Mary Chipman

Amitriptyline versus maprotiline in postherpetic neuralgia: a randomized, double-blind, crossover trial.

&NA; Amitriptyline (AT) relieves some patients with postherpetic neuralgia (PHN). Many patients suffer side effects and better therapies are necessary. The aim of this study was to evaluate the efficacy of maprotiline (MT) (noradrenergic) compared to AT (mixed noradrenergic and serotonergic) in this disorder. Thirty‐five patients entered a randomized, double‐blind, crossover trial of these two agents. We found that MT relieved PHN in many patients but was not as effective as AT. Side effects were troublesome with both agents. Relief of steady pain, brief pain and pain on tactile stimulation occurred. Four groups of responses were identified. Some patients reported relief with both agents, some with neither agent and others with only one of the drugs. Most patients were not depressed and analgesia was observed to occur without change in depression ratings in most patients who responded. This result provides evidence that in some patients AT may act via a selective noradrenergic mechanism in relieving PHN and that individuals may differ in the balance and type of neurotransmitters inhibiting pain. Selective noradrenergic agents may be effective if AT fails.

INJURY RISK ASSOCIATED WITH CANNABIS AND COCAINE USE

The purpose of this paper is to review the results and limitations of studies of injury risks associated with cannabis and cocaine use. Three types of fatal and non-fatal injuries are considered: injuries due to collisions, intentional injuries and injuries in general. Four types of studies were reviewed: (I) laboratory studies, (II) descriptive and analytic epidemiological studies on the prevalence of cannabis or cocaine use through drug testing of those injured, (III) studies of non-clinical samples, and (IV) studies of clinical samples of drug users. The research that utilized drug tests showed similar proportions testing positive for cannabis in fatal and non-fatal injury groups, and for collisions, violence and injuries in general. By contrast, large differences in the average proportions testing positive for cocaine were found among these same injury groups. For example, 28.7% of people with intentional injuries (primarily homicides) tested positive for cocaine, while 4.5% of injured drivers tested positive. Studies of non-clinical samples have shown that both cannabis and cocaine use are related to intentional injuries and injuries in general. Results indicate higher risk for all types of injuries among cannabis and cocaine clients in treatment. Strengths and limitations of the different types of studies are discussed. More rigorous studies are needed which should focus on ruling out alternative explanations for relationships between drug use and injuries.

Route Infrastructure and the Risk of Injuries to Bicyclists: A Case-Crossover Study

OBJECTIVES We compared cycling injury risks of 14 route types and other route infrastructure features. METHODS We recruited 690 city residents injured while cycling in Toronto or Vancouver, Canada. A case-crossover design compared route infrastructure at each injury site to that of a randomly selected control site from the same trip. RESULTS Of 14 route types, cycle tracks had the lowest risk (adjusted odds ratio [OR] = 0.11; 95% confidence interval [CI] = 0.02, 0.54), about one ninth the risk of the reference: major streets with parked cars and no bike infrastructure. Risks on major streets were lower without parked cars (adjusted OR = 0.63; 95% CI = 0.41, 0.96) and with bike lanes (adjusted OR = 0.54; 95% CI = 0.29, 1.01). Local streets also had lower risks (adjusted OR = 0.51; 95% CI = 0.31, 0.84). Other infrastructure characteristics were associated with increased risks: streetcar or train tracks (adjusted OR = 3.0; 95% CI = 1.8, 5.1), downhill grades (adjusted OR = 2.3; 95% CI = 1.7, 3.1), and construction (adjusted OR = 1.9; 95% CI = 1.3, 2.9). CONCLUSIONS The lower risks on quiet streets and with bike-specific infrastructure along busy streets support the route-design approach used in many northern European countries. Transportation infrastructure with lower bicycling injury risks merits public health support to reduce injuries and promote cycling.

The disablement experienced by traumatically brain-injured adults living in the community

The disablement that occurs following traumatic brain injury (TBI) can be extensive and severe and consequently has been difficult to report on in a comprehensive and thorough manner. We were able to address this difficulty by analysing a sub group of data from the Canadian Health and Activity Limitation Survey (HALS) using the theoretical framework of disablement developed by the World Health Organization, the International Classification of Impairment, Disability and Handicap (ICIDH). There were 454 survey respondents (representing 12,290 in the Canadian population) with disability resulting from a TBI and a mean time post-injury of 13 years. Three handicaps identified in the ICIDH were the focus of the study: physical independence, work, social integration. The prevalence of long term handicap was very high with 66% of the sample reporting the need for ongoing assistance with some activities of daily living, 75% not working, and 90% reporting some limitations or dissatisfaction with their social integration. Multivariate regression analysis was used to investigate the determinants of the handicaps. The determinants included: age, gender, level of education, living alone, physical environment, and specific disabilities. The implications of these findings are discussed in relation to rehabilitation issues, the usefulness of the ICIDH as a model to investigate outcomes, and directions for future research.

THE ROLE OF EXPOSURE IN COMPARISONS OF CRASH RISK AMONG DIFFERENT DRIVERS AND DRIVING ENVIRONMENTS

Crash rates based on drivers, driver-kilometers, and driver-days in the denominator were compared, using survey estimates of time and distance driven and the annual frequency of traffic crashes in Ontario. Rates by age, sex, and region were computed for all crashes and for crashes resulting in injury or fatality. Young male drivers remained at high risk for all types of denominator; older women had high rates when distance was included in the denominator. When time spent driving was substituted, men and women drivers over 60 had very similar rates. For comparisons of rural residents with urban and northern residents, time and distance give equivalent results. These findings suggest that apparent differences in crash risk per kilometre, whether for older women or for urban drivers, is explained by differences in typical driving speed and environment. Exposure time is better than distance to explain crash risk among drivers and regions with very different driving patterns and environments.

