Patricia M. Kluding

The Effect of Exercise on Neuropathic Symptoms, Nerve Function, and Cutaneous Innervation in People with Diabetic Peripheral Neuropathy

UNLABELLED Although exercise can significantly reduce the prevalence and severity of diabetic complications, no studies have evaluated the impact of exercise on nerve function in people with diagnosed diabetic peripheral neuropathy (DPN). The purpose of this pilot study was to examine feasibility and effectiveness of a supervised, moderately intense aerobic and resistance exercise program in people with DPN. We hypothesized that the exercise intervention can improve neuropathic symptoms, nerve function, and cutaneous innervation. METHODS A pre-test post-test design was used to assess change in outcome measures following participation in a 10-week aerobic and strengthening exercise program. Seventeen subjects with diagnosed DPN (8 males/9 females; age 58.4±5.98; duration of diabetes 12.4±12.2 years) completed the study. Outcome measures included pain measures (visual analog scale), Michigan Neuropathy Screening Instrument (MNSI) questionnaire of neuropathic symptoms, nerve function measures, and intraepidermal nerve fiber (IENF) density and branching in distal and proximal lower extremity skin biopsies. RESULTS Significant reductions in pain (-18.1±35.5 mm on a 100 mm scale, P=.05), neuropathic symptoms (-1.24±1.8 on MNSI, P=.01), and increased intraepidermal nerve fiber branching (+0.11±0.15 branch nodes/fiber, P=.008) from a proximal skin biopsy were noted following the intervention. CONCLUSIONS This is the first study to describe improvements in neuropathic and cutaneous nerve fiber branching following supervised exercise in people with diabetic peripheral neuropathy. These findings are particularly promising given the short duration of the intervention, but need to be validated by comparison with a control group in future studies.

Foot Drop Stimulation Versus Ankle Foot Orthosis After Stroke 30-Week Outcomes

Background and Purpose— Drop foot after stroke may be addressed using an ankle foot orthosis (AFO) or a foot drop stimulator (FDS). The Functional Ambulation: Standard Treatment versus Electric Stimulation Therapy (FASTEST) trial was a multicenter, randomized, single-blinded trial comparing FDS and AFO for drop foot among people ≥3 months after stroke with gait speed ⩽0.8 m/s. Methods— Participants (n=197; 79 females and 118 males; 61.14±11.61 years of age; time after stroke 4.55±4.72 years) were randomized to 30 weeks of either FDS or a standard AFO. Eight dose-matched physical therapy sessions were provided to both groups during the first 6 weeks of the trial. Results— There was significant improvement within both groups from baseline to 30 weeks in comfortable gait speed (95% confidence interval for mean change, 0.11–0.17 m/s for FDS and 0.12–0.18 m/s for AFO) and fast gait speed. However, no significant differences in gait speed were found in the between-group comparisons. Secondary outcomes (standard measures of body structure and function, activity, and participation) improved significantly in both groups, whereas user satisfaction was significantly higher in the FDS group than in the control group. Conclusions— Using either an FDS or an AFO for 30 weeks yielded clinically and statistically significant improvements in gait speed and other functional outcomes. User satisfaction was higher in the FDS group. Although both groups did receive intervention, this large clinical trial provides evidence that FDS or AFO with initial physical therapy sessions can provide a significant and clinically meaningful benefit even years after stroke. Clinical Trial Registration Information— URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01138995.

Exercise and Executive Function in Individuals with Chronic Stroke: A Pilot Study

Background and Purpose: Emerging evidence suggests that exercise may improve cognitive function in older adults. The purpose of this pilot study was to describe changes in measures of cognition and executive function in individuals with chronic stroke following participation in aerobic and strengthening exercise. Methods: A single-group, pretest-posttest design was used. Nine individuals with chronic stroke (mean age = 63.7 ± 9.1 years, mean time since stroke = 50.4 ± 37.9 months) completed a 12-week program of aerobic and strengthening exercise, 3 days per week. The primary outcome measures examined executive function (Digit Span Backwards and Flanker tests). Secondary measures examined various aspects of aerobic fitness ( O2peak and 6-minute walk distance) and function (Fugl-Meyer and 10-m walk speed). Results: Following the intervention, significant improvements were found in the Digit Span Backwards test (mean change = 0.56 ± 0.9 digits; P = 0.05), Fugl-Meyer score (mean change = 3.6 ± 5.7; P = 0.05), and Stroke Impact Scale total score (mean change = 33.8 ± 38.5; P = 0.02). A significant correlation was found between improved aerobic capacity and improved performance on the Flanker test (r = 0.74; P = 0.02). Discussion: The results of this study indicate that a 12-week aerobic and strengthening exercise program was associated with improvements in selected measures of executive function and functional capacity in people with stroke. Limitations of this study include the small sample size and lack of a comparison group. Conclusions: This pilot study contributes to the emerging evidence that exercise improves cognition in people with stroke. These benefits indicate the need for future study with a larger group to have sufficient power to further explore these relationships.

