Long-Term Complication of Three-Level Cervical Artificial Total Disc Replacement: A Case Report.

Anterior cervical discectomy and fusion (ACDF) has long been the standard surgical treatment for cervical degenerative disc disease (DDD); however, cervical artificial total disc replacement (cTDR) has gained increasing recognition in recent years due to its ability to maintain a natural range of motion and lower the rate of adjacent segment disease. Although cTDR is only approved for one or two levels in the United States, it has been used for three or more levels in other countries. We present a case of a 59-year-old male patient who underwent three-level cTDR (C4-C7) in Germany and presented 10 years later with progressive paracervical pain and worsening dysphagia. Magnetic resonance imaging (MRI) and computed tomography (CT) scan showed hardware loosening, progressive loss of bone around the device, and a cyst ventral to C4-C5 with mass effect on the hypopharynx. The patient was successfully treated with posterior cervical fusion and showed improvement in neck pain. This case underscores the significance of long-term follow-up and thoughtful consideration when selecting an appropriate treatment modality for patients afflicted with cervical DDD.

Intradural Extramedullary Cavernous Malformation of the Spinal Cord with Hemorrhagic Transformation and Rapid Expansion.

Intradural extramedullary cavernous malformations in the spinal cord are rarely occurring vascular lesions. Mostly they are clinically silent unless the hemorrhagic transformation causes subarachnoid hemorrhage or neurologic deficits. We report the case of a 51-year-old man who developed a headache and weakness of the lower limb. Spinal cord magnetic resonance imaging revealed that the cause of his symptoms was a spinal intradural and extramedullary cavernous malformation with hemorrhagic transformation causing subarachnoid hemorrhage and compression of the thoracic spinal cord. Surgical decompression of the spinal cord followed by the resection of the lesion resulted in significant neurological improvement. Early diagnosis and early surgical extirpation of the lesion should be done to prevent recurrent hemorrhagic transformation and development of neurological symptoms.

Retrosigmoid transhorizontal fissure approach to lateral pontine cavernous malformation: comparison to transpetrosal presigmoid retrolabyrinthine approach.

OBJECTIVE: The retrosigmoid (RS) approach is a classic route used to access deep-seated brainstem cavernous malformation (CM). The angle of access is limited, so alternatives such as the transpetrosal presigmoid retrolabyrinthine (TPPR) approach have been used to overcome this limitation. Here, the authors evaluated a modification to the RS approach, horizontal fissure dissection by using the RS transhorizontal (RSTH) approach. METHODS: Relevant clinical parameters were evaluated in 9 patients who underwent resection of lateral pontine CM. Cadaveric dissection was performed to compare the TPPR approach and the RSTH approach. RESULTS: Five patients underwent the TPPR approach, and 4 underwent the RSTH approach. Dissection of the horizontal fissure allowed for access to the infratrigeminal safe entry zone, with a direct trajectory to the middle cerebellar peduncle similar to that used in TPPR exposure. Operative time was longer in the TPPR group. All patients had a modified Rankin Scale score ≤ 2 at the last follow-up. Cadaveric dissection confirmed increased anteroposterior working angle and middle cerebellar peduncle exposure with the addition of horizontal fissure dissection. CONCLUSIONS: The RSTH approach leads to a direct lateral path to lateral pontine CM, with similar efficacy and shorter operative time compared with more extensive skull base exposure. The RSTH approach could be considered a valid alternative for resection of selected pontine CM.

Surgical Trapping of a Large Complex Middle Cerebral Artery Aneurysm With Double-Barrel Bypass: 3-Dimensional Operative Video.

