Endoscopic transorbital superior eyelid approach: anatomical study from a neurosurgical perspective

J Neurosurg 129:1203–1216, 2017

Recent studies have proposed the superior eyelid endoscopic transorbital approach as a new minimally invasive route to access orbital lesions, mostly in otolaryngology and maxillofacial surgeries. The authors undertook this anatomical study in order to contribute a neurosurgical perspective, exploring the anterior and middle cranial fossa areas through this purely endoscopic transorbital trajectory.

METHODS Anatomical dissections were performed in 10 human cadaveric heads (20 sides) using 0° and 30° endoscopes. A step-by-step description of the superior eyelid transorbital endoscopic route and surgically oriented classification are provided.

RESULTS The authors’ cadaveric prosection of this approach defined 3 modular routes that could be combined. Two corridors using bone removal lateral to the superior and inferior orbital fissures exposed the middle and anterior cranial fossa (lateral orbital corridors to the anterior and middle cranial base) to unveil the temporal pole region, lateral wall of the cavernous sinus, middle cranial fossa floor, and frontobasal area (i.e., orbital and recti gyri of the frontal lobe). Combined, these 2 corridors exposed the lateral aspect of the lesser sphenoid wing with the Sylvian region (combined lateral orbital corridor to the anterior and middle cranial fossa, with lesser sphenoid wing removal). The medial corridor, with extension of bone removal medially to the superior and inferior orbital fissure, afforded exposure of the opticocarotid area (medial orbital corridor to the opticocarotid area).

CONCLUSIONS Along with its minimally invasive nature, the superior eyelid transorbital approach allows good visualization and manipulation of anatomical structures mainly located in the anterior and middle cranial fossae (i.e., lateral to the superior and inferior orbital fissures). The visualization and management of the opticocarotid region medial to the superior orbital fissure are more complex. Further studies are needed to prove clinical applications of this relatively novel surgical pathway.

 

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

Acta Neurochirurgica (2018) 160:2263–2275

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 equilibriumof 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.

Esthesioneuroblastoma: A Patterns-of-Care and Outcomes Analysis of the National Cancer Database

Neurosurgery 83:940–947, 2018

BACKGROUND: The available literature to guide treatment decision making in esthesioneuroblastoma (ENB) is limited.

OBJECTIVE: To define treatment patterns and outcomes in ENB according to treatment modality using a large national cancer registry.

METHODS: This study is a retrospective cohort analysis of 931 patients with a diagnosis of ENB who were treated with surgery, radiation therapy, and/or chemotherapy in the United States between the years of 2004 and 2012. Log-rank statisticswere used to compare overall survival by primary treatment modality. Logistic regression modeling was used to identify predictors of receipt of postoperative radiotherapy (PORT). Cox proportional hazardsmodeling was used to determine the survival benefit of PORT. Subgroup analyses identified subgroups that derived the greatest benefit of PORT.

RESULTS: Primary surgery was the most common treatment modality (90%) and resulted in superior survival compared to radiation (P < .01) or chemotherapy (P < .01). On multivariate analysis, PORT was associated with decreased risk of death (hazard ratio [HR] 0.53, P<.01). PORT showed a survival benefit in Kadish stage C (HR 0.42, P<.01) and D (HR 0.09, P = .01), but not Kadish A (HR 1.17, P = .74) and B (HR 1.37, P = .80). Patients who received chemotherapy derived greater benefit from PORT (HR 0.22, P < .01) compared with those who did not (HR 0.68, P=.13). Predictors of PORT included stage, grade, extent of resection, and chemotherapy use.

CONCLUSION: Best outcomes were obtained in patients undergoing primary surgery. The benefit of PORT was driven by patients with stages C and D disease, and by those also receiving chemotherapy.

 

Telemetry in intracranial pressure monitoring: sensor survival and drift

Acta Neurochirurgica (2018) 160:21372144

Telemetric intracranial pressure (ICP) monitoring enable long-term ICP monitoring on patients during normal day activities and may accordingly be of use during evaluation and treatment of complicated ICP disorders. However, the benefits of such equipment depend strongly on the validity of the recordings and how often the telemetric sensor needs to be re-implanted. This study investigates the clinical and technical sensor survival time and drift of the telemetric ICP sensor: Raumedic Neurovent-P-tel.

