Connectomics as a prognostic tool of functional outcome in glioma surgery of the supplementary motor area: illustrative case.

BACKGROUND: The supplementary motor area (SMA) is essential in facilitating the commencement and coordination of complex self-initiated movements. Its complex functional connectivity poses a great risk for postoperative neurological deterioration. SMA syndrome can occur after tumor resection and comprises hemiakinesia and akinetic mutism (often, but unpredictably temporary). Although awake surgery is preferred for mapping and monitoring eloquent areas, connectomics is emerging as a novel technique to tailor neurosurgical approaches and predict functional prognosis, as illustrated in this case. OBSERVATIONS: The authors report on a patient presenting with recurrent oligodendroglioma after subtotal resection 7 years earlier. After extensive neuropsychological and neuroradiological assessment (including connectomics), awake surgery was indicated. No intraoperative deficits were recorded; however, the patient presented with postoperative right-sided akinesia and mutism. Postoperative neuroimaging demonstrated the connectome overlapping the preoperative one, and indeed, neurological symptoms resolved after 3 days. LESSONS: Comparison of the pre- and postoperative connectome can be used to objectively evaluate surgical outcomes and assess patient prognosis. To the best of the authors' knowledge, this is the first case demonstrating the feasibility of quantitative functional connectivity analysis as a prognostic tool for neurological improvement after surgery. A better understanding of brain networks is instrumental for improving diagnosis, prognosis, and treatment of neuro-oncological patients.

Prevalence of recurrence and retreatment of ruptured intracranial aneurysms treated with endovascular coil occlusion.

OBJECT: Endovascular coiling is a common treatment for ruptured intracranial aneurysms. However, concerns have been raised over the durability of this treatment. The aim of this study was to establish the rate of recurrence and retreatment of coiled aneurysms treated in our unit. METHODS: We performed a retrospective analysis of 264 surviving patients with ruptured aneurysms treated by endovascular coiling between November 2003 and April 2007. Data was collected on patient age, location of aneurysm, angiogram results and any subsequent retreatment. RESULTS: Follow-up angiography performed at 6 months was available in 239 cases (91%) and revealed 158 (66%) aneurysms completely occluded, 51 (21%) had neck recurrence and 31 (13%) had significant recurrence. Thirty (12.6%) aneurysms required retreatment over a mean follow-up period of 46 (range 24-66) months. Younger age predisposed to a higher risk of recurrence and retreatment. Aneurysms of the anterior communicating and anterior cerebral arteries were less likely to recur or require retreatment (relative risk 0.42 and 0.29, respectively); aneurysms of the posterior communicating arteries were more likely to recur (relative risk 2.22). Aneurysms of the basilar and carotid arteries were more likely to undergo retreatment (relative risk 2.84 and 2.46, respectively). CONCLUSION: Long-term follow-up is required for ruptured aneurysms treated by coiling. Certain subgroups may require closer follow-up due to the increased risk of recurrence or retreatment, such as younger patients and those with aneurysms of the posterior communicating, basilar or carotid arteries.

Delays in treating patients with good grade subarachnoid haemorrhage in London.

BACKGROUND AND PURPOSE: Spontaneous aneurysmal subarachnoid haemorrhage (SAH) is managed as a neurosurgical priority with guidelines and published literature emphasising the identification and the treatment of the ruptured aneurysm within 48 h of ictus. We audited the timing of management of good grade (WFNS 1 & 2) SAH in a neurosurgical unit in Greater London. We also reviewed the available services for treating SAH within Greater London. MATERIALS AND METHODS: Retrospective audit of patients admitted with SAH to St. George's Hospital between 31 May 2007 and 31 May 2009 was performed. Prospective telephone and public record review of the catchment area and neurovascular provisions of the seven London neurosurgical units were assessed. RESULTS: There were 141 WFNS grade 1 and 2 SAH patients admitted. Only a quarter were treated within 48 h of ictus. Patients destined for endovascular treatment waited significantly longer periods until treatment when compared with that of clipping group patients. The day of the week on which diagnostic angiography occurred was critical in determining treatment delays, probably due to the lack of routine provision of clipping at weekends and next day coiling services. We estimated that 440 good grade SAH are admitted per annum in Greater London. There are 20 neurovascular surgeons and 16 interventional neuroradiologists across seven neurosurgical units that routinely treat SAH. CONCLUSIONS: We have identified significant delays in treating three quarters of good grade SAH patients in London. This appears to be due to a lack of next day treatment availability. A collaborative strategy between the seven London neurosurgical units could reduce treatment delays.

Water movements in the brain: role of aquaporins.

About 80% of the brain is water. This review discusses the importance of the three brain water-channel proteins (AQP1, AQP4, AQP9) in brain physiology. AQP1 is expressed in the choroid plexus and participates in forming cerebrospinal fluid. AQP4, found in astrocyte foot processes, glia limitans and ependyma, facilitates water movement into and out of the brain, accelerates astrocyte migration and alters neuronal activity. Recently, AQP4 autoantibodies were discovered in patients with neuromyelitis optica, a demyelinating disease, and are now being used to diagnose this condition. AQP9 is present in some glia and neurons, but its function is unclear. Finally, we discuss how the discovery of AQP activators and inhibitors will be the next major step in this field.

Spontaneous hemorrhage of a spinal ependymoma: a rare cause of acute cauda equina syndrome: a case report.

STUDY DESIGN: An interesting case of spontaneous bleeding from an ependymoma of the filum terminale is presented. OBJECTIVES: To document a rare case of rapid neurologic deterioration as a consequence of spinal tumoral hemorrhage and to highlight important issues regarding tumor histologic subtype and the impact of anticoagulation that have emerged from an illuminating review of the literature. SUMMARY OF BACKGROUND DATA: To our knowledge, there have been only 8 reported cases of hemorrhage from an ependymoma of the filum terminale or conus medullaris causing acute cauda equina syndrome. Bleeding is described in the pathology texts as being a consequence of the vascular architecture of the myxopapillary subtype and so postulated to be more common in this group. Anticoagulation is recognized to increase the frequency of tumoral bleeding, but no studies report its effect of severity of clinical presentation. METHODS: We report the case of a 57-year-old woman who developed nontraumatic acute cauda equina syndrome, including sphincter compromise. She underwent a lumbosacral laminectomy for evacuation of a hematoma, at which stage a filum terminale ependymoma was excised. Histopathologic analysis demonstrated it to be of a nonmyxopapillary subtype. RESULTS: The patient demonstrated gradual improvement of the neurologic deficit. At 12-month follow-up, her saddle area sensory deficit has resolved, her right lower limb is much stronger allowing her to walk long distances, and she is successfully performing intermittent self-catheterization of her bladder. CONCLUSIONS: The possibility of an underlying tumor should always be borne in mind so that adequate preoperative planning can be undertaken. The presence of the myxopapillary subtype should not prevent a clinician from excluding other reasons for hemorrhage, and counseling when reinstituting anticoagulation must include warning against a worse prognosis from any future hemorrhage.