Large middle cerebral artery (MCA) bifurcation aneurysms are known vascular lesions that are usually symptomatic but often difficult to treat (whether with open or endovascular techniques), especially when the M2 branches originate from the aneurysm dome.1-7 The challenge lies in securing the aneurysm while fully maintaining the flow in the vessels arising from the dome. Standard microsurgical clipping or endovascular techniques are not feasible in perfectly treating these aneurysms. Revascularization of the MCA branches with bypass and trapping of the aneurysm is often necessary. Here, we present a case of a large complex partially thrombosed right MCA bifurcation aneurysm with both the superior and the inferior divisions arising from the dome. The patient initially presented with a right MCA stroke and left hemiparesis. Using radial artery as an interposition graft, 2 bypasses-internal maxillary artery to the inferior division and superficial temporal artery to the superior division-were performed. The aneurysm was trapped and decompressed by placing clips at the M1 terminus and the M2 origins. Intraoperative angiography and postoperative NOVA (VasSol Inc.) magnetic resonance angiography (MRA) confirmed patency and excellent flow in the bypass grafts. The patient's postoperative course was uncomplicated, and at 2-mo follow-up, had significant improvement of her hemiparesis. The patient provided informed consent for the procedure.

Technical Note: Extreme Lateral Supracerebellar Approach for Resection of Superior Cerebellar Peduncle Arteriovenous Malformations.

BACKGROUND: The surgical approaches to the region of the cerebello-mesencephalic sulcus and superior cerebellar peduncle (SCP) remain a neurosurgical challenge. OBJECTIVE: To present the use of the extreme lateral supracerebellar infratentorial (SC-IT) approach to treat arteriovenous malformations (AVMs) of the SCP, which is a different entity compared to brainstem AVMs. METHODS: We treated 4 patients with SCP AVMs in the last 5 yr at our institution. The mean age was 49.7 yr. The average nidus size was 2.12 cm. Of those, 3 patients presented with hemorrhage and 1 with headache and tinnitus. Extreme lateral SC-IT approach was used in all cases. RESULTS: Complete resection was achieved in all cases as verified with postoperative angiogram. In 1 case, intraoperative rupture with intraventricular hemorrhage was encountered, and the patient required temporary external ventricular drainage. There was no permanent complication or neurological deficit. The modified Rankin Scale (at discharge or follow-up) was less than 2 in all cases. CONCLUSION: The AVMs located primarily in the SCP are distinct compared to brainstem AVMs, and their management should be different. Extreme lateral SC-IT approach should be considered as a viable alternative surgical approach for resection of these AVMs, and excellent surgical results can be achieved.

Near Total Versus Gross Total Resection of Large Vestibular Schwannomas: Facial Nerve Outcome.

BACKGROUND: Large vestibular schwannomas (VSs) with brainstem compression are generally reserved for surgical resection. Surgical aggressiveness must be balanced with morbidity from cranial nerve injury. The purpose of the present investigation is to evaluate the clinical presentation, management modality, and patient outcomes following near total resection (NTR) vs gross total resection (GTR) of large VSs. OBJECTIVE: To assess facial nerve outcome differences between GTR and NTR patient cohorts. METHODS: Between January 2010 and March 2018, a retrospective chart review was completed to capture patients continuously who had VSs with Hannover grades T4a and T4b. NTR was decided upon intraoperatively. Primary data points were collected, including preoperative symptoms, tumor size, extent of resection, and postoperative neurological outcome. RESULTS: A total of 37 patients underwent surgery for treatment of large and giant (grade 4a and 4b) VSs. Facial nerve integrity was preserved in 36 patients (97%) at the completion of surgery. A total of 27 patients underwent complete resection, and 10 had near total (>95%) resection. Among patients with GTR, 78% (21/27) had House-Brackmann (HB) grade I-II facial nerve function at follow-up, whereas 100% (10/10) of the group with NTR had HB grade I-II facial nerve function. Risk of meningitis, cerebrospinal fluid leak, and sinus thromboses were not statistically different between the 2 groups. There was no stroke, brainstem injury, or death. The mean follow-up was 36 mo. CONCLUSION: NTR seems to offer a benefit in terms of facial nerve functional outcome compared to GTR in surgical management of large VSs without significant risk of recurrence.

Resection of a Posterior Fossa Endodermal Cyst With Exoscopic Assistance: 2-Dimensional Operative Video.

