Scientific Articles and Abstracts
Treating chronic hemiparesis with modified
biofeedback.
Eleven patients with chronic spastic
hemiparesis were treated with biosignal processing (BSP), a modified
biofeedback method in which the patient practices useful tasks, not
isolated individual movements. A surface EMG measures sequential
movements, and an acoustic signal monitors muscle exertion. The
patient first learns how the signal develops by using the unaffected
limb. Then the patient tries to reproduce the course of the signal
in the paretic limb. Patients received 12 to 30 treatments for upper
and/or lower extremities. We measured maximum strength as expressed
through the EMG signal; ability to perform the trained action as
measured by specific grading systems; and general increase in
movement competence during a Bobath movement test. Ten patients
showed improved strength; four made marked progress in the
performance of specific tasks with the upper extremity, as did four
with the lower extremity. Four patients in each group improved in
general movement. We recommend the integration of useful tasks into
movement exercises in EMG biofeedback therapy.
Wissel J. Et.al. Hosp. Am Urban, Berlin, Germany. Arch
Phys Med Rehabilitation
The effects of neuromuscular stimulation-induced muscle contraction
versus elevation on hand edema in CVA patients.
The
purpose of this study was to evaluate the efficacy of the use of
neuromuscular stimulation (NMS)-induced contraction of the paralyzed
muscles to produce an active muscle pump for removing excess fluid
and compare its effect with elevation of the upper extremity. The
effects of 30 minutes of NMS of the finger and wrist flexors and
extensors were compared with the effects of 30 minutes of limb
elevation alone. Each of eight cerebrovascular accident (CVA)
patients with visible hand edema received both treatments, one on
each of 2 consecutive days. Measures of hand and arm volume and
upper and lower arm girth were taken before and after each
treatment. Analyses comparing mean percentage change scores for both
treatments showed large and significant treatment effects for all
dependent measures. The finding suggests that NMS was more effective
for reduction of hand edema than limb elevation alone for this
sample of eight CVA patients.
Faghri PD.
University of Connecticut, USA. Journal Hand Therapy
Two
Coupled Motor Recovery Protocols Are Better Than One Electromyogram
Triggered Neuromuscular Stimulation and Bilateral Movements
Background and Purpose: Overcoming chronic hemiparesis
from a cerebrovascular accident (CVA) can be challenging for many
patiens, especially after the first 12 months after the CVA. With
the use of established motor control theories, the present study
investigated electromyogram (EMG)-triggered neuromuscular
stimulation and bilateral coordination training. Methods:
Twenty-five CVA subjects volunteered to participate in this motor
recovery protocol study. Subjects were randomly assigned to 1 of 3
groups: (1) coupled protocol of EMG-triggered stimulation and
bilateral movement (n=10); (2) EMG-triggered stimulation and
unilateral movement (n=10); or (3) control (n=5). all participants
completed 6 hours of rehabilitation during a 2-week period according
to group assignments. Motor capabilities of the wrist and fingers
were evaluated on the basis of 3 categories of motor tasks in a
pretest - posttest control group design. Results: Significant
findings for the (1) number of blocks moved in a functional task,
(2) chronometric reaction times to initiate movements, and (3)
sustained muscle contraction capability all favored the coupled
bilateral movement training and EMG-triggered neuromuscular
stimulation protocol group. In addition, the unilateral
movement/stimulation group exceeded the control group in the number
of blocks moved and rapid onset of muscle contractions. Conclusions:
This new evidence is convincing in that subjects in the coupled
protocol group were able to demonstrate enhanced voluntary motor
control across 3 categories of tasks. Chronic hemiparesis decreased
considerably in the wrist and fingers as CVA patients expanded their
motor repertoire.
Cauraugh J.H. et.al.
Journal: Stroke
Electrostimulation for Stroke rehabilitation:
Mechanisms and effect.
