Despite the growing recognition for analgesic needs in post-craniotomy patients, this remains a poorly studied area in neurological surgery. The class and regimen of analgesia that is most suitable for these patients remains controversial. The objective of this study is to examine the current beliefs and practices of Canadian neurosurgeons when managing post-craniotomy pain.

A survey was sent to all practicing Canadian neurosurgeons to examine the following aspects of analgesia in craniotomy patients: type of analgesics used, common side effects encountered, satisfaction with current regimen and the rationale for their practice.

Of 156 potential respondents, 103 neurosurgeons (66%) completed the survey. Codeine (59%) was the most prescribed firstline analgesic followed by morphine (38%). The use of a second-line opioid was significantly higher among codeine prescribers compared to morphine, 53% compared to 28% (p < 0.001). Nausea, constipation and neurologic depression were reported as common side effects by 76%, 66% and 27% of respondents respectively. Of the respondents, 90% reported a high level of satisfaction with their current choice of analgesia; nonetheless, they predominantly described their practice as personal preference or protocol driven rather than evidence-based.

Codeine - a weak opioid - is the most common first-line analgesic prescribed to craniotomy patients. This practice is associated with substantially increased reliance on potent opioids for rescue analgesia. Whether novel regimens can provide optimal pain control while minimizing neurologic and gastrointestinal side effects remains to be addressed by future trials.

To determine whether day length affects cognitive performance in rural and remote memory clinic patients.

A rural and remote memory clinic in Saskatoon, Saskatchewan provided an opportunity to examine how cognitive performance on the Mini-Mental State Exam (MMSE) is influenced by day length. Saskatchewan is an ideal location to test this association as day length varies greatly both seasonally and geographically. Following an initial assessment by the Rural and Remote Memory Clinic (RRMC) team in Saskatoon, patient follow-up appointments were performed either in-person or via telehealth videoconference. At each follow-up appointment the clinic neurologist administered the MMSE. The relationship between day length and MMSE scores at the sixweek follow-up appointment was analyzed in 154 patients. The mean daily temperature was controlled for in the analysis. Bivariate correlate and linear regression analyses were conducted.

There was no significant association between MMSE scores and either minutes of day length or mean daily temperature.

Day length does not appear to have significant effect on cognitive performance of rural and remote memory clinic patients.

Neuropathy is common in Waldenström's macroglobulinemia (WM, an IgM-associated lymphoplasmacytic lymphoma) and in IgM-monoclonal gammopathy of undetermined significance (IgM-MGUS). Paraneoplastic or paraimmune mechanisms are thought to be involved in the pathogenesis of these neuropathies. Attempts at distinguishing WM and IgM-MGUS neuropathies are lacking especially among bone marrow (BM) confirmed patients.

Retrospective analyses were performed on BM confirmed WM (N=30) and IgM-MGUS (N=73) neuropathy patients with neurologic assessments and hematologic features.

The presence of anemia and quantity of IgM monoclonal protein were significantly greater in WM. Based on multiple neurologic assessments differences were not found for: 1) length of time from neurologic symptom onset to evaluation; 2) chief complaint of painless loss of feeling in the feet, Romberg's sign and tremor; and 3) clinical motor, sensory and reflex abnormalities. Autonomic testing was normal in both diseases. Using nerve conduction (NCS) criteria for demyelination, 62% of IgM-MGUS and 27% of WM met this criteria (p=0.013). IgM MGUS patients had greater terminal conduction slowing by ulnar residual latency calculation (<0.01). The degree of axonal loss as measured by summated compound muscle action potentials and available nerve biopsy was not significantly different between diseases.

Although WM and IgM-MGUS must be distinguished for hematologic prognosis and treatment, clinical neuropathy presentations of WM and IgM-MGUS are similar and likely related to comparable axonal loss in both conditions. Despite these similarities, evidence of demyelination was found by electrophysiologic studies much more commonly in IgM-MGUS. This difference may reflect varied immune mechanism(s) in the two disorders.

The aim of this study was to evaluate whether magnetic resonance imaging (MRI) can be used as a noninvasive approach to assessment of disease severity and muscle damage in Myotonic Dystrophy type 1 (DM1).

The MRI findings in legs of 41 patients with DM1 were evaluated with respect to the tibialis anterior (TA) skeletal muscle impairment. Magnetic resonance imaging findings were compared with TA strength measurements obtained by quantitative manual testing, duration of the disease and with the length of the CTG repeats.