Neurenteric cysts are rare benign congenital tumors of endodermal origin that most commonly occur in the cervical and upper thoracic spine, with only about 10% to 18% of the reported cases occurring intracranially.1 A definitive preoperative diagnosis is complicated by the variable appearance of neurenteric cysts on magnetic resonance (MR) imaging.2 The recommended treatment of neurenteric cysts is complete surgical resection when possible.3,4 We present a case of a posterior fossa neurenteric cyst. A 33-yr-old man without medical history presented with left-sided headache and mild left-sided facial numbness and weakness. Admission MR imaging revealed a nonenhancing mass, which was hyperintense on T1-weighted MR images, compressing the brainstem anteriorly. The lesion was isointense on T2 FLAIR images and hypointense on diffusion-weighted imaging, initially read as possible epidermoid cyst. The patient underwent a left-sided retrosigmoid craniotomy via far lateral transcondylar approach. The tumor was adjacent to both vertebral arteries, the left PICA, and cranial nerves (CN) VII-XII with superior extension to CN V. The cyst was encased in a thin capsule, and its contents were yellowish in color and ranged from thick liquid to colloidal and caseous consistency. The cyst also contained heavily calcified portions, which were excised using sharp dissection. Images of the cyst wall show that it is focally lined with ciliated columnar epithelium with intracellular mucin confirming an endodermal or neurenteric cyst. After the operation, the patient's symptoms resolved, and he was discharged on postoperative day 4. Postoperative MR images confirmed gross total resection. The patient consented to video production.

Surgical Resection of a Complex Spetzler-Martin Grade IV Medial Sylvian Arteriovenous Malformation: 3-Dimensional Operative Video.

Sylvian arteriovenous malformations (AVMs) are challenging lesions for surgical management. They are classified according to the Sugita classification based on the location of the nidus in the sylvian fissure: pure, lateral, medial, and deep. Resection of these lesions are fraught with risks, as it requires extensive arachnoid dissection in the sylvian fissure in close proximity to surrounding eloquent tissue, and the presence of en passage arteries can resemble feeding arteries. In this video illustration, the authors describe a complex, Spetzler-Martin Grade IV right sylvian AVM and its surgical resection. By Sugita classification, this was a medial sylvian AVM, with an associated flow related middle cerebral artery (MCA) bifurcation aneurysm. Informed consent was obtained from the patient prior to the procedures. The AVM was embolized preoperatively, and surgical resection was carried out via a pterional approach. The detail of the AVM resection is described in the video clip. Postoperative digital subtraction angiography showed complete excision of the lesion, and the patient was discharged to home on postoperative day 6 without any neurological deficit. In 1-yr follow-up angiogram, beside complete obliteration of the AVM, the flow-related MCA bifurcation aneurysm as well as the M1 and M2 vessels have decreased in size and are much less prominent in comparison to the pretreatment angiography.

Staged Approach for Petroclival Meningioma Resection.

Introduction Petroclival meningiomas represent very uncommon and challenging tumors. Surgical morbidity is high due to the difficult and complex approaches to this area. In the present video presentation, we demonstrate a staged-approach surgical resection for petroclival meningioma. Patient and Methods A 47-year- old female was incidentally diagnosed with right sizable petroclival meningioma ( Fig. 1 ). The decision to proceed with a staged approach was made based on size and extension of the tumor to both the middle and posterior fossa. At the first stage we performed a right anterior petrosectomy with the patient in the supine position and the head turned 45 degrees to the left. Residual tumor was left behind along its inferior pole. At the second stage, 2 weeks after the 1st surgery, a right retrosigmoid craniotomy was performed with the patient placed on left park-bench position and the residual tumor was removed. The patient tolerated both stages very well without significant neurological deficits except a transient diplopia after the first stge. Postoperative magnetic resonance imaging (MRI) revealed gross total resection of the tumor. Conclusion Staged approach for petroclival meningiomas represents a safe and effective surgical management, tolerable for the patient and more comfortable for the neurosurgeon. The link to the video can be found at: https://youtu.be/QJJchjAwD5c .