Modified Total-Body Recumbent Stepper Exercise Test for Assessing Peak Oxygen Consumption in People With Chronic Stroke

Background: Assessment of peak oxygen consumption (V̇o2peak) using traditional modes of testing such as treadmill or cycle ergometer can be difficult in individuals with stroke due to balance deficits, gait impairments, or decreased coordination. Objective: The purpose of this study was to quantitatively assess the validity and feasibility of a modified exercise test using a total-body recumbent stepper (mTBRS-XT) in individuals after stroke. Design: A within-subject design, with a sample of convenience, was used. Participants. Eleven participants (7 male, 4 female) with a mean of 40.1 months (SD=32.7) after stroke, a mean age of 60.9 years (SD=12.0), and mild to severe lower-extremity Fugl-Myer test scores (range=13–34) completed the study. Methods: Participants performed 2 maximal-effort graded exercise tests on separate days using the mTBRS-XT and a cycle ergometer exercise protocol to assess cardiorespiratory fitness. Measurements of V̇o2peak and peak heart rate (peak HR) were obtained during both tests. Results: A strong relationship existed between the mTBRS-XT and the cycle ergometer exercise test for V̇o2peak and peak HR (r=.91 and .89, respectively). Mean V̇o2peak was significantly higher for the mTBRS-XT (16.6 mL×kg−1×min−1[SD=4.5]) compared with the cycle ergometer exercise protocol (15.4 mL×kg−1×min−1 [SD=4.5]). All participants performed the mTBRS-XT. One individual with severe stroke was unable to pedal the cycle ergometer. No significant adverse events occurred. Conclusion: The mTBRS-XT may be a safe, feasible, and valid exercise test to obtain measurements of V̇o2peak in people with stroke. Health care professionals may use the mTBRS-XT to prescribe aerobic exercise based on V̇o2peak values for individuals with mild to severe deficits after stroke.

Lower-Extremity Strength Differences Predict Activity Limitations in People With Chronic Stroke

Background: Body system impairments following stroke have a complex relationship with functional activities. Although gait and balance deficits are well-documented in people after stroke, the overlapping influence of body impairments makes it difficult to prioritize interventions. Objective: This study examined the relationship between prospectively selected measures of body function and structure (body mass index, muscle strength, sensation, and cognition) and activity (gait speed, gait endurance, and functional balance) in people with chronic stroke. Design: This was a cross-sectional, observational study. Methods: Twenty-six individuals with mean (SD) age of 57.6 (11) years and time after stroke of 45.4 (43) months participated. Four variables (body mass index, muscle strength difference between the lower extremities, sensation difference between the lower extremities, and Mini-Mental Status Exam score) were entered into linear regression models for gait speed, Six-Minute Walk Test distance, and Berg Balance Scale score. Results: Lower-extremity strength difference was a significant individual predictor for gait speed, gait endurance, and functional balance. Cognition significantly predicted only gait speed. Limitations: The authors did not include all possible factors in the model that may have influenced gait and balance in these individuals. Conclusions: Strength deficits in the hemiparetic lower extremity should be an important target for clinical interventions to improve function in people with chronic stroke.

Exertion Fatigue and Chronic Fatigue Are Two Distinct Constructs in People Post-Stroke

Background and Purpose— Post-stroke fatigue is a common and neglected issue despite the fact that it impacts daily functions, quality of life, and has been linked with a higher mortality rate because of its association with a sedentary lifestyle. The purpose of this study was to identify the contributing factors of exertion fatigue and chronic fatigue in people post-stroke. Methods— Twenty-one post-stroke people (12 males, 9 females; 59.5±10.3 years of age; time after stroke 4.1±3.5 years) participated in the study. The response variables included exertion fatigue and chronic fatigue. Participants underwent a standardized fatigue-inducing exercise on a recumbent stepper. Exertion fatigue level was assessed at rest and immediately after exercise using the Visual Analog Fatigue Scale. Chronic fatigue was measured by the Fatigue Severity Scale. The explanatory variables included aerobic fitness, motor control, and depressive symptoms measured by peak oxygen uptake, Fugl-Meyer motor score, and the Geriatric Depression Scale, respectively. Results— Using forward stepwise regression, we found that peak oxygen uptake was an independent predictor of exertion fatigue (P=0.006), whereas depression was an independent predictor of chronic fatigue (P=0.002). Conclusion— Exertion fatigue and chronic fatigue are 2 distinct fatigue constructs, as identified by 2 different contributing factors.

