Endoventricular Deep Brain Stimulation of the Third Ventricle: Proof of Concept and Application to Cluster Headache

Neurosurgery 79:806–815, 2016

The third ventricle (3rd V) is surrounded by centers related to satiety, homeostasis, hormones, sleep, memory, and pain. Stimulation of the wall of the 3rd V could be useful to treat disorders related to dysfunction of the hypothalamus.

OBJECTIVE: To assess safety and efficacy of endoventricular electrical stimulation of the hypothalamus using a floating deep brain stimulation (DBS) lead laid on the floor of the 3rd V to treat refractory cluster headaches (CH).

METHODS: Seven patients, aged 24 to 60 years, experiencing chronic CH (mean chronic duration 5.8 6 2.5 years) were enrolled in this pilot, prospective, open study assessing the safety and potential efficacy of chronic DBS of the 3rd V. Number of attacks was collected during baseline and was compared with those occurring at 3, 6, and 12 months postoperation. Any side effects that occurred during or after surgery were reported. Effect on mood was assessed using the Hospital Anxiety and Depression scale during baseline and at 6 and 12 months postoperation.

RESULTS: Insertion of the lead into the posterior 3rd V and chronic stimulation was feasible and safe in all patients. The voltage ranged from 0.9 to 2.3 volts. The most common side effect was transient trembling vision during stimulation. At 12 months, 3 of 7 patients were pain free, 2 had 90% improvement, 1 of 7 had 75% improvement, and 1 of 7 was not significantly improved.

CONCLUSION: This proof of concept demonstrates the feasibility, safety, and potential efficacy of 3rd V DBS using an endoventricular road that could be applied to treat various diseases involving hypothalamic areas. Read the rest of this entry »

Clinical characteristics and outcome of aneurysmal subarachnoid hemorrhage with intracerebral hematoma

subarachnoid-hemorrhage-and-intracerebral-hematoma-caused-by-aneurysms-of-the-anterior-circulation

J Neurosurg 125:1344–1351, 2016

Intracerebral hematoma (ICH) with subarachnoid hemorrhage (SAH) indicates a unique feature of intracranial aneurysm rupture since the aneurysm is in the subarachnoid space and separated from the brain by pia mater. Broad consensus is lacking regarding the concept that ultra-early treatment improves outcome. The aim of this study is to determine the associative factors for ICH, ascertain the prognostic value of ICH, and investigate how the timing of treatment relates to the outcome of SAH with concurrent ICH.

Methods The study data were pooled from the SAH International Trialists repository. Logistic regression was applied to study the associations of clinical and aneurysm characteristics with ICH. Proportional odds models and dominance analysis were applied to study the effect of ICH on 3-month outcome (Glasgow Outcome Scale) and investigate the effect of time from ictus to treatment on outcome.

Results Of the 5362 SAH patients analyzed, 1120 (21%) had concurrent ICH. In order of importance, neurological status, aneurysm location, aneurysm size, and patient ethnicity were significantly associated with ICH. Patients with ICH experienced poorer outcome than those without ICH (OR 1.58; 95% CI 1.37–1.82). Treatment within 6 hours of SAH was associated with poorer outcome than treatment thereafter (adjusted OR 1.67; 95% CI 1.04–2.69). Subgroup analysis with adjustment for ICH volume, location, and midline shift resulted in no association between time from ictus to treatment and outcome (OR 0.99; 95% CI 0.94–1.07).

Conclusions The most important associative factor for ICH is neurological status on admission. The finding regarding the value of ultra-early treatment suggests the need to more robustly reevaluate the concept that hematoma evacuation of an ICH and repair of a ruptured aneurysm within 6 hours of ictus is the most optimal treatment path.

KEY WORDS intracerebral hematoma; subarachnoid hemorrhage; outcome assessment; intracranial aneurysm; vascular disorders

Resection of highly language-eloquent brain lesions based purely on rTMS language mapping without awake surgery

resection-of-highly-language-eloquent-brain-lesions-based-purely-on-rtms-language-mapping-without-awake-surgery

Acta Neurochir (2016) 158:2265–2275

The resection of left-sided perisylvian brain lesions harbours the risk of postoperative language impairment. Therefore the individual patient’s language distribution is investigated by intraoperative direct cortical stimulation (DCS) during awake surgery. Yet, not all patients qualify for awake surgery. Non-invasive language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) has frequently shown a high correlation in comparison with the results of DCS language mapping in terms of language-negative brain regions. The present study analyses the extent of resection (EOR) and functional outcome of patients who underwent left-sided perisylvian resection of brain lesions based purely on rTMS language mapping.

