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Biomedical subjects

Alexander W Dromerick

Publications and source records attributed to Alexander W Dromerick.

13 recordsLinked to original sources
PubMed2006

Upper extremity muscle activation during recovery of reaching in subjects with post-stroke hemiparesis.

OBJECTIVE: To investigate upper extremity muscle activation and recovery during the first few months after stroke. METHODS: Subjects with hemiparesis following stroke were studied performing a reaching task at an acute time point (mean=9 days post-stroke) and then again at a subacute time point (mean=109 days post-stroke). We recorded kinematics and electromyographic activity of six upper extremity muscles. RESULTS: At the acute time point, the hemiparetic group had delayed muscle onsets, lower modulation ratios, and higher relative levels of muscle activation (%MVIC) during reaching than controls. From the acute to the subacute time points, improvements were noted in all three variables. By the subacute phase, muscle onsets were similar to controls, while modulation ratios remained lower than controls and %MVIC showed a trend toward being greater in the hemiparetic group. Changes in muscle activation were differentially related to changes in reaching performance. CONCLUSIONS: Our data show that improvements in muscle timing and decreases in the relative level of volitional activation may underlie improved reaching performance in the early months after stroke. SIGNIFICANCE: Given that stroke is one of the leading causes of persistent physical disability, it is important to understand how the ability to activate muscles changes during the early phases of recovery after injury.

Adult↗
PubMed2006

Hemiplegic shoulder pain syndrome: interrater reliability of physical diagnosis signs.

OBJECTIVE: To determine the interrater reliability of shoulder physical diagnosis signs in the acute stroke rehabilitation setting. DESIGN: Prospective inception cohort. SETTING: Academic inpatient stroke rehabilitation service. PARTICIPANTS: People admitted to stroke rehabilitation service. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Neer impingement test, Speed test, acromioclavicular shear test, Rowe shoulder score, and palpation. RESULTS: Two examiners evaluated 46 consecutively admitted participants at 18.9+/-14.1 days after stroke. Percentage agreement was 78% or higher on all tests. The kappa statistic was in the fair to excellent interrater reliability range on all tests except those involving the acromioclavicular joint, for which findings were infrequent. CONCLUSIONS: Most of the shoulder physical diagnosis signs used in this study have sufficient interrater reliability for use in future clinical studies of hemiplegic shoulder pain.

Adult↗
PubMed2006

Measurement of upper-extremity function early after stroke: properties of the action research arm test.

OBJECTIVE: To examine the responsiveness and validity of the Action Research Arm Test (ARAT) in a population of subjects with mild-to-moderate hemiparesis within the first few months after stroke. DESIGN: Data were collected as part of the Very Early Constraint-Induced Therapy for Recovery from Stroke trial, an acute, single-blind randomized controlled trial of constraint-induced movement therapy. Subjects were studied at baseline (day 0), after treatment (day 14), and after 90 days (day 90) poststroke. SETTING: Inpatient rehabilitation hospital; follow-up 3 months poststroke. PARTICIPANTS: Fifty hemiparetic subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: At each time point, subjects were tested on: (1) the ARAT, (2) clinical measures of sensorimotor impairments, (3) in the kinematics laboratory where they performed reach and grasp movements, and (4) clinical measures of disability. Blinded raters performed all evaluations. Analyses at each time point included calculating effect size as indicators of responsiveness, and correlation and regression analyses to examine relationships between ARAT scores and other measures. RESULTS: The ARAT is responsive to change, with effect sizes greater than 1.0 and responsiveness ratios of 7.0 at 3 months poststroke. ARAT scores were related to sensorimotor impairment measures, 3-dimensional kinematic measures of movement performance, and disability measures at all 3 time points. CONCLUSIONS: The ARAT is a responsive and valid measure of upper-extremity functional limitation and therefore may be an appropriate measure for use in acute upper-extremity rehabilitation trials.

Biomechanical Phenomena↗
PubMed2006

Activity-based therapies.

Therapeutic activity is a mainstay of clinical neurorehabilitation, but is typically unstructured and directed at compensation rather than restoration of central nervous system function. Newer activity-based therapies (ABTs) are in early stages of development and testing. The ABTs attempt to restore function via standardized therapeutic activity based on principles of experimental psychology, exercise physiology, and neuroscience. Three of the best developed ABTs are constraint-induced therapy, robotic therapy directed at the hemiplegic arm, and treadmill training techniques aimed at improving gait in persons with stroke and spinal cord injury. These treatments appear effective in improving arm function and gait, but they have not yet been clearly demonstrated to be more effective than equal amounts of traditional techniques. Resistance training is clearly demonstrated to improve strength in persons with stroke and brain injury, and most studies show that it does not increase hypertonia. Clinical trials of ABTs face several methodological challenges. These challenges include defining dosage, standardizing treatment parameters across subjects and within treatment sessions, and determining what constitutes clinically significant treatment effects. The long-term goal is to develop prescriptive ABT, where specific activities are proven to treat specific motor system disorders. Activity-based therapies are not a cure, but are likely to play an important role in future treatment cocktails for stroke and spinal cord injury.

