Franck-Emmanuel Roux

What makes surgical tumor resection feasible in Broca's area? Insights into intraoperative brain mapping.

OBJECTIVESurgical resection of mass lesions in Brocas area is controversial. To demonstrate that pathology may influence the localization of functional areas and language performance, we reviewed our experience of awake craniotomies in Brocas area. METHODSSixteen consecutive patients who underwent awake craniotomy and direct brain mapping for resective surgery in Brocas area were analyzed. Six patients had well-circumscribed lesions, whereas 10 patients had infiltrative gliomas. A short version of the Boston Diagnostic Aphasia Examination test was used for language assessment. RESULTSInferior frontal language sites were found in all but 4 patients. In patients with cavernomas or well-circumscribed tumors, 9 of 9 (100%) of the positive sites were located in the classic Brocas area (BA 44/45). By contrast, in those patients with gliomas, only 5 of 20 (25%) of the positive sites were located in BA 44/45. Patients with infiltrative gliomas demonstrated more deficits in the pre and postoperative periods than those with well-circumscribed mass lesions. All patients returned to their baseline abilities within 6 months. CONCLUSIONIntraoperative language maps generated in cases with well-circumscribed lesions are different from those generated in cases with infiltrative gliomas. This supports the view that interindividual language variability and displacement of critical structures by mass effect should first be considered for circumscribed lesions, whereas reshaping should largely be attributed to brain plasticity in gliomas. Surgery in Brocas area can be safely conducted using awake craniotomy and brain mapping.

Anatomical correlates for category-specific naming of objects and actions: a brain stimulation mapping study.

The production of object and action words can be dissociated in aphasics, yet their anatomical correlates have been difficult to distinguish in functional imaging studies. To investigate the extent to which the cortical neural networks underlying object‐ and action‐naming processing overlap, we performed electrostimulation mapping (ESM), which is a neurosurgical mapping technique routinely used to examine language function during brain‐tumor resections. Forty‐one right‐handed patients who had surgery for a brain tumor were asked to perform overt naming of object and action pictures under stimulation. Overall, 73 out of the 633 stimulated cortical sites (11.5%) were associated with stimulation‐induced language interferences. These interference sites were very much localized (<1 cm2), and showed substantial variability across individuals in their exact localization. Stimulation interfered with both object and action naming over 44 sites, whereas it specifically interfered with object naming over 19 sites and with action naming over 10 sites. Specific object‐naming sites were mainly identified in Brocas area (Brodmann area 44/45) and the temporal cortex, whereas action‐naming specific sites were mainly identified in the posterior midfrontal gyrus (Brodmann area 6/9) and Brocas area (P = 0.003 by the Fishers exact test). The anatomical loci we emphasized are in line with a cortical distinction between objects and actions based on conceptual/semantic features, so the prefrontal/premotor cortex would preferentially support sensorimotor contingencies associated with actions, whereas the temporal cortex would preferentially underpin (functional) properties of objects. Hum Brain Mapp 35:429–443, 2014.

Spinal meningioma surgery in elderly patients with paraplegia or severe paraparesis: a multicenter study.

OBJECTIVEIn a multicenter study, 102 patients aged 70 years or older with paraplegia or severe paraparesis, and who underwent operation for spinal meningiomas, are presented to correlate surgery and outcome and to determine the most influential factors that affected this outcome. METHODSFive French neurosurgical centers participated in this retrospective study between 1990 and 2007. Pre- and postoperative neurological status were assessed using a grading system. All patients underwent operation, and neurological evaluations were conducted 3 months and 1 year after surgery. The median follow-up period was 49.5 months (range, 12–169 months). Data were analyzed using a multiple logistic regression model. RESULTSTwenty-six patients were paraplegic (Grade 4). Complete tumor removal was obtained in 93 patients. There was no surgical mortality, and morbidity was 9%. Three months after surgery, 7 of the patients were unchanged, 87 patients had improved, and 8 were not evaluated. One year after surgery, 7 of the 100 surviving patients were clinically unchanged and 93 had improved. Of those who had improved, 49 patients experienced complete recovery. CONCLUSIONAdvanced age did not seem to contraindicate surgery, even in patients with severe preoperative neurological deficits and/or an American Society of Anesthesiologists class of III. Quality of life can be improved in most cases.

Third Ventriculocisternostomy for Shunt Failure.

BACKGROUNDnOur objective was to analyze the relevance, potential prognostic factors, and complications of endoscopic third ventriculostomy (ETV) in patients with shunt failures.nnnMETHODSnAmong 721 ETVs performed between 1999 and 2013, we studied 53 patients with shunts (31 men, 21 less than 18 years of age) who had an ETV performed for shunt failures as the result of various causes. We included all initial causes of hydrocephalus except adult chronic (i.e., normal pressure) and pediatric communicant hydrocephalus. The mean duration between initial shunting for hydrocephalus and the ETV procedure was more than 11 years (137 months; range, 1 month to 34 years). Successful ETV procedure was defined as clinical improvement and shunt independence extending until the last follow-up visit.nnnRESULTSnThe success rate of the ETV procedure was 70% (37 of the 53 cases) with a mean follow-up of 51 months (from 3 to 157 months) and was not related to the age of the patient (P = 0.922), to the cause of hydrocephalus (P = 0.622), or to the number of shunt failures (P = 0.459). We also found no statistical difference (P = 0.343) between patients whose shunt had been in place for less than 5 years and those shunted more than 5 years. The presence of an infected shunt was not predictive of ETV failure (P = 0.395). No significant intraoperative or postoperative complications were noted.nnnCONCLUSIONnThis study confirms that ETV should be considered as the first therapeutic option before shunt revision in cases of initial obstructive hydrocephalus.