Methods Four patients with left-sided perisylvian brain lesions (two gliomas WHO III, one glioblastoma, one cavernous angioma) underwent rTMS language mapping prior to surgery. Data from rTMS language mapping and rTMS-based diffusion tensor imaging fibre tracking (DTI-FT) were transferred to the intraoperative neuronavigation system. Preoperatively, 5 days after surgery (POD5), and 3 months after surgery (POM3) clinical follow-up examinations were performed.

Results No patient suffered from a new surgery-related aphasia at POM3. Three patients underwent complete resection immediately, while one patient required a second rTMSbased resection some days later to achieve the final, complete resection.

Conclusions The present study shows for the first time the feasibility of successfully resecting language-eloquent brain lesions based purely on the results of negative language maps provided by rTMS language mapping and rTMS-based DTI-FT. In very select cases, this technique can provide a rescue strategy with an optimal functional outcome and EOR when awake surgery is not feasible.

Microscopic versus endoscopic approaches for craniopharyngiomas

microscopic-versus-endoscopic-approaches-for-craniopharyngiomas

Neurosurg Focus 41 (6):E5, 2016

Resection remains the mainstay of treatment for craniopharyngiomas with the goal of radical resection, if safely possible, to minimize the rate of recurrence. Endoscopic endonasal and microscopic transcranial surgical approaches have both become standard methods for the treatment for craniopharyngiomas. However, the approach selection paradigm for craniopharyngiomas is still a point of discussion. Choosing the optimal surgical approach can play a significant role in maximizing the extent of resection and surgical outcome while minimizing the risks of potential complications.

Craniopharyngiomas can present with a variety of different sizes, locations, and tumor consistencies, and each individual tumor has distinct features that favor one specific approach over another.

The authors review standard cranial base techniques applied to craniopharyngioma surgery, using both the endoscopic endonasal approach and traditional open microsurgical approaches, and analyze factors involved in approach selection. They discuss their philosophy of approach selection based on the location and extent of the tumor on preoperative imaging as well as the advantages and limitations of each surgical corridor, and they describe the operative nuances of each technique, using a personalized, tailored approach to the individual patient with illustrative cases and videos.

Diffusion Tensor Imaging: A Possible Biomarker in Severe Traumatic Brain Injury and Aneurysmal Subarachnoid Hemorrhage?

diffusion-tensor-imaging-a-possible-biomarker-in-severe-traumatic-brain-injury-and-aneurysmal-subarachnoid-hemorrhage

Neurosurgery 79:786–793, 2016

A great need exists in traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (aSAH) for objective biomarkers to better characterize the disease process and to serve as early endpoints in clinical studies. Diffusion tensor imaging (DTI) has shown promise in TBI, but much less is known about aSAH.

OBJECTIVE: To explore the use of whole-brain DTI tractography in TBI and aSAH as a biomarker and early endpoint.

METHODS: Of a cohort of 43 patients with severe TBI (n = 20) or aSAH (n = 23) enrolled in a prospective, observational, multimodality monitoring study, DTI data were acquired at approximately day 12 (median, 12 days; interquartile range, 12-14 days) after injury in 22 patients (TBI, n = 12; aSAH, n = 10). Whole-brain DTI tractography was performed, and the following parameters quantified: average fractional anisotropy, mean diffusivity, tract length, and the total number of reconstructed fiber tracts. These were compared between TBI and aSAH patients and correlated with mortality and functional outcome assessed at 6 months by the Glasgow Outcome Scale Extended.

RESULTS: Significant differences were found for fractional anisotropy values (P = .01), total number of tracts (P = .03), and average tract length (P = .002) between survivors and nonsurvivors. A sensitivity analysis showed consistency of results between the TBI and aSAH patients for the various DTI measures.

CONCLUSION: DTI parameters, assessed at approximately day 12 after injury, correlated with mortality at 6 months in patients with severe TBI or aSAH. Similar patterns were found for both TBI and aSAH patients. This supports a potential role of DTI as early endpoint for clinical studies and a predictor of late mortality.

