Factors affecting the extent of resection and neurological outcomes following transopercular resection of insular gliomas.

BACKGROUND: Surgical resection of insular gliomas is a challenge. TO resection is considered more versatile and has lower risk of vascular damage. In this study, we aimed to understand the factors that affect resection rates, ischemic changes and neurological outcomes and studied the utility of IONM in patients who underwent TO resection for IGs. METHODS: Retrospective analysis of 66 patients with IG who underwent TO resection was performed. RESULTS: Radical resection was possible in 39% patients. Involvement of zone II and the absence of contrast enhancement predicted lower resection rate. Persistent deficit rate was 10.9%. Although dominant lobe tumors increased immediate deficit and fronto-orbital operculum involvement reduced prolonged deficit rate, no tumor related factor showed significant association with persistent deficits. 45% of patients developed a postoperative infarct, 53% of whom developed deficits. Most affected vascular territory was lenticulostriate (39%). MEP changes were observed in 9/57 patients. 67% of stable TcMEPs and 74.5% of stable strip MEPs did not develop any postoperative motor deficits. Long-term deficits were seen in 3 and 6% patients with stable TcMEP and strip MEPs respectively. In contrast, 25% and 50% of patients with reversible strip MEP and Tc MEP changes respectively had persistent motor deficits. DWI changes were clinically more relevant when accompanied by MEP changes intraoperatively, with persistent deficit rates three times greater when MEP changes occurred than when MEPs were stable. CONCLUSION: Radical resection can be achieved in large, multizone IGs, with reasonable outcomes using TO approach and multimodal intraoperative strategy with IONM.

Tumor location and neurocognitive function-Unravelling the association and identifying relevant anatomical substrates in intra-axial brain tumors.

Background: Neurocognitive function is a key outcome indicator of therapy in brain tumors. Understanding the underlying anatomical substrates involved in domain function and the pathophysiological basis of dysfunction can help ameliorate the effects of therapy and tailor directed rehabilitative strategies. Methods: Hundred adult diffuse gliomas were co-registered onto a common demographic-specific brain template to create tumor localization maps. Voxel-based lesion symptom (VLSM) technique was used to assign an association between individual voxels and neuropsychological dysfunction in various domains (attention and executive function (A & EF), language, memory, visuospatial/constructive abilities, and visuomotor speed). The probability maps thus generated were further co-registered to cortical and subcortical atlases. A permutation-based statistical testing method was used to evaluate the statistically and clinically significant anatomical parcels associated with domain dysfunction and to create heat maps. Results: Neurocognition was affected in a high proportion of subjects (93%), with A & EF and memory being the most affected domains. Left-sided networks were implicated in patients with A & EF, memory, and language deficits with the perisylvian white matter tracts being the most common across domains. Visuospatial dysfunction was associated with lesions involving the right perisylvian cortical regions, whereas deficits in visuomotor speed were associated with lesions involving primary visual and motor output pathways. Conclusions: Significant baseline neurocognitive deficits are prevalent in gliomas. These are multidomain and the perisylvian network especially on the left side seems to be very important, being implicated in dysfunction of many domains.

Microvascular Decompression for Trigeminal Neuralgia Caused by Vascular Compression on the Trigeminal Sensory Nucleus and Descending Trigeminal Tract.

BACKGROUND: Trigeminal neuralgia (TN) is characterized by paroxysmal episodes of severe shocklike orofacial pain typically resulting from arterial compression on the trigeminal root entry zone. However, neurovascular conflict in more proximal parts of the trigeminal pathway within the pons is extremely rare. METHODS: The authors present a case of microvascular decompression for TN caused by dual arterial compression on the dorsolateral pons, along with a brief literature review. RESULTS: Our patient was a 74-year-old man with episodic left-sided facial stabbing pain. Brain magnetic resonance imaging revealed a dual arterial compression on dorsolateral pons, the known site of the trigeminal sensory nucleus and descending trigeminal tract. Microvascular decompression was performed via a retrosigmoid approach. Complete pain relief and partial improvement of the facial hypesthesia were achieved immediately after surgery and the Barrow Neurological Institute (BNI) pain intensity score improved from V to I, and the BNI hypesthesia score decreased from III to II within a month following surgery. The literature review identified 1 case of TN secondary to an arteriovenous malformation in root entry zone with lateral pontine extension. One month following partial coagulation of the draining vein, the patient was reportedly able to reduce medication dosage by half to achieve an improvement of BNI pain intensity score from V to IIIa. CONCLUSIONS: Neurovascular compression in the trigeminal tract and nucleus is a rare but potential cause of TN. A thorough investigation of the trigeminal pathway should be considered during preoperative evaluation and intraoperative inspection, particularly if no clear offending vessel is identified.

Vision Loss Following Vertebral Artery Injury during Surgery for Atlantoaxial Instability.

Background: A number of complications following surgery aimed at atlantoaxial fixation have been reported. However, there is no report in the literature describing visual loss following vertebral artery injury. Objective: Vision loss as a complication of vertebral artery injury during surgery for atlantoaxial fixation is reported. Material and Methods: This is a report of two patients who were operated for atlantoaxial instability by the Goel technique of atlantoaxial fixation. During surgery, there was an injury to the vertebral artery and the artery had to be sacrificed. Results: Both patients suffered severe visual loss following surgery. One patient had a partial visual recovery that started within few days of surgery while the other patient remained completely blind. Conclusions: Although rare, visual loss can be a complication of vertebral artery sacrifice during surgery for atlantoaxial stabilization.

Report of an eight-year experience with Camille's transarticular technique of cervical spinal stabilization.