Methods Implanted telemetric ICP sensors in the period from January 2011 to December 2017 were identified, and medical records reviewed for complications, explantation reasons, and parameters relevant for determining clinical and technical sensor survival time. Explanted sensors were tested in an experimental setup to study baseline drift.

Results In total, implantation of 119 sensors were identified. Five sensors (4.2%) were explanted due to skin dResultsamage, three (2.5%) due to wound infection, and two (1.7%) due to ethylene oxide allergy. No other complications were observed. The median clinical sensor survival time was 208 days (95% CI 150–382). The median technical sensor survival time was 556 days (95% CI 382–605). Explanted sensors had a median baseline drift of 2.5 mmHg (IQR 2.0–5.5).

Conclusion In most cases, the ICP sensor provides reliable measurements beyond the approved implantation time of 90 days. Thus, the sensor should not be routinely removed after this period, if ICP monitoring is still indicated. However, some sensors showed technical malfunction prior to the CE-approval, underlining that caution should always be taken when analyzing telemetric ICP curves.

 

Image-Guided Robotic Radiosurgery for Trigeminal Neuralgia

Neurosurgery 83:1023–1030, 2018

Frameless, non-isocentric irradiation of an extended segment of the trigeminal nerve introduces new concepts in stereotactic radiosurgery for medically resistant trigeminal neuralgia (TN).

OBJECTIVE: To report the results of the largest single-center experience about imageguided robotic radiosurgery for TN.

METHODS: A cohort of 138 patients treated with CyberKnife®  (Accuray Incorporated, Sunnyvale, California) radiosurgery with a minimum follow-up of 36 mo were recruited. Pain relief, medications, sensory disturbances, rate and time of pain recurrence were prospectively analyzed.

RESULTS: Median follow-up was 52.4 mo; median dose 75 Gy; median target length 5.7- mm; median target volume 40 mm3; median prescription dose 60 Gy (80% isodose line). Actuarial pain control rate (Barrow Neurological Institute [BNI] class I-IIIa) at 6, 12, 24, and 36 mo were 93.5%, 85.8%, 79.7%, and 76%, respectively. Overall, 33 patients (24%) required a second treatment. Overall, 18.1% developed sensory disturbances after 16.4 ± 8.7 mo. One patient (0.7%) developed BNI grade IV dysfunction; 6 (4.3%) developed BNI grade III (somewhat bothersome) hypoesthesia after retreatment; BNI grade II (not bothersome) hypoesthesia was reported by 18 patients (11 after retreatment). Shorter nerve length (<6mmvs 6 mm), smaller nerve volume (<30mm3 vs>30mm3), and lower prescription dose (<58 vs>58 Gy) were associated with treatment failure (P=.01, P=.02, P=.03, respectively). Re-irradiation independently predicted sensory disturbance (P < .001).

CONCLUSION: Targeting a 6-mm segment of the trigeminal nerve with a prescribed dose of 60 Gy appears safe and effective. Persistent pain control was achieved in most patients with acceptable risk of sensory complications, which were typically found after re-irradiation.

KEYWORDS: Trigeminal neuralgia, Pain, Stereotactic radiosurgery, Robotic, Image-guided, CyberKnife

 

Long-Term Outcome Following Stereotactic Radiosurgery for Glomus Jugulare Tumors

Neurosurgery 83:1007–1014, 2018

Glomus jugulare tumors (GJTs) are rare benign tumors, which pose significant treatment challenges due to proximity to critical structures.

OBJECTIVE: To evaluate the long-term clinical and radiological outcomein patients undergoing stereotactic radiosurgery (SRS) for GJTs through retrospective study.

METHODS: Forty-two patientswith 43 GJTswere treated using Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden) at our institute from 1997 to 2016. Clinical, imaging, and radiosurgery data were collected from an institutional review board approved database.