Clipping of previously coiled cerebral aneurysms

clipping-previously-coiled-aneurysms

J Neurosurg 125:1337–1343, 2016

With the increasing number of aneurysms treated with endovascular coiling, more recurrences are beingencountered. The aim of this study was to evaluate the efficacy and safety of microsurgical clipping in the treatment ofrecurrent, previously coiled cerebral aneurysms and to identify risk factors that can affect the outcomes of this procedure.

Methods:  One hundred eleven patients with recurrent aneurysms whose lesions were managed by surgical clipping between January 2002 and October 2014 were identified. The rates of aneurysm occlusion, retreatment, complications,and good clinical outcome were retrospectively determined. Univariate and multivariate logistic regressions were performed to identify factors associated with these outcomes.

Results:  The mean patient age was 50.5 years, the mean aneurysm size was 7 mm, and 97.3% of aneurysms were located in the anterior circulation. The mean follow-up was 22 months. Complete aneurysm occlusion, as assessed by intraoperative angiography, was achieved in 97.3% of aneurysms (108 of 111 patients). Among patients, 1.8% (2 of 111 patients) had a recurrence after clipping. Retreatment was required in 4.5% of patients (5 of 111) after clipping. Major complications were observed in 8% of patients and mortality in 2.7%. Ninety percent of patients had a good clinical outcome. Aneurysm size (OR 1.4, 95% CI 1.08–1.7; p = 0.009) and location in the posterior circulation were significantly associated with higher complications. All 3 patients who had coil extraction experienced a postoperative stroke. Aneurysm size (OR 1.2, 95% CI 1.02–1.45; p = 0.025) and higher number of interventions prior to clipping (OR 5.3, 95% CI 1.3–21.4; p = 0.019) were significant predictors of poor outcome. An aneurysm size > 7 mm was a significant predictor of incomplete obliteration and retreatment (p = 0.018).

Conclusions:  Surgical clipping is safe and effective in treating recurrent, previously coiled cerebral aneurysms. Aneurysm size, location, and number of previous coiling procedures are important factors to consider in the management of these aneurysms. http://thejns.org/doi/abs/10.3171/2015.10.JNS151544

aneurysm, clipping, previously coiled, Recurrence, vascular disorders

Emerging Applications of Therapeutic Ultrasound in Neuro-oncology

emerging_applications_of_therapeutic_ultrasound_in

Neurosurgery 79:643–654, 2016

Transcranial focused ultrasound (FUS) can noninvasively transmit acoustic energy with a high degree of accuracy and safety to targets and regions within the brain. Technological advances, including phased-array transducers and real-time temperature monitoring with magnetic resonance thermometry, have created new opportunities for FUS research and clinical translation.

Neuro-oncology, in particular, has become a major area of interest because FUS offers a multifaceted approach to the treatment of brain tumors. FUS has the potential to generate cytotoxicity within tumor tissue, both directly via thermal ablation and indirectly through radiosensitization and sonodynamic therapy; to enhance the delivery of therapeutic agents to brain tumors by transiently opening the blood-brain barrier or improving distribution through the brain extracellular space; and to modulate the tumor microenvironment to generate an immune response.

In this review, we describe each of these applications for FUS, the proposed mechanisms of action, and the preclinical and clinical studies that have set the foundation for using FUS in neuro-oncology.

Electrical stimulation of the parahippocampal gyrus for prediction of posthippocampectomy verbal memory decline

provocative-test-for-verbal-memory-decline

J Neurosurg 125:1053–1060, 2016

Epilepsy surgery is of known bene t for drug-resistant temporal lobe epilepsy (TLE); however, a certain number of patients suffer signi cant decline in verbal memory after hippocampectomy. To prevent this disabling compli- cation, a reliable test for predicting postoperative memory decline is greatly desired. Therefore, the authors assessed the value of electrical stimulation of the parahippocampal gyrus (PHG) as a provocation test of verbal memory decline after hippocampectomy on the dominant side.

Methods Eleven right-handed, Japanese-speaking patients with medically intractable left TLE participated in the study. Before surgery, they underwent provocative testing via electrical stimulation of the left PHG during a verbal en- coding task. Their pre- and posthippocampectomy memory function was evaluated according to the Wechsler Memory Scale-Revised (WMS-R) and/or Mini-Mental State Examination (MMSE) before and 6 months after surgery. The rela- tionship between postsurgical memory decline and results of the provocative test was evaluated.

