To examine time delays and identify factors that affect wait times from index neurological event to carotid endarterectomy in patients with symptomatic carotid stenosis treated at a regional neurosurgical referral centre.

We performed a retrospective audit over two years of all patients who underwent a carotid endarterectomy at University Hospital, London, Ontario. The number of days was calculated from first neurological event through until surgery.

Eighty-nine carotid endarterectomies (CEAs) were performed by four surgeons during the years 2006 and 2007. From the first neurological event, the median wait time for surgery was 111 days, while from the last event the median wait time was 83 days. There was 19 days' wait between specialist / TIA clinic appointment and the receipt of neurosurgical referral. Median wait time for diagnostic imaging was eight days for carotid Doppler ultrasound and 15 days for CT or MR angiography. There was a 44 day wait from receipt of neurosurgical referral to the date of surgery. Only three patients (4%) received CEA within two weeks of their last neurological event. There was a trend towards a difference in wait times between inpatients and outpatients, but no difference between females compared with males, or between patients presenting with stroke versus TIA.

Median wait times for CEA after first neurological event was over three months at our center, reflecting the diagnostic workup required in TIA as well as the lack of a systematic approach. This is the subject of continued study at our institution.

Cushing disease (CD) constitutes a challenging condition for the pituitary surgeon. Given the variety of factors affecting outcomes in CD, it is uncertain whether the newer endoscopic technique improves the results of surgery.

A review was conducted of CD cases at our institution between 2000 and 2010. Analysis was done to: determine if surgical technique had an effect on outcome, identify the predictors of outcome and provide details of failed cases. Remission was defined as normal postoperative 24-hour urinary free cortisol (24-h UFC), suppression of morning serum cortisol to <50 nmol/L after 1mg of dexamethasone or being dependent on steroid replacement.

Forty-two patients met our inclusion criteria. Average follow-up period was 33 months. There were 15 macroadenomas and 27 microadenomas. Seventeen patients had an endoscopic transsphenoidal surgery and twenty-five patients had a microscopic transsphenoidal procedure. Long-term overall remission was achieved in 26 (62%) patients. There was no significant difference in remission rates between the two techniques (p value 0.757). Patient's subjective symptomatic improvement and drop of morning serum cortisol in the postoperative period to less than 100 nmol/L correlated with long-term remission (p value 0.0031and 0.0101, respectively) while repeat surgery was the only predictor of the lack of postoperative remission (p value 0.0008).

Revision surgery predicted poor remission rate for CD. Within the power of our study size, there was no difference in outcome between the endoscopic and microscopic approaches. Surgical outcomes should be reviewed in association with remission criteria used in a study.

To review our institutional experience with Gamma Knife (GK) stereotactic radiosurgery in treating large vestibular schwannomas (VS) of 3 to 4 cm diameter.

We conducted a retrospective cohort review of all patients treated with GK for VS at our institution between November 2003 and March 2012. Data on age, sex, VS volume, location and maximal diameter, House-Brackmann (HB) facial nerve scores pre and post-GK, Gardner-Robertson (GR) hearing score pre and post-GK, GK treatment parameters, VS response time, complications and clinical outcome was recorded.

A total of 28 patients during the defined time period were identified. Three patients were lost to follow-up. Mean follow-up was 34.5 months. Tumor control occurred in 92%, and was maintained in 85.7% at two years. Facial nerve or hearing preservation occurred in all treated compared to pre-GK status, as per HB and GR grading. Transient complications occurred in 80%. Temporary vestibular dysfunction occurred in seven patients (28%). One patient (4%) had the permanent complication of worsening pre-GK hemifacial spasm. Four patients (16%) developed hydrocephalus post-GK.

GK stereotactic radiosurgery as a primary treatment modality for large VS can provide acceptable tumor control rates with good facial nerve and hearing preservation, and low complication rates.