RESULTS: Most patients were females (n = 35, 83.3%) and median age was 61 yr (range 23- 88 yr).Median tumor volume and diameterwere 5 cc and 3 cm, respectively,with a median follow-up of 62.3 mo (3.4-218.6 mo). Overall, 20 patients (47.6%) improved clinically and 14 (33.3%) remained unchanged at last follow-up. New onset or worsening of hearing loss was noted in 6 patients (17.2%) after SRS. The median prescription dose to the tumor margin was 15 Gy (12-18 Gy). Median reduction in tumor volume and maximum tumor diameter at last follow-up was 33.3% and 11.54%, respectively. The 5-yr and 10-yr tumor control rates were 87%±6% and 69%±13%, respectively. There was no correlation between maximum or mean dose to the internal acoustic canal and post-GK hearing loss (P > .05).

CONCLUSION: SRS is safe and effective in patients with GJTs and results in durable, longterm control. SRS has lower morbidity than that associated with surgical resection, particularly lower cranial nerve dysfunction, and can be a first-line management option in these patients.

Supratotal Resection of Diffuse Frontal Lower Grade Gliomas with Awake Brain Mapping, Preserving Motor, Language, and Neurocognitive Functions

World Neurosurg. (2018) 119:3039

Extended margin tumor resection beyond the abnormal area detected by magnetic resonance imaging, defined as supratotal resection, could improve the out- comes of patients with lower grade gliomas (LGGs). The aim of the present study was to assess the surgical outcomes of awake brain mapping to achieve supratotal resection with determination of the normal brain tissue boundaries beyond the tumor of frontal LGGs, in both dominant and nondominant hemispheres.

METHODS: We analyzed the data from 9 patients with diffuse frontal LGGs who had undergone supratotal resection with awake surgery from January 2016 to November 2017.

RESULTS: The frontal aslant tract was identified as the functional boundary in 4 of 5 left frontal tumor cases (80%). Working memory impairments during dorsolateral prefrontal cortex stimulation with digit span and/or visual N-back tasks were detected in all 4 patients (100%) with right-frontal tumor. The neurocognitive outcomes were significantly improved after surgery, as shown by the mean Wechsler adult intelligence scale III scores for verbal in- telligence quotient (P [ 0.04) and verbal comprehension (P [ 0.03) and the mean Wechsler memory scale-revised scores for generalized memory (P [ 0.04) and delayed recall (P [ 0.04).

CONCLUSIONS: The results of the present study have provided evidence that awake mapping can enable the preservation of higher neurocognitive function, including working memory and spatial cognition in patients with nondominant right frontal tumors. Despite the small number of cases, our findings suggest the surgical benefit of awake surgery for supratotal resection of diffuse frontal LGGs.

Conscious sedation with dexmedetomidine compared with asleep-awake-asleep craniotomies in glioma surgery

J Neurosurg 129:1223–1230, 2018

Awake craniotomies have become a feasible tool over time to treat brain tumors located in eloquent regions. Different techniques have been applied in neurooncology centers. Both “asleep-awake-asleep” (asleep) and “conscious sedation” were used subsequently at the authors’ neurosurgical department. Since 2013, the authors have only performed conscious sedation surgeries, predominantly using the alfa2-receptor agonist dexmedetomidine as the anesthetic drug. The aim of this study was to compare both mentioned techniques and evaluate the clinical use of dexmedetomidine in the setting of awake craniotomies for glioma surgery.

METHODS The authors retrospectively analyzed patients who underwent operations either under the asleep condition using propofol-remifentanil or under conscious sedation conditions using dexmedetomidine infusions. In the asleep group patients were intubated with a laryngeal mask and extubated for the assessment period. Adverse events, as well as applied drugs with doses and frequency of usage, were recorded.

RESULTS From 224 awake surgeries between 2009 and 2015, 180 were performed for the resection of gliomas and included in the study. In the conscious sedation group (n = 75) significantly fewer opiates (p < 0.001) and vasoactive (p < 0.001) and antihypertensive (p < 0.001) drugs were used in comparison with the asleep group (n = 105). Furthermore, the postoperative length of stay (p < 0.001) and the surgical duration (p < 0.001) were significantly lower in the conscious sedation group.