Results Left hippocampectomy was performed in 7 of the 11 patients. In 3 patients with a positive provocative rec- ognition test, verbal memory function, as assessed by the WMS-R, decreased after hippocampectomy, whereas in 4 patients with a negative provocative recognition test, verbal memory function, as assessed by the WMS-R or MMSE, was preserved.

Conclusions Results of the present study suggest that electrical stimulation of the PHG is a reliable provocative test to predict posthippocampectomy verbal memory decline.

 

Maximizing safe resection of low- and high-grade glioma

dti-gliomas

J Neurooncol (2016) 130:269–282

Surgical resection plays a central role in the management of gliomas. In this study, we review the evidence in support of extent of resection to improve survival, symptom management, and time to malignant transformation in low- and high-grade gliomas, and summarize the findings from our literature search regarding the role of extent of resection and intraoperative practices to maximize safety.

There is a growing body of evidence supporting improved overall survival, improved progression-free survival, and superior quality of life with greater extent of resection.

Additionally, a better understanding of central nervous system plasticity allows for a staged approach to the surgical management of low- and intermediate-grade gliomas.

A number of intraoperative techniques have been utilized to offer safer glioma surgery with greater extent of resection. Approaches such as awake brain tumor surgery can be safely performed with low failure rates and excellent long-term functional outcomes.

Hydrocephalus: an underrated long-term complication of microvascular decompression for trigeminal neuralgia

External lumbar drain- A pragmatic test for prediction of shunt outcomes in idiopathic normal pressure hydrocephalus

Acta Neurochir (2016) 158:2203–2206

Hydrocephalus is a common complication of posterior fossa surgery, but its real incidence after microvascular decompression (MVD) for idiopathic trigeminal neuralgia (TN) still remains unclear. The aim of this study was to focus on the potential association between MVD and hydrocephalus as a surgery-related complication.

Methods All patients who underwent MVD procedure for idiopathic TN at our institute between 2009 and 2014 were reviewed to search for early or late postoperative hydrocephalus.

Results There were 259 consecutive patients affected by idiopathic TN who underwent MVD procedure at our institution between 2009 and 2014 (113 men, 146 women; mean age 59 years, range 30–87 years; mean follow-up 40.92 months, range 8–48 months). Nine patients (3.47 %) developed communicating hydrocephalus after hospital discharge and underwent standard ventriculo-peritoneal shunt. No cases of acute hydrocephalus were noticed.

Conclusions Our study suggests that late communicating hydrocephalus may be an underrated potential long-term complication of MVD surgery.

 

Surgical excision of symptomatic sacral perineurial Tarlov cyst

tarlov-cysts

Eur Spine J (2016) 25:3385–3392

Symptomatic sacral perineural cysts are extremely rare. The aim of this retrospective study is to investigate the outcome of 15 consecutive patients treated by microsurgical resection of the cyst and to review the literature.

Methods The authors retrospectively reviewed their clinical data archive from 2002 to 2014. Fifteen patients who were operated on due to symptomatic sacral perineural cysts were enrolled in the study. Patients’ symptoms, radiographs, intra-operative findings, and clinical results were evaluated. All 15 patients underwent microsurgical excision of the cyst. The literature on this topic available in PubMed was also reviewed.

Results There were 5 men and 10 women included in the study, with a mean age of 31 years (range 7–60 years). Preoperative symptoms include low back pain, coccydynia, buttock pain, perianal pain and radicular pain. All of the patients underwent surgical resection. The mean follow-up was 54 months (range 3–160 months). All the patients experienced complete or substantial resolution of the preoperative local and radicular pain after surgery.

Conclusions Cyst excision is an effective and safe technique for symptomatic sacral perineural (Tarlov) cysts. Careful patient selection is vital to the management and treatment of this difficult and controversial pathology.

The evolving utility of diffusion tensor tractography in the surgical management of temporal lobe epilepsy

the-evolving-utility-of-diffusion-tensor-tractography-in-the-surgical-management-of-temporal-lobe-epilepsy

Acta Neurochir (2016) 158:2185–2193

Diffusion tensor imaging (DTI) is a relatively new imaging modality that has found many peri-operative applications in neurosurgery.

Methods A comprehensive survey of the applications of diffusion tensor imaging (DTI) in planning for temporal lobe epilepsy surgery was conducted. The presentation of this literature is supplemented by a case illustration.

