The science and questions surrounding chronic traumatic encephalopathy.

Recently, the pathobiology, causes, associated factors, incidence and prevalence, and natural history of chronic traumatic encephalopathy (CTE) have been debated. Data from retrospective case series and high-profile media reports have fueled public fear and affected the medical community's understanding of the role of sports-related traumatic brain injury (TBI) in the development of CTE. There are a number of limitations posed by the current evidence that can lead to confusion within the public and scientific community. In this paper, the authors address common questions surrounding the science of CTE and propose future research directions.

Percutaneous screw fixation versus open fusion for the treatment of traumatic thoracolumbar fractures: A retrospective case series of 185 Patients with a single-level spinal column injury.

STUDY DESIGN: Retrospective Single-Center Review of Data at a Level 1 Trauma Center. OBJECTIVE: Compare deformity correction and surgical outcomes of percutaneous instrumentation and open fusion in traumatic thoracolumbar fractures. METHODS: In our retrospective study, all patients undergoing elective spine surgery for TL fractures at a Level 1 trauma center between 2000 and 2017 were reviewed. Patients who underwent percutaneous fixation were given the option of hardware removal after the fracture had healed. RESULTS: A total of 185 patients were included in the study, with 109 treated with an open fusion, and 76 with percutaneous fixation. Twenty-five patients in the latter group had the instrumentation removed after the fracture had healed. None of them required reoperation. In the open fusion group 54.1% of patients required a decompressive laminectomy. Percutaneous fixation patients had a shorter operative time (98.3 min vs 214 min, p < 0.0001), shorter length of stay (9.8 days vs 13.5 days, p = 0.04), and less blood loss (68.4 cc vs 691 cc, p < 0.001). They also had a better correction of their traumatic kyphosis after surgery (p = 0.005). CONCLUSION: Percutaneous fixation is a valuable option for the treatment of TL fractures in cases without evidence of neural compression. It is still unclear whether hardware removal helps prevent adjacent segment degeneration. Percutaneous fixation could allow for better reduction of the fracture with improvement of postoperative alignment.

Clinical diagnosis and successful treatment of inflammatory cerebral amyloid angiopathy.

INTRODUCTION: Cerebral amyloid angiopathy is a major cause of lobar hemorrhage in older adults, and of microvascular ischemic disease. The rarest form of this disease is an inflammatory form causing seizures. It is important to recognize because the patients usually respond to a brief course of immunosuppression. METHODS: Case report. RESULTS: A 66-year-old man developed gradual cognitive decline, insidiously increasing headaches, and then had a likely seizure. MRI showed diffuse white matter edema, and innumerable superficial microhemorrhages characteristic of amyloid angiopathy. He was empirically treated with oral prednisone and an anticonvulsant. His symptoms improved and the white matter edema resolved over several months. ApoE genotype was 4/4, which is commonly found in inflammatory amyloid angiopathy. CONCLUSIONS: Inflammatory cerebral amyloid angiopathy can be clinically diagnosed and treated without brain biopsy. Clinical diagnosis is important because of the good response to a brief course of steroids in most cases.

Interactions between melatonin and estrogen may regulate cerebrovascular function in women: clinical implications for the effective use of HRT during menopause and aging.

A number of clinical trials associated with the Women's Health Initiative (WHI) have assessed the potential benefits of hormone replacement therapy (HRT) for protection against the development of cardiovascular disease and memory loss in menopausal women. The results of the WHI Memory Study suggest that HRT increases the risk of stroke and dementia in menopausal women. This finding has called into question the results of hundreds of basic science studies that have suggested that estrogen could protect brain cells from damage and improve cognition. A number of researchers have argued that inappropriate formulation, improper dosing, a limited study population, and poor timing of administration likely contributed to the reported findings from the clinical trial. Regarding appropriate formulation, it has been suggested that interactions between estrogen and other hormones should be considered for further investigation. A review of the literature has led us to conclude that a thorough investigation into such hormonal interactions is warranted. We hypothesize that the increased risk of cerebrovascular disease observed in menopausal women may, in part, be due to changes in the circulating levels of melatonin and estrogen and their modulatory affects on many relevant endothelial cell biological activities, such as regulation of vascular tone, adhesion to leukocytes, and angiogenesis, among others. Our hypothesis is supported by numerous studies demonstrating the reciprocal inhibitory effects of melatonin and estrogen on vascular tone, neuroprotection, and receptor expression. We believe that a thorough analysis of the distribution, localization, expression, quantification, and characterization of hormonal receptor subtypes, as well as changes in structural morphology in diseased and normal, healthy cerebrovascular tissue, will substantially aid in our understanding of the effects of HRT on the cerebrovascular circulation. The application of new molecular biological techniques such as tissue microarray analysis, gene and protein arrays, and multi-photon confocal microscopy may be of tremendous benefit in this regard.