CONCLUSIONS Use of dexmedetomidine creates excellent conditions for awake surgeries. It sedates moderately and acts as an anxiolytic. Thus, after ceasing infusion it enables quick and reliable clinical neurological assessment of patients. This might lead to reducing the amount of administered antihypertensive and vasoactive drugs as well as the length of hospitalization, while likely ensuring more rapid surgery.

 

Decision Making in theWait-and-Scan Approach for Vestibular Schwannomas: Is There a Price to Pay in Terms of Hearing, Facial Nerve, and Overall Outcomes?

Neurosurgery 83:858–870, 2018

The wait-and-scan modality has emerged as an important strategy in the management of vestibular schwannoma (VS) as it has been demonstrated that many tumors grow slowly or do not show any growth over long periods.

OBJECTIVE: To analyze long-term outcomes of wait-and-scan in the treatment of patients with VS, discuss the factors contributing to the decision making, determine the inherent risks of the policy, and compare our results with literature.

METHODS: In total, 576 patients with sporadic unilateral VS who were managed with wait-and-scan were reviewed retrospectively. Of these, a subset of 154 patients with 5-yr follow-up was separately analyzed. The tumor characteristics including patterns of growth, rate of growth, hearing outcomes, and likely factors affecting the above parameters were analyzed.

RESULTS: The mean period of follow-up was 36.9 ± 30.2 mo. The mean age was 59.2 ± 11.6 yr. Thirteen different patterns of tumor growth were observed. Eighty-four (54.5%) of 154 tumors with 5-yr follow-up showed no growth throughout 5 yr. Fifty-six (36.4%) tumors showedmixed growth rates. Only 57 (37%) patients had serviceable hearing at the start of follow-up, but 32 (56.1%) maintained it at the end of follow-up. One hundred fifty (26%) of the 576 patients who failed wait-and-scan had to be taken up for surgery.

CONCLUSION: While there may be no price to pay in wait-and-scan as far as hearing is concerned, this may not be the case for facial nerve outcomes, wherein the results may be better if the patients are taken earlier for surgery.

Outcomes of Operative Treatment for Adult Cervical Deformity

Neurosurgery 83:1031–1039, 2018

Despite the potential for profound impact of adult cervical deformity (ACD) on function and health-related quality of life (HRQOL), there are few high-quality studies that assess outcomes of surgical treatment for these patients.

OBJECTIVE: To determine the impact of surgical treatment for ACD on HRQOL.

METHODS: We conducted a prospective cohort study of surgically treated ACD patients eligible for 1-yr follow-up. Baseline deformity characteristics, surgical parameters, and 1-yr HRQOL outcomes were assessed.

RESULTS: Of 77 ACD patients, 55 (71%) had 1-yr follow-up (64% women, mean age of 62 yr, mean Charlson Comorbidity Index of 0.6, previous cervical surgery in 47%). Diagnoses included cervical sagittal imbalance (56%), cervical kyphosis (55%), proximal junctional kyphosis (7%) and coronal deformity (9%). Posterior fusion was performed in 85% (mean levels = 10), and anterior fusion was performed in 53% (mean levels = 5). Three-column osteotomy was performed in 24%of patients.One year following surgery, ACD patients had significant improvement in Neck Disability Index (50.5 to 38.0, P<.001), neck pain numeric rating scale score (6.9 to 4.3, P<.001), EuroQol 5 dimension (EQ-5D) index (0.51 to 0.66, P< .001), and EQ-5D subscores: mobility (1.9 to 1.7, P=.019), usual activities (2.2 to 1.9, P=.007), pain/discomfort (2.4 to 2.1, P < .001), anxiety/depression (1.8 to 1.5, P = .014).

CONCLUSION: Based on a prospective multicenter series of ACD patients, surgical treatment provided significant improvement in multiple measures of pain and function, including Neck Disability Index, neck pain numeric rating scale score, and EQ-5D. Further follow-up will be necessary to assess the long-term durability of these improved outcomes.