Animals↗
PubMed2006

Screening patients with stroke for rehabilitation needs: validation of the post-stroke rehabilitation guidelines.

BACKGROUND: The authors assessed patients with acute stroke to determine whether the systematic use of brief screening measures would more efficiently detect cognitive and sensory impairment than standard clinical practice. METHODS: Fifty-three patients admitted to an acute stroke unit were assessed within 10 days of stroke onset. Performance on the screening measures was compared to information obtained from review of the patient's chart at discharge. Cognition, language, visual acuity, visual-spatial neglect, hearing, and depression were evaluated. RESULTS: Formal screening detected significantly more impairments than were noted in patient charts in every domain. Only 3 patients had no impairments identified on screening; all remaining patients had at least 1 impairment detected by screening that was not documented in the chart. Thirty-five percent had 3 or more undetected impairments. Memory impairment was most likely to be noted in the chart; for all other domains tested, undocumented impairment ranged from 61% (neglect) to 97% (anomia). CONCLUSION: Many acute stroke patients had cognitive and perceptual deficits that were not documented in their charts. These data support the Post-Stroke Rehabilitation Guidelines for systematic assessment even when deficits are not immediately apparent. Systematic screening may improve discharge planning, rehabilitation treatment, and long-term outcome of persons with stroke.

Aged↗
PubMed2006

Relationships between sensorimotor impairments and reaching deficits in acute hemiparesis.

OBJECTIVE: To determine the relationships between sensorimotor impairments and upper extremity reaching performance during the acute phase of stroke and to determine which, if any, measures of sensorimotor impairment can predict variance in reaching performance during this phase. METHODS: Sensorimotor impairments of upper extremity (UE) strength, active range of motion, isolated movement control, light touch sensation, joint position sense, spasticity, and shoulder pain were evaluated in a group of 46 individuals with acute hemiparesis (mean time since insult = 9.2 days). Subjects performed a reaching task to a target placed on their affected side. Three-dimensional kinematic analyses were used to assess reaching speed, accuracy, and efficiency. Forward stepwise multiple linear regression analyses were used to determine which impairment was the best predictor of variance in reaching performance. RESULTS: Measures of UE strength predicted the largest proportion of variance in the speed, accuracy, and efficiency of forward reaching. Isolated movement control, somatosensory deficits, and elbow spasticity predicted smaller amounts of variance in reaching performance. CONCLUSIONS: The authors' data show that deficits in strength appear to be the most influential sensorimotor impairment associated with limited reaching performance in subjects with acute hemiparesis.

Adult↗
PubMed2006

Recovery of grasp versus reach in people with hemiparesis poststroke.

BACKGROUND AND OBJECTIVE: The authors recently found that grasping was not relatively more disrupted than reaching in people with acute hemiparesis. They now extend this work to the recovery of reach versus grasp. METHODS: Hemiparetic subjects were tested acutely, after 90 days, and then after 1 year poststroke, and a control group was evaluated once. Using kinematic techniques, subjects were studied performing reach and reach-to-grasp movements. The authors quantified 3 characteristics of performance for each movement: speed, accuracy, and efficiency, where an efficient movement was defined as a movement directly to the target without extraneous or abnormally circuitous movements. To evaluate the relative deficits and recovery in reach versus grasp, performance measures were converted to z scores using control group means and standard deviations. RESULTS: The authors' results showed that, starting with small deficits in speed acutely, both reach speed and grasp speed improved over time. Deficits in accuracy were greater in the reach than the grasp acutely, and these deficits lessened such that by the 90-day time point, the relative accuracy of the 2 movements was the same. In contrast, deficits in efficiency were greater in the grasp than the reach acutely, and grasp efficiency did not recover. The majority of recovery in reaching and grasping occurred by the 90-day time point, with little change occurring between the 90-day and 1-year time points. CONCLUSIONS: The authors hypothesize that, in chronic hemiparesis, purposeful movements requiring distal control may be more impaired than purposeful movements requiring proximal control, not because of the initial lesion, but because, over the course of recovery, spared components of the descending motor systems may be able to compensate for the accuracy deficits in reaching (proximal control) but not the efficiency deficits in grasping (distal muscular control).

Adaptation, Physiological↗
PubMed2005

Deficits in grasp versus reach during acute hemiparesis.

We studied how acute hemiparesis affects the ability to perform purposeful movements of proximal versus distal upper extremity segments. Given the gradient of corticospinal input to the spinal motoneuron pools, we postulated that movement performance requiring distal segment control (grasping) should be more impaired than movement performance requiring proximal segment control (reaching) in people with hemiparesis. We tested subjects with acute hemiparesis and control subjects performing reach and reach-to-grasp movements. Three characteristics of movement performance were quantified for each movement: speed, accuracy, and efficiency. For the reach, we calculated peak wrist velocity, endpoint error, and reach path ratio. For the grasp, we calculated peak aperture rate, aperture at touch, and aperture path ratio. To evaluate the relative deficits in reaching versus grasping, performance measures were converted to z-scores using control group means and standard deviations. For both the movements, movement times were longer and performance was more variable in the hemiparetic group compared to the control group. Hemiparetic z-scores indicated that relative deficits in movement speed were small in the two movements, with deficits in grasp being slightly greater than deficits in reach. Relative deficits in accuracy showed a trend for being larger in the reach compared to the grasp, but this difference did not reach statistical significance. In contrast, relative deficits in efficiency were larger in the grasp compared to the reach, with reaching efficiency near the range of normal performance. When considering data across all three movement characteristics, the ability to perform a purposeful movement with the distal segments was not clearly more disrupted than the ability to perform a purposeful movement with the proximal segments in people with acute hemiparesis.

