Abstract
Eleven
spinal cord injured patients participated in this study. They were classified
into two groups: (a) stimulated by percutaneous intramuscular electrodes, and
(b) stimulated by surface electrodes.
In
this study, we mainly evaluated the effect of stimulation using percutaneous
intramuscular electrodes, in reducing spasticity and thus improving the
activities of daily living (ADL) in patients with incomplete paraplegia. Next,
we compared the results of percutaneous intramuscular stimulation versus
surface stimulation in the incomplete paraplegic patients.
In
the percutaneous intramuscular electrodes group, 5 of 7 patients were improved
in ADL. On the other hand, in the
surface electrodes group, none of the patients had any decrease in their level
of spasticity.
Introduction
Incomplete
injury to the spinal cord causes disability of gait due to spasticity and
muscle weakness [1]. There are various approaches currently in the treatment of
spasticity: physical rehabilitation,
nerve block, drugs for muscle relaxation (antispasticity medication), orthosis,
and electrical stimulation. Recently there have been many reports on spasticity
reduction owing to therapeutic electrical stimulation (TES). Several forms of
electrical stimulus like epidural and peripheral nerve implantation [5], mostly
using surface electrodes, have been described.
We
think that surface electrodes have some problems. They are due to requiring
troublesome daily placement and removal, discomfort when excessive stimulation
is given by surface electrodes. We have been using percutaneous intramuscular
functional electrical stimulation (
The purpose of this paper is to
show the effectiveness of electrical stimulation, using percutaneous
intramuscular electrodes, in reducing spasticity and thus improving the daily
activities in patients with incomplete paraplegia. The second purpose of this
study was to compare the results of percutaneous intramuscular stimulation
versus surface stimulation in the incomplete paraplegic patients.
Patients
Eleven
SCI individuals, 8 men and 3 women, participated in this study. The patients
were classified into two groups: (a) stimulated by percutaneous intramuscular electrodes,
and (b) stimulated by surface electrodes. There were 7 patients in the
percutaneous intramuscular electrodes group and 4 in the surface electrodes
group.
The
average age of the patients in the percutaneous intramuscular electrodes group
was 39 years (range, 22-62 yeas). Injuries were classified as cervical in 2
patients, and thoracic in 5, with the interval between injury and therapeutic
stimulus ranged from 13 to 103 months. The cause of the injury was traumatic in
5, infectious in 1 and spinal infarction in 1. The
average follow-up time was 42.3months (range, 3 to 66 months). Table 1 is a
summary of percutaneous intramuscular electrodes group.
In
the surface electrodes group, the average patient age was 54 years (range,
40-73 yeas). Injuries were classified as cervical in 1 patient, and thoracic in
3. All patients were injured by traumatic episodes. The average follow-up time
was 4months (range, 2 months to 5 months). Table 2 is a summary of the surface
electrodes group.
All
patients had retained some voluntary movement or walking ability (Frankel C or
D). None of the patients received another treatment to control their
spasticity.
Methods
In
the percutaneous intramuscular electrodes group, the FESMATE developed by
Nippon Electric Company was used for TES in this study (Fig. 1). A stimulation
frequency of 20Hz was used. The pulse amplitude was modulated from 0 to –15V up
to sensory tolerance. Rectangular pulse trains were used with 200 microseconds
pulse width. Percutaneous intramuscular electrodes (Nippon Seisen
Co. Ltd.) were implanted into the motor points of the muscles (Fig. 2).
Electrical stimulation started two weeks after implantation. Table 3 shows the
protocol of TES. At the beginning, the stimulation was applied for 5 minutes,
three times daily. For the following two weeks, TES was conducted five times
daily for 5 minutes each. After 4 weeks from the beginning, the
Table.1: Patient Characteristics in the percutaneous
intramuscular electrodes group
Table.2: Patient Characteristics in the surface electrodes group
stimulation was extended to 15 minutes, five times per day.
In the surface electrodes group, PULSECURE-PURO (OG GIKEN Co. Ltd.) was used
for stimulation (Fig. 3). A stimulation frequency of 20-30Hz, a pulse duration of 300microseconds, and a stimulation
amplitude of up to 90mA was used. The surface electrodes were placed over motor
points of the quadriceps and hamstrings.
Spasticity in the lower limbs was assessed using the modified Ash worth scale. All patients were evaluated preoperatively and postoperatively by the senior author. To further evaluate the effects of TES, the following parameters were also studied; activities of daily living, gait analysis, muscular strength in the lower limbs and patient’s assessment. The results were subjectively graded as excellent, good, fair, and poor.
Results
In
the percutaneous intramuscular electrodes group, in patients 1, 2, and 3, the
spasticity significantly decreased after stimulation for a period of about 1
week. These 3 patients regained muscle strength and smooth flexion-extension
movement in their lower limbs so they felt that they had less difficulty during
walking. As a result, these patients abandoned their wheel chair and walked
with crutches. Patient 3 claimed that he could sleep through
the
night uninterrupted by spasms,which routinely
woke him up