Teresa Jacobson Kimberley

Observation of Amounts of Movement Practice Provided During Stroke Rehabilitation

UNLABELLED Lang CE, MacDonald JR, Reisman DS, Boyd L, Jacobson Kimberley T, Schindler-Ivens SM, Hornby TG, Ross SA, Scheets PL. Observation of amounts of movement practice provided during stroke rehabilitation. OBJECTIVE To investigate how much movement practice occurred during stroke rehabilitation, and what factors might influence doses of practice provided. DESIGN Observational survey of stroke therapy sessions. SETTING Seven inpatient and outpatient rehabilitation sites. PARTICIPANTS We observed a convenience sample of 312 physical and occupational therapy sessions for people with stroke. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES We recorded numbers of repetitions in specific movement categories and data on potential modifying factors (patient age, side affected, time since stroke, FIM item scores, years of therapist experience). Descriptive statistics were used to characterize amounts of practice. Correlation and regression analyses were used to determine whether potential factors were related to the amount of practice in the 2 important categories of upper extremity functional movements and gait steps. RESULTS Practice of task-specific, functional upper extremity movements occurred in 51% of the sessions that addressed upper limb rehabilitation, and the average number of repetitions/session was 32 (95% confidence interval [CI]=20-44). Practice of gait occurred in 84% of sessions that addressed lower limb rehabilitation and the average number of gait steps/session was 357 (95% CI=296-418). None of the potential factors listed accounted for significant variance in the amount of practice in either of these 2 categories. CONCLUSIONS The amount of practice provided during poststroke rehabilitation is small compared with animal models. It is possible that current doses of task-specific practice during rehabilitation are not adequate to drive the neural reorganization needed to promote function poststroke optimally.

Comparison of amounts and types of practice during rehabilitation for traumatic brain injury and stroke

Patients with acquired neurological deficits may capitalize on cortical reorganization to recover functional skills that have been lost. Research in neuroplasticity proposes that a high number of repetitions may lead to cortical reorganization. The purposes of this study were to quantify the number and type of activities performed by patients with traumatic brain injury (TBI) and stroke in physical and occupational therapy sessions to determine whether (1) the number of repetitions approaches the numbers in neuroplasticity research, (2) there were differences based on patient diagnosis, and (3) patient or therapist characteristics affected the type or amount of activities performed. Forty-eight patient and forty provider subjects participated. One hundred seven therapy sessions were observed. Data from therapy sessions were counted and categorized. Neither patient group approached the total number of repetitions neuroplasticity research suggests may be required for neuroplastic change. Repetitions per session did not differ between groups. Subjects with TBI performed more repetitions per minute in three categories (total upper-limb repetitions, gait steps, and transfers) than subjects with stroke. Therapists with <1 year or >15 years of neurological therapy experience instructed patients in fewer functional repetitions per minute than did therapists with 5 to 15 years of experience.

Neural Substrates for Motor Imagery in Severe Hemiparesis

Background. The beneficial effects of imagined movements on motor learning and performance suggest that motor imagery is functionally close to preparatory and executive motor processes. Objective. The purpose of this study was to examine the cortical processes associated with imagery of movement of the wrist in subjects with severe hemiparesis. Methods. During fMRI, subjects with stroke performed alternating blocks of imagining wrist-tracking movements with the hemiparetic hand, active wrist-tracking movements with the unaffected hand, and resting. Control subjects performed the same tasks using an assigned hand. Cortical activation in the primary motor (M1), primary sensory (S1), supplementary motor area (SMA), and pre-SMA regions was determined through a laterality index of active voxels and signal intensity. Ability to imagine was assessed with an Imagery Rating Scale. Results.All subjects displayed primarily contralateral control during the track condition. Healthy subjects demonstrated contralateral control in all areas during the imagine condition, whereas subjects with stroke displayed primarily contralateral activation in S1 but ipsilateral in M1 and SMA. The percentage change in signal intensity was greater in the ipsilateral hemisphere in subjects with stroke than in the ipsilateral hemisphere in healthy subjects during the imagine condition. Additionally, subjects with self-reported low ability to imagine displayed no difference in activation compared to those with high imagery ability. Conclusions. These findings are consistent with other works demonstrating primarily ipsilateral control of the hemiparetic hand in subjects with functional movement and lay the groundwork for further investigation into the ability of mental imagery to affect functionally relevant cortical control in subjects recovering from stroke.

Lasting effects of repeated rTMS application in focal hand dystonia

PURPOSE Focal hand dystonia (FHD) is a rare but potentially devastating disorder involving involuntary muscle spasms and abnormal posturing that impairs functional hand use. Increased cortical excitability and lack of inhibitory mechanisms have been associated with these symptoms. This study investigated the short- and long-term effects of repeated administrations of repetitive-transcranial magnetic stimulation (rTMS) on cortical excitability and handwriting performance. METHODS Six subjects with FHD and nine healthy controls were studied. All subjects with FHD received rTMS (1Hz) to the premotor cortex (PMC) for five consecutive days; of those, three subjects received five days of sham rTMS completed ten days prior to real treatment. Healthy subjects received one real rTMS session. Cortical silent period (CSP) and measures of handwriting performance were compared before and after treatment and at ten-day post-treatment follow-up. RESULTS At baseline, significant differences in CSP and pen pressure were observed between subjects with FHD and healthy controls. Differences in CSP and pen velocity between subjects in real and sham rTMS groups were observed across treatment sessions and maintained at follow-up. CONCLUSIONS After five days of rTMS to PMC, reduced cortical excitability and improved handwriting performance were observed and maintained at least ten days following treatment in subjects with FHD. These preliminary results support further investigation of the therapeutic potential of rTMS in FHD.

