Horseback-riding-associated traumatic brain injuries - Oklahoma, 1992-1994

Morbidity and Mortality Weekly Report, March 15, 1996

Each year, traumatic brain injury(*) (TBI) is associated with 52,000 deaths and accounts for one third of all injury deaths in the United States (2); in addition, approximately 80,000 persons who survive TBI incur some loss of function, residual disability, and increased medical-care needs because of these injuries (3). Major causes of TBI are motor-vehicle crashes, falls, assaults, and sports and recreational activities (3,4). During 1992-1993 in Oklahoma, horseback riding was the leading cause of sports-related TBI (5). To further characterize horseback-riding-associated TBIs, the Oklahoma State Department of Health (OSDH) and CDC analyzed these injuries for 1992-1994. This report summarizes the findings of this analysis.

In 1992, the OSDH established surveillance statewide in Oklahoma for all cases of TBI resulting in death or hospitalization. A case is defined as a TBI recorded on a medical examiner report or coded on a hospital discharge report as specified by International Classification of Diseases, Ninth Revision, codes N800.0-801.9, N803.0-804.9, and N850.0-854.1. Medical records of persons with TBI are reviewed by state injury-prevention service personnel at all 125 hospitals in the state either one, two, or four times per year (frequency depends on the size of the hospital). A standardized data-collection form is completed for each case. Information for all fatal cases is provided by the state Office of the Chief Medical Examiner, which investigates all trauma deaths. Horseback riding and other causes of injury are specified in the narrative of the medical record or medical examiner report.

During 1992-1994, a total of 9409 Tbis occurred in Oklahoma, of which 109 (1.2%), including three deaths, were associated with horseback riding; 23 other Tbis were attributable to horses but were not riding-associated. The numbers of these injuries were nearly equal among females (55) and males (54), and riders ranged in age from 3 years to 71 years (median: 30 years). Cases occurred more commonly during the spring (38) and summer (34) than winter (19) and autumn (18). Nearly one half (48%) of the riding-associated Tbis occurred on a Saturday or Sunday. Of 93 cases for which time of injury was known, 64 (69%) occurred between noon and 8 p.m. Of the 105 cases for which the mechanism of injury was specified, 100 (95%) involved riders who struck their heads either on the ground or a nearby object after failing from the horse, four (4%) who were kicked or rolled on by the horse after falling from the horse, and one (1%) who fell to the ground after his head struck a pole while riding. Of the 96 persons for whom information on type of activity was available, most (86 [90%1) were associated with recreational activity, and 10 (10%) were work-associated. A total of 107 persons were hospitalized (two persons died at the scene) and accounted for 388 hospital days (median duration of stay: 2 days).

Among the 106 survivors of riding-associated Tbis, 84 (79%) had one or more indicators of brain injury severity: 67 (63%) had loss of consciousness, 49 (46%) had post-traumatic amnesia, and 14 (13%) had persistent neurologic sequelae on discharge from the hospital (e.g., seizures or cognitive, hearing, vision, speech, and/or motor impairment). Among those hospitalized, the Abbreviated Injury Severity (AIS) scores([dagger]) for the head region ranged from two (moderate) (64% of cases) to five (critical) (5% of cases). TBI was listed as the first (of a maximum of 10) discharge diagnosis for 90% of the hospitalized cases and as the first or second diagnosis for 99%.

Among the 23 Tbis attributable to horses not identified as riding-associated, 21 (91%) resulted from a direct kick to the head by a horse; one person died, and two others required cardiopulmonary resuscitation. Thirteen (57%) of these occurred among children aged [less than or equal to] 10 years. Of the 19 cases for which place of injury was specified, 15 occurred on a farm.

Reported by. P Archer, MPH, S Mallonee, MPH, S Lantis, MPH, Oklahoma State Dept of Health. Div of Acute Care, Rehabilitation Research, and Disability Prevention, National Center for Injury Prevention and Control, CDC.

Editorial Note: Even though only 1% of the TBIS in Oklahoma were associated with horseback riding, the medical burden of these injuries is substantial as reflected by the adverse neurologic outcomes and number of hospitalization days. In addition, the horseback-riding-associated TBIS described in this report probably underestimate the total number of all such injuries receiving medical care. For example, during 1991, 66% of persons in the United States who received medical care for Tbis were not hospitalized (4), and 79% of regular (i.e., six or more times per year) horseback riders who incurred a concussion or other nonfacial head injury were not hospitalized (6; CDC, unpublished data, 1995). in Oklahoma, only persons with Tbis who are hospitalized are identified by the surveillance system.