 

Impact of aneurysm shape on morbidity after clipping of unruptured intracranial aneurysms

Acta Neurochirurgica (2018) 160:2169–2176

Complex aneurysm shape is a predominant risk factor for aneurysm rupture but its impact on clinical outcome after clipping remains unclear. The objective of the present study was to compare complications and morbidity after clipping of unruptured single-sac aneurysms (SSAs) and aneurysms with multiple sacs (MSAs).

Methods A retrospective, single-center study was conducted for patients that were treated between 2010 and 2018. We analyzed
surgical parameters, treatment-related complications, and morbidity, defined as any increase in the modified Rankin scale at 3-
month follow-up.

Results We identified 101 patients (mean age: 52.9 ± 10.5 years) that underwent clipping for 57 SSAs and 44 MSAs. The two
groups were comparable regarding aneurysm size and neck width. Clipping of MSAs was associated with a longer operation time
(p = 0.008) and increased use of intraoperative indocyanine green (p = 0.016) than SSAs. Complications occurred more often in
the MSA group (29.5%) than in the SSA group (14.0%; p = 0.057). Morbidity was significantly higher in the MSA group
(20.5%) than in the SSA group (3.5%, p = 0.009). In the univariate analysis, the odds of morbidity were 7.1 times greater for
MSAs than for SSAs (95% CI 1.4–34.7).

Conclusions Morbidity after microsurgical clipping is significantly increased in MSAs as compared to SSAs. This may be
attributed to a more difficult clip placement with stronger manipulation of the aneurysm dome and the surrounding brain tissue.

 

Coiling Versus Microsurgical Clipping in the Treatment of Unruptured Middle Cerebral Artery Aneurysms: A Meta-Analysis

Neurosurgery 83:879–889, 2018

Open microsurgical clipping of unruptured intracranial aneurysms has long been the gold standard, yet advancements in endovascular coiling techniques have begun to challenge the status quo. OBJECTIVE: To compare endovascular coiling with microsurgical clipping among adults with unruptured middle cerebral artery aneurysms (MCAA) by conducting a meta-analysis.

METHODS: A systematic search was conducted from January 2011 to October 2015 to update a previous meta-analysis. All studies that reported unruptured MCAA in adults treated by microsurgical clipping or endovascular coiling were included and cumulatively analyzed.

RESULTS: Thirty-seven studies including 3352 patients were included. Using the randomeffects model, pooled analysis of 11 studies of microsurgical clipping (626 aneurysms) revealed complete aneurysmal obliteration in 94.2% of cases (95% confidence interval [CI] 87.6%-97.4%). The analysis of 18 studies of endovascular coiling (759 aneurysms) revealed complete obliteration in 53.2% of cases (95% CI: 45.0%-61.1%). Among clipping studies, 22 assessed neurological outcomes (2404 aneurysms), with favorable outcomes in 97.9% (95% CI: 96.8%-98.6%). Among coiling studies, 22 examined neurological outcomes (826 aneurysms), with favorable outcomes in 95.1% (95% CI: 93.1%-96.5%). Results using the fixed-effect models were not materially different.

CONCLUSION: This updated meta-analysis demonstrates that surgical clipping for unruptured MCAA remains highly safe and efficacious. Endovascular treatment for unruptured MCAAs continues to improve in efficacy and safety; yet, it results in lower rates of occlusion.

 

Advances in intraoperative brain mapping

Neurosurg Focus 45 (Suppl2):Intro, 2018

In the last decade, there has been significant interest among neurosurgeons in intraoperative brain mapping in cases of lesions in eloquent cortex and subcortical regions. This has occurred because foundational studies have provided strong evidence for the value of maximal safe resection of glioma.

Further evidence of the important role of cortical and subcortical stimulation mapping in achieving a safe, maximal resection has come forth.

Clinicians are also becoming aware of the limitations of preoperative imaging studies for definitive intraoperative decision-making.
Preoperative mapping techniques are commonly used, but the extent to which they are relied upon is quite variable.

In some centers, preoperative imaging techniques are used to guide the decision to choose cortical stimulation mapping, in other centers, it directs where the mapping may start, and in others, it is used in case the intraoperative mapping is ambiguous. It should be noted that there is significant variability in techniques in obtaining and processing this functional imaging data. Surgeons should become familiar both with this variability in general and with the protocols at their own center before relying on functional imaging for crucial decision-making.