Results The authors have found that DTI is well utilized in epilepsy surgery, primarily in the tractography of Meyer’s loop. DTI has also been used to demonstrate extratemporal connections that may be responsible for surgical failure as well as perioperative planning. The tractographic anatomy of the temporal lobe is discussed and presented with original DTI pictures.

Conclusions The uses of DTI in epilepsy surgery are varied and rapidly evolving. A discussion of the technology, its limitations, and its applications is well warranted and presented in this article.

Reoperation for Recurrent Glioblastoma and Its Association With Survival Benefit

multifocal glioblastoma

Neurosurgery 79:678–689, 2016

Glioblastoma is the most common and aggressive primary brain tumor. Despite current treatment, recurrence is inevitable. There are no clear guidelines for treatment of recurrent glioblastoma.

OBJECTIVE: To investigate factors at initial surgery predictive of reoperation, and the prognostic variables associated with survival, including reoperation for recurrence.

METHODS: A retrospective cohort study was performed, including adult patients diagnosed with glioblastoma between January 2010 and December 2013. Student t test and Fisher exact test compared continuous and categorical variables between reoperation and nonreoperation groups. Univariable and Cox regression multivariable analysis was performed.

RESULTS: In a cohort of 204 patients with de novo glioblastoma, 49 (24%) received reoperation at recurrence. The median overall survival in the reoperation group was 20.1 months compared with 9.0 months in the nonreoperation group (P = .001). Reoperation was associated with longer overall survival in our total population (hazard ratio, 0.646; 95% confidence interval, 0.543-0.922; P = .016) but subject to selection bias. Subgroup analyses excluding patients unlikely to be considered for reoperation suggested a much less significant effect of reoperation on survival, which warrants further study with larger cohorts. Factors at initial surgery predictive for reoperation were younger age, smaller tumor size, initial extent of resection $50%, shorter inpatient stay, and maximal initial adjuvant therapy. When unfavorable patient characteristics are excluded, reoperation is not an independent predictor of survival.

CONCLUSION: Patients undergoing reoperation have favorable prognostic characteristics, which may be responsible for the survival difference observed. We recommend that a large clinical registry be developed to better aid consistent and homogenous data collection.

Back pain improvement after decompression without fusion or stabilization in patients with lumbar spinal stenosis and clinically significant preoperative back pain

lumbar stenosis

J Neurosurg Spine 25:596–601, 2016

The relief of leg symptoms by surgical decompression for lumbar stenosis is well supported by the literature. Less is known about the effect on back pain. Some surgeons believe that the relief of back pain should not be an expected outcome of decompression and that substantial back pain may be a contraindication to decompression only; therefore, stabilization may be recommended for patients with substantial preoperative back pain even in the absence of well-accepted indications for stabilization such as spondylolisthesis, scoliosis, or sagittal malalignment. The purpose of this study is to determine if patients with lumbar stenosis and substantial back pain—in the absence of spondylolisthesis, scoliosis, or sagittal malalignment—can obtain significant improvement after decompression without fusion or stabilization.

Methods Analysis of the National Neurosurgery Quality and Outcomes Database (N2QOD) identified 726 patients with lumbar stenosis (without spondylolisthesis or scoliosis) and a baseline back pain score ≥ 5 of 10 who underwent surgical decompression only. No patient was reported to have significant spondylolisthesis, scoliosis, or sagittal malalignment. Standard demographic and surgical variables were collected, as well as patient outcomes including back and leg pain scores, Oswestry Disability Index (ODI), and EuroQoL 5D (EQ-5D) at baseline and 3 and 12 months postoperatively.

Results The mean age of the cohort was 65.6 years, and 407 (56%) patients were male. The mean body mass index was 30.2 kg/m2, and 40% of patients had 2-level decompression, 29% had 3-level decompression, 24% had 1-level decompression, and 6% had 4-level decompression. The mean estimated blood loss was 130 ml. The mean operative time was 100.85 minutes. The vast majority of discharges (88%) were routine home discharges. At 3 and 12 months postoperatively, there were significant improvements from baseline for back pain (7.62 to 3.19 to 3.66), leg pain (7.23 to 2.85 to 3.07), EQ-5D (0.55 to 0.76 to 0.75), and ODI (49.11 to 27.20 to 26.38).

