Scientific Articles and Abstracts
Dual
therapy shown to aid stroke recovery
A combination
therapy that pairs special exercises with electrical stimulation of
the muscles can help patients who have one arm weakened by stroke, a
small study suggests. Researchers at the University of Florida,
Gainesville, found that patients who went through 2 weeks of the
therapy regained more arm function compared with those not on the
dual treatment. Dr. James H. Cauraugh and Sangbum Kim report their
findings in the June, 2002 issue of Stroke: Journal of the American
Heart Association. One part of the combination therapy involves
placing electrodes on patients' forearms to stimulate their working
muscles as they perform various tasks--such as reaching for,
grasping and moving small blocks. This small shot of electricity is
known as electromyogram-triggered neuromuscular stimulation, or
EMG-triggered stimulation. The other aspect of the therapy requires
patients to perform movements with both the stroke-affected and
healthy arm. Such bilateral movement, in contrast to moving only the
affected side, is thought to potentially recruit new nerve pathways
to assist the weakened limb. Cauraugh told Reuters Health that the
electrical-stimulation therapy--which he said has grown increasingly
popular over the past 5 years--gives a "boost" to the muscles at the
back of the forearm, helping patients extend their wrists and
fingers. Few studies have looked at bilateral movement in stroke
recovery, but researchers have long known that executing the same
motion with both arms facilitates the movement of the individual
arm, according to Cauraugh. "When the same movement signal is sent
to both arms, then movements are readily executed," he explained.
And he said, combining EMG stimulation and bilateral movement "takes
advantage of the strengths of each." To test this idea, the Florida
researchers had 10 patients train with the combination therapy,
while 10 others received electrical stimulation while moving only
their weakened arms. A third, "control" group of five patients
exercised the impaired limb only, with no electrical stimulation.
All had suffered strokes at least one year before the study, and had
continuing weakness on one side of the upper body. After 2 weeks of
therapy, those in the bilateral/stimulation group were outperforming
the other two groups in tests of movement and muscle contraction,
the report indicates. The researchers also found marked improvements
among patients who received EMG-triggered stimulation while moving
only their stroke-affected arm. They were able, for example, to move
more blocks than control-group patients were, and showed faster
reaction times when cued to move their wrists and fingers. However
they note, the even greater improvements in the
bilateral/stimulation group suggest that the two approaches together
are "better than one." Cauraugh said he will continue to study how
the injured brain can "reorganize" with the help of behavioral
therapies and try to identify those that provide the greatest
movement recovery.
Amy Norton Reuters
Health
A
control study of muscle force recovery in hemiparetic patients
during treatment with functional electrical stimulation.
A group of forty-nine hemiparetic patients with limited
emotional, communication and sensibility involvement and with recent
lesion of cerebrovascular aetiology was randomly divided into two
groups of twenty-four and twenty-five subjects. Both groups received
traditional physiotherapy treatment for one hour/day, one group
received twenty min/day of peroneal nerve stimulation. The maximum
voluntary dorsal flexion moments of the ankle joint of the affected
and non affected extremities were measured with an isometric brace
twice a week for one month and for both groups. The recovery of
moment in the stimulated group turned out to be about three times
greater than in the control group and considerably less dependent
upon age, time from lesion, initial value, side of lesion. Three
patients using a peroneal brace at home as an assisting device were
again evaluated two months later and a further improvement was
observed. This work gives statistical support to previous
observations based on very few cases and provides a statistically
reliable answer concerning the entity of FES induced recovery of
muscle force in hemiparetic subjects.
Merletti
R. et al Scand J Rehabilitation Med.
Positional feedback and electrical stimulation: an
automated treatment for the hemiplegic wrist.
Positional
feedback (PF) and electrical stimulation were combined in a new
treatment modality for facilitating wrist extension in stroke
patients. Thirty adult hemiparetic patients lacking normal voluntary
wrist extension were randomly placed in control and study groups.
The control group received conventional therapy while the study
group received positional feedback stimulation training (PFST) in
addition to conventional treatment. At the end of the 4-week
program, study patients showed a 280% increase in isometric
extension torque when the wrist was positioned in 30 degrees of
extension and 70% increase when positioned in 30 degrees of flexion.
Control patients showed no significant changes in torque. Study
patients made an average 200% gain in selective range of motion over
their starting levels while controls made only a 50% increase.
Treatment using automated PFST equipment allows controlled
repetitive isotonic exercise and facilitation of wrist extension
without continuous one-on-one therapist/patient supervision.
Bowman B. et al Arch Phys Med Rehabilitation
Electrically induced recovery of gait components for
older patients with chronic stroke.