Diabetic Neuropathy Part 1: Overview and Symmetric Phenotypes

Diabetes is the most common cause of neuropathy in United States and neuropathies are the most common complication of diabetes mellitus, affecting up to 50% of patients with type 1 and type 2 diabetes mellitus. Symptoms usually include numbness, tingling, pain, and weakness. Dizziness with postural changes can be seen with autonomic neuropathy. Metabolic, vascular, and immune theories have been proposed for the pathogenesis of diabetic neuropathy. Axonal damage and segmental demyelination can be seen with diabetic neuropathies. Management of diabetic neuropathy should begin at the initial diagnosis of diabetes and mainly requires tight and stable glycemic control.

The relationship between fatigue, aerobic fitness, and motor control, in people with chronic stroke. A pilot study

ABSTRACT Background: Fatigue is a commonly neglected issue despite the high incidence rate reported in people post‐stroke. Objective: To explore the relationship between fatigue, aerobic fitness, and motor control in people with chronic stroke. Methods: Nine people post‐stroke participated in this cross‐sectional study (7 females, mean age=56.8 (11.8) years, range 47‐73, time post‐stroke=47.6 (51.2) months, range 11‐140). Participants performed a six‐minute‐walk exercise in order to induce fatigue, followed immediately by a Fatigue Index (FI) scale to report fatigue at the moment. The distance walked (6MWD) was documented. On a separate visit, aerobic fitness was characterized by VO2Peak using a cycle‐ergometer. In addition, Fugl‐Meyer (FM) test was administered to assess motor control of the hemiparetic side. Pearson Product Correlation Coefficient and multiple linear regression were used to analyze the relationships between FI, VO2Peak and FM. Results: VO2Peak showed significant positive correlations with FM (r=.779, p=.013) and 6MWD (r=.726, p=.027). Fatigue index displayed significant negative correlations with VO2Peak (r=‐.739, p=.023) and FM (r=‐.873, p=.002), but not with 6MWD (r=‐.620, p=.075). Using stepwise multiple regression, we found that that FM was an independent predictor of FI (p=.002) and explained 76.2% of variance in FI (R2=.762). Conclusion: Our data suggests that motor control capability may be a good predictor of fatigue in people post‐stroke. Fatigue is a complex phenomenon; a quantifiable measure that is sensitive to multiple components is needed in order to distinguish the nature of fatigue and its contributing factors.

Multidimensional exercise for people with Parkinson's disease: A case report

The primary impairments associated with Parkinsons disease occur in combination with the secondary, preventable effects of immobility. A community-based fitness program may help increase activity and maintain function in people in the early or middle stages of the disease. This article describes a unique program designed to reduce fall risk and promote independent exercise for people with Parkinsons disease. Two 66-year-old males, both community ambulators and in early or middle stages of Parkinsons disease, participated in 3 months of various physical activities. Group balance classes were held twice weekly during the first month, participants joined a fitness center and self-directed their exercise program during the second month, and group Tai Chi classes were held twice weekly during the third month. At conclusion of the program, participants were given suggestions for continued physical fitness activities. After the 3-month program, improvements were noted for both individuals in functional reach, Timed Up and Go, and Berg Balance scores. Both participants continued to exercise regularly for at least 8 months following the program. Two individuals with Parkinsons disease demonstrated improvement in their balance test performance over a 3-month period. Perhaps most importantly, these participants independently continued exercising after completing this program.

Single limb exercise induces femoral artery remodeling and improves blood flow in the hemiparetic leg poststroke.

Background and Purpose— After stroke, individuals have decreased mobility of the hemiparetic leg, which demands less muscle oxygen consumption; thus, blood flow decreases. The purpose of this study was to determine the effect of single limb exercise (SLE) on femoral artery blood flow, diameter, and peak flow velocity in the hemiparetic leg after stroke. Methods— Twelve individuals (60.6±14.5 years of age; 5 male) with chronic stroke (69.1±82.2 months; 5 with right-sided hemiparesis) participated in the study. The intervention consisted of a SLE knee extension/flexion protocol 3 times per week for 4 weeks. Using Doppler ultrasound, bilateral femoral artery blood flow, diameter, and peak flow velocity were assessed at baseline, after 2 weeks, and after 4 weeks of SLE. Results— Using repeated-measures analysis of variance, femoral artery blood flow, arterial diameter, and blood flow velocity in the hemiparetic limb were significantly improved (P<0.0001) after the SLE. No significant changes occurred in the nontrained limb for any outcome measures. Conclusions— These data suggest that a 4-week SLE training program that increases muscular activity in the hemiparetic limb improves femoral artery blood flow, diameter, and peak velocity. SLE may be an important training strategy in stroke rehabilitation to minimize the vascular changes that occur poststroke due to decreased activity of the hemiparetic limb.