We present our experience with Camille's cervical transarticular screw fixation technique. During the period June 2012 to April 2020, 2422 screws were implanted in 321 patients by Camille's transarticular cervical spinal screw fixation technique. The indications of screw implantation were radiculopathy/myelopathy related to cervical spondylosis in 258 cases, cervical OPLL in 54 cases and Hirayama disease in 9 cases. The follow-up ranged from 6 to 92 months. In the entire series, there were no nerve or vessel injury or any other intraoperative 'complications' related to screw implantation. There was no instance of screw pull out or screw failure. There was no metal implant related infection. Satisfactory arthrodesis of all the treated spinal segments was observed on investigations done at a minimum follow-up of 6 months. Camille's transarticular screw fixation technique is a relatively simple surgical procedure and provides a safe, strong and reliable arthrodesis at the fulcrum of spinal movements.

Transarticular Fixation Following Mobilization of "High-Riding" Vertebral Artery.

BACKGROUND AND IMPORTANCE: The article identifies the feasibility of transarticular screw fixation after mobilizing the vertebral artery in cases where it is in a "high-riding" location. CLINICAL PRESENTATION: A 42-yr-old male patient had a 4-yr history of progressive quadriparesis. Investigations revealed severe basilar invagination. There was assimilation of atlas and C2-3 fusion. The vertebral artery was "high-riding" into the pedicle-facet of C2 vertebra on both sides. Vertebral artery loop was exposed and mobilized inferiorly on both sides after careful drilling of pedicular bone on the posterior aspect of the dome of the artery. C2 facetal bone on the anterior face of the vertebral artery dome was now available for screw insertion. The C1-2 facets and the articulation were directly in line, making transarticular screw fixation relatively straightforward. The wide bone space available permitted insertion of 2 screws in a transarticular fashion on both sides. The patient had satisfactory clinical improvement. Imaging after 22 mo showed bone fusion across the facets. CONCLUSION: Mobilization of the high-riding vertebral artery loop can help salvage the surgical procedure of lateral mass stabilization.

Outcome of Osteophytes After Only-Fixation as Treatment for Multilevel Cervical Spondylosis-A Minimum of 12 Months Follow-Up.

OBJECTIVE: This report analyzes the significance of osteophytes in the overall pathologic scheme in patients with single-level or multilevel cervical spinal degeneration. METHODS: From January 2010 to December 2018, 249 patients with cervical spondylosis were surgically treated. The alterations in ventral compression caused by disc bulges, osteophytes, and ligament buckling (disc-osteophye-ligament [DOL] complex) at single or multiple levels were evaluated after surgical treatment that involved only spinal fixation and did not involve any kind of bone or soft tissue decompression. Delayed (≥1 year after surgery) postoperative imaging was available in 165 patients and these patients formed the study group. Forty-five patients underwent facet distraction arthrodesis (group A), 106 patients underwent only-fixation involving transarticular screw insertion (group B), and 14 patients underwent hybrid fixation that involved both intra-articular spacers and transarticular fixation techniques (group C) as the surgical treatment. RESULTS: The size of the DOL complex at the segments that underwent fixation was reduced in 136 patients. The size of the DOL complex or its related dural or neural compression did not increase in any of the cases evaluated. Reduction in the size of DOL was more pronounced in patients in group A in both immediate postoperative and delayed images and in patients in group C at spinal levels at which facet distraction was performed using facet distraction spacers. CONCLUSIONS: Spinal stabilization reduces the size of osteophytes. Facet distraction spacers are more effective in reduction of the size of DOL in both immediate and delayed postoperative periods.

Atlantoaxial Instability as a Cause of Craniovertebral and Cervical Spinal Alterations and Dorsal Kyphoscoliosis.

BACKGROUND: Musculoskeletal and neural alterations secondary to chronic atlantoaxial instability are evaluated. CASE DESCRIPTION: An 11-year-old girl presented with major symptoms of progressively worsening dorsal kyphoscoliosis (spinal kyphoscoliosis [SKS]). In addition to dorsal SKS, investigations revealed multiple craniovertebral and cervical spinal musculoskeletal abnormalities, Chiari formation, and syringomyelia. Dynamic imaging revealed atlantoaxial instability. Atlantoaxial stabilization resulted in rapid improvement in SKS, regression of tonsillar herniation, and resolution of syrinx. CONCLUSIONS: The experience with the case showcases wide ranged spinal consequences as a result of chronic atlantoaxial instability.

Ossified Anterior Foramen Magnum Meningioma: Report of Long-Term Surgical Outcome.

BACKGROUND: Technical surgery-related issues for large ossified/calcified meningioma that encased one or both vertebral arteries located anterior to brainstem in the region of foramen magnum are discussed. Relatively long-term outcome of successful surgery is reported. CASE DESCRIPTION: Three women were operated on for symptoms of progressive quadriparesis. Investigations revealed ossified meningioma located anterior to the brainstem. One or both vertebral arteries were encased within the confines of the tumor. Large size, bone-hard consistency, location anterior to the brainstem, and intimate vascular relationship made the surgery a formidable surgical problem. A midline posterior suboccipital approach was used to resect these tumors. Radical tumor resection was achieved in all cases successfully. Tumor drilling or heavy tumor breaking instruments were not necessary to debulk the tumor. Histologic examination in all 3 cases revealed psammomatous meningioma. During the follow-up period that ranged from 2 to 12 years, all 3 patients were leading a normal life, and there has been no documented recurrence in any case. CONCLUSIONS: Successful resection of "ossified" meningioma is associated with satisfactory long-term clinical outcome.