The angiotensin-1 converting enzyme (ACE) gene is known to have two polymorphic alleles insertion/deletion(I/D). People with the DD genotype have been shown to be at greater risk of cerebral infarction, but only in some studies. Identification of cerebral infarction susceptibility genes and quantification of associated risks have been hampered by conflicting results from underpowered case-control studies. This meta-analysis was made to look specifically into the genetics of cerebral infarction among Han Chinese population.

Genetic associations studies published from January 1, 1990 to December 30, 2007 were collected from databases of MEDLINE, EMBASE, CBM and CNKI. Data were extracted using standardised forms and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

Twenty-nine original case-control studies of Han Chinese population, comprising 3654 patients with cerebral infarction and 3058 controls were included in the meta-analysis. Using the random effects model, the pooled ORs of ACE DD genotype VS ID+ II was 1.91 (95% CI 1.56 to 2.34, P<0.00001).

These data suggest that the ACE DD genotype may be a risk factor for cerebral infarction in Han Chinese population. A large scale case-control study is needed to clarify the functional effect of the polymorphism of the ACE I/D gene in the pathogenesis of cerebral infarction in Han Chinese population.

Friedreich's ataxia (FRDA) is an inherited recessive disorder characterized by progressive neurological disability and heart abnormalities. A deficiency in the protein frataxin causes this disease. Frataxin deficiency leads to progressive iron accumulation in mitochondria, excessive free radical production and dysfunction of respiratory chain complexes. The expansion (GAA) repeat in the first intron causes decreased frataxin expression by interfering with transcription.

Activity of mitochondrial respiratory chain complex I (measured as NADH ferricyanide reductase) and intracellular ATP measurement was performed on lymphocyte of FRDA patients (n=12) and control subjects (n=25).

Our findings showed that complex I activity and intracellular ATP were significantly reduced (P=0.001) in patients compared with controls and we found strong correlation between complex I activity and intracellular ATP content in FRDA patients (r = 0.93; P<0.002). 8.6 and 9.0 kb deletion in mtDNA was detected in 9 patients out of 12 (75%) by multiplex polymerase chain reaction (PCR) and Southern blot analysis.

This study suggested that a biochemical defect in complex I activity and ATP production, which may be due to iron accumulation in mitochondria, can be involved in age of onset of FRDA.

Recently a high prevalence of asystole was found in individuals with refractory epilepsy.

To measure the prevalence and characterize the pattern of ictal bradycardia (IB) in our cohort.

We analyzed ictal heart rate (HR) and seizure localization in 69 consecutive individuals with intractable epilepsy. Ictal bradycardia was defined by HR less than 60 beat per min (bpm) and a fall of more than 30 bpm.

Ictal bradycardia was observed in 1.9% of seizures and in five individuals (7.2%), who presented IB in 5.7% of their seizures. Four of them had also relative IB (a decrease of HR of more than10 bpm) in the majority of their seizures. Four additional individuals showed relative IB.

Ictal bradycardia occurs more frequently than previously thought in individuals with refractory epilepsy. Recognition of individuals with small to moderate ictal HR decrease may help to identify those at greatest risk for asystole.

Most estimates of the prevalence of seizure disorders in Canada derive from national surveys which differ in sampling and case-finding methods. This study used health care utilization data to make a population-based estimate of the prevalence of epileptic seizures and of epilepsy in children in British Columbia (BC).

All BC residents between 0-19 years-of-age in 2002-3 enrolled in the Medical Services Plan were included. Epileptic seizures were defined using ICD-9 codes; health care utilization data was obtained from BC Linked Health Database. The period prevalence of epileptic seizures and of epilepsy was determined by age, urban/rural region and socioeconomic status.

8,125 of 1,013,816 children were identified as having an epileptic seizure of which 5,621 were classified as epilepsy - 5.5 per 1,000 children (95% CI: 5.4-5.7). The prevalence of epilepsy in infants and preschoolers was higher than that reported in the literature. A higher prevalence of epilepsy was observed also among those with low socioeconomic status. A higher prevalence of epilepsy was observed in those health regions with a higher proportion of First Nations and a lower prevalence was observed in health regions with a higher proportion of visible minorities.

