Recovery of functional connectivity of the sensorimotor network after surgery for diffuse low-grade gliomas involving the supplementary motor area.

OBJECTIVE The supplementary motor area (SMA) syndrome is a well-studied lesional model of brain plasticity involving the sensorimotor network. Patients with diffuse low-grade gliomas in the SMA may exhibit this syndrome after resective surgery. They experience a temporary loss of motor function, which completely resolves within 3 months. The authors used functional MRI (fMRI) resting state analysis of the sensorimotor network to investigate large-scale brain plasticity between the immediate postoperative period and 3 months' follow-up. METHODS Resting state fMRI was performed preoperatively, during the immediate postoperative period, and 3 months postoperatively in 6 patients with diffuse low-grade gliomas who underwent partial surgical excision of the SMA. Correlation analysis within the sensorimotor network was carried out on those 3 time points to study modifications of its functional connectivity. RESULTS The results showed a large-scale reorganization of the sensorimotor network. Interhemispheric connectivity was decreased in the postoperative period, and increased again during the recovery process. Connectivity between the lesion side motor area and the contralateral SMA rose to higher values than in the preoperative period. Intrahemispheric connectivity was decreased during the immediate postoperative period and had returned to preoperative values at 3 months after surgery. CONCLUSIONS These results confirm the findings reported in the existing literature on the plasticity of the SMA, showing large-scale modifications of the sensorimotor network, at both inter- and intrahemispheric levels. They suggest that interhemispheric connectivity might be a correlate of SMA syndrome recovery.

Robot-assisted spine surgery: feasibility study through a prospective case-matched analysis.

PURPOSE: While image guidance and neuronavigation have enabled a more accurate placement of pedicle implants, they can inconvenience the surgeon. Robot-assisted placement of pedicle screws appears to overcome these disadvantages. However, recent data concerning the superiority of currently available robots in assisting spinal surgeons are conflicting. The aim of our study was to evaluate the percentage of accurately placed pedicle screws, inserted using a new robotic-guidance system. METHOD: 20 Patients were operated on successively by the same surgeon using robotic assistance (ROSA™, Medtech) (Rosa group 10 patients, n = 40 screws) or by the freehand conventional technique (Freehand group 10 patients, n = 50 screws). Patient characteristics as well as the duration of the operation and of exposure to X rays were recorded. RESULTS: The mean age of patients in each group (RG and FHG) was 63 years. Mean BMI and operating time among the RG and FHG were, respectively, 26 and 27 kg/m(2), and 187 and 119 min. Accurate placement of the implant (score A and B of the Gertzbein Robbins classification) was achieved in 97.3% of patients in the RG (n = 36) and in 92% of those in the FHG (n = 50). Four implants in the RG were placed manually following failed robotic assistance. CONCLUSION: We report a higher rate of precision with robotic as compared to the FH technique. Providing assistance by permanently monitoring the patient's movements, this image-guided tool helps more accurately pinpoint the pedicle entry point and control the trajectory. Limitations of the study include its small sized and non-randomized sample. Nevertheless, these preliminary results are encouraging for the development of new robotic techniques for spinal surgery.

Surgical-site infection in spinal injury: incidence and risk factors in a prospective cohort of 518 patients.

PURPOSE: To investigate the incidence of surgical-site infection (SSI) and determinate the risk factors of SSI in the context of spinal injury. METHODS: From February 1, 2011 to July 31, 2011, for a multicentre cohort of patients with acute spinal injury, we prospectively censored those with SSI for at least 12 months. We recorded epidemiologic characteristics and details of surgical procedure and postoperative care for each patient. We calculated the incidence of SSI at 1, 3 and 12 months after surgery. Univariate and multivariate analysis were used to establish the association of risk factors and SSI. We studied clinical outcomes by a visual analog scale for pain and physical and mental component summaries (PCS and MCS) of the Medical Outcomes Survey 36-Item Short Form (SF-36). RESULTS: At 1 year, among 518 patients, we recorded 25 SSI events, with median occurrence at 16 days (25-75 % quartile: 13-44 days). Incidence of SSI was 3.2 % (95 % confidence interval [1.9-5.3 %]) at 1 month, 3.7 % (95 % [2.2-5.8 %]) at 3 months and 4.6 % (95 % CI [3-6.9 %]) at 12 months. On multivariate analysis, age, presence of diabetes and surgical duration were predictors of SSI (p = 0.009, p = 0.047, and p = 0.015 respectively). At 12 months, infected and non-infected patients did not differ in pain (p = 0.58) or SF-36 PCS (p = 0.8) or MCS (p = 0.68). CONCLUSIONS: In this large prospective multicentre study in the context of spinal injury, we obtained an equivalent incidence rate and risk factors of SSI as found in the literature for elective spinal surgery.