In this issue of Neurosurgical Focus, we are pleased to show some of the recent advances and new applications of intraoperative brain mapping.
A variety of techniques and protocols are discussed in this issue. A variety of pathologies, including glioma, metastatic tumor, vascular lesions, and epileptic foci, are addressed through transcortical, trans-sylvian, transventricular, and intrahemispheric routes. The common theme in each of these cases is to apply cortical and subcortical stimulation in at-risk areas in order to minimize risk and maximize resection.

Readers should take note of stimulation parameters in each video and understand that there is practice variability that has evolved in each center. Whether a center is using monopolar or bipolar stimulation (or both), electrocorticography or not, common themes include careful observation and recording of stimulation response after escalation of intensity in a well-organized operative plan. Resection of the lesion is then performed, with the patient awake, or monitored, until the lesion is out or until the early onset of a new deficit. This careful monitoring is essential for safety and avoiding anything more than a temporary deficit.

Important tips for comfortable and safe awake surgical techniques are also a common theme in the video cases in this issue.
Finally, emerging technologies and older technologies, such as transcranial magnetic stimulation and subdural grid mapping, are discussed, along with advantages and disadvantages.
This month’s issue shows an excellent cross-section of the variety of contemporary applications of cortical stimulation mapping. We would like to thank the authors for their outstanding contributions to the field.

Glaucoma in patients with shunt-treated normal pressure hydrocephalus

J Neurosurg 129:1078–1084, 2018

Changes in the pressure gradient between intraocular and intracranial compartments at the lamina cribrosa level are a possible explanation of normal tension glaucoma (NTG). Shunt-treated normal pressure hydrocephalus (NPH) is a model for testing whether the increase (time from disease onset to CSF shunt placement, i.e., “protection period”) and decrease (time from shunt placement to observation, i.e., “exposure period”) in intracranial pressure (ICP) are glaucoma protective or risk factors, respectively. The authors estimated the prevalence of NTG in patients with shunt-treated NPH and calculated the extent of optic nerve exposure to changes in the trans–lamina cribosa gradient.

METHODS Data obtained in patients with NPH who had undergone ventriculoperitoneal (VP) shunt placement were analyzed. Patients with more than 6 months’ follow-up, no pathologies associated with ICP changes or CSF dynamics disturbances, and no surgical or valve-related complications were scheduled for ophthalmic evaluation.

RESULTS Nine of 22 patients had NTG, which is about a 40-fold increase in rate compared with the rate in the general elderly population without hydrocephalus (p < 0.001). The median protection period was 12.0 months in patients with NTG and 18.0 months in those without NTG (p = 0.033). The median ICP decrease multiplied by duration of exposure in months was 76.0 mm Hg × months in the NTG group and 24.1 mm Hg × months in the no-NTG group (p = 0.048). The patients’ median adjusted age (adjusted for “protection” and “exposure” times) was 85.1 years in the NTG group and 78.8 years in the no-NTG group (p = 0.001).

CONCLUSIONS A crucial risk factor for development of NTG in patients with shunt-treated NPH is the duration of optic nerve exposure to the lowering of ICP. Patients with NPH who are candidates for CSF shunting should be informed of the risk of incurring glaucoma. Longitudinal studies could provide estimates of tolerated times for a given ICP decrease.

Simple presurgical method of predicting C5 palsy after cervical laminoplasty using C5 nerve root ultrasonography