Objective: To
compare the gains for chronic stroke patients in volitional gait
pattern attained from treatment with functional neuromuscular
stimulation (FNS) and intramuscular electrodes (IM) with gains
attained using conventional therapy, including treatment with FNS
using surface electrodes (surface-stimulation). Design: This
single-subject research design consisted of a series of two
subjects. Three months of conventional therapy and
surface-stimulationb were followed by treatment using the FNS-IM
system. Two stroke patients had cerebrovascular accident 1 or 4 yr
before the study and ambulated with a cane. Interventions consisted
of 3 months of conventional exercise and gait training including
surface-stimulation, followed by 7-14 months of treatment with the
FNS-IM system. Treatments occurred up to 3 times/wk for 1-hr
sessions and a home program. Outcome measures consisted of six
kinematic gait components, as measured by a six-camera video-based
data-acquisition system. Coordination of isolated joint movement was
measured according to the Fugl-Meyer scale. Results: Both subjects
improved during conventional therapy to some degree. During FNS-IM
treatment, gains were made beyond those attained during conventional
therapy. Statistically significant differences were found between
conventional and FNS-IM therapy. Conclusions: For these two
subjects, gains in volitional control of gait were made during
conventional treatment (including surface-stimulation); for these
two subjects during FNS-IM treatment, additional gains were made in
volitional gait pattern, beyond those attained during conventional
therapy. Functional electrical stimulation-assisted walking for
persons with incomplete spinal injuries: changes in the kinematics
and physiological cost of overground walking.
Daly J. et al, Walsh University, N. Canton, Ohio, USA.
Am J Phys Med Rehabil.
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
Physiotherapy
Electrical stimulation for swallowing disorders
caused by stroke.
Background: An estimated 15 million
adults in the United States are affected by dysphagia (difficulty
swallowing). Severe dysphagia predisposes to medical complications
such as aspiration pneumonia, bronchospasm, dehydration,
malnutrition, and asphyxia. These can cause death or increased
health care costs from increased severity of illness and prolonged
length of stay. Existing modalities for treating dysphagia are
generally ineffective, and at best it may take weeks to months to
show improvement. One common conventional therapy, application of
cold stimulus to the base of the anterior faucial arch, has been
reported to be somewhat effective. We describe an alternative
treatment consisting of transcutaneous electrical stimulation (ES)
applied through electrodes placed on the neck. Objective: Compare
the effectiveness of ES treatment to thermal-tactile stimulation
(TS) treatment in patients with dysphagia caused by stroke and
assess the safety of the technique. Methods: In this controlled
study, stroke patients with swallowing disorder were alternately
assigned to one of the two treatment groups (TS or ES). Entry
criteria included a primary diagnosis of stroke and confirmation of
swallowing disorder by modified barium swallow (MBS). TS consisted
of touching the base of the anterior faucial arch with a metal probe
chilled by immersion in ice. ES was administered with a modified
hand-held battery-powered electrical stimulator connected to a pair
of electrodes positioned on the neck. Daily treatments of TS or ES
lasted 1 hour. Swallow function before and after the treatment
regimen was scored from 0 (aspirates own saliva) to 6 (normal
swallow) based on substances the patients could swallow during a
modified barium swallow. Demographic data were compared with the
test and Fisher exact test. Swallow scores were compared with the
Mann-Whitney U test and Wilcoxon signed-rank test. Results: The
treatment groups were of similar age and gender (p > 0.27),
co-morbid conditions (p = 0.0044), and initial swallow score (p =
0.74). Both treatment groups showed improvement in swallow score,
but the final swallow scores were higher in the ES group (p >
0.0001). In addition, 98% of ES patients showed some improvement,
whereas 27% of TS patients remained at initial swallow score and 11%
got worse. These results are based on similar numbers of treatments
(average of 5.5 for ES and 6.0 for TS, p = 0.36). Conclusions: ES
appears to be a safe and effective treatment for dysphagia due to
stroke and results in better swallow function than conventional TS
treatment.
Freed M. et al Resp. Care Dep.
Univ. Cleveland, USA Respiratory Care
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 mo 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 mo 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 Am J. Phys Dep. Physical
Medicine and Rehabilitation, Cleveland, USA Med Rehabilitation
Does
neurorehabilitation play a role in the recovery of walking in
neurological populations?
This review demonstrates that
neuro-rehabilitation approaches, based on recent neuroscience
findings, can enhance locomotor recovery after a spinal cord injury
or stroke. Findings are presented from more than 20 clinical studies
conducted by numerous research groups on the effect of locomotor
training using either body weight support (BWS), functional
electrical stimulation (FES), pharmacological approaches or a
combination of them. Among the approaches, only BWS-assisted
locomotor training has been demonstrated to have a greater effect
than conventional or locomotor training alone. However, when study
results were combined and weighted for the number of subjects, the
results indicated that there is a gradient of effects from small
changes with the immediate application of FES or BWS to larger
changes when locomotor training is combined with FES or BWS or
pharmacological approaches. The findings of these studies suggest
that these neuro-rehabilitation approaches do play a role in the
recovery of walking in subjects with spinal cord injury or stroke.
