the outcome of patients with a BM due to RCC, and to determine the predictive factors for survival. METHODS: Consecutive patients who underwent treatment between 1997 and 2012 were identified retrospectively from a database (n=28, median age of 57.8 years, sex ratio M/F: 3.7). Main criteria collected concerned survival time. Other data collected were relative to initial histology, clinical findings at the time of BM diagnosis (diagnosis circumstances, KPS), radiological findings and BM characteristics (number, size and localization), treatment of BM (including surgery, stereotactic radiosurgery [SRS], systemic treatments, whole brain radiotherapy [WBRT]) and the outcome of surgery if performed. Statistical analysis of survival was performed using the Kaplan-Meier method. RESULTS: Median survival was 13.3 months, 1-year survival was 60.2%, 2-year survival was 16.4%. Univariate analysis showed the existence of intracranial hypertension (P=0.01), other systemic metastasis (P=0.049), the absence of deep metastasis (P=0.03) which are all linked to shorter survival. Age, KPS, initial histology of RCC, number, size, localization, and hemorrhage in BM were not correlated to survival. The median survival in the surgical resection group was 25.3 months versus 8.6 months (P=0.02). The main criteria for the selection of the surgical group were a single BM (P=0.04), and superficial metastasis (P=0.02). CONCLUSIONS: Three predictive factors for longer survival in BMRCC were the absence of intracranial hypertension, the absence of acute metastasis and the absence of extracranial metastasis. Surgical removal, when possible, seems to benefit patient survival.

Distal middle cerebral artery aneurysm: A proposition of microsurgical management.

OBJECTIVES: Based on a cohort of patients treated on distal middle cerebral artery (MCA) aneurysm by microsurgical approach, the objectives were to assess the following: the postoperative functional outcome, study the causes of early neurological deterioration and to determine the predictive factors of favourable outcome. PATIENTS AND METHODS: From a neurovascular prospective database, this retrospective longitudinal study included all the patients treated for cerebral aneurysm located on the distal segment of the MCA over two decades (January 1990-December 2011). The patients were all treated by microsurgical clipping exclusion. Any aneurysm was associated to infectious angiopathy. Data were retrieved from the patient's medical charts. The outcome was analysed twice: during the immediate postoperative period and at 6 months according to the modified Rankin scale. The relative risk was estimated for each variable and the prognostic factors were assessed using a multivariate logistic regression model (P<0.05). RESULTS: Twenty-eight patients, mean age 40±13.3 years (median: 43 years; range 6-70 years) were divided into the ruptured group (n=20) and unruptured group (n=8). In the ruptured group, the initial clinical status was good (WFNS I-III) in 12 patients (60%) and poor in eight (40%) with an intracerebral haematoma (ICH) in 11 (55%). For both groups, the aneurysm location on the distal MCA decreased at a rate from 64.8% of the insular segment to 25% of the opercular then 10.7% to the cortical. During the hospital stay, neurological deterioration occurred in 16 patients (57.2%). The diagnosed causes were cerebral ischaemia in 10 (35.6%), initial ICH in three (10.7%), hydrocephalus in two (7.1%) and epilepsy in one (7.1%). At 6 months, a favourable outcome (mRS 0-2) was observed in 19 patients (68.1%), a definitive morbidity in seven (24.9%) and death in two (7.2%). Based on the prognostic factors, only the absence of immediate postoperative neurological deterioration was identified as significant for a favourable outcome. CONCLUSION: These rare cerebral aneurysms resulted in a high proportion of poor initial status related to a frequent ICH. Cerebral ischaemia was a major cause of the immediate neurological deterioration and the absence of immediate neurological deterioration was the single identified prognostic factor.

Elderly patients with aneurysmal subarachnoid hemorrhage: Coils but also clips.

The ageing of the population in good health or without severe morbidity expose them to the occurrence of a subarachnoid hemorrhage (SAH) and requires effective management. Currently, the pertinence of cerebral aneurysm treatment by clipping or coiling is accepted for patients in the 8th or 9th decade of life, and the risk of postoperative morbidity induced by our therapeutic alternative must be carefully assessed. In these decades, the female/male sex ratio for aneurysmal SAH was greater in female who had a 1.6 times higher ratio than in male. The initial clinical status did not appear worse with age despite the frequent severity of bleeding observed on CT scan probably due to the large subarachnoid space. The aneurysm distribution and size were similar to those classically reported in the global population. The endovascular (EV) coiling appears as the first option with a favorable outcome rate estimated at 48% to 63%. Nevertheless, the benefit of EV coiling compared to microsurgical clipping for treatment of ruptured aneurysm in the elderly has not been demonstrated in a large randomized study. This is the reason why the vascular section of the French Society of Neurosurgery developed a prospective and randomized study of the aneurysmal SAH (PHRC 2007-042/HP) on the elderly patients.