J Neurosurg Spine 29:365–370, 2018

The incidence of C5 palsy after cervical laminoplasty is approximately 5%. Because C5 palsy is related to cervical foraminal stenosis at the C4–5 level, the authors hypothesized that cervical foraminal stenosis can be diagnosed by examining the C5 nerve root (NR) using ultrasonography. The purpose of this study was to investigate whether postoperative C5 palsy could be predicted using ultrasonography.
METHODS This study used a prospective diagnosis design. In total, 140 patients undergoing cervical laminoplasty were examined with ultrasound. The cross-sectional area (CSA) of the C5 NR was measured on both sides before surgery, and the incidence of postoperative C5 palsy was examined. The difference between the CSA of the patients with and without C5 palsy and the lateral differences in the C5 palsy group were determined.
RESULTS The incidence of C5 palsy was 5% (7 cases). Symptoms manifested at a median of 5 days after surgery (range 1–29 days). The CSA of the C5 NR on the affected side was significantly enlarged in the C5 palsy group compared with that in the no–C5 palsy group (p = 0.001). In addition, in the patients who had C5 palsy, the CSA of the C5 NR was significantly enlarged on the affected side compared with that on the unaffected side (p = 0.02). Receiver operating characteristic analysis indicated that the best threshold value for the CSA of the C5 NR was 10.4 mm2 , which provided 91% sensitivity and 71% specificity.
CONCLUSIONS C5 palsy may be predicted preoperatively using ultrasound. The authors recommend the ultrasonographic measurement of the CSA of the C5 NR prior to cervical laminoplasty.

Pulsatile versus non-pulsatile tinnitus in idiopathic intracranial hypertension

Acta Neurochirurgica (2018) 160:2025–2029

Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension (IIH) that can have a profound effect on quality of life. We aim to determine tinnitus symptom response after dural venous sinus stenting (DVSS) or CSF diversion with a shunt, in patients with both pulsatile (PT) and non-pulsatile tinnitus (NPT).

Methods: Single-centre cohort of IIH patients (2006–2016) who underwent 24-h ICP monitoring (ICPM). An un-paired t test compared ICP and pulse amplitude (PA) values in IIH patients with PT vs. NPT.

Results: We identified 59 patients with IIH (56 F:3 M), mean age 32.5 ± 9.49 years, 14 of whom suffered from tinnitus. Of these 14, seven reported PT and seven reported NPT. Patients with tinnitus had a mean 24-h ICP and PA of 9.09 ± 5.25 mmHg and 6.05 ± 1.07 mmHg respectively. All 7 patients with PT showed symptom improvement or resolution after DVSS (n = 4), secondary DVSS (n=2) or shunting (n = 1). In contrast, of the 7 with NPT, only 1 improved post intervention (DVSS), despite 2 patients having shunts and 5 having DVSS.

Conclusions: NPT and PT were equally as common in our group of IIH patients. DVSS appears to be an effective management option for IIH patients with a clear history of pulsatile tinnitus. However, non-pulsatile tinnitus was more persistent and did not respond well to either DVSS or CSF diversion.

Minimally Invasive Trigeminal Ablation: Novel Transoral Technique for Targeted Treatment of V3

World Neurosurg. (2018) 118:193-196

Trigeminal neuralgia (TN) is a chronic orofacial pain syndrome that presents with debilitating shooting pains in the V3 nerve distribution. The condition is traditionally responsive to anticonvulsant therapy; however, cases that become refractory to medications often require surgical intervention.

CASE DESCRIPTION: We present a case of TN that was treated with minimally invasive trigeminal ablation. The patient presented with a 6-year history of TN that had been resistant to medical management. The patient opted for minimally invasive management, refused stereotactic radiosurgery, and was treated using the minimally invasive trigeminal ablation approach. At 16 weeks postoperatively, the patient reported complete alleviation of pain with minimal sensorineural numbness.

CONCLUSIONS: The endoscopic approach allows for precise targeting through visual guidance, which is ideal in patients undergoing neuroablation for pain within specific nerve distributions. This is the first documented case of an endoscopic minimally invasive transoral approach toward ablative TN management.

Prognosis of Symptoms and Complications After Microvascular Decompression for Hemifacial Spasm

World Neurosurg. (2018) 118:e557-e561

The aim of this study was to identify potential prognostic factors of hemifacial spasm (HFS) after microvascular decompression (MVD), to establish the appropriate way to tackle postprocedure symptoms and complications (PPSCs), and to find the incidence and duration of PPSCs.

