Background: Superior semicircular canal dehiscence (SSCD) is a recently described rare condition. SSCD symptoms include vertigo, oscillopsia, autophony, sound hypersensitivity , and conductive hearing loss. Patients with sever symptoms may require surgical treatment. Tranmastoid and middle fossa (MCF) approaches are common approaches. Methods: We are presenting our experience at the Ottawa Hospital over the last three years. Also we describe our multidisciplinary surgical approach and modalities to localize the SSCD intraoperatively. Demographic data, presenting symptoms, co-morbidities, radiologic imaging, and surgery length were recorded. All patients had hearing and vestibular tests before and after their surgeries. Results: 14 surgeries were performed in 11 patients (three patients had bilateral SSCD). Most patients were males (82%). Age range was 32-68 years. Surgeries were done by a team of a neurosurgeon and a neuro-otologist. Localization of SSCD was done using stereotactic guidance. Five layers’ reconstruction was performed in all patients. All patients had significant improvement in symptoms without sensorineural hearing loss. None of the patients developed post-operative hematoma, infection, seizures, CSF leakage or facial palsy. LOS was 1-2 days. Conclusions: MCF with multi layers reconstruction should be considered as a safe and effective approach in severely symptomatic patients. We demonstrated that this approach has minimal risks especially in regards to sensorineural hearing loss.

Background: Unlike non-Hodgkin’s lymphoma, central nervous system involvement with classical Hodgkin’s lymphoma is exceedingly rare, thus information regarding treatment and prognostication of the disease is lacking. Methods: This case report was prepared using hospital charts, and PubMed for the literature search. Our case was compared and contrasted against similar cases in the literature. Results: We present the case of a 47 year old female who presented with a left parietal dural-based lesion which proved to be Stage IE primary CNS classical Hodgkin’s lymphoma. After surgery and whole brain radiation therapy, the patient has remained in complete remission over nine years. Conclusions: Despite the dearth of information available regarding CNS Hodgkin’s lymphoma, our case is consistent with the findings in the literature that long-term survival is possible in patients achieving a complete response to treatment, especially in those patients who present with sole CNS involvement. To our knowledge, this represents the longest reported survival in the literature and contributes to our understanding of prognosis in patients with CNS Hodgkin’s lymphoma.

Background: Cerebral venous sinus thrombosis (CVST) is a possible complication of closed head trauma with reported devastating outcomes. Its incidence however is unclear but believed to be frequent in patients with skull base fractures. The natural history of this under-recognized entity is not yet described, but a sensitive screening method is required to definitively address this question. Methods: Case report with literature review. Results: We report the case of a patient that sustained a severe head injury as the pedestrian in a motor vehicle accident. The patient required required a craniectomy to evacuate an acute subdural hematoma. Post-operatively, a CT venogram was performed and showed patent venous sinuses. A few days later, a double order resulted in a CTV being repeated erroneously but revealed the interval development of significant thrombosis of his left transverse sinus extending to his left internal jugular vein. We report on this patient’s outcome and follow-up. Conclusions: Further understanding of sinus thrombosis in the setting of TBI is warranted. The natural history is unclear, and most cases are discovered once symptomatic or after developing complications. Our case shows that current protocols have the potential of missing significant cases and study into the optimal timing of imaging is necessary.

Background: Colloid cysts of the third ventricle are a rare entity with an unclear natural history. Although intervening in the setting of a symptomatic patient is fairly straightforward, decision-making for asymptomatic patients is not. Few studies address this question and proposed risk factors for cyst progression vary.A cyst diameter exceeding 1 cm is a common indication for surgery. This is rooted in the belief that the natural history is continued growth. A few cases have recently surfaced that suggests some cysts may spontaneously regress without complication. We describe our experience with two such cases and contrast it with those of others. Methods: We collected all cases of “colloid cysts” identified as incidental findings on Brain CT scans in a large urban center with available follow-up. We then conducted a comprehensive review of the literature. Results: Among all incidental cases from our database, none required surgery and two were found to decrease in size on neuroimaging surveillance with interesting evolution in MRI signal characteristics. These cysts remain asymptomatic at last follow up. Conclusions: The natural history of colloid cysts includes spontaneous regression. This should be mentioned in counseling asymptomatic patients.

