Stroke QUERI Project - Effectiveness of Rehabilitation in Stroke Patients with Executive Function Disorders

Project Number B2845V funded by RR&D.
July 1, 2002 - June 30, 2008

Patients with post-stroke cognitive impairment experience less recovery of physical function and more dependence in living, beyond that explained by stroke severity (Paolucci et al., 1996; MacNeill & Lichtenberg, 1997). Minorities and low socioeconomic strata patients have higher rates of impairment (Horner et al., 1991). Our recent research shows that such restricted recovery, specifically for instrumental (complex) activities of daily living (IADLs), occurs in patients with mild to moderate cognitive impairment versus unimpaired stroke patients despite a similar rehabilitation process (Zinn et al., 2001). We believe that impaired executive functioning may be responsible for this apparent inability to benefit more fully from stroke rehabilitation. The cognitive processes comprising executive functions (such as attention, planning, problem solving, motivation and self-monitoring) are foundational skills that would likely be prerequisites for successful rehabilitation. Hanks et al. (1999) demonstrated that executive function deficits impact rehabilitation outcomes in a general rehabilitation population. While executive functions are known to be affected by frontal and subcortical lesions, common in stroke (Bogousslavsky et al., 1996; Tatemichi et al., 1993), no controlled studies exist that establish the incidence of executive function deficits in a stroke cohort, nor investigate the interaction of the executive functions and rehabilitation in stroke patients.

The objects of this study are threefold. 1) To ascertain the incidence of executive dysfunction in a stroke cohort. 2) To determine the association between executive dysfunction and rehabilitation process (utilization) and key health outcomes (e.g., IADL function). 3) To identify points of intervention through observation of rehabilitation sessions for patients with impaired executive functions, in order to develop therapeutic techniques to improve their ability to benefit from rehabilitation.

A prospective, inception cohort of stroke patients will be assessed using an 80-minute battery (split into two sessions) of commonly-used pencil-and-paper neuropsychological tests 3-5 days after stroke onset. These assessments will be in addition to but totally separate from their regular course of treatment. Data on their referral to, and utilization of, rehabilitation (including provider, therapeutic procedure(s) and number of sessions) will be tracked through VA procedure codes and Rehabilitation department records. Baseline assessments, consisting of Lawton Scale of Instrumental Activities of Daily Living (LSIADL) and the Center for Epidemiologic Studies scale for Depression (CES-D) will be obtained by rehabilitation or study personnel. The Functional Independence Measure (FIM), mandated by the VA, is routinely administered by Rehabilitation personnel. Data for assessing stroke severity, measured by the Canadian Neurological Scale, and the Charlson comorbidity index, will be obtained from the medical chart. Phone administered assessments of functioning (FonFIM and LSIADL), depression (CES-D) and Stroke-Specific Quality of Life scale (SS-QOL) will be obtained at 6 months post-discharge.

In order to develop rehabilitation techniques that target the appropriate behaviors at the appropriate level, data must be collected on which behaviors attributable to executive function deficits cause the greatest interference with treatment, and exactly how these behaviors reduce the comprehension, implementation and/or recall of the interventions offered by physical, occupational and recreational therapists. The current study is designed to produce this data. Subsequent studies will employ this data to develop interventions that can be employed by rehabilitation therapists throughout the treatment process. We believe that targeting the precise treatment-interfering behaviors produced by deficits of executive functions will result in post-rehabilitation gains in activities of daily living. The reduction of disabilities in an aging population is an increasingly important research goal as the number of older persons and the rate of stroke survival increases in this country.