METHODS: Two hundred and forty-eight patients with HFS were monitored between December 2009 and December 2014. The mean follow-up duration was 24 months (range, 6e67 months). We divided patients based on their PPSC status and investigated the following factors: age, sex, spasm side, facial nerve block before MVD (botulinum toxin treatment), acupuncture before MVD, duration of HFS, hypertension, diabetes, hepatitis B virus (HBV) infection status, herpes simplex virus infection status, smoking status and alcohol use, offending vessels, Chiari malformation, electrophysiologic monitoring results, and postoperative HFS. Univariable analysis and multivariate logistic regression were used to find potential risk factors. Kaplan-Meier analysis was used to show the duration of postprocedure facial palsy.

RESULTS: Age (odds ratio [OR], 1.037; 95% confidence interval [CI], 1.004e1.072; P [ 0.03) and HBV status (OR, 18.256; 95% CI, 2.723e122.415; P [ 0.03) were positive predictors of PPSCs. Postoperative HFS (OR, 0.249; 95% CI, 0.084e0.0739; P [ 0.012) may be a protective factor for postprocedure facial palsy. Most PPSCs related to cranial nerves recovered spontaneously in 3 months. Infections and cerebrospinal fluid leakages were controlled by medical intervention in 1e2 weeks. The permanent complication rate was only 4.8%.

CONCLUSIONS: Although the incidence of PPSCs after MVD is very high, most PPSCs related to cranial nerves recovered spontaneously in several days. Permanent complications after MVD for HFS are rare. Age may relate to the occurrence of PPSCs, and postoperative HFS may be a protective factor for patients with facial palsy after MVD.

Patient-Reported Outcome Measures in Neurosurgery

Neurosurgery 83:622–630, 2018

Patient-reported outcome measures (PROMs) play an important role in the evaluation of health outcomes, quality of life, and satisfaction, and have been successfully utilized in many areas of clinical medicine and surgical practice. The prevalence of PROMs in neurosurgery is not known.

OBJECTIVE: To review the PROMs that have been utilized in the published neurosurgery literature to date.

METHODS: Articles were searched in MEDLINE, EMBASE, HMIC HealthManagement Information Consortium, PsycARTICLES, and PsycINFO using search terms related to neurosurgery and PROMs, published from 1806 to August 2016. A total of 268 articles were identified that were stratified by the inclusion and exclusion criteria leading to a total of 137 articles. Twenty-six PROMs, involving both adult and pediatric populations,were identified.

RESULTS: A large number of generic and disease-specific PROMs are used in the neurosurgical literature. Generic PROMs are usually nonspecific measures of health status. Disease specific PROMs may not address issues relevant to neurosurgical procedures. There are very few neurosurgery-specific PROMs that take into account the impact of a neurosurgical procedure on a specific condition.

CONCLUSION: PROMs that currently feature in the neurosurgical literature may not address the specific outcomes relevant to neurosurgical practice. There is an emergent need for generic and disease-specific PROMs to be validated in neurosurgical patients and neurosurgery-specific PROMs developed to address unmet needs of patients undergoing neurosurgical procedures.

 

Autonomic Function in Insular Glioma

World Neurosurg. (2018) 118:e951-e955

Autonomic nervous system dysfunction is a known entity in strokes involving insula. It causes significant morbidity and mortality. No study to date has demonstrated autonomic nervous system dysfunction in patients with insular glioma. This is an exploratory study to identify the
subclinical autonomic dysfunctions in insular glioma.

METHODS: A total 50 patients with newly diagnosed insular glioma in the age group of 18e60 years were evaluated with heart rate variability (HRV). All the HRV parameters in patients with insular glioma were compared with normal healthy age- and sex-matched control patients.

RESULTS: There was a significant difference (P < 0.05) in most of the HRV parameters between patients and control patients. Patients with left insular glioma showed significantly increased heart rate (P [ 0.027), low-frequency normalized units (P [ 0.048), and also increased low-frequency/highfrequency ratio (P [ 0.015), which indicates sympathetic
dominance. Patients with seizures had significantly lower values of total power (P [ 0.042). No significant difference was found in terms of the extent and size of the tumor or histopathologic grades of gliomas.

CONCLUSIONS: Patients with insular gliomas have significant impairment of autonomic functions, with left insular glioma showing sympathetic dominance. Suppression of autonomic function is greater in those presenting with seizures.