Age-specific prevalence rates in BC children for epilepsy, determined from population-based administrative records, were similar to published data except in children under five years. We found a gradient of increased prevalence with decreased level of income. Prevalence rates based on utilization data have the potential to guide program planning for children with epileptic seizures.

To investigate the use of computed tomography (CT) scans in patients with suspected acute mild traumatic brain injury (mTBI) presenting to emergency departments.

850 potential mTBI cases were identified through reviews of three months of health records from nine selected emergency departments across the province of Ontario. Records for review were selected using the International Classification of Disease, 9th revision, Clinical Modification codes and Injury codes.

Patients who received head CT were significantly older (p<0.01), had documented loss-of-consciousness (LOC) &/or Post-TraumaticAmnesia (PTA) (p<0.001), documented nausea (p<0.01), documented vomiting (p<0.001), abnormal neurological exam results (p<0.01), had visited an urban center (p<0.001), and/or arrived by ambulance (p<0.001). The significant predictors of CT scan prescription (in a forward stepwise logistic regression) were urban location of hospital (OR=5.14; p≤0.001), LOC &/or PTA (OR=4.83; p≤0.001), vomiting (OR=2.56; p≤0.01), arrival by ambulance (OR=2.15; p≤0.001), nausea (OR=1.92; p=≤0.02) and older age (OR=1.02; p≤0.01).

These data extend our knowledge regarding the use of CT during acute diagnosis and management of suspected mTBI patients. In addition to confirming previously reported risk factors of intracranial complication, geographical location of hospital and arrival mode were found to be significant predictors of CT use. The results suggest that the management patterns for acute mTBI are inconsistent. The implications of this are discussed.

Neuromonitoring during paediatric (and adult) spinal deformity surgery helps to reduce the risk of both permanent and short term neurological damage. A shortage of neurophysiologists and technicians limits the availability of this service. Not all surgeons believe neuromonitoring offers neuroprotection during spinal surgery. This study aimed to document the degree to which paediatric patients undergoing spinal deformity correction surgery have their spinal cord function monitored.

A questionnaire was sent electronically to all of the surgical members of the Canadian Paediatric Spinal Deformity Study Group.

Results were received from 9/9 centres indicating that monitoring was performed in 7/9 centres, with one further centre awaiting staffing. Whilst half of those centres that do monitor only monitor sensory and motor evoked potentials, the remaining centres also use EMG and EEG to assess the state of the patient intraoperatively.

Despite a shortage of staff, most paediatric spinal deformity surgeons in Canada who wish to, are able to neurophysiologically monitor their surgical cases. Neuromonitoring appears to be becoming a standard of care, at least for paediatric spinal deformity surgery. There is an urgent need for the establishment of national standards for both technologists and interpreters, as well as training programmes for both these groups.

To evaluate the effect of a group education program with personal rehabilitation for idiopathic Parkinson's disease (IPD).

A single-blind, randomized, controlled clinical trial, with a pre-test/post-test quasi-experimental design. Fortyfour stable, non-demented patients with IPD were randomly assigned to an intervention group (n=23) and control group (n=21). Three group lectures on health education specific to IPD were delivered to the intervention group. The theme of lectures was “Not a lonely journey, as your friend, we—experts specializing in IPD— would love to join with you.” Three domains of the management of IPD were mentioned: “How to manage your routine Meal, Moving and Mood after suffering from IPD” Each lecture was scheduled for 45 minutes (excluding breaks), and designed as an interactive dialogue rather than a traditional lecture. To strengthen the impact of the lectures, relevant information was published on a website: http://www.parkinsonism.cn/. Following the group lecture, individualized and tailored rehabilitation made up of 24 half-hour sessions over eight weeks were provided for the intervention group.

