Pneumocephalus in subthalamic deep brain stimulation for Parkinson's disease: a comparison of two different surgical techniques considering factors conditioning brain shift and target precision.

BACKGROUND: Precise placement of electrodes in deep brain stimulation (DBS) may be influenced by brain shift caused by cerebrospinal fluid leaking or air inflow. We compared accuracy and treatment outcomes between a standard technique and one aiming at reducing brain shift. METHODS: We retrospectively reviewed 46 patients (92 targets) treated with bilateral subthalamic-DBS for Parkinson's disease. The patients were divided into two groups: group A surgery was performed in supine position with standard burr hole, dural opening, fibrin glue and gelfoam plugging. Group B patients were operated in a semi-sitting position with direct dural puncture to reduce CSF loss. We analysed target deviation on head CT performed immediately after surgery and at 1 month merged with preoperative MRI planning. We recorded pneumocephalus volume, brain atrophy and target correction by intraoperative neurophysiology (ION). RESULTS: In group A, the mean pneumocephalus volume was 10.55 cm3, mean brain volume 1116 cm3, mean target deviation 1.09 mm and ION corrected 70% of targets. In group B, mean pneumocephalus was 7.60 cm3 (p = 0.3048), mean brain volume 1132 cm3 (p = 0.6526), mean target deviation 0.64 mm (p = 0.0074) and ION corrected 50% of targets (p = 0.4886). Most leads' deviations realigned to the planned target after pneumocephalus reabsorbtion suggesting a deviation caused by displacement of anatomical structures due to brain shift. Definitive lead position was always decided with ION. CONCLUSIONS: The modified DBS technique significantly reduced errors of electrode placement, though such difference was clinically irrelevant. ION corrected a high amount of trajectories in both groups (70% vs 50%). The choice of either strategy is acceptable.

Radiological outcomes for endovascular treatment of posterior communicating artery aneurysms: a retrospective multicenter study of the occlusion rate.

Although several innovations in techniques and implantable devices were reported over the last decades, a consensus on the best endovascular treatment for intracranial aneurysms originating from the posterior communicating artery is still missing. This work investigates radiological outcomes of different endovascular techniques for posterior communicating artery aneurysms treatment in a retrospective multi-centric cohort. We included patients endovascularly treated for posterior communicating artery aneurysms from 2015 through 2020 in six tertiary referral hospitals. We evaluated the relationship between patients and aneurysms characteristics, baseline neurological status, radiological outcomes, and the different endovascular techniques. Overall, 250 patients were included in this study. Simple coiling was the most frequent treatment in 171 patients (68%), followed by flow-diverter stenting in 32 cases (13%). Complete occlusion was reported in 163 patients (65%), near-complete occlusion in 43 (17%), and incomplete occlusion in 44 (18%). Radiological follow-up was available for 247 (98%) patients. The occlusion rate was stable in 149 (60%), improved in 49 (19%), and worsened in 51 (21%). No significant difference in exclusion rate was seen between ruptured and unruptured aneurysms at the last follow-up (p = 0.4). Posterior communicating artery thrombosis was reported in 25 patients (9%), transient ischemic attack in 6 (2%), and in 38 patients (15%), subsequent procedures were needed due to incomplete occlusion or reperfusion. Endovascular strategies for posterior communicating artery aneurysms represent effective and relatively safe treatments. Simple coiling provides a higher immediate occlusion rate, although recanalization has been frequently reported, conversely, flow-diversion devices provide good long-term radiological outcomes.

Transcallosal approach for intraventricular gliomas: neuropsychological outcome and functionality of the corpus callosum.

The transcallosal approach is commonly used for surgery of lateral and third ventricle lesions. Cognitive deficits due to the transcallosal approach still remain controversial. Even if enormous efforts have been made in order to understand specific functions of the corpus callosum, still little is known. The present study was aimed to evaluate the neuropsychological results and the functionality of the corpus callosum in transferring visual, auditory and tactile information between the two hemispheres in a group of patients who were treated using the transcallosal approach. The study evaluated the neuropsychological status of five selected patients presenting low-grade lesions of lateral ventricles that had not previously undergone surgical treatments and that did not receive radiotherapy and chemotherapy. All patients were administered an extensive neuropsychological testing postoperatively and the interhemispheric transfer of visual, auditory and tactile information was also evaluated. Two patients were tested preoperatively. Incisions of 2.4 cm maximum of the corpus callosum length were operated. The postoperative cognitive profile was normal. In some patients, a postoperative subnormal performance in memory functions was found but it cannot be attributable to the surgical approach given that it was altered even pre-surgically. Small incisions of the corpus callosum preserved the integrity of this anatomical structure in transferring lateralized information between the two hemispheres. The transcallosal approach is a safe surgical route to lateral ventricles lesions and the neuropsychological evaluation of these cases could give new insights in the comprehension of corpus callosum functions.