Background: Patients who require hospitalization for a mild or moderate traumatic brain injury (TBI) are often discharged home with uncertainty around their full recovery. This study examines the frequency and severity of common post-TBI symptoms, as assessed by the Rivermead Post-Concussion Symptoms Questionnaire (RPCQ). Methods: All adult TBI inpatients discharged home from the Neurosurgery service were interviewed by phone at two weeks by a rehab-based nurse practitioner. RPCQ components (cognitive, emotional, and somatic) were analyzed; findings and management recommendations were communicated to family practitioners and the treating neurosurgeon. Results: In 46 patients, cognitive symptoms were present in 52%, 91% had somatic, and 100% had emotional symptoms. Fatigue was the most common symptom (67%). Double vision was the least common symptom (4%). Recommendations for managing symptoms, return to work, and need for formal clinical assessment were provided for 37% of cases. Conclusions: All patients admitted to neurosurgery with mild or moderate TBI had symptoms at two weeks. The RPCQ is a low-cost structured evaluative tool which highlights needs and provides guidance for patients and care-givers; it also seems effective in identifying those who may require formal clinical assessment.

Background: Traditional neurosurgical techniques and/or stereotactic radiotherapy, although effective for solid tumors, can be associated with high morbidity and be relatively ineffective for long-term control of cystic sellar/parasellar tumors. The rationale of our study was to examine the efficacy and safety of stereotactic intracavitary instillation of 90yttrium colloid for the primary treatment of cystic tumors. Methods: As part of a Health Canada approved clinical trial, we have enrolled nine patients (6 females, 3 males; mean age 64, range 43 to 83 years) for treatment of symptomatic and/or enlarging cysts. Ten cystic sellar/parasellar lesions underwent right frontal stereotactic insertion of 90yttrium colloid to deliver a radiation dose of 200 Gy to the cyst wall. Results: Compared with pre-treatment cyst volumes (mean 4.6 cc; range 0.8-16.1 cc), the cysts decreased in size at 3 months (2.6 cc; 0.2-10 cc) with further shrinkage (n=5) at 9 months (1 cc; 0.1-2.7 cc). Of 9 patients with pre-operation visual field defects, 6 showed improvement. The single complication was a delayed (1 month) incomplete CNIII palsy. Conclusions: Our early experience indicates that 90yttrium colloid delivered to a cystic craniopharyngioma provides an efficacious alternative to open surgery for primary treatment of these cystic lesions.

Background: Patients with spontaneous intracerebral hemorrhage (ICH) suffer significant morbidity and mortality with lengthy critical care and hospital stays. Minimally invasive techniques for ICH removal have shown a positive relationship between hemorrhage volume reduction and patient outcome. We describe our single centre experience with endoscopic assisted, neuronavigation guided ICH evacuation using the Apollo system. Methods: Patients with ICH treated with the Apollo system since October 2014 were included in this retrospective review. ICH volume, clot reduction, midline shift, ICU and hospital length of stay, discharge disposition and last known functional outcome were assessed. Results: 58 patients were treated, mean age 54.1 years. Starting clot volume was 55.1±30.5cc, which was reduced to 10.2±12cc post-operatively, an average reduction of 80.6±25%. Midline shift improved from 7.1±4.5mm to 4.4±3.2mm. Length of ICU stay was 10.2±7.6 days. Covariate analysis showed greater relative reduction in ICH volume correlated with shorter ICU stay (p=0.01). In-hospital mortality was 27.3%; 29.1% of patients were discharged home either form hospital directly, or after a period of short-stay rehab. Conclusions: Significant hematoma volume reduction and improvement in midline shift is possible with the Apollo system. Degree of reduction of hematoma volume was associated with a shorter ICU Stay. Randomized controlled studies will be required to determine long term clinical benefit.