The program ran smoothly and IPD patients were satisfied with this program. After only eight weeks, the health-related quality of life (HR-QOL) in the intervention group improved significantly (p<0.001). Patients and their caregivers in this group also reported their mood elevations following the program.

Group education combined with personal rehabilitation program appears to be a beneficial and practical intervention, not only complementing the medical treatment for IPD patients but also meeting the growing demand for long-term care.

There is lack of published data on bulbar signs among the healthy population. This study aims to determine the range of normality of bulbar signs particularly among the elderly.

Systemic examination of bulbar signs was carried out according to a predetermined protocol on a cohort of young and elderly healthy subjects.

A total of 206 subjects were recruited in the study, 104 young adults with mean age of 20 years, and 102 elderly with mean age of 73 years. Uvula deviation was seen in 28 (26.9%) young subjects and 22 (21.6%) elderly. Irregular tongue border was seen in 17 subjects, unilateral in 4 subjects. Fourteen (6.8%) subjects had deviation on tongue protrusion. Occasional tremor of tongue on protrusion is common in both young and old. Persistent (severe) tongue tremor on protrusion was seen in 18.6% of the elderly, and 4.8% of the young. None of the subjects had tremor of tongue at rest. In gag reflex, absence of gagging response was common in elderly, seen in two thirds of the subjects on stimulation of the posterior pharyngeal wall. However, all the subjects had uvular movement. Habituation or suppression of gagging response was seen in close to 90% of young males.

There is wide range of normality in bulbar signs in normal population, particularly among the elderly.

Superficial anastomotic veins (SAVs) have been studied extensively but little attention has been paid to clinical studies. The aim of this study is to provide variations in the drainage patterns of SAVs depending on the intraoperative findings.

A total of 251 craniotomies due to intractable temporal lobe epilepsy were performed between 1972 and 1987 at the Montreal Neurological Institute. The courses of the three largest SAVs including the vein of Trolard (VT), vein of Labbe (VL) and superficial Sylvian vein (SSV) were studied.

All three veins showed variable courses. The most common predominant vein was the combination of the VL + SSV. The VT and VL were frequently coursed at the level of the central vein and middle temporal vein, respectively. On the right hemisphere the SSV was the predominant type while the VL tended to be predominant on the left hemisphere. A combination of VL and SSV was predominant in patients with right and/or left hemispheric dominance.

The SAVs showed considerable variation in their courses and it is difficult to define an exact pattern although some courses showed constant directions. Attention should be paid not to damage these veins since in a considerable number of cases a single dominant vein may be responsible for draining a majority of the lateral surface of cerebral hemisphere.

Dural sinus malformation (DSM) is a term used to describe congenital vascular malformations characterized by massive dilation of one or more dural sinuses: these dilatations are typically associated with arteriovenous shunts. Such malformations can present antenatally but their early natural history and anatomy is poorly defined.

We reviewed five years of autopsy experience and retrieved three primary vascular malformations of the fetal dural sinuses with ultrasound, magnetic resonance imaging (MRI) and post-mortem correlation.

Fetal ultrasound and MRI obtained between 19 and 23 weeks gestational age demonstrated in all cases dilation of the dural sinuses. In two cases vascular thromboses were present in either the dilated dural sinus (one of three) or the associated arteriovenous fistula (one of three). All cases were autopsied at 22-23 weeks gestational age. In one there was imaging and autopsy evidence of remodeling of the dural sinuses associated with a pial arteriovenous fistula. In two cases, no arteriovenous malformation was identified on initial imaging, but only became evident at autopsy. One case showed morphological overlap with vein of Galen aneurysmal malformation, with a midline arteriovenous shunt and vein of Galen ectasia. The other demonstrated a perisylvian dural arteriovenous fistula.

In utero thrombosis of feeding vascular malformations or of the dural sinus malformation may be prominent. The early in utero developmental trajectory of dural sinus malformation (DSM) is poorly defined and deserves further study.