In most studies, treatment decisions of brainstem glioma are based solely on MRI features and do not incorporate a histopathological diagnosis. In the current study, we sought to compare MRI characteristics with histopathological findings of bainstem glioma.

From April 2003 through April 2012, 150 patients were diagnosed with brainstem gliomas by MRI and microsurgically treated in Tiantan Hospital, Beijing, China. All the MRI and histopathological findings of these patients were respectively reviewed.

Of the 150 patients, 65 were female and 85 were male, 120 were adults and 30 were children (age < 18 years), 108 were low-grade glioma (72.0%), 35 were high-grade glioma (23.3%). The accuracy of the MRI diagnosis for brainstem glioma was 95.3%. Data analysis of the MRI findings revealed that a focal lesion was associated with a more favorable histopathological diagnosis in intrinsic (P=0.005) and exophytic (P=0.001) brainstem glioma patients. In the intrinsic diffuse type, tumors without enhancement had more favorable pathological findings (P=0.009).

To our knowledge, this is the largest case series of this nature reported in the literature to date. The results of this study suggest that MRI features of brainstem gliomas could predict some pathological features and guide prognosis, choice of biopsy and treatment modalities. The pathology of tumors with a focal appearance on MRI was associated with a prognosis that was significantly better than their diffuse counterparts. For the intrinsic diffuse gliomas, non-enhancing tumors had pathology suggestive of a favorable prognosis.

The overall prognosis of brainstem gliomas is very poor, and the current treatment cannot significantly prolong the overall survival of these patients; therefore, studying the molecular biological mechanisms of the occurrence and development of brainstem gliomas has important significance for their treatment. The Wnt/β-catenin signaling pathway is closely associated with the occurrence and development of tumors, but its relationship with brainstem gliomas remains unclear.

This study used Western blot and immunohistochemistry methods to detect the expressions of Wnt/β-catenin signaling pathway-related components such as Wnt-1, Wnt-2, β-catenin and C-myc in six cases of normal brain tissues and 24 cases of brainstem gliomas and analyzed the relationship between their expressions and clinicopathological characteristics.

Wnt-1 had no obvious expression in normal brain tissues and did not show any significant difference between high- and low-grade brainstem gliomas; the expressions of Wnt-2, β-catenin and C-myc in high-grade brainstem gliomas were significantly higher than that in low-grade brainstem gliomas and normal brain tissues and were positively correlated with the expression of Ki-67. Moreover, the expressions of Wnt-2 and C-myc were significantly associated with the prognosis of brainstem glioma patients; additionally, there was a trend toward increased β-catenin expression with shorter survival, but there was no statistical difference.

Wnt/β-catenin signaling pathway might be abnormally activated and plays an important role in the occurrence and development of brainstem gliomas. Wnt-2, β-catenin and C-myc may be potential targets for brainstem glioma treatment.

The current methods to predict recurrence and aggressive behaviour of meningiomas rely mainly on histological grading, histological subtype, proliferative index, as well as brain invasion. In many instances, histological grade alone fails to predict recurrence in the grade I and grade II meningiomas. Deletions of 1p and 14q have previously been reported to correlate with poor prognosis in terms of either recurrence or higher histological grades. The Her2neu (ErbB2) amplification has been shown to be a useful predictor of aggressive behaviour in breast and ovarian tumours, but its significance in meningioma is so far uncertain.

In order to determine the cytogenetic differences between 22 recurrent and 25 non-recurrent meningiomas of all grades, we used fluorescent in situ hybridization (FISH) DNA probes for 1p36, 14q11.2 and 17q11.2-12 (Her2neu) on formalin fixed paraffin embedded (FFPE) tissue from the Brain Tumour Tissue Bank (BTTB), London Health Science Center (LHSC).

We showed a positive association for meningioma recurrence correlated with 1p36 deletion plus or minus 14q 11.2 deletions in all grades of meningiomas. The Her2neu amplification was strongly associated with 1p/14q co-deletion in cases of recurrent meningiomas, especially the higher grade tumours.