The prognosis with postherpetic neuralgia.

One hundred and fifty-six patients with moderate to severe postherpetic neuralgia (PHN) were followed for up to 11 years. Nearly half of all patients were doing well at the final assessment (median 2 years) and more than half of these were on no therapy at this time. The most commonly used agents associated with a good outcome were antidepressants, topical capsaicin and analgesics of various kinds. Longer duration PHN appeared to have a worse prognosis. More of these patients were noted to be using some form of treatment at follow up. A group of patients seemed to follow a progressive course and were refractory to all treatments used in this study.

Canadian minor hockey participants' knowledge about concussion

BACKGROUND AND OBJECTIVES In Canada and the USA, ice hockey is a cause of traumatic brain injury. Post-concussive symptoms are the most important feature of the diagnosis of concussion in sports and it is recommended that athletes not return to play while still symptomatic. Lack of knowledge of concussions could therefore be one of the main detriments to concussion prevention in hockey. The purpose of this research is to describe what minor league hockey players, coaches, parents and trainers know about concussion and its management. METHODS A questionnaire to assess concussion knowledge and return to play guidelines was developed and administered to players at different competitive levels (n = 267), coaches, trainers and parents (total adults n = 142) from the Greater Toronto Area. RESULTS Although a majority of adults and players could identify mechanisms responsible for concussion, about one-quarter of adults and about a quarter to a half of children could not recall any symptoms or recalled only one symptom of a concussion. A significant number of players and some adults did not know what a concussion was or how it occurred. Almost half of the players and a fifth of the adults incorrectly stated that concussion was treated with medication or physical therapy. Nearly one quarter of all players did not know if an athlete experiencing symptoms of concussion should continue playing. CONCLUSIONS This study demonstrated that a significant number of people held misconceptions about concussion in hockey which could lead to serious health consequences and creates a need for better preventive and educational strategies.

Evaluation of the ThinkFirst Canada, Smart Hockey, brain and spinal cord injury prevention video

Objective: The ThinkFirst Canada Smart Hockey program is an educational injury prevention video that teaches the mechanisms, consequences, and prevention of brain and spinal cord injury in ice hockey. This study evaluates knowledge transfer and behavioural outcomes in 11–12 year old hockey players who viewed the video. Design: Randomized controlled design. Setting: Greater Toronto Minor Hockey League, Toronto Ontario. Subjects: Minor, competitive 11–12 year old male ice hockey players and hockey team coaches. Interventions: The Smart Hockey video was shown to experimental teams at mid-season. An interview was conducted with coaches to understand reasons to accept or refuse the injury prevention video. Main outcome measures: A test of concussion knowledge was administered before, immediately after, and three months after exposure to the video. The incidence of aggressive penalties was measured before and after viewing the video. Results: The number of causes and mechanisms of concussion named by players increased from 1.13 to 2.47 and from 0.67 to 1.22 respectively. This effect was maintained at three months. There was no significant change in control teams. There was no significant change in total penalties after video exposure; however, specific body checking related penalties were significantly reduced in the experimental group. Conclusion: This study showed some improvements in knowledge and behaviours after a single viewing of a video; however, these findings require confirmation with a larger sample to understand the sociobehavioural aspects of sport that determine the effectiveness and acceptance of injury prevention interventions.

Time vs distance as measures of exposure in driving surveys

A survey of drivers carried out in Ontario in 1988 has provided data on time spent driving as well as the distances driven for licensed drivers of both sexes in six age groups and three regions. Substantial differences were found in times, distances, and distance/time ratios among these groups. Men drove 50% greater distances, but spent only 30% more time driving than women; speed, averaged over each days driving, was lower for older drivers than for younger drivers. Differences in speed reflect differences in the driving done in urban or rural areas, and differences in the opportunity for road crashes; such differences, whether based on units of time or distance, will also affect both the comparisons of accident rates and the perceptions of risk among different groups of drivers. A definition of exposure to risk of road crash is required that considers both time and distance appropriately.

Comparing the effects of infrastructure on bicycling injury at intersections and non-intersections using a case–crossover design

Background This study examined the impact of transportation infrastructure at intersection and non-intersection locations on bicycling injury risk. Methods In Vancouver and Toronto, we studied adult cyclists who were injured and treated at a hospital emergency department. A case–crossover design compared the infrastructure of injury and control sites within each injured bicyclists route. Intersection injury sites (N=210) were compared to randomly selected intersection control sites (N=272). Non-intersection injury sites (N=478) were compared to randomly selected non-intersection control sites (N=801). Results At intersections, the types of routes meeting and the intersection design influenced safety. Intersections of two local streets (no demarcated traffic lanes) had approximately one-fifth the risk (adjusted OR 0.19, 95% CI 0.05 to 0.66) of intersections of two major streets (more than two traffic lanes). Motor vehicle speeds less than 30 km/h also reduced risk (adjusted OR 0.52, 95% CI 0.29 to 0.92). Traffic circles (small roundabouts) on local streets increased the risk of these otherwise safe intersections (adjusted OR 7.98, 95% CI 1.79 to 35.6). At non-intersection locations, very low risks were found for cycle tracks (bike lanes physically separated from motor vehicle traffic; adjusted OR 0.05, 95% CI 0.01 to 0.59) and local streets with diverters that reduce motor vehicle traffic (adjusted OR 0.04, 95% CI 0.003 to 0.60). Downhill grades increased risks at both intersections and non-intersections. Conclusions These results provide guidance for transportation planners and engineers: at local street intersections, traditional stops are safer than traffic circles, and at non-intersections, cycle tracks alongside major streets and traffic diversion from local streets are safer than no bicycle infrastructure.