Superior interhemispheric approach for midline meningioma from the anterior cranial base.

BACKGROUND: For suprasellar meningioma, the fronto-basal exposure is considered the standard approach. The superior interhemispheric (IH) approach is less described in the literature. OBJECTIVE: To assess the surgical complications, functional outcome (visual, olfaction), morbidity and mortality rates and late recurrence, after resection by superior IH approach of midline skull base meningioma. METHODS: Between 1998 and 2008, 52 consecutive patients with midline meningioma on the anterior portion of the skull base (mean age: 63.8 ± 13.1; sex ratio F/M: 3.7) were operated on via the superior IH approach. After a mean follow-up of 56.9 ± 32.9 months, an independent neurosurgeon proposed a prospective examination of functional outcome to each patient, as well as a visual and olfactory function assessment. RESULTS: Fifty-two patients were divided into a group with olfactory groove meningioma (n=34) and another with tuberculum sellae meningioma (n=18). The outcome was characterized by postoperative complications in 13 patients (25%), mortality rate in two (3.8%) and long-term morbidity at in 17 (37%) of 50 surviving patients. Based on multivariate analysis, no prognosis factor was significant as regards the favorable outcome. The mean postoperative KPS score (86.6 ± 9.4) was significantly improved. However, dysexecutive syndrome was observed in four patients (8%), hyposmia-anosmia in 34 (68%) and visual acuity deteriorated in one (2%). CONCLUSION: The superior IH approach could be considered a safe anteriorly orientated midline approach for removal OGM and TSM meningioma.

Usefulness of multislice computerized tomography angiography in preoperative diagnosis of ruptured cerebral aneurysms.

OBJECTIVE: Non-invasive imaging methods have become primordial in subarachnoid hemorrhage. The aim of our study was to evaluate the sensitivity and specificity of multislice computed tomographic angiography (MSCTA) for the diagnosis of cerebral aneurysm. METHODS: The 28 included consecutive patients with SAH underwent both MSCTA and digital subtraction angiography (DSA). The MSCTA studies were interpreted by two independent readers (A and B) for the presence, the location and size of the aneurysm comparatively to the DSA as reference examination. RESULTS: In 20 patients, 38 aneurysms were diagnosed and in eight no aneurysm was found. Per patient basis, the diagnostic sensitivity and specificity were excellent. Per aneurysm basis, the diagnostic sensitivity and specificity of MSCTA were, respectively, 97.4 and 100% for reader A, 100 and 100% for reader B. For aneurysms less than 3mm, sensitivity was 100% for both readers. Interobserver agreement was excellent for the detection of aneurysm (kappa=0.98, 95% CI [0.96-1]). Intertechnique and interobserver agreements were excellent for the measurement of aneurysms (slope=0.86, r=0.91 p=3.1x10(-7) and slope=1.04, r=0.99, p<10(-6), respectively). CONCLUSION: MSCTA was an accurate and reproducible non-invasive imaging technique for preoperative diagnosis of ruptured cerebral aneurysm. The MSCTA may be proposed in first intention after the diagnosis of SAH was established, with special care regarding injection procedure and a strict reading method using native images and thin MPR.

[Spontaneous supratentorial cerebral hemorrhage: role of surgical treatment]. / Hémorragie cérébrale supratentorielle spontanée: quelle place pour un traitement chirurgical?

Until very recently, no specific therapies have been demonstrated to improve outcome after spontaneous intracerebral haemorrhage (ICH). The STICH (surgical treatment for intracerebral haemorrhage) study showed no overall benefit from early surgery when compared with initial conservative treatment. In contrast, the stereotactic aspiration technique can be safely performed and in a uniform manner. Despite the reduction of ICH volume, no improvement in mortality and functional result was obtained. Endoscopy is a new therapeutic option for ICH with good results for hematoma removal. Based on these feasibility studies, a randomized control trial regarding this procedure would be required to assess the efficacy of this procedure. Due to the lack of benefit observed in the recent STICH trial, emergency surgical evacuation should be reserved for patients with large lobar haemorrhage, mass effect and rapidly deteriorating clinical condition.

[Unruptured intracranial aneurysm: possible therapeutic strategies?]. / Anévrismes intracrâniens non rompus: que proposer?