Techniques for pneumocephalus and brain shift reduction in DBS surgery: a review of the literature.

Deep brain stimulation has become an established therapeutic choice to manage the symptoms of medically refractory Parkinson's disease. Its efficacy is highly dependent on the accuracy of electrodes' positioning in the correct anatomical target. During DBS procedure, the opening of the dura mater induces the displacement of neural structures. This effect mainly depends on the loss of the physiological negative intracranial pressure, air inflow, and loss of cerebrospinal fluid. Several studies concentrated on correcting surgical techniques for DBS electrodes' positioning in order to reduce pneumocephalus which may result in therapeutic failure. The authors focused in particular on reducing the brain air window and maintaining the pressure gradient between intra- and extracranial compartments. A significant reduction of pneumocephalus and brain shift was obtained by excluding the opening of the subarachnoid space, by covering the dura mater opening with tissue sealant and by reducing the intracranial pressure in general anesthesia. Smaller burr hole diameters were not statistically relevant for reducing air inflow and displacement of anatomical targets. The review of the literature showed that conserving a physiological intra-extracranial pressure gradient plays a fundamental role in avoiding pneumocephalus and consequent displacement of brain structures, which improves surgical accuracy and DBS long-term results.

Single-approach vertebral osteosynthesis in the treatment of spinal osteolysis by spondylodiscitis.

OBJECTIVEBoth spontaneous and iatrogenic spondylodiscitis are becoming ever more frequent, yet there are no definite treatment guidelines. For many years the treatment protocol was conservative medical management or surgical debridement with patients immobilized or bedridden for weeks and often resulting in spinal deformity. The eventual development of spinal deformity can be difficult to treat. Over the last few years, the authors have preferred a single-approach instrumented arthrodesis when spondylolysis that evolves in deformity from somatic wedging occurs.METHODSThe authors retrospectively reviewed the clinical, radiological, and surgical records of 11 patients treated over the past 3 years for spondylodiscitis with osteosynthesis.RESULTSOverall, the authors treated 11 patients: 3 cases with tuberculous spondylodiscitis (1 dorsal, 2 lumbar); 6 cases with Staphylococcus aureus spondylodiscitis (1 cervical, 2 dorsal, 2 lumbar, 1 dorsolumbar); 1 spondylodiscitis with postsurgical lumbar deformity; and in 1 dorsolumbar case the germ was not identified. Surgical approaches were chosen according to spinal level: In 8 dorsolumbar cases a posterior osteosynthesis was achieved. In 1 cervical case an anterior approach was performed with autologous bone graft from iliac crest. In 2 thoracolumbar cases a posterolateral costotransversectomy was needed. In 1 lumbosacral case iliac somatic grafting was used. Ten patients received adequate antibiotic treatment with clinical remission, and 1 case is in initial follow-up. No complications due to instrumentation were recorded. Spinal deformity was prevented in 10 cases, whereas preexisting spinal deformity was partially corrected in 1 case. In all cases, arthrodesis achieved vertebral stability.CONCLUSIONSThis study has the limitations of a retrospective review with a limited number of patients. Instrumentation does not appear to hamper healing from infection. Moreover, spinal stabilization, which is assisted by the infectious process even in the absence of bone graft, allows early mobilization. Instrumented osteosynthesis should be preferred for spondylodiscitis with osteolysis and spinal instability because it allows early mobilization and rehabilitation whenever necessary. It prevents spinal deformity and does not hamper healing of infections.

Spondylocostal Dysostosis (Jarcho-Levin Syndrome) in an Adult Patient with Consanguineous Parents, in Long-Term Follow-Up.