Trigeminal Nerve Stimulation: A Novel Method of Resuscitation for Hemorrhagic Shock.

OBJECTIVES: To determine if trigeminal nerve stimulation can ameliorate the consequences of acute blood loss and improve survival after severe hemorrhagic shock. DESIGN: Animal study. SETTING: University research laboratory. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Severe hemorrhagic shock was induced in rats by withdrawing blood until the mean arterial blood pressure reached 27 ± 1 mm Hg for the first 5 minutes and then maintained at 27 ± 2 mm Hg for 30 minutes. The rats were randomly assigned to either control, vehicle, or trigeminal nerve stimulation treatment groups. The effects of trigeminal nerve stimulation on survival rate, autonomic nervous system activity, hemodynamics, brain perfusion, catecholamine release, and systemic inflammation after severe hemorrhagic shock in the absence of fluid resuscitation were analyzed. MEASUREMENTS AND MAIN RESULTS: Trigeminal nerve stimulation significantly increased the short-term survival of rats following severe hemorrhagic shock in the absence of fluid resuscitation. The survival rate at 60 minutes was 90% in trigeminal nerve stimulation treatment group whereas 0% in control group (p < 0.001). Trigeminal nerve stimulation elicited strong synergistic coactivation of the sympathetic and parasympathetic nervous system as measured by heart rate variability. Without volume expansion with fluid resuscitation, trigeminal nerve stimulation significantly attenuated sympathetic hyperactivity paralleled by increase in parasympathetic tone, delayed hemodynamic decompensation, and improved brain perfusion following severe hemorrhagic shock. Furthermore, trigeminal nerve stimulation generated sympathetically mediated low-frequency oscillatory patterns of systemic blood pressure associated with an increased tolerance to central hypovolemia and increased levels of circulating norepinephrine levels. Trigeminal nerve stimulation also decreased systemic inflammation compared with the vehicle. CONCLUSIONS: Trigeminal nerve stimulation was explored as a novel resuscitation strategy in an animal model of hemorrhagic shock. The results of this study showed that the stimulation of trigeminal nerve modulates both sympathetic and parasympathetic nervous system activity to activate an endogenous pressor response, improve cerebral perfusion, and decrease inflammation, thereby improving survival.

Surgical outcome in smaller symptomatic vestibular schwannomas. Is there a role for surgery?

BACKGROUND: Currently, there is no consensus in the initial management of small vestibular schwannomas (VSs). They are routinely watched and/or referred for radiosurgical treatment, although surgical removal is also an option. We hereby evaluate clinical outcomes of patients who have undergone surgical removal of smaller symptomatic VSs. METHODS: Patients with vestibular schwannomas (grade T1-T3b according to Hannover classification) were reviewed. Patients with symptomatic tumors who underwent surgery were evaluated. Their preoperative hearing status was based on the guideline of the committee on hearing and equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) foundation. Their postoperative facial nerve function, hearing status, vestibular symptoms, and degree of tumor resection were assessed. RESULTS: Thirty patients were selected for surgery via a retrosigmoid approach based on their age, symptoms, and their own decision-making after discussion of management options. Most patients presented with hearing loss. Seventeen patients had useful hearing preoperatively. Among them, 10 patients (59%) preserved useful hearing (class A or B) postoperatively. MRI at 1-year follow-up confirmed complete resection in 26/29 patients. Also, 29 patients (97%) had HB grade I-II, and 1 patient had HB III at 1-year follow-up. Except for 1 patient with CSF leak, 1 patient with delayed facial nerve palsy, and 2 patients with asymptomatic sigmoid sinus occlusion, there were no other new morbidities. CONCLUSION: Although both observation and radiosurgery are valid options in the management of smaller size vestibular schwannomas, surgical treatment seems to offer a high rate of facial nerve preservation, a reasonable rate of hearing sparing, and a high total resection rate. Clinicians should consider surgical treatment as a valid option in the initial management of symptomatic small vestibular schwannomas in younger patients.