Acute Disease↗
PubMed2003

Relation of postvoid residual to urinary tract infection during stroke rehabilitation.

OBJECTIVES: To examine (1) risk factors for urinary tract infection (UTI) during stroke rehabilitation and (2) the relation of postvoid residual (PVR) to the frequency of UTI. DESIGN: Prospective case series. SETTING: Academic specialty stroke rehabilitation service. PARTICIPANTS: One hundred one consecutive admissions for stroke rehabilitation. INTERVENTIONS: Not applicable. Main outcome measure Presence or absence of UTI. RESULTS: Previously undiagnosed UTI was found in 28 of 101 subjects. Two or more PVR determinations of 150mL or more were an independent risk factor for UTI. In multivariate analysis, factors associated with increased risk of UTI included only use of beta-blockers and 2 peak PVR determinations of 150mL or more. Single determinations were not significant. CONCLUSION: The optimal PVR for initiating bladder catheterization during stroke rehabilitation remains unknown, but the risk of UTI increases only when 2 or more ultrasound PVR readings are more than 150mL.

Aged↗
PubMedDate not supplied

Sensitivity to changes in disability after stroke: a comparison of four scales useful in clinical trials.

Although most current stroke intervention trials use disability scales to determine outcome, little is known about the sensitivity to change of these scales. The use of a more sensitive measure would increase the statistical power of rehabilitation treatment trials. We applied four well-known disability scales to a group of stroke rehabilitation inpatients to compare sensitivity to change. Ninety-five consecutive admissions to a stroke rehabilitation service were assessed for disability on admission and discharge. Two global scales, the Modified Rankin Scale (MRS) and the International Stroke Trial Measure (ISTM), were compared with two activities of daily living (ADL) scales, the Barthel Index (BI) and the Functional Independence Measure (FIM). We determined the number of patients that each scale detected a clinically significant change in disability. Standardized response means (SRM) and receiver operating characteristic (ROC) analyses were performed. The MRS detected change in 55 subjects, including all who changed on the ISTM; the ISTM detected change in only 23 subjects. The BI detected change in 71 subjects but demonstrated ceiling effects with 26% of subjects scoring >95. The FIM was most sensitive, detecting change in 91 subjects; no patient achieved a maximum score. The SRM of the FIM was superior to that of the BI (2.18 versus 1.72), and ROC analysis revealed C-statistics of 0.82 for the BI, 0.59 for the MRS, and 0.51 for the ISTM. Global scales were much less sensitive to changes in disability than were ADL scales. Though ADL scales may take longer to administer, their increased sensitivity may make them more useful in treatment trials by allowing fewer subjects to be enrolled.

Activities of Daily Living↗
PubMedDate not supplied

Relationships between upper-limb functional limitation and self-reported disability 3 months after stroke.

This study explored relationships between upper-limb (UL) functional limitations and self-reported disability in stroke patients with relatively pure motor hemiparesis who were enrolled in an acute rehabilitation treatment trial. All participants were enrolled in the VECTORS (Very Early Constraint Treatment for Recovery from Stroke) study. VECTORS is a single-center pilot clinical trial of early application of constraint-induced movement therapy (CIMT). All 39 subjects who completed 90 days of VECTORS were included in this analysis. Trained study personnel who were blinded to the treatment type performed all evaluations. Data in this article examine relationships between assessments performed 90 days after stroke. Functional limitation measures included the Action Research Arm (ARA) test and Wolf Motor Function Test (WMFT), and self-reported disability measures included the Functional Independence Measure (FIM) and Motor Activity Log (MAL) (by telephone). Mean plus or minus standard deviation time from stroke onset to randomization was 9.4 plus or minus 4.3 days, and median time to follow-up was 99 days (range 68-178). Subjects with perfect or near-perfect scores on the ARA test or WMFT reported residual disability on the FIM and MAL. Quality of movement on the WMFT (functional ability score) was not strongly associated with self-reported frequency, and speed of movement on the WMFT (timed score) was not associated with self-reported frequency (MAL amount of use). In this early UL intervention trial, we found that perceived disability measures captured information that was not assessed by functional limitation and impairment scales. Our results indicate that excellent motor recovery as measured by functional limitation and impairment scales did not equal restoration of everyday productive UL use and speed of task completion did not translate to actual use. Our results confirm the need for a measurement strategy that is sensitive to change, assesses a broad performance range, and detects meaningful clinical improvements in early rehabilitation intervention trials.

Activities of Daily Living↗