Incorporation of extruded coils into the third nerve in association with third nerve palsy.

The extrusion of the coil complex outside of the aneurysmal dome is thought to be an important mechanism by which the aneurysm neck and fundus recanalize, but the migration of the coil loops and their incorporation inside vital nervous structures has not been clearly described. We reviewed the medical literature on coil extrusion and migration and report a rare case of third nerve palsy due to direct damage caused by coil loop migration that resolved after surgery. A 25-year-old woman presented with subarachnoid hemorrhage and painful left third nerve palsy. The angiogram revealed a supraclinoid internal carotid aneurysm incorporating the origin of the left posterior communicating artery. Her aneurysm was coiled. The 8 month follow-up angiogram revealed a major recurrence of her aneurysm. It was decided to surgically clip the aneurysm. At surgery, coil loops were found in the subarachnoid space and embedded into the third nerve. At 1 month follow-up she had recovered well, and only had very subtle diplopia upon fatigue. Coil extrusion is a fairly common phenomenon that should be suspected in instances of major aneurysmal recurrence. Surgical treatment is recommended, and special care should be taken when mobilizing the extruded coil mass.

New-generation oral anticoagulants for the prevention of stroke: implications for neurosurgery.

A new generation of oral anticoagulants, namely direct thrombin inhibitors and factor Xa inhibitors, have recently been approved for clinical use in patients with atrial fibrillation. These novel families of drugs have been shown to have favorable efficacy and safety profiles in multiple clinical settings, particularly in the prevention of atrial fibrillation-related stroke, and are likely to become part of everyday practice, making a crossover to neurosurgical patients inevitable. Concern has risen regarding the complexity of managing intracranial and intraspinal hemorrhages related to these drugs. This review aims to provide an update on the most recent advances in oral anticoagulant drug therapy from a neurosurgeon's perspective. We discuss current evidence for the use of these novel agents, their limitations, existing methods of drug-level monitoring, and controversies related to anticoagulation reversal. We also discuss specific topics such as anticoagulation resumption after intracranial or intraspinal bleeding, perioperative anticoagulant administration, and the possibility of combination with tissue plasminogen activator in the setting of acute ischemic stroke. A special focus is given to the incidence of intracranial and intraspinal hemorrhage associated with each drug.

Advances in surgical management of malignancies of the cranial base: the extended transbasal approach.

The extended transbasal approach combines a bifrontal craniotomy with an orbital nasal and potentially a sphenoethmoidal osteotomy to provide excellent access to malignancies of the anterior, middle and posterior skull base. The approach enables the en bloc resection of tumors within the frontal lobes, orbits, paranasal sinuses and sphenoclival corridors without brain retraction and may obviate the need for transfacial access. We present our 7-year experience during which 29 patients underwent surgery with the extended transbasal exposure. In 25 patients the extended transbasal approach was used alone; in the remaining four it was combined with additional approaches. With exception of two patients, all lesions were removed en bloc. Reconstruction was accomplished with the use of pericranium and in some instances a temporalis muscle pedicle or a gracilis microvascular free flap. There were no mortalities associated with this approach. Seven patients experienced infections, four patients experienced cerebral spinal fluid (CSF) leakage, two patients who had received adjuvant radiation experienced scalp necrosis, three patients experienced pneumocephalus, and 29 patients experienced cranial neuropathies, the majority of which were loss of olfaction. The average follow-up for our patients was 34 months with a range of 2--62 months.

Surgical treatment of posterior circulation aneurysms.

Distal basilar aneurysms appear to produce symptoms from hemorrhage or enlargement at least as frequently as their anterior circulation counterparts. Once giant size has been reached, the future of the patient is indeed bleak. The diagnostic evaluation and therapeutic strategy to successfully combat these lesions requires thoughtful interaction between the neurosurgeon, the neuroradiologist, and medical and critical care physicians. In my opinion, patients are best served by referral to centers equipped for these complex and dangerous procedures.