Surgical treatment of a complex Grade III Spetzler-Martin posterior temporal arteriovenous malformation.

Grade III Spetzler-Martin arteriovenous malformations (AVMs) are a distinct subgroup of brain AVMs. Their variety in terms of location, type of venous drainage, and size makes them the most heterogenous group in the AVM classification. The surgical risk of treatment is also variable depending on the specifics of a given Grade III AVM. In this video illustration, the authors describe the technical nuances of surgical resection of a very complex Grade III left posterior temporal AVM. According to supplementary grading, the unruptured aspect and patient age give this lesion a Grade III; therefore, the combined grading gives the patient a score of 6, which puts him at moderate risk of morbidity for surgery. The indication for surgery was based on the patient's young age, lifetime risk of hemorrhage, and the location of the AVM in the left inferior/posterior temporal gyrus. The patient underwent 2 sessions of preoperative embolization of the posterior cerebral artery and the external carotid artery feeders prior to craniotomy. The day after the second embolization, the patient was operated on via a posterior temporobasal craniotomy. The dural supply attached to the draining vein was left intact during the dural exposure. The detail of the AVM resection is described in the video clip. A total resection was achieved, and the patient's neurological examination was intact after the procedure. The video can be found here: https://youtu.be/fj5Cxw3kpXQ .

Neuroprotective Effects of Trigeminal Nerve Stimulation in Severe Traumatic Brain Injury.

Following traumatic brain injury (TBI), ischemia and hypoxia play a major role in further worsening of the damage, a process referred to as 'secondary injury'. Protecting neurons from causative factors of secondary injury has been the guiding principle of modern TBI management. Stimulation of trigeminal nerve induces pressor response and improves cerebral blood flow (CBF) by activating the rostral ventrolateral medulla. Moreover, it causes cerebrovasodilation through the trigemino-cerebrovascular system and trigemino-parasympathetic reflex. These effects are capable of increasing cerebral perfusion, making trigeminal nerve stimulation (TNS) a promising strategy for TBI management. Here, we investigated the use of electrical TNS for improving CBF and brain oxygen tension (PbrO2), with the goal of decreasing secondary injury. Severe TBI was produced using controlled cortical impact (CCI) in a rat model, and TNS treatment was delivered for the first hour after CCI. In comparison to TBI group, TBI animals with TNS treatment demonstrated significantly increased systemic blood pressure, CBF and PbrO2 at the hyperacute phase of TBI. Furthermore, rats in TNS-treatment group showed significantly reduced brain edema, blood-brain barrier disruption, lesion volume, and brain cortical levels of TNF-α and IL-6. These data provide strong early evidence that TNS could be an effective neuroprotective strategy.

A User-Configurable Headstage for Multimodality Neuromonitoring in Freely Moving Rats.

Multimodal monitoring of brain activity, physiology, and neurochemistry is an important approach to gain insight into brain function, modulation, and pathology. With recent progress in micro- and nanotechnology, micro-nano-implants have become important catalysts in advancing brain research. However, to date, only a limited number of brain parameters have been measured simultaneously in awake animals in spite of significant recent progress in sensor technology. Here we have provided a cost and time effective approach to designing a headstage to conduct a multimodality brain monitoring in freely moving animals. To demonstrate this method, we have designed a user-configurable headstage for our micromachined multimodal neural probe. The headstage can reliably record direct-current electrocorticography (DC-ECoG), brain oxygen tension (PbrO2), cortical temperature, and regional cerebral blood flow (rCBF) simultaneously without significant signal crosstalk or movement artifacts for 72 h. Even in a noisy environment, it can record low-level neural signals with high quality. Moreover, it can easily interface with signal conditioning circuits that have high power consumption and are difficult to miniaturize. To the best of our knowledge, this is the first time where multiple physiological, biochemical, and electrophysiological cerebral variables have been simultaneously recorded from freely moving rats. We anticipate that the developed system will aid in gaining further insight into not only normal cerebral functioning but also pathophysiology of conditions such as epilepsy, stroke, and traumatic brain injury.