Background: The Canadian Neurosurgery Research Collaborative (CNRC) was founded in November 2015 as a resident-led national network for multicentre research. We present an annual report of our activities. Methods: CNRC meetings and publications were reviewed and summarized. The status of ongoing and future studies was collected from project leaders. Results: In its first year, the CNRC produced two papers accepted for publication in the Canadian Journal of Neurological Sciences: A CNRC launch letter and a study of operative volume at Canadian neurosurgery residency programs. Three manuscripts are in preparation: 1) a study of the demographics of Canadian neurosurgery residents, 2) an assessment of mobile devices usage patterns and 3) a validation study of the most utilized neurosurgery mobile apps. In addition, protocols for two multi-centre studies are currently undergoing national Research Ethics Board review: A retrospective study of the incidence and predictors of cerebellar mutism and a prospective registry of external ventricular drain procedures and complications. The network is now a registered not-for-profit organization endorsed by the Canadian Neurosurgical Society. Conclusions: The CNRC is a feasibile, relevant and productive resident-led national research network. As the CNRC matures, we look forward to expanding the scope and impact of its projects.

Background: Historically, description of patient visual acuity and visual field changes following intracranial procedures has been very rudimentary. Clinicians and researchers have relied on the use of vague descriptions like “improved”, “worsened”, and “unchanged” to describe outcomes following resections of tumours affecting the optic apparatus, which are difficult to quantify in a clinical setting. Methods: We present a novel way to describe a patient’s visual function as a combination of visual acuity and visual field assessment that is simple to use and can be used by surgeons, and researchers to gauge visual outcomes following tumour resection. Results: With our scale we were able to capture the overall visual change while being sensitive enough to define the overall quantity of improvement or worsening quantitatively, using categories that are clinically relevant and understandable. Conclusions: The implementation of pre- and post- operative assessment provides clinically relevant information for surgeons and is robust for routine use.

Background: Occasionally low grade gliomas (LGGs) are identified incidentally while asymptomatic. The diagnosis of incidental LGGs has become more frequent due to increase in access to medical imaging. While management of these lesions remains controversial, early surgery has been suggested to improve outcome. Methods: All LGGs treated between 2004 and 2016 at our institution were reviewed. Patients with incidentally discovered glioma were identified and retrospectively reviewed. “Incidental” was defined as an abnormality on imaging that was obtained for a reason not attributable to the glioma. Outcomes were measured by overall survival, progression free survival and malignant progression free survival. Results: Thirty-four out of 501 adult patients who were treated for low grade glioma were discovered incidentally. Headache (26%, n=9) and screening (21%, n=7) were the most common indications for brain imaging. The mean duration follow up was 5 years. Twelve patients had disease progression, 5 cases of malignant progression and 4 deaths. Oligodendroglioma was diagnosed in 16 and astrocytoma in 15 patients. Twenty-five (74%) patients had IDH1 mutation and demonstrated prolonged survival. Conclusions: This retrospective cohort of incidentally discovered LGGs were surgically removed with minimal surgical risk. There is improved overall survival likely attributable to the underlying favorable biology of the disease indicated by the presence of IDH1 mutation.

Background: Neurocysticercosis is the world’s leading cause of epilepsy and the most common helminthic disease affecting the human nervous system. It is relatively rarely seen in developed nations, and usually presents clinically with seizures. Methods: This case report was prepared using the patient’s hospital chart, and a review of the literature was undertaken using PubMed. This case was subsequently compared and contrasted to the known neurocysticercosis literature. Results: This is the case of an otherwise healthy 38 year old Nepalese female who presented with a history of headaches. Nonspecific in nature, they had worsened in the past couple of weeks, thus prompting appropriate imaging of the head. A large 4 cm ring enhancing lesion with edema and mass effect was discovered in the right anterior temporal lobe. No other neurological findings were found on exam. Pathological analysis confirmed a larval scolex of T. solium. Conclusions: Aside from being an unusual pathology to be seen in Manitoba, this case is unique in both its clinical and radiographic presentations. There were no seizures noted on presentation, and a significant amount of mass effect was seen around a large lesion, all unusual features for neurocysticercosis.

