Delayed Cerebrospinal Fluid Rhinorrhea Associated With Ethmoidal Encephalocele After Resection of Remote Meningioma.

Diagnosis and treatment of neurosurgical pathology present unique challenges in underserved areas, and many conditions may go undiagnosed, misdiagnosed, or untreated for prolonged periods. The development of an unusual complication, seemingly unrelated to an area of neurosurgical intervention, may be particularly perplexing to non-neurosurgical providers, particularly in areas where neurosurgical procedures have not historically been available. A 44-year-old male presented with a giant meningioma which was successfully resected. A nasal encephalocele was noted preoperatively but was not addressed due to lack of associated symptoms and distance from the tumor. The patient lived on a remote island and was lost to follow-up. He developed delayed cerebral spinal fluid (CSF) rhinorrhea three months after surgery, which was diagnosed and treated by local providers as allergic rhinitis for 11 months until he presented with new-onset seizure. Imaging demonstrated descent of the lateral ventricle into the encephalocele. The encephalocele was amputated and the skull base defect was repaired successfully. The alteration of ventricular anatomy and CSF fluid dynamics following tumor resection appears to have created an environment where a non-traumatic CSF leak could develop where it had previously shown no signs of developing. It may be prudent to treat skull base defects prophylactically to prevent this type of complication, particularly in patients of remote regions where regular follow-up is difficult.

Deep Temporal Nerve Transfer for Facial Reanimation: Anatomic Dissections and Surgical Case Report.

BACKGROUND: Facial nerve palsy is a disabling condition that may arise from a variety of injuries or insults and may occur at any point along the nerve or its intracerebral origin. OBJECTIVE: To examine the use of the deep temporal branches of the motor division of the trigeminal nerve for neural reconstruction of the temporal branches of the facial nerve for restoration of active blink and periorbital facial expression. METHODS: Formalin-fixed human cadaver hemifaces were dissected to identify landmarks for the deep temporal branches and the tension-free coaptation lengths. This technique was then utilized in 1 patient with a history of facial palsy due to a brainstem cavernoma. RESULTS: Sixteen hemifaces were dissected. The middle deep temporal nerve could be consistently identified on the deep side of the temporalis, within 9 to 12 mm posterior to the jugal point of the zygoma. From a lateral approach through the temporalis, the middle deep temporal nerve could be directly coapted to facial temporal branches in all specimens. Our patient has recovered active and independent upper facial muscle contraction, providing the first case report of a distinct distal nerve transfer for upper facial function. CONCLUSION: The middle deep temporal branches can be readily identified and utilized for facial reanimation. This technique provided a successful reanimation of upper facial muscles with independent activation. Utilizing multiple sources for neurotization of the facial muscles, different potions of the face can be selectively reanimated to reduce the risk of synkinesis and improved control.

Tentorial sling for microvascular decompression in patients with trigeminal neuralgia: a description of operative technique and clinical outcomes.

OBJECTIVE: Trigeminal neuralgia is a debilitating pain disorder most often caused by arterial compression of the trigeminal nerve, although there are other etiologies. Microvascular decompression (MVD) remains the most definitive treatment for this disorder, with cure rates reported between 60% and 80%. Traditional MVD techniques involve a retrosigmoid craniotomy with placement of an inert foreign material, such as Teflon, between the nerve and compressive vessel. Recurrence of trigeminal neuralgia after MVD has been associated with vessel migration, adhesion formation, and arterial pulsation against the Teflon abutting the nerve. Additionally, foreign materials such as Teflon have been reported to trigger inflammatory responses, resulting in recurrence of trigeminal pain. An alternative method for decompression involves the use of a sling to transpose the compressive vessel away from the nerve. Results of various sling techniques as a decompressive strategy are limited to small series and case reports. In this study, the authors present their experience utilizing a tentorial sling for MVD in patients with trigeminal neuralgia. METHODS: Institutional review board approval was obtained in order to contact patients who underwent MVD for trigeminal neuralgia via the tentorial sling technique. Clinical outcomes were assessed utilizing the Barrow Neurological Institute (BNI) pain intensity score immediately after surgery and at the time of the study. RESULTS: The tentorial sling technique was performed in 45 patients undergoing MVD for trigeminal neuralgia. In 41 of these patients, this procedure was their first decompressive surgery. Immediate postoperative relief of pain (BNI score I) was achieved in 80% of patients undergoing their first decompressive procedure. At last follow-up, 73% of these patients remained pain free. Three patients experienced recurrent trigeminal pain, with surgical exploration demonstrating an intact tentorial sling. The complication rate was 6.6%. CONCLUSIONS: Transposition techniques for MVD have been described previously in small series and case reports. This study represents the largest experience in which the utilization of a tentorial sling for MVD in patients with trigeminal neuralgia is described. The technique represents a novel method for decompression of the trigeminal nerve by transposition of the offending vessel without the use of foreign material. Although the authors' preliminary results parallel the historical cure rate, further outcome data are required to assess long-term durability of this method.