Conclusions Through the 1st postoperative year, patients with lumbar stenosis—without spondylolisthesis, scoliosis, or sagittal malalignment—and clinically significant back pain improved after decompression-only surgery.

The paramedian supracerebellar transtentorial approach to the posterior fusiform gyrus

the-paramedian-supracerebellar-transtentorial-approach-to-the-posterior-fusiform-gyrus

Acta Neurochir (2016) 158:2149–2154

The posterior fusiform gyrus lies in a surgically challenging region. Several approaches have been described to access this anatomical area. The paramedian supracerebellar transtentorial (SCTT) approach benefits from minimal disruption of normal neurovascular tissue. The aim of this study was to demonstrate its application to access the posterior fusiform gyrus.

Methods Three brains and six cadaveric heads were examined. A stepwise dissection of the SCTT approach to the posterior fusiform gyrus was performed. Local cortical anatomy was studied. The operability score was applied for comparative analysis on surgical anatomy.

Results The major posterior landmark used to identify the fusiform gyrus with respect to the medial occipitotemporal gyrus was the collateral sulcus, which commonly bifurcated at its caudal extent. Compared with other surgical approaches addressed to access the region, SCTT demonstrated the best operability in terms of maneuverability arc. Favorable tentorial anatomy is the only limiting factor.

Conclusions The supracerebellar transtentorial approach is able to provide access to the posterior fusiform gyrus via a minimally disruptive, anatomic, microsurgical corridor.

Surgery of insular and paralimbic diffuse low-grade gliomas: technical considerations

insular-lgg-2

J Neurooncol (2016) 130:289–298

Once considered a ‘‘no man’s land’’ especially when invaded by a diffuse low grade glioma (DLGG), the insula remains to this day a surgical challenge. Surgery for insular DLGG involves consideration of its hidden location under the potentially eloquent operculae, the proximity to vascular tree and high density of functions not only in the insular cortex but also in the white fiber pathways passing under the insular lobe. The natural history of DLGG and the potential benefits and consequences of the surgical approach also need a close look.

In the last decade, a better knowledge of the functional anatomy and connectivity of this region, as well as an improvement in surgical techniques as direct stimulation mapping, combined with an increasing literature showing a favorable impact of maximal resection for DLGG, were deciding factors in the paradigmatic shift from expectative treatment to early surgical management.

Here, our goal is to discuss the structural and functional aspects of the insula, the specificities of insular and paralimbic DLGG by emphasizing the technical considerations of surgery in this region, as well as its oncological and functional outcomes. In summary, this new strategy based upon early maximal safe surgical resection showed both oncological benefit and preservation of quality of life—or even an improvement thanks to epilepsy relief.

Predictors of an unfavorable outcome 1.5 and 12 years after a first, uncomplicated lumbar disc surgery

How to predict return to work after lumbar discectomy- answers from the NeuroPoint-SD registry

Eur Spine J (2016) 25:3520–3527

To identify predictors of both intermediate and long-term unfavorable outcomes after first time, uncomplicated lumbar disc surgery.

Methods Patients (n = 120) who had undergone lumbar disc surgery were followed up 1.5 and 12 years thereafter. Baseline assessments were carried out 5–8 days after surgery. Clinical outcome was assessed in both follow-ups using the Low Back Pain Rating Scale. Statistical analysis included binary logistic and linear regression.

Results Unfavorable outcomes were found in 50.5 % (1.5 years) and 52.6 % (12 years) of patients available for follow-up examination. Low pre-operative physical activity and severe pain in the first week after surgery were predictive of an unfavorable post-operative outcome at both follow-ups.

Conclusions Identified predictors suggest that particular emphasis should put on comprehensive post-operative care at large and encouragement to adapt a physically active lifestyle in particular in rehabilitation concepts after first time uncomplicated lumbar disc surgery.