Intracranial unruptured aneurysm (ICUA) has become a common condition for patient consultation. The mortality rate after fissuration is estimated to be between 52% and 85.7%. The final therapeutic decision results from a balance between the risk of rupture and risks related to the aneurysmal exclusion. Analysis of the risk of rupture risk enables a classification of risk factors. Depending on the circumstances of diagnosis, we considered the ICUA at high risk of rupture for incidental ICUA larger than 7 mm and in the event of associated aneurysms. Classifying by morphologic features, high-risk ICUA were located in the vertebrobasilar system (RR: 4.4; 95%CI: 2.7-6.8), those with a size between 7 and 12 mm (RR: 3.3; 95%CO: 1.3-8.2), larger than 12 mm (RR: 17; 95%CI: 8-36.1), those that were multilobular or a larger size and those ones with a index P/L superior to 3.4 (risk x20). Familial ICUA would expose to a major rupture risk (2 to 7 times sporadic ICUA). Some systemic factors were related to ICUA rupture: arterial hypertension (RR: 1.46; 95%CI: 1.01-2.11) and smoking addiction (RR: 3.04; 95%CI: 1.21-7.66). After microsurgical exclusion, the morbidity and mortality rates were 10% and 2% respectively. Some microsurgical morbidity factors were identified: age (32%>65 years), size (14%>15 mm), vertebrobasilar location and temporary occlusion. The rupture incidence after microsurgical exclusion was estimated 0.26%/year. After endovascular exclusion, the morbidity and mortality rates were 8% and 1% respectively. The complete exclusion rate varied between 47% and 67%. The rupture risk was estimated at 0.9%/year. Treatment recommendations were classified into 3 categories.

[Ruptured anterior communicating artery aneurysm. Therapeutic options in 119 consecutive cases]. / Anevrismes rompus de l'artère communicante antérieure. Choix thérapeutique à propos d'une série consécutive de 119 cas.

BACKGROUND AND PURPOSE: The respective roles of endovascular and surgical treatment must be clearly defined in the management of ruptured anterior communicating artery (AcoA) aneurysm. The aim of our study was to report our results, using the aneurysm direction as the main morphological argument to choose between microsurgery and endovascular embolization. Morbidity and mortality, causes of unfavorable outcome and morphological results were also assessed. PATIENTS AND METHODS: Our prospective study included 119 patients: 89 treated by microsurgery and 30 undergoing embolization with Guglielmi Detachable Coils (GDC). When the aneurysm had an anterior direction (fundus of the aneurysm in front of the pericallosal arteries), we attempted microsurgery. If the fundus of the aneurysm was behind the pericallosal arteries, we selected the most adapted procedure after discussion with the neurovascular team, taking into account the physiological status, treatment risk and neck size. Preoperative status of the patients was assessed according to the Hunt and Hess (HH) classification. Cerebral CT-scan and angiograms were routinely performed after treatment to determine causes of unfavorable outcome (GOS>1) and the morphological results. RESULT: Overall clinical outcome was excellent (GOS1) for 63.0% of patients, good (GOS2) for 10.1%, fair (GOS3) for 13.4%, poor (GOS4) for 2.5%. The mortality rate was 10.9%. Among the 82 patients in good preoperative grade (HHIII), 8 (21.6%) achieved an excellent outcome. However permanent morbidity or death occurred in 15 patients (78.4%). Permanent disability and death were related to initial subarachnoid hemorrhage and were observed 21.3% of patients in the microsurgical group and 30.0% in the endovascular group [Fisher's Exact Test; p=0.33]. Procedure-related permanent disability and death rates were 9.0% for the microsurgical group and 23.3% for the endovascular group (p=0.06) respectively. In the microsurgical group, the only morphologic characteristic which significantly correlated with the occurrence of vessel occlusion was the fundus direction (p=0.03). The difference between endovascular and microsurgical procedures in the achievement of complete occlusion was considered significant (p=0.04). CONCLUSION: In our experience, the direction of the aneurysm was the main morphological criterion in choosing between microsurgery or endovascular procedure for the treatment of AcoA aneurysm. We propose that microsurgical clipping should be preferred for AcoA aneurysms with anterior direction, and depending on morphological criteria, endovascular packing for those with posterior direction.

[French neurosurgical practice in Neuro-Oncology (national survey--part I)]. / Neurochirurgie et neuro-oncologie: état des lieux (I). Généralités, plan cancer, enquête nationale.