These cytogenetic markers can be applied in addition to histological grading for predicting the risk of recurrence and biological behaviour.

Determining factors predictive of the natural risk of rupture of cerebral aneurysms is difficult. We studied morphological factors associated with rupture in a study model of patients with mirror location intracranial aneurysms, one aneurysm that had ruptured and one that had not, each patient served as their own control attempting to eliminate confounding variables.

We collected five one-dimensional measurements and four two-dimensional indices from three-dimensional rotational digital subtraction angiography images of patients in the proposed study model and explored their correlation with aneurysm rupture. Parameters were analyzed with a paired Student's t test for significance and significant parameters were further examined by multivariate conditional logistic regression analysis.

Fifty-two patients with 52 pairs of intracranial aneurysms in a mirror location were studied. The maximum perpendicular height, neck diameter, maximum width, maximum height, aspect ratio, size ratio, and bottleneck factor were significantly associated with ruptured aneurysms on bivariate analysis. A logistic regression analysis showed that only size ratio, which was defined as the ratio of the maximal height to parent artery average diameter, is independently correlated with ruptured intracranial aneurysms.

In a case-control study of patients with mirror location intracranial aneurysms, size ratio was identified as the unique morphological factor associate with the rupture of cerebral aneurysms.

Admission to an Epilepsy Monitoring Unit (EMU) is essential for pre-surgical evaluation of patients with medically-refractory epilepsy; however, prolonged referral times and resource limitations are significant access barriers. Therefore, identification of pre-EMU variables that predict potential surgical candidates can assist in the triage of patient admissions to the EMU.

In this hypothesis-generating study, a retrospective analysis of patients admitted for pre-surgical evaluation to the Toronto Western Hospital EMU (2004-2011) was performed. Univariate and multivariate logistic regression was used to identify variables that could independently predict subsequent surgical candidacy following EMU evaluation.

Four hundred and fourteen patients were admitted to the EMU. Overall, 259 patients (62.5%) were identified as potential surgical candidates. One hundred and seven patients (25.8%) required invasive electroencephalogram (iEEG) implantations; of 75 patients consenting to iEEG analysis 39 underwent a subsequent resective procedure. Male patients and those with a lesion on MRI were 1.9 times more likely to be surgical candidates (95% CI 1.18-2.98 and 0.94-3.80, respectively), while patients with non-localizable seizures were seven times less likely (95% CI 0.02-1.25).

In this retrospective, hypothesis-generating study male gender, presence of a lesion on MRI and localizable seizures on routine outpatient EEG analysis independently predicted subsequent resective epilepsy surgical candidacy in EMU patients. Upon validation by other studies, these variables may be considered by clinicians referring patients to the EMU in order to improve wait times and optimize patient care.

The allocation of limited healthcare resources poses a constant challenge for clinicians. One everyday example is the prioritization of elective neurosurgical operating room (OR) time in circumstances where cancellations may be encountered. The bioethical framework, Accountability for Reasonableness (A4R) may inform such decisions by establishing conditions that should be met for ethically-justifiable priority setting.

Here, we describe our experience in implementing A4R to guide decisions regarding elective OR prioritization.

The four primary expectations of the A4R process are: (1) relevance, namely achieved by support for the process and criteria for decisions amongst all stakeholders; (2) publicity, satisfied by the effective communication of the results of the deliberation; (3) challengeability through a fair appeals process; and (4) Oversight of the process to ensure that opportunities for its improvement are available.

A4R may be applied to inform OR time prioritization, with benefits to patients, surgeons and the institution itself. We discuss various case-, patient-, and surgeon-related factors that may be incorporated into the decision-making process. Furthermore, we explore challenges encountered in the implementation of this process, including the need for timely neurosurgical decision-making and the presence of hospital-based power imbalances.

The authors recommend the implementation of a fair, deliberative process to inform priority setting in neurosurgery, as demonstrated by the application of the A4R framework to allocate limited OR time.