Several factors contribute to the potential for recovery including
the site, etiology, and chronicity of the injury, as well as the
type, duration, and specificity of the intervention and whether
interventions are combined. Furthermore, how these
neuro-rehabilitation approaches may take advantage of the plasticity
process following neurological lesion is also discussed.
Barbeau H. et al Physical and Occupational Therapy,
McGill University, Montreal, Canada. Ann N Y Acad Sci.
FES and
spasticity.
A model of hemiplegic spasticity based on
electromyographical and biomechanical parameters measured during
passive muscle stretching is presented. Two components of spasticity
can be distinguished -phasic and tonic. This classification depends
on the pattern of stretch reflex activity which can be either phasic
or tonic as well as on the muscle stretch/tension characteristic.
Stretch reflex, as a control loop, is in phasic spasticity
characterized by increased sensitivity to velocity of stretching. In
tonic spasticity, sensitivity to length of stretching is increased.
After the injury, phasic spasticity appears first and invokes
monosynaptic reflex pathways. The intensity of tonic spasticity
increases with the duration of disability and hence causes changes
in muscle fiber biomechanical properties. The model mentioned above
has been used to evaluate the effects of FES on spasticity.
Hemiplegic patients with implanted peroneal nerve stimulator for
gait correction were followed up for one year starting a week before
implantation. Long-term use of FES resulted in decrease of tonic
spasticity in both ankle joint antagonistic muscle groups. In
stimulated tibialis anterior muscle, the phasic type of spasticity
increased. To obtain the correlation between changes in spasticity
and functional abilities of patients, the maximal voluntary
isometric contraction of both muscle groups was also measured. An
improvement in voluntary strength was also observed. This can be
taken as additional evidence that tonic spasticity is of greater
physiological and clinical significance than phasic spasticity. It
may be concluded that use of FES can decrease tonic spasticity and,
if applied early after the injury, can prevent the appearance of
tonic spasticity.
Stefanovska A. et al IEEE
Trans Biomed Eng.
The
quantitative measurement of spasticity: effect of cutaneous
electrical stimulation.
The goal of this research was to
determine if cutaneous electrotherapy would temporarily reduce
muscle spasticity. Five traumatically brain injured (TBI) and five
spinal cord injured (SCI) subjects, all with clinically evident
spasticity, received surface electrical stimulation over the
tibialis anterior muscle. Using the Spasticity Measurement System,
stiffness around the ankle was measured before, immediately after,
and 24 hours after treatment. With stimulation, ipsilateral ankle
viscoelastic stiffness immediately decreased in 9 of 10 subjects and
remained significantly depressed for up to 24 hours. Contralateral
ankle spasticity did not significantly change. Using the same
subjects under sham conditions, no significant decrements in
spasticity occurred. In a subjective survey, only SCI participants
reported functionally evident spasticity reductions. Also within
this subgroup, efficacy of treatment was directly proportional to
the severity of pre-stimulation clonus. We conclude that (1)
cutaneous electrotherapy transiently decreases both TBI and SCI
related spasticity and (2) pre-stimulation clonus may function as a
clinical indicator of SCI patients most likely to benefit from this
process. Seib T. et al Univ. of Washington School
of Medicine, Seattle. Arch Phys Med Rehabilitation
Spasticity in spinal cord injured patients:
Short-term effects of surface electrical stimulation.
Twelve spinal cord injured subjects participated in a
study of the short-term effects on leg spasticity of electrical
stimulation of the quadriceps. Spasticity was quantified through the
use of a normalized relaxation index (R2n) obtained from the
pendulum drop test both before and after measurement of isometric
quadriceps torque in response to 20 minutes of cyclic electrical
stimulation. Two or three baseline evaluations were made on each
subject, tests being at least one day apart. By comparing the first
prestimulus baseline assessment of spasticity with that obtained
poststimulus, we obtained a measure of changes in spasticity brought
about by fatiguing exercise. We found that spasticity significantly
(p less than or equal to 0.005) decreased after stimulation. To
investigate whether this change was due to electrical stimulation or
was a function of the performance of the drop test itself (ie,
passive range of motion of the knees), drop-to-drop variability
during the pendulum drop test both before and after stimulation was
assessed. A comparison was made of the R2n value of the last drop
before stimulation to that of the first drop afterward, to assess
the direct effect of stimulation on spasticity. Spasticity decreased
significantly (p less than or equal to 0.05) during the leg ranging
inherent in the drop test itself, particularly for subjects with
shorter times postinjury. Spasticity also decreased significantly as
a direct result of electrical stimulation. This latter change could
be accounted for by an interaction of peak quadriceps torque and the
initial measure of spasticity before stimulation.
Robinson C. et al Rehabilitation R & D Center,
Veterans Adm. Hospital, Hines, USA Arch Phys Med
Rehabilitation
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