Surgical management of diffuse low-grade gliomas associated with other intracranial diseases.

BACKGROUND: The association of diffuse, low-grade glioma (DLGG) with other intracranial pathologies is a rare condition, raising the question of what constitutes its most effective therapeutic management. It is not known whether this is a simple coincidence or whether there is a higher significant risk involved with the co-existence of DLGG and another disease. We report the first consecutive series of nine patients who underwent surgical resection for such a glioma. METHOD: We reviewed DLGGs removed between 1998 and 2013 that were associated with another intracranial pathology. For all cases, we collected and analyzed information regarding clinico-radiological features, surgical procedures, and clinical outcomes. RESULTS: Nine consecutive patients (four men, five women, mean age: 38.8 years) presented with a conjunction of DLGG and another disease: two cases of vestibular schwannoma, two pituitary adenomas, two meningiomas, one lymphoma, one arteriovenous malformation, and one case of multiple sclerosis. The DLGG was diagnosed because of seizures in four patients and incidentally in the other five patients. The average delay between the diagnosis of the glioma and its resection was 40.8 months (range 1-84 months). The mean follow-up after surgery was 43 months (6-120 months). Gross-total or subtotal resection was achieved in all cases. There were no cases of mortality or permanent morbidity associated with surgery. The Karnofsky Performance Scale score was 90 or 100 in all cases. The associated pathology was treated surgically in three cases, medically in four cases, and tracked under observation in two cases. These intracranial diseases, especially meningiomas and pituitary adenomas, might have a significant higher risk to be associated with DLGGs in comparison with their incidence and prevalence in the general population. CONCLUSIONS: Active management of this rare, dual pathology allows patients to enjoy a normal and prolonged quality of life. We therefore suggest considering early and maximal surgical resection as the first therapeutic option for DLGGs combined with another intracranial disease, as is done in the case of isolated DLGGs.

Crossed aphasia elicited by intraoperative cortical and subcortical stimulation in awake patients.

OBJECT: Crossed aphasia (aphasia resulting from a right hemispheric lesion among right-handed patients) is rare. The authors describe for the first time transient crossed aphasia elicited by intraoperative electrostimulation of both cortex and white matter pathways in awake patients. METHODS: Three right-handed adults underwent surgery for a right-sided glioma. Because slight language disorders occurred during partial seizures or were identified on preoperative cognitive assessment, with right activations detected on language functional MR imaging in 1 patient, awake craniotomy was performed using intraoperative cortico-subcortical electrical functional mapping. RESULTS: Transient language disturbances were elicited by stimulating discrete cortical areas (inferior frontal gyrus and posterior part of the superior temporal gyrus) and white matter pathways (inferior frontooccipital fasciculus and arcuate fasciculus). A subtotal resection was achieved in all cases, according to functional boundaries. Postoperatively, 1 patient experienced a transient dysphasia, which resolved after speech rehabilitation, with no permanent deficit. CONCLUSIONS: These original findings highlight the possibility of finding crucial cortico-subcortical language networks in the right hemisphere in a subgroup of atypical right-handed patients. These findings provide new insights into the neural basis of language, by underlining the role of the right inferior occipitofrontal fasciculus in semantics and that of the right arcuate fasciculus in phonology, and by supporting the hypothesis of a mirror organization between the right and left hemispheres. The authors suggest that, in right-handed patients, if language disturbances are detected during seizures or on presurgical neuropsychological assessment, especially when right activations are observed on language functional MR imaging, awake craniotomy with intraoperative language mapping should be considered.