Muscle MRI abnormalities were observed in 80% of DM1 patients, ranging from edema-like abnormalities alone to severe atrophy / fatty replacement. Edema-like abnormalities seem to be an earlier MRI marker of the disease. Fatty infiltration/atrophy correlated with the TA muscle force (r = 0.95), the severity (P = 0.00001) of the disease but not with the duration of the disease (P = 0.3) or the length of the CTG repeats (P > 0.10), measured in peripheral leukocytes. Evaluation of other muscles of the legs revealed that the medial gastrocnemius and soleus muscles were the most frequently and severely affected muscles, while tibialis posterior muscles were relatively spared. Edema-like abnormalities are most frequently observed in the skeletal muscles of the anterior compartment.

Muscle MRI is helpful to depict muscle abnormalities but does not seem to be a reliable indicator of skeletal muscle involvement in DM1 since the decrease in TAmuscle force is not correlated with MRI abnormalities in some patients.

We carried out a population-based study of dystrophin mutations in patients followed by members of the Canadian Paediatric Neuromuscular Group (CPNG) over a ten-year period.

We aimed to describe the changes in diagnostic testing for dystrophinopathy and to determine the frequency of dystrophin mutations from 2000 to 2009.

De-identified data containing the clinical phenotypes, diagnostic methods, and mutational reports from dystrophinopathy patients followed by CPNG centres from January 2000 to December 2009 were analyzed using descriptive statistics.

773 patients had a confirmed diagnosis of dystrophinopathy based on genetic testing (97%), muscle biopsy (2%), or family history (1%). 573 (74%) had complete deletion/duplication analysis of all 79 exons or whole gene sequencing, resulting in 366 (64%) deletions, 64 (11%) duplications, and 143 (25%) point mutations. The percentage of patients who were diagnosed using currently accepted genetic testing methods varied across Canada, with a mean of 63% (SD 23). 246 (43%) mutations involved exons 45 to 53. The top ten deletions (n=147, 26%) were exons 45-47, 45-48, 45, 45-50, 45-55, 51, 45-49, 45-52, 49-50, and 46-47. 169 (29%) mutations involved exons 2 to 20. The most common duplications (n=29, 5.1%) were exons 2, 2-7, 2-17, 3-7, 8-11, 10, 10-11, and 12.

This is the most comprehensive report of dystrophin mutations in Canada. Consensus guidelines regarding the diagnostic approach to dystrophinopathy will hopefully reduce the geographical variation in mutation detection rates in the coming decade.

Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial syndrome on a disease spectrum with Kearns-Sayre syndrome (KSS). Clinical presentation is variable and our experience suggested that phenotypic differences exist in CPEO with onset after age 20.

This descriptive study is a retrospective chart review of 40 patients with late-onset CPEO. Clinical features, laboratory and neurophysiology results were reviewed.

Multisystem dysfunction was very common in this series. Gastrointestinal dysfunction was more common than expected (60%) as was migraine headache (40%). Clinical characteristics on the KSS disease spectrum were uncommon in this series with only 2.5% having pigmentary retinopathy, 5% with cardiac conduction abnormality, and 22.5% having endocrinopathy (most often thyroid dysfunction rather than diabetes). Neurophysiology abnormalities included length-dependent axonal polyneuropathy in 44% (sometimes subclinical) and myopathic EMG changes in 26%. Exposure to sources of acquired mitochondrial toxicity including cigarette use and hepatitis C infection were more common than expected in this series.

Phenotype was different in this late-onset series compared with previous reports in CPEO patients. In this series of late-onset patients, multi-organ dysfunction was more common than previously reported in CPEO, and some classical mitochondrial manifestations, such as pigmentary retinopathy were rare. We suggest that acquired mitochondrial toxicity may have a role in the pathogenesis of adult-onset CPEO.

Escalating focal sensorimotor seizures, progressive neurologic deficit and cognitive decline with associated typical magnetic resonance imaging (MRI) findings or pathological confirmation constitute the syndrome of Rasmussen's encephalitis.

Three patients with this clinical scenario had long-term follow-up after being given the antiviral drug ganciclovir 10 mg/kg/day IV for ten days within one to three months of disease onset.

Seizures occurred at least hourly and were localized to the Rolandic region. The MRIs were normal in one patient and in two showed changes consistent with ongoing seizures. Two patients, one whose short-term outcome was reported previously, had immediate and sustained cessation of seizures and resolution of their neurologic deficit. One patient with seizures from both hemispheres did not respond and went on to hemispherectomy that confirmed chronic encephalitis. Seizures continued in five other patients treated 6 to 72 months after disease onset.

The sustained seizure control after ganciclovir in two of three patients suggests this drug may be effective when given early in the course of this subacute intractable focal epilepsy syndrome.

New evidence suggests that levetiracetam may be as effective as traditional agents, with better safety profile.

To synthesize evidence regarding efficacy and tolerability of levetiracetam as first line, adjunctive or prophylactic antiepileptic agent.

