Christopher J. Jankosky

Viruses and vitamin D in the etiology of type 1 diabetes mellitus and multiple sclerosis

Although specific viruses have been associated with autoimmune diseases, none fulfill Kochs criteria of causation. The etiologies of such diseases appear to be complex and multifactorial. For example, one might propose that the etiology of type 1 diabetes mellitus results from a toxic metabolite of nitrosamines during an enteroviral infection. Multiple sclerosis might result from a cascade of events involving several herpes virus infections activated during periods of vitamin D deficiency. We encourage investigators to consider Rotmans sufficient-component causal model when developing hypotheses for testing for the etiology of chronic diseases. Delineating the web of causation may lead to additional strategies for prevention and treatment of several autoimmune diseases.

Headache Disorders in the Millennium Cohort: Epidemiology and Relations With Combat Deployment

(Headache 2011;51:1098‐1111)

Repeated low-level blast exposure: A descriptive human subjects study

The relationship between repeated exposure to blast overpressure and neurological function was examined in the context of breacher training at the U.S. Marine Corps Weapons Training Battalion Dynamic Entry School. During this training, Students are taught to apply explosive charges to achieve rapid ingress into secured buildings. For this study, both Students and Instructors participated in neurobehavioral testing, blood toxin screening, vestibular/auditory testing, and neuroimaging. Volunteers wore instrumentation during training to allow correlation of human response measurements and blast overpressure exposure. The key findings of this study were from high-memory demand tasks and were limited to the Instructors. Specific tests showing blast-related mean differences were California Verbal Learning Test II, Automated Neuropsychological Assessment Metrics subtests (Match-to-Sample, Code Substitution Delayed), and Delayed Matching-to-Sample 10-second delay condition. Importantly, apparent deficits were paralleled with functional magnetic resonance imaging using the n-back task. The findings of this study are suggestive, but not conclusive, owing to small sample size and effect. The observed changes yield descriptive evidence for potential neurological alterations in the subset of individuals with occupational history of repetitive blast exposure. This is the first study to integrate subject instrumentation for measurement of individual blast pressure exposure, neurocognitive testing, and neuroimaging.

Systematic Review of Military Motor Vehicle Crash–Related Injuries

CONTEXT Motor vehicle crashes account for nearly one third of U.S. military fatalities annually. The objective of this review is to summarize the published evidence on injuries due specifically to military motor vehicle (MMV) crashes. EVIDENCE ACQUISITION A search of 18 electronic databases identified English language publications addressing MMV crash-related injuries between 1970 and 2006 that were available to the general public. Documents limited in distribution to military or government personnel were not evaluated. Relevant articles were categorized by study design. EVIDENCE SYNTHESIS The search identified only 13 studies related specifically to MMV crashes. Most were case reports or case series (n=8); only one could be classified as an intervention study. Nine of the studies were based solely on data from service-specific military safety centers. CONCLUSIONS Few studies exist on injuries resulting from crashes of military motor vehicles. Epidemiologic studies that assess injury rates, type, severity, and risk factors are needed, followed by studies to evaluate targeted interventions and prevention strategies. Interventions currently underway should be evaluated for effectiveness, and those proven effective in the civilian community, such as graduated driver licensing, should be considered for implementation and evaluation in military populations.

Estimated Incidence of Multiple Sclerosis Among United States Armed Forces Personnel Using the Defense Medical Surveillance System

BACKGROUND The comprehensive longitudinal medical records of the U.S. Armed Forces provide a valuable tool to study the epidemiology of multiple sclerosis (MS) in persons from a diverse demography. OBJECTIVE This studys objectives were to estimate the frequencies, incidence rates (IRs), trends, and correlates of MS among active component U.S. military members from 2000 to 2009. METHODS An International Classification of Diseases, 9th Revision, code algorithm was used to identify MS cases from the Defense Medical Surveillance System database. IRs were determined by dividing the number of cases of MS by the total person-time of the active component during each year. RESULTS During the 10-year period, there were 1,827 incident cases of MS with an overall IR of 12.9 per 100,000 person-years (p-yrs). Black non-Hispanics had a higher IR: (18.3 per 100,000 p-yrs) than White non-Hispanics (12.5 per 100,000 p-yrs). The incidence of MS by birth month and geographic home did not show a clear trend of seasonality or latitudinal gradient. CONCLUSIONS This investigation is the first longitudinal study of MS incidence in U.S. Armed Forces personnel. The study demonstrates higher IRs than seen in other populations and reveals a novel pattern of MS incidence by race.

Occupational Effect on the Occurrence of Idiopathic Venous Thromboembolism

Few studies have explored the effects of various occupations on venous thromboembolism occurrence. We examined idiopathic venous thromboembolism (IVTE) occurrence by occupation, body size, and age in the U.S. military. To capture idiopathic cases, exclusion criteria included recognized venous thromboembolism risk factors. Each case was matched to three controls on branch of service, sex, rank/grade, race, and education level. Body mass index, age, and occupation were analyzed with chi2 and logistic regression. Of 2,167 cases, most were male (87%), white (69%), enlisted (78%), averaging 36 years old. IVTE odds increased with age (p < 0.001). Every occupation showed greater odds than pilots/aircrew (p < 0.001), especially infantry/artillery/combat arms, which showed twice the odds, followed by health care workers. Normal weight was protective, especially in pilots/aircrew (OR 0.52, p = 0.03) and repair/engineering (OR 0.72, p < 0.001). Our analysis found a lower risk of IVTE among pilots and aircrew compared to other military occupations. Body size had less impact than expected in aircraft and vehicle operators. Greater odds in health care workers and infantry/artillery/combat arms than in pilots/aircrew and armor/motor transport occupational groups may reflect prolonged standing. Limitations include potential miscoding of health records and potential misclassification. Future IVTE research should explore job functions and worker characteristics.

Headache disorders in the millennium cohort

(Headache 2011;51:1098‐1111)

Headache Disorders in the Millennium Cohort: Epidemiology and Relations With Combat Deployment: July/August 2011

(Headache 2011;51:1098‐1111)