Background: Recurrent ophthalmoplegic cranial neuropathy (ROCN), previously called ophthalmoplegic migraine, is characterized by recurrent episodes of headache and ophthalmoplegia of unclear etiology. Characteristic neuroimaging findings can support the diagnosis. Methods: A case report and review of the literature. Results: We present a 6-year-old girl with a past history of migraine headaches associated with retroorbital pain since 4 years of age. Family history is positive for migraine. She presented with a half a day history of left eye ptosis, 10 days post a resolved gastroenteritis which was associated with headaches. Examination showed only a left eye ptosis, pupil-sparing with no exotropia or diplopia. There was no headache. The rest of the neurologic examination was normal. Investigations showed normal blood tests and lumbar puncture. MRI head showed on thin cuts asymmetric nodular thickening (4mm) of the origin of the cisternal segment of the left oculomotor nerve, with corresponding homogeneous enhancement post gadolinium infusion. Clinical resolution occurred spontaneously within 48 hours. A review of the literature highlights focal thickening and enhancement of the affected cranial nerve, with resolution of enhancement post-acute phase. Conclusions: Focal thickening and enhancement of affected cranial nerve is seen in the majority of pediatric ROCN. These findings are best seen with thin MRI cuts and gadolinium infusion.

Background: Stiff person syndrome (SPS) is a rare disorder presenting with progressive stiffness and spasms of the musculature of the trunk and limbs. SPS is reported very rarely in children and adolescents, with 5 cases over 25 years in a recent 99 patient cohort. Methods: Case Study Results: Herein we report a 15 year old female, presenting with acute onset of rapidly progressive spasticity of the lower extremities. Initial exam was remarkable for markedly limited left knee range of motion, in addition to asymmetrical knee spastic catch and hyper-reflexia. EMG revealed almost continuous motor unit activity which dissipated with voluntary muscle contraction. Diagnosis was confirmed by high titres of glutamate decarboxylase (GAD65) antibodies >25,000 units/ml. The patient was initially treated with IVIG, baclofen, and diazepam followed by IV methylprednisolone, with mild subjective improvements. One day following the first rituximab treatment, she achieved spontaneous knee flexion and regained the ability to ambulate independently. There is a residual spastic catch at the knees. Conclusions: This case highlights that SPS, albeit extremely rare, should be considered in the differential diagnosis of acquired spasticity in children. Also noteworthy is the relatively rapid resumption of function with aggressive immunomodulatory treatments in this historically devastating disorder.

Background: ETV/CPC has become an increasingly common technique for the treatment of infant hydrocephalus. Both flexible and rigid neuroendoscopy can be used, with little empirical evidence directly comparing the two. We, therefore, used a propensity-matched cohort and survival analysis to assess the comparative efficacy of flexible and rigid neuroendoscopy. Methods: Individual data were collected through retrospective review of infants < 2 years of age, treated at one of 2 hospitals: 1) Boston Children’s Hospital, exclusively utilizing flexible neuroendoscopy, and 2) Nicklaus Children’s Hospital, exclusively utilizing rigid neuroendoscopy. Patient characteristics and post-operative outcome were assessed. A propensity score (PS) model was developed to balance patient characteristics in the case mix. Results: A PS model was developed with 5 independent variables: chronological age, sex, hydrocephalus etiology, prior CSF diversion, and prepontine scarring. PS analysis revealed that compared to flexible neuroendoscopy, rigid neuroendoscopy had an ETV/CPC failure OR of 1.43 and 1.31 respectively, compared to unadjusted OR of 2.40. Furthermore, in a Cox regression analysis controlled by propensity score, rigid neuroendoscopy had a HR of 1.10, compared to unadjusted HR of 1.61. Conclusions: Much of the difference in ETV/CPC outcome between endoscopy types is attributed to the case mix. An observational study or randomized controlled trial is required to provide evidence-based guidelines.