Safety of 6-Hz Primed Low-Frequency rTMS in Stroke

Background. Suppression of activity in the contralesional motor cortex may promote recovery of function after stroke. Furthermore, the known depressant effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) can be increased and prolonged by preceding it with 6-Hz priming stimulation. Objective. The authors explored the safety of 6-Hz primed low-frequency rTMS in 10 patients with ischemic stroke. Methods. Priming consisted of 10 minutes of 6-Hz rTMS applied to the contralesional hemisphere at 90% of resting motor threshold delivered in 2 trains/min with 5 s/train and 25-second intervals between trains. Low-frequency rTMS consisted of an additional 10 minutes of 1-Hz rTMS at 90% of resting motor threshold without interruption. Possible adverse effects were assessed with the National Institutes of Health Stroke Scale (NIHSS), the Wechsler Adult Intelligence Scale—Third Edition (WAIS-III), the Hopkins Verbal Learning Test—Revised (HVLT-R), the Beck Depression Inventory—Second Edition (BDI-II), a finger movement tracking test, and individual self-assessments. Pretest, treatment, and posttest occurred on the first day with follow-up tests on the next 5 weekdays. Results. There were no seizures and no impairment of NIHSS, WAIS-III, or BDI-II scores. Transient impairment occurred on the HVLT-R. Transient tiredness was common. Occasional reports of headache, neck pain, increased sleep, reduced sleep, nausea, and anxiety occurred. Conclusion. Because there were no major adverse effects, the authors concluded that the treatment was safe for the individuals in this study and that further investigation is now warranted to examine efficacy and safety of serial treatments of 6-Hz primed low-frequency rTMS.

Safety, Feasibility, and Efficacy of Vagus Nerve Stimulation Paired With Upper-Limb Rehabilitation After Ischemic Stroke

Background and Purpose— Recent animal studies demonstrate that vagus nerve stimulation (VNS) paired with movement induces movement-specific plasticity in motor cortex and improves forelimb function after stroke. We conducted a randomized controlled clinical pilot study of VNS paired with rehabilitation on upper-limb function after ischemic stroke. Methods— Twenty-one participants with ischemic stroke >6 months before and moderate to severe upper-limb impairment were randomized to VNS plus rehabilitation or rehabilitation alone. Rehabilitation consisted of three 2-hour sessions per week for 6 weeks, each involving >400 movement trials. In the VNS group, movements were paired with 0.5-second VNS. The primary objective was to assess safety and feasibility. Secondary end points included change in upper-limb measures (including the Fugl–Meyer Assessment-Upper Extremity). Results— Nine participants were randomized to VNS plus rehabilitation and 11 to rehabilitation alone. There were no serious adverse device effects. One patient had transient vocal cord palsy and dysphagia after implantation. Five had minor adverse device effects including nausea and taste disturbance on the evening of therapy. In the intention-to-treat analysis, the change in Fugl–Meyer Assessment-Upper Extremity scores was not significantly different (between-group difference, 5.7 points; 95% confidence interval, −0.4 to 11.8). In the per-protocol analysis, there was a significant difference in change in Fugl–Meyer Assessment-Upper Extremity score (between-group difference, 6.5 points; 95% confidence interval, 0.4 to 12.6). Conclusions— This study suggests that VNS paired with rehabilitation is feasible and has not raised safety concerns. Additional studies of VNS in adults with chronic stroke will now be performed. Clinical Trial Registration— URL: https://www.clinicaltrials.gov. Unique identifier: NCT01669161.

Establishing the definition and inter-rater reliability of cortical silent period calculation in subjects with focal hand dystonia and healthy controls.

The purpose of this paper is to describe a clearly defined manual method for calculating cortical silent period (CSP) length that can be employed successfully and reliably by raters after minimal training in subjects with focal hand dystonia (FHD) and healthy subjects. A secondary purpose was to explore intra-subject variability of the CSP in subjects with FHD vs. healthy subjects. Two raters previously naïve to CSP identification and one experienced rater independently analyzed 170 CSP measurements collected in 6 subjects with focal hand dystonia (FHD) and 9 healthy subjects. Intraclass correlation coefficient (ICC) was calculated to quantify inter-rater reliability within the two groups of subjects. The relative variability of CSP in each group was calculated by the coefficient of variation (CV). Relative variation between raters within repeated measures of individual subjects was also quantified by CV. Reliability measures were as follows-mean of three raters: all subjects: ICC=0.976; within healthy subjects: ICC=0.965; in subjects with FHD: ICC=0.956. The median within-subject variability for the healthy group was CV=7.33% and in subjects with FHD:CV=11.78%. The median variability of calculating individual subject CSP duration between raters was CV=10.23% in subjects with dystonia and CV=10.46% in healthy subjects. Manual calculation of CSP results in excellent reliability between raters of varied levels of experience. Healthy subjects display less variability in CSP. Despite greater variability, the CSP in impaired subjects can be reliably calculated across raters.