Trigeminal neuralgia (TN) often remains difficult to treat despite multiple available medications, and can severely impact on the quality of life of affected patients. Gamma knife radiosurgery has recently emerged as a minimally-invasive alternative to surgery for patients suffering from drug-resistant TN. The goal of this study was to report the short-term efficacy of gamma knife radiosurgery for TN and assess its impact on the quality of life of patients treated in the first 18 months of our experience.

Patients with medically-refractory TN or with unacceptable drug side effects were considered for radiosurgery. A maximum dose of 80 Gy was administered to the affected nerve using a single 4-mm isocenter. Follow-up assessments were made at 2, 4 and 6 months, with evaluation of pain relief, drug reduction and quality of life. Factors impacting treatment response were assessed using Cox regression analysis.

A total of 67 patients were treated. Significant pain relief was seen in 77.6% of patients, including 32.6% who became pain-free. Patients were able to discontinue all medications in 34.3% or reduce drug intake by more than 50% in an additional 28.4% of cases. No variable was found to predict pain relief although older age (>66 years) approached statistical significance. Sensory side effects were seen in 14.9% of patients. Quality of life improved in the majority of patients after radiosurgery.

Gamma knife radiosurgery is a safe and effective management alternative for trigeminal neuralgia, providing good or excellent pain relief and improvement in quality of life in the majority of patients with few side effects.

Neurovascular compression (NVC) may cause cranial mononeuropathy but lacks a definitive diagnostic investigation. We hypothesized that the arterial pressure wave (APW) would interact at the neurovascular interface in NVC to inhibit transmission of transcranial magnetic stimulation (TMS) stimuli to affected muscles.

We report a novel neurophysiological method coupling cardiovascular physiology with TMS. The electrocardiogram (ECG) and arterial pressure wave (APW) were coupled to triggering of cortical TMS in a patient with NVC-induced spinal accessory (CNXI) mononeuropathy. Outcome measures included motor evoked potential (MEP) amplitudes and firing probabilities of normal and affected trapezieus (TPZ). Values at intervals in proximity to the APW (40/80/120/160ms) were compared to baseline (800ms) using ANOVA and student t-test.

Electrocardiogram triggered TMS of CNXI pathways with 100% reliability. MEP amplitudes were decreased in proximity to the APW, particularly at 120ms (0.21±0.04 mV versus 0.39±0.10mV, p=0.003). TPZ firing probabilities were similarly inhibited (43.8% versus 88.2%, p=0.009). No effect of APW proximity was observed on the unaffected side (p=0.868). Procedures were well tolerated.

Vascular compression causes CNXI mononeuropathy. Transcranial magnetic stimulation-cardiovascular coupling may evaluate neurovascular junction interactions and non-invasively diagnose NVC.

To explore the influence of environmental conditions on pattern visual evoked potential (VEP) recordings.

Fourteen subjects with no known ocular pathology were recruited for the study. In an attempt to optimize the recording conditions, VEP recordings were performed in both the seated and recumbent positions. Comparisons were made between recordings using either LCD or CRT displays and recordings obtained in silence or with quiet background music. Paired recordings (in which only one variable was changed) were analyzed for changes in P100 latency, RMS noise, and variability.

Baseline RMS noise demonstrated a significant decrease in the variability during the first 50msec accompanied by a 73% decrease in recording time for recumbent position when compared to the seated position (p<0.05). Visual evoked potentials recorded using LCD monitors demonstrated a significant increase in the P100 latency when compared to CRT recordings in the same subjects. The addition of background music did not affect the amount of RMS noise during the first 50msec of the recordings.

This study demonstrates that the use of the recumbent position increases patient comfort and improves the signal to noise ratio. In contrast, the addition of background music to relax the patient did not improve the recording signal. Furthermore, the study illustrates the importance of avoiding low-contrast visual stimulation patterns obtained with LCD as they lead to higher latencies resulting in false positive recordings. These findings are important when establishing or modifying a pattern VEP recording protocol.