The Implication of Anterior Communicating Complex Rotation and 3-Dimensional Computerized Tomography Angiography Findings in Surgical Approach to Anterior Communicating Artery Aneurysms.

BACKGROUND: To investigate the usefulness of 3-dimensional computerized tomography angiography (3D-CTA) in the microsurgical management of anterior communicating artery (AcomA) aneurysms. METHODS: Twenty-six consecutive patients with AcomA aneurysms (22 ruptured) underwent microsurgical clipping. Detailed angioanatomic assessment of the AcomA complex and operative approach was based on the 3D-CTA. RESULTS: The 3D-CTA showed a dominant proximal anterior cerebral artery (A1) segment in 61% and symmetric A1s in 39% of aneurysms. Dominant A1 segments presented with rotation of the AcomA complex toward the contralateral side in 63%, toward the ipsilateral side in 25%, and without rotation in 12%. With symmetric A1s, the AcomA was parallel to the coronal plane in 90% and a right-sided approach was carried out in these patients. In rotated AcomA complexes, the virtual 3D views were compared to determine the side of the approach. For superior projecting aneurysms, we determined that the approach from the side in which the A1-distal anterior cerebral artery (posterior communicating) angle was posterior was more favorable. For posterior projecting aneurysms, the approach from the side where the A1-distal anterior cerebral artery (posterior communicating) angle was more anterior was more favorable. For anteroinferior projecting aneurysms, an approach from the dominant A1 side was chosen regardless of AcomA complex rotation. Postoperative 3D-CTA showed complete exclusion of 24 aneurysms (>92%) and 2 small remnants (<2 mm). Outcome was excellent or good (modified Rankin score 0-2) in 88% of patients. CONCLUSIONS: Rotation of the AcomA complex and dome projection are important angioanatomic elements in determining the surgical exposure and side of the approach. This study illustrates the role of 3D-CTA in the management of these difficult lesions by individualizing the surgical approach.

Neuro-oncology biotech industry progress report.

The Brain Tumor Biotech Center at the Feinstein Institute for Medical Research, in collaboration with Voices Against Brain Cancer hosted The Brain Tumor Biotech Summit at in New York City in June 2015. The focus was once again on fostering collaboration between neuro-oncologist, neurosurgeons, scientists, leaders from biotechnology and pharmaceutical industries, and members of the financial community. The summit highlighted the recent advances in the treatment of brain tumor, and specifically focused on targeting of stem cells and EGFR, use of prophage and immunostimulatory vaccines, retroviral vectors for drug delivery, biologic prodrug, Cesium brachytherapy, and use of electric field to disrupt tumor cell proliferation. This article summarizes the current progress in brain tumor research as presented at 2015 The Brain Tumor Biotech Summit.

Development of a brain monitoring system for multimodality investigation in awake rats.

Multimodal brain monitoring is an important approach to gain insight into brain function, modulation, and pathology. We have developed a unique micromachined neural probe capable of real-time continuous monitoring of multiple physiological, biochemical and electrophysiological variables. However, to date, it has only been used in anesthetized animals due to a lack of an appropriate interface for awake animals. We have developed a versatile headstage for recording the small neural signal and bridging the sensors to the remote sensing units for multimodal brain monitoring in awake rats. The developed system has been successfully validated in awake rats by simultaneously measuring four cerebral variables: electrocorticography, oxygen tension, temperature and cerebral blood flow. Reliable signal recordings were obtained with minimal artifacts from movement and environmental noise. For the first time, multiple variables of cerebral function and metabolism were simultaneously recorded from awake rats using a single neural probe. The system is envisioned for studying the effects of pharmacologic treatments, mapping the development of central nervous system diseases, and better understanding normal cerebral physiology.