OBJECTIVE: The aim of this work is to summarize the elements of the "Cancer Plan" applicable to neurosurgical practice, and to give the results of a national inquiry concerning the daily practice of Neuro-Oncology from the neurosurgical point of view. METHOD: The Neuro-Oncology Group of the French Society of Neurosurgery has submitted a questionnaire to every department of Neurosurgery in France. RESULTS: The response rate of the public centers was 96.5%. Moreover, responses were available from 7 private centers. The results are detailed in the text. CONCLUSION: This national survey highlights the interest and implication of French neurosurgeons in the field of Neuro-Oncology. But also, to be in accordance with the guidelines for good clinical practice, the importance of developing official neuro-oncological networks in order to offer the best access to clinical and fundamental data and hence optimise patient's care. The publication of the "Cancer Plan", the creation of a National Neuro-Oncology Group, and the results of this survey (actual multidisciplinary approach, better information and transparency, individualized care of the patients), are in the line with updating our daily practice, even though discrepancies remain among centers. French neurosurgeons must continue along the same path, but at the same time there is a need for additional help to definitely reach a truly, and homogeneous, optimized care of neuro-oncological patients.

[Bilateral chronic subdural hematoma: spontaneous intracranial hypotension?]. / Hématome sous-dural chronique bilatéral: une hypotension intracrânienne spontanée?

We report a case of bilateral chronic subdural hematoma (SDH) in a 48-year-old man, who presented with postural headaches, tinnitus and progressive confusion without intoxication, head trauma or abnormal hemostasis. Magnetic resonance imaging revealed cerebellar tonsillar herniation in the foramen magnum and a deformation of the brainstem. Outcome was normal after surgery. We discuss about the rare causes of SDH in young adults.

Angiographic cerebral vasospasm and delayed ischemic deficit on anterior part of the circle of Willis. Usefulness of transcranial Doppler.

BACKGROUND AND PURPOSE: After subarachnoid hemorrhage (SAH), cerebral vasospasm (VS) may be revealed by cerebral angiography, during follow-up clinical examination with the occurrence of delayed ischemic deficit (DID). Moreover, transcranial Doppler (TCD) could be useful in determining the level of the velocimetric threshold. The aims of the study were, on a prospectively collected series of 460 patients, to assess angiographic VS incidence, to determine possible risk factors, and to evaluate diagnostic sensitivity and specificity of TCD. PATIENTS AND METHOD: A total of 460 patients consecutively operated on for an aneurysm located on the anterior portion of the circle of Willis (mean age 47.2 +/- 14 years, sex ratio F/M=1.18) were included in the study. Preventive treatment against VS was administered in all patients. On the 10(th) day, we performed the following routine examinations: cerebral angiography, CT scan and TCD. RESULTS: Angiographic VS occurred in 38.5% of the patients, and the single risk factor was delayed admission (p=0.02, Mann-Whitney test). DID occurred in 15.6% and was complicated by cerebral infarct in 4.7%. The risk factors were admission date (p=0.001, Mann-Whitney test) and severity of arterial narrowing (significant tendency). Diagnostic sensitivity of TCD decreased from 83.6% for MCA aneurysms, to 66.6% for ICA aneurysms and 40.6% for AcoA aneurysms. Diagnosis specificity remained between 88.6% and 97.6% for the 3 locations. CONCLUSION: The unique risk factor for angiographic VS and DID was the admission date. TCD demonstrated high specificity but its sensitivity was too low for the aneurysms located far from the middle cerebral artery bifurcation.

Axonal regrowth through a collagen guidance channel bridging spinal cord to the avulsed C6 roots: functional recovery in primates with brachial plexus injury.

Intraspinal implantation of a collagen guidance channel (CGC) to promote axon regeneration was investigated in marmosets with brachial plexus injury. After avulsion of the right C5, C6 and C7 spinal roots, a CGC containing (group B) or not (group A) a nerve segment, or a nerve graft (group C), was ventro-laterally implanted into the cord to bridge the ventral horn and the avulsed C6 roots. No spinal cord dysfunction was observed following surgery. Two months later, the postoperative flaccid paralysis of the lesioned arm improved. In five months, a normal electromyogram of the affected biceps muscle was recorded in all repaired animals. Motor evoked potentials were obtained with a mean amplitude of 13.37 +/- 13.66 microV in group A, 13.21 +/- 5.16 microV in group B and 37.14 +/- 35.16 microV in group C. The force of biceps muscle contraction was 27.33 +/- 20.03 g (group A), 24.33 +/- 17.03 g (group B) and 37.38 +/- 21.70 g (group C). Retrograde tracing by horseradish peroxidase showed labelled motoneurons ipsilaterally located in the C5 and C6 ventral horn, nearby the implantation site. The mean labelled neurons was 32.33 +/- 21.13, 219.33 +/- 176.29 and 64.33 +/- 23.54 in group A, B and C respectively. Histological analysis presented numerous myelinated and unmyelinated regenerating axons in the implant of these animals. Statistical analysis did not show significant difference among the three repaired groups. Our results indicate that spinal neurons can regenerate through a CGC to avulsed nerve roots and induce motor recovery in primates.