Purpose: The aims of this project
are to assess the efficacy of EMG-controlled neuromuscular
stimulation in enhancing the upper-extremity motor recovery of
chronic stroke survivors, and to determine whether EMG-controlled
neuromuscular stimulation mediates its effect on motor recovery via
central mechanisms. Methodology: Phase I of the study will identify
neurophysiologic measures of brain function that correlate with
objective measures of motor impairment. Chronic stroke survivors
will be evaluated with objective measures of motor impairment
(active range of motion, joint torques, Fugl-Meyer Motor Assessment,
and EMG initiation and termination characteristics) and
neurophysiologic measures of central motor function (Single Photon
Emission Computed Tomography, Transcortical Magnetic Stimulation and
Somatosensory Evoked Potentials). Phase II will consist of a
single-blinded, randomized clinical trial to assess the effects of
EMG-controlled neuromuscular stimulation on objective measures of
motor impairment and measures of central motor function identified
in phase I. Progress: A total of 20 chronic stroke survivors will be
enrolled in phase I over a 2-year period, and 34 chronic stroke
survivors in phase II over a 3-year period. Implications: This study
will demonstrate that EMG-controlled neuromuscular stimulation
enhances the motor recovery of chronic stroke survivors, and that
the motor recovery is mediated by central mechanisms. The proposed
intervention may be effective for acute stroke survivors and persons
with other forms of cerebral motor dysfunction such as traumatic
brain injury, cerebral palsy and multiple sclerosis. EMG-controlled
neuromuscular stimulation may also be effective for lower limb motor
recovery. Finally, techniques developed for assessing central motor
function may be useful for evaluating other interventions directed
at stroke rehabilitation.
John Chae MD et.al.
Center for Physical Medicine and Rehabilitation University of
Cleveland, USA
EMG-Controlled stimulator for stroke
rehabilitation.
Purpose: The general purpose of this
project is to develop a device for facilitating motor relearning for
stroke survivors. The device will detect weak electromyographic
(EMG) signals generated by a paretic muscle and consequently deliver
stimulation currents to the same muscle to result in its strong
contraction. The device will consist of a set of electrodes for
sensing and stimulation and electronic circuitry for signal
processing and stimulus generation. Methodology: During Phase I, we
shall pursue the following objectives to produce and assess a
pre-prototype device: first, we shall develop a tripolar
intramuscular electrode that is suitable for both EMG sensing and
muscle stimulation. The electrode should have a diameter small
enough to be loaded into a 19-gauge hypodermic needle for
percutaneous implantation. It should be durable enough to withstand
muscle contraction without breakage for at least 4 weeks, and
sufficiently flexible and include an anchoring mechanism capable of
maintaining the intended position for the same period. Then we shall
develop electronic circuits that, when connected to the tripolar
intramuscular electrode, can reliably detect EMG signals and deliver
stimulation pulses to the target muscle. The detecting circuitry
should be able to detect very weak EMG signals, in the order of 1 µV
in a paretic muscle, while having high immunity to the very strong
stimulation artifact generated by the stimulus current. The
stimulation circuitry should be able to generate charge-balanced,
current-regulated, biphasic pulses for safe and effective
intramuscular stimulation. Finally, we shall evaluate the
performance of the sensing-stimulation system in three stroke
survivors. The implantation of the intramuscular electrode should be
simple for the physician and well tolerated by the patients. The
patient should be able to control the stimulation reliably after a
short period of training and adjustment. The desirable exercise
modes should be obtained in the paretic limbs without accompanying
pain or discomfort. The use of the device should result in improved
range of motion and flexion-extension torque at the involved joints.
Progress: Electrodes have been designed and developed for the
purpose of sensing EMG signals and stimulating the muscle from which
those EMG signals were detected. A laboratory version of the
EMG-controlled stimulator has been developed. The device is capable
of processing two EMG signals and using them to control the onset
and termination of stimulation pulses from four stimulation
channels. Future plans: The tripolar electrodes and the
EMG-controlled stimulator will be tested on a number of persons with
hemiplegia. After the system has been miniaturized, subjects will
use the device for exercise at home, and the effectiveness of the
intervention will be assessed.
