Remote Traumatic Brain Injury Is Associated with Motor Dysfunction in Older Military Veterans.
BACKGROUND
Traumatic brain injury (TBI) has been identified as a risk factor for Parkinson's disease (PD). Motor dysfunction among TBI-exposed elders without PD has not been well characterized. We sought to determine whether remote TBI is a risk factor for motor dysfunction on exam and functionally relevant motor dysfunction in day-to-day life among independently living elders without PD.


METHODS
This is a cross-sectional cohort study of independently living retired military veterans aged 50 or older with (n = 78) and without (n = 85) prior TBI-all without diagnosed PD. To characterize multidimensional aspects of motor function on exam, the Unified Parkinson's Disease Rating Scale (UPDRS) Motor Examination was performed by a board-certified neurologist and used to calculate a modified UPDRS (mUPDRS) global motor score and four domain scores (tremor, rigidity, bradykinesia, and posture/gait). Functionally relevant motor dysfunction was assessed via self-report of falls within the past year.


RESULTS
In analyses adjusted for demographics and comorbidities that differed between groups, compared with veterans without TBI, those with moderate-to-severe TBI were more likely to have fallen in past year (33% vs. 14%, risk ratio 2.5 [95% confidence interval 1.1-5.4]), had higher (worse) mUPDRS global motor (p = .03) and posture/gait scores (p = .02), but not higher tremor (p = .70), rigidity (p = .21), or bradykinesia scores (p = .22). Mild TBI was not associated with worse motor function.


CONCLUSIONS
Remote moderate-to-severe TBI is a risk factor for motor dysfunction-defined as recent falls and impaired posture/gait-among older veterans. TBI-exposed older adults may be ideal candidates for aggressive fall-screening and prevention strategies.
Memory and Aging Center, Department of Neurology, University of California San Francisco.|San Francisco Veterans Affairs Medical Center, California.
Raquel C
RC
Gardner
San Francisco Veterans Affairs Medical Center, California.
Carrie B
CB
Peltz
Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, Maryland.
Kimbra
K
Kenney
San Francisco Veterans Affairs Medical Center, California.|Division of Geriatrics.
Kenneth E
KE
Covinsky
Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, Maryland.
Ramon
R
Diaz-Arrastia
Memory and Aging Center, Department of Neurology, University of California San Francisco.|San Francisco Veterans Affairs Medical Center, California.|Department of Psychiatry.|Department of Epidemiology and Biostatistics, University of California San Francisco.
Kristine
K
Yaffe
D000058:Accidental Falls; D000368:Aged; D000369:Aged, 80 and over; D000070642:Brain Injuries, Traumatic / Q000150:complications*; D003430:Cross-Sectional Studies; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D010300:Parkinson Disease / Q000209:etiology*; D012307:Risk Factors; D014481:United States; D014728:Veterans
Falls; Parkinson’s disease; Risk factors