Effect of Surgery on Gait and Sensory Motor Performance in Patients With Cervical Spondylotic Myelopathy

Evaluation of spinal cord compression and hyperintense intramedullary lesions on T2-weighted sequences in patients with cervical spondylotic myelopathy using flexion-extension MRI protocol

Neurosurgery 79:701–707, 2016

Cervical spondylotic myelopathy (CSM) is a common disease of aging that leads to gait instability resulting from loss of leg sensory and motor functions. The results of surgical intervention have been studied using a variety of methods, but no test has been reported that objectively measures integrative leg motor sensory functions in CSM patients.
OBJECTIVE: To determine the feasibility of using a novel single leg squat (SLS) test to measure integrative motor sensory functions in patients with CSM before and after surgery.
METHODS: Fifteen patients with CSM were enrolled in this prospective study. Clinical data and scores from standard outcomes questionnaires were obtained before and after surgery. Patients also participated in experimental test protocols consisting of standard kinematic gait testing, the Purdue pegboard test, and the novel SLS test.
RESULTS: The SLS test protocol was well tolerated by CSM patients and generated objective performance data over short test periods. In patients who participated in postoperative testing, the group measures of mean SLS errors decreased following surgery. Gait velocity measures followed a similar pattern of group improvement postoperatively. Practical barriers to implementing this extensive battery of tests resulted in subject attrition over time. Compared with kinematic gait testing, the SLS protocol required less space and could be effectively implemented more efficiently.
CONCLUSIONS: The SLS test provides a practical means of obtaining objective measures of leg motor sensory functions in patients with CSM. Additional testing with a larger cohort of patients is required to use SLS data to rigorously examine group treatment effects.

 

 

Virtual and stereoscopic anatomy: when virtual reality meets medical education

virtual-and-stereoscopic-anatomy-when-virtual-reality-meets-medical-education

J Neurosurg 125:1105–1111, 2016

The authors sought to construct, implement, and evaluate an interactive and stereoscopic resource for teaching neuroanatomy, accessible from personal computers.

Methods Forty fresh brains (80 hemispheres) were dissected. Images of areas of interest were captured using a manual turntable and processed and stored in a 5337-image database. Pedagogic evaluation was performed in 84 graduate medical students, divided into 3 groups: 1 (conventional method), 2 (interactive nonstereoscopic), and 3 (interactive and stereoscopic). The method was evaluated through a written theory test and a lab practicum.

Results Groups 2 and 3 showed the highest mean scores in pedagogic evaluations and differed significantly from Group 1 (p < 0.05). Group 2 did not differ statistically from Group 3 (p > 0.05). Size effects, measured as differences in scores before and after lectures, indicate the effectiveness of the method. ANOVA results showed significant difference (p < 0.05) between groups, and the Tukey test showed statistical differences between Group 1 and the other 2 groups (p < 0.05). No statistical differences between Groups 2 and 3 were found in the practicum. However, there were significant differences when Groups 2 and 3 were compared with Group 1 (p < 0.05).

Conclusions The authors conclude that this method promoted further improvement in knowledge for students and fostered significantly higher learning when compared with traditional teaching resources.

Comparison of elevated intracranial pressure pulse amplitude and disproportionately enlarged subarachnoid space (DESH) for prediction of surgical results in suspected idiopathic normal pressure hydrocephalus

External lumbar drain- A pragmatic test for prediction of shunt outcomes in idiopathic normal pressure hydrocephalus

Acta Neurochir (2016) 158:2207–2213

To compare the prognostic value of pulse amplitude on intracranial pressure (ICP) monitoring and disproportionately enlarged subarachnoid space hydrocephalus (DESH) on magnetic resonance imaging (MRI) for predicting surgical benefit after shunt placement in idiopathic normal pressure hydrocephalus (iNPH).

Method Patients with suspected iNPH were prospectively recruited from a single centre. All patients received preoperative MRI and ICP monitoring. Patients were classified as shunt responders if they had an improvement of one point or more on the NPH score at 1 year post-surgery. The sensitivity, specificity, Youden index, and positive and negative predictive values of the two diagnostic methods were calculated.

Results Sixty-four of 89 patients clinically improved at 1 year post-surgery and were classed as shunt responders. Positive DESH findings had a sensitivity of 79.4 % and specificity of 80.8 % for predicting shunt responders. Fifty-five of 89 patients had positive DESH findings: 50 of these responded to VP shunt, giving a positive and negative predictive value of 90.9 % and 61.8 %, respectively. Fifty-seven of 89 patients had high ICP pulse amplitude. High ICP pulse amplitude had a sensitivity of 84.4 %, specificity of 88 %, positive predictive value of 94.7 % and negative predictive value of 61.8 % for predicting shunt responders.

Conclusions Both positive DESH findings and high ICP pulse amplitude support the diagnosis of iNPH and provide additional diagnostic value for predicting shunt-responsive patients; however, high ICP amplitude was more accurate than positive DESH findings, although it is an invasive test.

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