Eligible studies were randomized controlled trials (RCTs) of levetiracetam used in adults with epilepsy. MEDLINE, EMBASE, CENTRAL, CINHAL, PAPERSFIRST, PROCEEDINGSFIRST, PROQUEST and conference proceedings identified studies (to September 30, 2010). Two investigators independently selected, appraised studies, collected and analyzed data.

Of ten eligible randomized trials, eight investigated adjunctive levetiracetam for refractory seizures, one as monotherapy for newly diagnosed seizures, one as monotherapy for prophylaxis. Eight RCTs of adjunctive levetiracetam were of moderate quality (GRADE criteria), with two showing lack of allocation concealment. Meta-analyses showed adjunctive levetiracetam was more effective than placebo in achieving at least 50% reduction of seizure frequency, when added to baseline antiepileptic regimen (pooled RR 2.15 [1.65,2.82], I2 = 45%, p value (heterogeneity) = 0.08, p value (overall effect) < 0.01). Likelihood of serious adverse events necessitating withdrawal from study was not significantly different between levetiracetam and control (pooled RR 1.37 [0.88,2.13], I2 = 0%, p value (heterogeneity) = 0.84, p value (overall effect) = 0.17). Subgroup analyses suggested similar effects across different dosages. Sensitivity analysis of studies with adequate concealment showed similar effects.

Levetiracetam is an effective adjunctive agent for refractory epilepsy. More studies are needed to establish whether it is effective as monotherapy for newly diagnosed seizures, and for prophylaxis in traumatic brain injury.

Migraine is a risk factor for ischemic stroke. Sterile vascular inflammation may develop during migraine attacks. This study aims to investigate procalcitonin (PCT) levels amongst migraine patients as they are important markers for infection and sepsis, but can also be found at elevated levels in various cases of inflammation.

Eighty adult migraine patients participated in our study. Patients were initially separated into two main groups; Group-1 consisted of 34 patients who had migraines during the attack period. Group-2 consisted of 46 patients during the period in-between attacks. Afterwards, patients were further divided into four subgroups based on their aura status; Group-1a Migraine without aura, 27 patients during attack period, Group-1b Migraine with aura, 7 patients during attack period, Group-2a Migraine without aura, 40 patients during the period in-between attacks, Group-2b Migraine with aura, 6 patients during the period in-between attacks.

Average PCT levels in patients during attack periods were found to be higher than the average PCT levels of patients during the period in-between attacks. These elevated levels were determined to be statistically significant(p<0.01). Serum PCT levels of the patients with migraine without aura during the attack period were significantly higher than those of patients during the period in-between attacks(p<0.01).

Based on significantly high levels of PCT, our results support the idea that sterile inflammation plays a role in migraine pathogenesis. Further studies are necessary to understand whether PCT is a marker for ischemic stroke risk in patients who go through frequent migraine attacks.

Motor deficits associated with Parkinson's disease (PD) have been well described, yet little attention has been paid to non-motor symptoms, especially cortical visual dysfunction. We investigated stereopsis, as well as the relationship between stereopsis and other cognitive function, in a sample of PD patients.

We used Titmus stereotest plates for assessing stereopsis. Fifty-nine subjects (29 PD patients and 30 normal controls) were included in this study. The included patients underwent a neurological examination, clinical rating scale and neuropsychological tests.

Drug naïve PD patients showed decreased stereopsis on the Titmus fly stereopsis test (Pearson χ2=23.80, p<0.001) compared to PD patients with normal stereopsis. The Hoehn-Yahr stages and Unified Parkinson's Disease Rating Scale motor scores were significantly higher in patients with PD with abnormal stereopsis than in patients with PD with normal stereopsis (p=0.026; p=0.046). The frequency of abnormal visual perception/constructive function was greater in patients with PD with abnormal stereopsis compared to patients with PD with normal stereopsis (Pearson χ2=5.11, p=0.024).

These findings suggest that stereopsis deficits and visual perception/constructive dysfunction are common in de novo PD patients.

5-hydroxytryptamine receptor 2A (5-HT2A) participates in diverse psychiatric disorders by regulating the activity of serotonin. Some previous studies have also suggested that the receptor is involved in cognitive abilities of disease groups. We hypothesize that some functional genetic variants in 5-HT2A have certain specific influences on cognitive abilities in a normal population.

To confirm this hypothesis, two polymorphisms (rs6313 and rs4941573) in 5-HT2A were selected, and a population-based study was performed in a young healthy Chinese Han cohort.

The results indicated that the rs6313 and rs4941573 were associated with touching blocks and mental rotation-3D error ratio in males, and the rs4941573 was associated with visuo-spatial working memory in the whole cohort.

All the findings suggest that 5-HT2A participates in human spatial cognitive abilities and spatial working memory.