Cervical spine injuries resulting from diving accidents in swimming pools: outcome of 34 patients

Cervical spine injuries after diving into private swimming pools can lead to dramatic consequences. We reviewed 34 patients hospitalized in our center between 1996 and 2006. Data was collected from their initial admission and from follow-up appointments. The injuries were sustained by young men in 97% (mean age 27) and the majority happened during the summer (88%). Fractures were at C5–C7 in 70%. American Spinal Injury Association class (ASIA) on admission was A for 8 patients, B for 4, C for 4, D for 1, and E for 17. There were 23 surgical spine stabilizations. Final ASIA class was A for 6 patients, B for 1, C for 3, D for 5, and E for 18. The mean duration of hospitalization was 21.3xa0days in our neurosurgical center (mean overall cost: 36,000xa0Euros/patient) plus 10.6xa0months in rehabilitation center for the 15 patients admitted who had an ASIA class A to C. Mean overall direct cost for a patient with class A is almost 300,000xa0Euros, compared to around 10,000xa0Euros for patients with class D and E. In addition, a profound impact on personal and professional life was seen in many cases including 11 divorces and 7 job losses. Dangerous diving into swimming pools can result in spinal injuries with drastic consequences, including permanent physical disability and a profound impact on socio-professional status. Moreover, there are significant financial costs to society. Better prevention strategies should be implemented to reduce the impact of this public health problem.

Neurosurgical work during the Napoleonic wars: Baron Larrey's experience

OBJECTIVESnConsidered as the most famous French military surgeon, Dominique-Jean Larrey (1766-1842), who joined all the campaigns of Napoleon, wrote his memoirs and several medical articles. This paper discusses how in the Napoleonic times, Larrey dealt with neurosurgical diseases or injuries.nnnPATIENTS AND METHODSnWe reviewed four main publications of Larrey published between 1812 and 1838 and analyzed the type of neurosurgical cases presented and their treatment.nnnRESULTSnThese works include his practice of what we call now neurosurgery since most injuries described concern the skull or spine. He seemed to treat patients with humanity, integrity and perseverance. Larrey dealt with many aspects of neurosurgery, such as cranial or spinal trauma surgery, and also infectious diseases. He saw many head injuries inflicted not only by muskets or artillery, but also with spears and sabers. Unlike some others, Larrey advocated the use of trepanation in many situations as practiced, for instance, in the treatment of depressed fractures or in presence of subdural collections. On the other hand, this surgeon who saw thousands of amputees during his career did not mention the phantom limb phenomenon in his memoirs. Similarly, the issue of cerebral localizations is only mentioned in his last work, published in 1838.nnnCONCLUSIONSnIn his work, Larrey (and all his contemporaries) dealt essentially with cranial surgery, as in skull fractures where the brain could potentially have been injured by bone fragments. The time for brain surgery had not come yet.

Functional architecture of the somatosensory homunculus detected by electrostimulation

We performed a prospective electrostimulation study, based on 50 operated intact patients, to acquire accurate MNI coordinates of the functional areas of the somatosensory homunculus. In the contralateral BA1, the hand representation displayed not only medial‐to‐lateral, little‐finger‐to‐thumb, but also rostral‐to‐caudal discrete somatotopy, with the tip of each finger located more caudally than the proximal phalanx. The analysis of the MNI body coordinates showed rare inter‐individual variations in the medial‐to‐lateral somatotopic organization in these patients with rather different intensity thresholds needed to elicit sensations in different body parts. We found some similarities but also substantial differences with the previous, seminal works of Penfield and his colleagues. We propose a new drawing of the human somatosensory homunculus according to MNI space.

Hemangioblastoma of the corpus callosum: A case report and review of the literature on its origin

A third case of corpus callosum hemangioblastoma (HB) is presented. With no preoperative embolization, surgery was uneventful and the postoperative course was excellent. Based on the literature, we attempted to clarify the histogenesis of HB and to explain why they are exceptional in the supratentorial region in contrast to the posterior cranial fossa. The VHL gene is expressed particularly in Purkinje cells of the cerebellum, but this expression is also possible in supratentorial structures. Its mutation leads to developmental arrest of angioblasts that become potentially neoplastic cells. These CD133-positive pluripotent neoplastic angioblasts, similar to stem cells, may be immature HB in the brain. They also express VEGF, coexpress Epo/EpoR, and are capable of differentiation into primitive vascular structures. This coexpression may not only mediate developmental stagnation, but may also induce HB proliferation. Therefore, HB tumorigenesis may be initiated during embryogenesis and may originate from angiomesenchyma because of the expression of three cell types (stromal cells, pericytes, and endothelial cells) in vimentin. Their capacity for proliferation and differentiation in HB depends on the microenvironment.