Altered ulnar nerve kinematic behavior in a cadaver model of entrapment.

BACKGROUND: Ulnar nerve entrapment at the elbow is more than a compressive lesion of the nerve. The tensile biomechanical consequences of entrapment are currently marginally understood. OBJECTIVE: To evaluate the effects of tethering on the kinematics of the ulnar nerve as a model of entrapment neuropathy. METHODS: The ulnar nerve was exposed in 7 fresh cadaver arms, and markers were placed at 1-cm increments along the nerve, centered on the retrocondylar region. Baseline translation (pure sliding) and strain (stretch) were measured in response to progressively increasing tension produced by varying configurations of elbow flexion and wrist extension. Then the nerves were tethered by suturing to the cubital tunnel retinaculum and again exposed to progressively increasing tension from joint positioning. RESULTS: In the native condition, for all joint configurations, the articular segment of the ulnar nerve exhibited greater strain than segments proximal and distal to the elbow, with a maximum strain of 28 ± 1% and translation of 11.6 ± 1.8 mm distally. Tethering the ulnar nerve suppressed translation, and the distal segment experienced strains that were more than 50% greater than its maximum strain in an untethered state. CONCLUSION: This work provides a framework for evaluating regional nerve kinematics. Suppressed translation due to tethering shifted the location of high strain from articular to more distal regions of the ulnar nerve. The authors hypothesize that deformation is thus shifted to a region of the nerve less accustomed to high strains, thereby contributing to the development of ulnar neuropathy.

A new kid on the block: Outcomes with Kcentra 1 year after approval.

BACKGROUND: As the population ages, more trauma patients are admitted with coagulopathy. Fresh frozen plasma is effective in reversing coagulopathy caused by warfarin; however, it is not appropriate for all patients. Prothrombin complex concentrates (PCCs) are an alternative for patients who require emergent reversal, minimal-volume administration and who have a supratherapeutic international normalized ratio (INR). A four-factor PCC initially approved in Europe is now available in the United States. We sought to review our experience with Kcentra (4F-PCC) in the first year following Food and Drug Administration approval. METHODS: All trauma patients admitted to an academic Level 1 trauma center between July 15, 2013, and July 15, 2014, who received 4F-PCC for reversal of warfarin-induced coagulopathy were reviewed. 4F-PCC was given as per protocol. Univariate analysis was performed to examine patient demographics, injury characteristics, coagulation studies, 4F-PCC dose, vitamin K use, transfusions, response to reversal, duration of reversal, complications, and mortality. RESULTS: Twenty-six patients met study criteria. Of these patients, 34.6% were reversed because of intracranial hemorrhage. The mean INR decreased from 5.7 ± 6.1 (range, 1.6-30) to 1.5 ± 0.4 (range, 1.2-2.6) after 4F-PCC administration. One patient (3.8%) received concurrent fresh frozen plasma. For patients with an initial INR greater than 5.0, the mean INR decreased from 12.0 ± 8.2 to 1.6 ± 0.5. Forty-eight hours following 4F-PCC administration, mean INR for all patients remained 1.4 ± 0.4 (range, 1.0-2.6). Of the patients, 80.8% received vitamin K over this period. Fourteen patients had a pre-4F-PCC thromboelastogram; four were hypocoagulable. Two patients had repeat thromboelastograms after 4F-PCC was given, which demonstrated normal coagulation. Of the patients with intracranial hemorrhage, 66.7% showed radiographic progression of the initial insult on post-4F-PCC head computed tomography, while only 11.1% progressed clinically. In-hospital mortality was 0%. There were no thromboembolic complications. CONCLUSION: 4F-PCC effectively reverses elevated INRs in trauma patients with warfarin-induced coagulopathy, with results lasting more than 48 hours after administration. LEVEL OF EVIDENCE: Therapeutic study, level V.