Background: Pediatric hydrocephalus is one of the most common neurosurgical conditions and is a major contributor to the global burden of surgically treatable diseases. Methods: The authors conducted a literature review around the topic of pediatric hydrocephalus in the context of global surgery, the unique challenges to creating access to care in low-income countries, and current international efforts to address the problem. Results: Developing countries face the greatest burden of pediatric hydrocephalus due to high birth rates and greater risk of neonatal infections. This burden is related to more general global health challenges, including malnutrition, infectious diseases, maternal and perinatal risk factors, and education gaps. Unique challenges pertaining to the treatment of hydrocephalus in the developing world include a preponderance of postinfectious hydrocephalus, limited resources, and restricted access to neurosurgical care. In the 21st century, several organizations have established programs that provide hydrocephalus treatment and neurosurgical training in Africa, Central and South America, Haiti, and Southeast Asia. These international efforts have employed various models to achieve the goals of providing safe, sustainable, and cost-effective treatment. Conclusions: Broader commitment from the pediatric neurosurgery community, increased funding, public education, surgeon training, and ongoing surgical innovation will be needed to meaningfully address the global burden of untreated hydrocephalus.

Background: Absence epilepsy (AE) is believed to be generated by a thalamocortical network. Our laboratory showed that hippocampal neuronal firings were synchronous with the SWDs in the gamma butyrolactone (GBL) model of AE in rats. Here, we hypothesize that high frequency oscillations (HFOs) in the hippocampus and other parts of the limbic system were phase modulated by SWDs Methods: GBL (200 mg/kg i.p) was injected to induce SWDs in 6 male Long-Evans rats. Spontaneous local field potentials (LFPs) were recorded from electrodes implanted in the hippocampus and ventrolateral thalamus bilaterally and the right frontal cortex. For each LFP, modulation index (MI) gives the cross-frequency amplitude modulation of the HFOs (;90-250 Hz) by the phase of the SWD frequency at 2-8 Hz Results: Phase modulation of the HFOs by 2-8 Hz frequency increased for >45 min after GBL injection. MI increase was higher for hippocampal than thalamic LFPs, and not significant for frontal cortical LFP. MI for the nucleus accumbens LFP (N= 1 rat) also increased after GBL Conclusions: The modulation of HFOs (presumed local neural activity) by SWD frequency provides further support that the hippocampus and connected limbic system may become synchronous with the SWDs in AE

Background: Deep brain stimulation (DBS) is the application of electrical currents via depth electrodes to regulate neuronal activity. DBS has been shown as a productive intervention for seizure control in patients with drug-resistance. This case had both a failed response to antiepileptic drugs (AEDs) and a temporal lobectomy. Methods: This case details the evolution of epilepsy in a 29-year-old female with seizures since the age of around 10. The patient has been followed for 6 months to monitor the treatment effects. No medication changes were made post-procedure. Results: The patient experienced a seizure frequency of 2-5 events per month. The patient had a right temporal lobectomy at age 12, which led to only 3 years in remission. The events are complex partial seizures characterized by unresponsive staring, lip smacking, hand automatisms and confusion. The patient failed 7 AEDs. Intracranial recording showed the most frequent activity coming from the left anterior and posterior hippocampus. Two depth electrodes were implanted accordingly. Stimulation began in September 2016 and the patient has since had only 2 seizures. Conclusions: Deep brain stimulation provides extensive relief for this case of intractable epilepsy. The patient’s level of awareness, mood, and quality of life all improved significantly in response to treatment.

Background: Epilepsy surgery remains one of the most underused of all current medical interventions. It is estimated that less than 1% of patients with drug-resistant epilepsy are referred to specialized centers. The average delay from onset of seizures to surgical procedures is between 10 to 20 years Methods: In this study we describe the waiting times from the diagnosis of epilepsy to the assessment and epilepsy surgery at the epilepsy center of the University of Saskatchewan (SEP) Results: We included 70 patients assessed in the epilepy program between 2007 and 2015. Mean age of patients was 42.2+13. The time from the diagnosis of epilepsy to the referral was 16 years. The times for the for assesment and testing were the following: to the first consult with the epileptologist was 208 months, to the neuropsychological test was 201 months, to the video-EEG telemetry 219 months, to the first consult to neurosurgery 227 months and finally to the epilepsy surgery was 238 months. Conclusions: This study shows that patients with complex epilepsy in Canada are waiting significant time to be properly diagnosed and treated. Our study shows similar waiting times to otehrdeveloped countries suggesting a global problem in the reference of patients to epilepsy programs.