fMRI reliability in subjects with stroke

Abstract Functional MRI (fMRI) has become one of the most commonly used neuroimaging tools to assess the cortical effects associated with rehabilitation, learning, or disease recovery in subjects with stroke. Despite this, there has been no systematic study of the reliability of the fMR signal in this population. The purpose of this study was to examine the within- and between-session reliability of fMRI in cortical and cerebellar structures in subjects with stroke during a complex, continuous visual motor task performed with the less affected hand. Nine subjects with stroke underwent four testing trials during two sessions separated by three weeks. Subjects performed a drawing task using an MRI compatible joystick while in the MRI. Methods of analysis evaluated included: percent signal intensity change, active voxel count and a voxel by voxel stat value analysis within and between testing sessions. Reliability was determined with Interclass correlation coefficients (ICC) in the following regions of interest: primary motor (M1), primary sensory (S1), premotor cortex (PMC), medial cerebellum (MCB), and lateral cerebellum (LCB). Results indicate that intensity change has superior reliability to the other methods of analysis (Average ICC across brain regions and trials: intensity change: 0.73, voxel count: 0.58, voxel by voxel: 0.67) and that generally with any analysis method, within-session reliability was higher than between-session, as indicated by higher ICC values across brain regions. Overall, when comparing between-session results, moderate to good reliability was obtained with intensity change (ICC: M1: 0.52, S1: 0.80, SMA: 0.78, PMC: 0.94, MCB: 0.86, and LCB: 0.59). These results show good reliability in subjects with stroke when performing a continuous motor task. These findings give confidence for interpreting fMRI test/retest research in subjects with stroke.

Reliability of fMRI during a Continuous Motor Task: Assessment of Analysis Techniques

The purpose of this study was to determine which method of functional magnetic resonance image analysis had the highest reliability in cortical and cerebellar areas during a continuous motor task. Fourteen subjects underwent 4 testing trials during 2 testing sessions separated by 3 weeks. Subjects performed a joystick task. Methods of analysis evaluated included: percent signal intensity change, active voxel count, and percent contribution. Two types of activation thresholds were evaluated: P≤ .05 and false discovery rate = .05. Reliability was determined with intraclass correlation coefficients and a repeated measure ANOVA was used to determine whether there was a significant difference between trials. A group analysis was assessed with coefficient of variation. Results indicate within session reliability was higher than between session and that signal intensity is more reliable than voxel count analysis. The intraclass correlation coefficients across different regions of interest varied depending on analysis technique. The data did not support a clear difference between thresholds. The group analysis also found less variability with intensity measures than voxel count. A stabilization effect was seen after the first trial of the experiment, suggesting that in pretest/posttest designs, a more stable result may be obtained by performing a test trial prior to actual data collection.

Focal Hand Dystonia: Individualized Intervention With Repeated Application of Repetitive Transcranial Magnetic Stimulation

OBJECTIVES To examine for individual factors that may predict response to inhibitory repetitive transcranial magnetic stimulation (rTMS) in focal hand dystonia (FHD); to present the method for determining optimal stimulation to increase inhibition in a given patient; and to examine individual responses to prolonged intervention. DESIGN Single-subject design to determine optimal parameters to increase inhibition for a given subject and to use the selected parameters once per week for 6 weeks, with 1-week follow-up, to determine response. SETTING Clinical research laboratory. PARTICIPANTS A volunteer sample of subjects with FHD (N = 2). One participant had transcranial magnetic stimulation responses indicating impaired inhibition, and the other had responses within normative limits. INTERVENTIONS There were 1200 pulses of 1-Hz rTMS delivered using 4 different stimulation sites/intensity combinations: primary motor cortex at 90% or 110% of resting motor threshold (RMT) and dorsal premotor cortex (PMd) at 90% or 110% of RMT. The parameters producing the greatest within-session increase in cortical silent period (CSP) duration were then used as the intervention. MAIN OUTCOME MEASURES Response variables included handwriting pressure and velocity, subjective symptom rating, CSP, and short latency intracortical inhibition and facilitation. RESULTS The individual with baseline transcranial magnetic stimulation responses indicating impaired inhibition responded favorably to the repeated intervention, with reduced handwriting force, an increase in the CSP, and subjective report of moderate symptom improvement at 1-week follow-up. The individual with normative baseline responses failed to respond to the intervention. In both subjects, 90% of RMT to the PMd produced the greatest lengthening of the CSP and was used as the intervention. CONCLUSIONS An individualized understanding of neurophysiological measures can be an indicator of responsiveness to inhibitory rTMS in focal dystonia, with further work needed to determine likely responders versus nonresponders.