Pig models of neurodegenerative disorders: Utilization in cell replacement-based preclinical safety and efficacy studies.

An important component for successful translation of cell replacement-based therapies into clinical practice is the utilization of large animal models to conduct efficacy and/or safety cell dosing studies. Over the past few decades, several large animal models (dog, cat, nonhuman primate) were developed and employed in cell replacement studies; however, none of these models appears to provide a readily available platform to conduct effective and large-scale preclinical studies. In recent years, numerous pig models of neurodegenerative disorders were developed using both a transgenic approach as well as invasive surgical techniques. The pig model (naïve noninjured animals) was recently used successfully to define the safety and optimal dosing of human spinal stem cells after grafting into the central nervous system (CNS) in immunosuppressed animals. The data from these studies were used in the design of a human clinical protocol used in amyotrophic lateral sclerosis (ALS) patients in a Phase I clinical trial. In addition, a highly inbred (complete major histocompatibility complex [MHC] match) strain of miniature pigs is available which permits the design of comparable MHC combinations between the donor cells and the graft recipient as used in human patients. Jointly, these studies show that the pig model can represent an effective large animal model to be used in preclinical cell replacement modeling. This review summarizes the available pig models of neurodegenerative disorders and the use of some of these models in cell replacement studies. The challenges and potential future directions in more effective use of the pig neurodegenerative models are also discussed.

An early venous abnormality: a potential cause of arteriovenous malformation recurrence.

In adults, complete surgical resection of arteriovenous malformations (AVMs) is generally curative. Recurrence of AVMs is extremely rare and most often delayed over many years. The authors report the case of a man in his 20s with rapid AVM recurrence and dual blood supply from the dura and intracerebral vessels. Early recurrence of the AVM allowed documentation of the early events associated with this recurrence. This was evidenced by the first appearance of an early vein without any signs of abnormal vasculature, suggesting that abnormality of the venous drainage system might be an inciting event in the recurrence and perhaps genesis of AVMs.

Cortical mapping and frameless stereotactic navigation in the high-field intraoperative magnetic resonance imaging suite.

Frameless stereotactic neuronavigation provides tracking of surgical instruments on radiographic images and orients the surgeon to tumor margins at surgery. Bipolar electrical stimulation mapping (ESM) delineates safe limits for resection of brain tumors adjacent to eloquent cortex. These standard techniques could complement the capability of intraoperative MR (iMR) imaging to evaluate for occult residual disease during surgery and promote more complete tumor removal. The use of frameless neuronavigation in the high-field iMR imaging suite requires that a few pieces of standard equipment be replaced by nonferromagnetic instruments. Specific use of ESM in a high-field iMR imaging suite has not been reported in the literature. To study whether frameless neuronavigation and electrical stimulation mapping could be successfully integrated in the high-field iMR imaging suite, the authors employed these modalities in 10 consecutive cases involving patients undergoing conscious craniotomy for primary brain tumors located in or adjacent to eloquent cortices. Equipment included a custom high-field MR imaging-compatible head holder and dynamic reference frame attachment, a standard MR imaging-compatible dynamic reference frame, a standard MR imaging machine with a table top that could be translated to a pedestal outside the 5-gauss line for the operative intervention, and standard neuronavigational and cortical stimulation equipment. Both ESM and frameless stereotactic guidance were performed outside the 5-gauss line. The presence of residual neoplasm was evaluated using iMR imaging; resection was continued until eloquent areas were encountered or iMR imaging confirmed complete removal of any residual tumor. Mapping identified essential language (5 patients), sensory (6), and motor (7) areas. The combined use of frameless stereotactic navigation, ESM, and iMR imaging resulted in complete radiographic resection in 7 cases and resection to an eloquent margin in 3 cases. Postoperative MR imaging confirmed final iMR imaging findings. No patient experienced a permanent new neurological deficit. Familiar techniques such as frameless navigation and ESM can be rapidly, inexpensively, safely, and effectively integrated into the high-field iMR imaging suite.