A 24-year-old woman presented to neurosurgical consultation for chronic back pain. The patient was long term in wheelchair for vertebral deformity. She was the third child of first-degree consanguineous parents. The 2 older brothers had also vertebral malformations. The radiological images showed butterfly vertebra, vertebral fusion, hemivertebrae, scoliosis, and rib malformation. The patient was in follow-up for restrictive lung disease. Motor evoked potentials and lower limb electromyography were normal. We recommended conservative treatment for the back pain with antalgic and physical therapy. Diagnosis of spondylocostal dysostosis, or Jarcho-Levin syndrome, was made based on radiological features. Radiological mages are pathognomonic. Spondylocostal dysostosis is a rare hereditary disorder associated with multiple vertebral and rib anomalies. The entity is distinct from spondylothoracic dysostosis, which has a higher mortality due to respiratory complications. The patient was not compliant for genetic familiar counseling. At 12-year follow-up, the patient was in periodic respiratory and motor rehabilitation therapy.

Hippocampal deep brain stimulation: persistent seizure control after bilateral extra-cranial electrode fracture.

Hippocampal deep brain stimulation (DBS) can provide an effective alternative for intractable temporal lobe epilepsy. In this case report, we describe a peculiar outcome after a post-traumatic wire-disconnection of a bilateral hippocampal DBS device. The patient presented a postoperative long-term significant reduction in seizure frequency even with an absent electric stimulation. This case gives the possibility to consider alternatives in epilepsy surgery, based on stimulation interference (lesional or electrical disturbing) in the epileptogenic zone.

Inhibition of PI3K Signalling Selectively Affects Medulloblastoma Cancer Stem Cells.

Medulloblastoma is the most common malignant brain tumor of childhood. Although survival has slowly increased in the past years, the prognosis of these patients remains unfavourable. In this context, it has been recently shown that the intracellular signaling pathways activated during embryonic cerebellar development are deregulated in MDB. One of the most important is PI3K/AKT/mTOR, implicated in cell proliferation, survival, growth, and protein synthesis. Moreover, a fraction of MDB cells has been shown to posses stemlike features, to express typical neuronal precursor markers (Nestin and CD133), and to be maintained by the hypoxic cerebellar microenvironment. This subpopulation of MDB cells is considered to be responsible for treatment resistance and recurrence. In this study, we evaluated the effects of PI3K/AKT pathway inhibition on primary cultures of MDB and particularly on the cancer stem cell (CSC) population (CD133(+)). PI3K inhibition was able to counteract MDB cell growth and to promote differentiation of stemlike MDB cells. Moreover, PI3K/AKT pathway suppression induced dramatic cell death through activation of the mitochondrial proapoptotic cascade. Finally, analysis on the stem cells fraction revealed that the MDB CSC population is more sensitive to PI3K targeting compared to the whole cancerous population and its nonstem cell counterpart.

Anterior thalamic nucleus deep brain Stimulation (DBS) for drug-resistant complex partial seizures (CPS) with or without generalization: long-term evaluation and predictive outcome.

BACKGROUND: Drug-resistant epileptic patients account for 40 % of cases of epilepsy. Consequently, specific therapeutic options could be surgical resection or, if not indicated, deep brain stimulation (DBS). The aim of this study is to review data from patients affected by drug-resistant complex partial epilepsy with or without generalization treated by anterior thalamic nucleus (AN) DBS to evaluate the efficacy and potential future applications of this approach as a standard method for palliative seizure control. METHODS: Six patients affected by drug-resistant complex partial seizures underwent AN DBS from March 2007 to February 2011. The preoperative tests consisted of electroencephalography (EEG), video EEG, morphologic and functional magnetic resonance imaging (MRI), non-acute positron emission tomography (PET), neuropsychological evaluation, Liverpool seizure scale, and Quality Of Life In Epilepsy (QOLIE). These tests and a seizure diary were also administered during a follow-up of at least 3 years. RESULTS: The improvement in terms of decrease of seizures was more than 50 % in patients affected by complex partial seizures strictly related to limbic system origin. The amelioration was unsatisfactory for patients having anatomical lesions outside the limbic structures with evidence of late diffusion in limbic areas. One patient died 40 days after surgery for reasons not concerned with DBS. CONCLUSIONS: Although the limited number of enrolled patients limits the reliability of data, the results are in accordance with those found in the recent literature and deserve to be considered for further studies regarding real efficacy, indications, stimulation parameters, side effects, and complications.