Zi-Ping Fang,
PhD et.al. Cleveland FES Center, USA
Biofeedback and functional electric stimulation in
stroke rehabilitation.
The study examined the efficacy
of functional electric stimulation (FES) and biofeedback (BFB)
treatment of gait dysfunction in patients with hemiplegia after
stroke. These two therapeutic modalities were tested alone and in
combination in a prospective, controlled, randomized trial. The
authors hypothesized that in concurrent use, these two modalities
would complement one another. Thirty-six hemiplegic patients
undergoing rehabilitation after stroke were accepted for study and
randomized into four groups to receive either control, FES, BFB, or
combined therapies. Each patient received 30 minutes of treatment
three times per week for six weeks, in addition to their general
rehabilitation program. Quantitative gait analysis was performed
biweekly on each subject during the experimental therapy and for
four weeks afterward. Thirty-two subjects completed the study.
Combined therapy with BFB and FES resulted in improvements in both
knee and ankle minimum flexion angles during swing phase that were
statistically significant with p = 0.05 and p = 0.02, respectively.
Velocity of gait, cycle time, and symmetry of stance phases also
improved. The length of time elapsed since the stroke did not prove
to be a significant factor.
Cozean C.D. et.al.
Ohio State University. Arch Phys Med Rehabilitation
Electrical stimulation in early stroke rehabilitation
of the upper limb with inattention.
Use of electrical
stimulation early in stroke rehabilitation may benefit recovery of
function. This case report describes the clinical outcomes following
electrical stimulation for the supraspinatus of a 25-year-old
patient four weeks after a right-sided stroke. In this patient, use
of electrical stimulation for a total of four hours in 4.5 weeks,
appeared to have a number of benefits: subluxation was reduced and
patient attention to the arm was increased. There was also a notable
improvement in functional use of the arm when task-specific upper
limb training was incorporated. Whilst not conclusive, the results
of this case study reinforce the value of electrical stimulation in
the early management of the upper limb in a stroke patient who
clearly demonstrated inattention to his upper limb. The results also
highlight the need for well controlled studies to investigate
the benefits of electrical stimulation and to establish the optimal
timing and parameters for this intervention. Therapists can then
more effectively optimise effective upper limb rehabilitation
following stroke.
Mackenzie-Knapp M. School of
Physiotherapy, La Trobe University, Bundoora, Australia. Aust J.
Physiother.
Percutaneous, intramuscular neuromuscular electrical
stimulation for the treatment of shoulder subluxation and pain in
chronic hemiplegia: a case report.
This case report
describes the first survivor with chronic stroke who was treated
with percutaneous, intramuscular neuromuscular electrical
stimulation (NMES) for shoulder subluxation and pain. The patient
developed shoulder subluxation and pain within 2 mo of his stroke.
After discharge from acute inpatient rehabilitation, he developed
shoulder and hand pain, which was treated with subacromial bursa
steroid injection and ibuprofen with eventual resolution. The
patient remained clinically stable until approximately 15 months
after his stroke-when he developed severe shoulder pain associated
with shoulder abduction, external rotation, and downward traction.
The patient could not tolerate transcutaneous NMES because of the
pain of stimulation. At approximately 17 mo post-stroke, the
patient's posterior deltoid, middle deltoid, and supraspinatus
muscles were percutaneously implanted with intramuscular electrodes.
After 6 wk of percutaneous, intramuscular NMES treatment, marked
improvements in shoulder subluxation and pain, and modest
improvements in activities of daily living and motor function were
noted. One year after the onset of treatment, the patient remained
pain free, but subluxation had recurred. However, the patient was
able to volitionally reduce the subluxation by abducting his
shoulder. The patient remained pain free for up to 40 months after
the initiation of percutaneous, intramuscular NMES treatment. This
case report demonstrates the feasibility of using percutaneous,
intramuscular NMES for treating shoulder subluxation and pain in
hemiplegia.
Chae J. et.al. Dep.of Physical
Medicine and Rehabilitation, Cleveland, USA. Am J Phys Med
Rehabilitation
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