Abstract
LIB-Stimulation has proved its efficacy before in a reasonable number of
patients with complete and irreversible denervation following destruction of
brachial and/or lumbosacral plexus. Tetanic contraction force can be increased
in these patients by up to 400%. In patients, a maximum of 30% of normal values
of voluntary contraction force was reached, in rabbits up to 100% and even more
than normal. In the animal experiment, reinnervation was not inhibited, but
even supported, and the present study was looking for effects in man.
Design/Methods
A series of 19 patients with high-grade pareses following plexus lesions
were investigated. In group I (n=12), patients were treated with
LIB-stimulation (30-70 ms impulse width, 6-16 Hz, 20-50 mA, bidirectional
balanced rectangular shape of impulse) twice daily, with a total stimulation
time of 5-6 minutes/muscle group. Group II (n=7) did not receive any
electrotherapy. Each patient received physiotherapy, observation time was 6
months. Contraction force was measured using a hand-held myometer, the amount
of reinnervation was estimated by measuring nerve conduction velocity (NCV) and
polyphasic muscle action potentials.
Results
Contraction force and NCV increased to a higher amount in each of the
patients with electrotherapy. Additionally, the results of motor scales, rating
scales of the activities of daily living and a well-being scale indicated a
better improvement in the electrotherapy-group.
Conclusions:
According to the present data in a small number of patients, this type of
electrotherapy may not only help to prevent disuse atrophy on a long term basis
to allow full benefit in the event that some nerve regeneration does eventually
occur, but it also may improve regeneration and reinnervation, resp. Further
studies have to be done to check these preliminary results.
1.
Introduction
Background
In previous studies of our group (Ref. 1-3), electrical stimulation with
balanced bidirectional rectangular impulses of high intensity and long pulse
duration (LIB-stimulation) has proved to be effective in maintaining and
restoring muscle contraction force in fast muscles of rabbit. Additionally, the
morphological sequelae of denervation atrophy was stopped and muscle bulk was
restored.
LIB-Stimulation has also proved its efficacy before in a reasonable number
of patients with complete and irreversible states of denervation following
destruction of brachial and/or lumbosacral plexus. Tetanic contraction force
was increased in these patients by up to 400% and reached - at maximum - 30% of
normal values of voluntary contraction force (in rabbits up to 100% and more!).
It has been discussed, whether electrical stimulation could or could not
disturb collateral or terminal sprouting during reinnervation. As in own
previous animal experiments, reinnervation was not inhibited, but even
supported, the present study was designed to look for effects in man. The
question was whether LIB-electrotherapy would disturb reinnervation mechanisms
or whether it could have even a positive influence on the clinical course of
reinnervation
1.1.
Previous
Work
Design/Methods
Patients/Denervation
A series of 19 patients (11 male, 8 female, 41±15 years) with high-grade
pareses (average MRC-grade 2.5, 1.5-4.0) following traumatic brachial plexus
lesions were investigated. The average time course of denervation was 5 months.
No previous electrotherapy had taken place, each of the patients received a
30-minute physiotherapy at least four times weekly
Electrical stimulation/therapy
In group I (n=12), patients were treated with LIB-stimulation (30-70 ms
impulse width, 6-16 Hz, 20-50 mA, bidirectional balanced rectangular shape of
impulse) twice daily, with a total stimulation time of 5-6 minutes/muscle
group. Patients in group II (n=7) did not receive any electrotherapy. Each
patient received physiotherapy, observation time was 6 months.
Fig. 1: LIB-Impulse form
Evaluation
Contraction force was measured using a hand-held myometer, the amount of
reinnervation was estimated by measuring nerve conduction velocity (NCV) of the
forearm median nerve and polyphasic muscle action potentials.
Activities of daily living (ADL) were measured by the Barthel-Index (BI)
and the Functional Independence Measure (FIM). Additionally, a well-being scale
(Befindlichkeitsskala nach von Zerssen, Bf-S) was used to estimate the
patient´s life quality.
Results
Physiological measurements:
Contraction forces of several muscles tested increased to a higher amount
in each of the patients with electrotherapy (overall significance: p≤.04,
see Fig. 2).
The forearm NCV of the median nerve increased by 6.5±4.0 m/s in the
electrotherapy group and by 4.1±4.3 m/s in the control group (p≤.01).
Similar results were obtained measuring the distal motor latency (not shown).
Polyphasic muscle action potentials:
The average amount of polyphasic MAPs in the investigated muscles was 24±8
% in the electrotherapy group and 25±8 % in the control group. No statistically
significant difference was found.
Fig. 2: Increase of muscle contraction force (kp)
Rehabilitation measurements
The rating scales of the activities of daily living both the BI and the FIM improved better in the electrotherapy-group (p≤.02). The same result was obtained considering the well-being scale (Fig. 3).
Fig. 3: ADL- and well-being results (gen. %)
2. Summary and Conclusions
According to the present data in a small number of
patients, this type of electrotherapy shows some clear benefits for
regeneration in patients with denervation following peripheral nerve lesions.
It may not only help to prevent denervation atrophy (to allow full benefit in
the event that some nerve regeneration does eventually occur), it is also able
to increase the intensity of regeneration and probably the amount of reinnervation. Further studies
have to be done.
Acknowledgment
The author wishes to acknoledge the financial support of the Deutsche Gesellschaft für Elektrostimulation und Elektrotherapie e.V. (GESET)
References
[1] K.F. Eichhorn, W. Schubert, E. David,
“Maintenance, Training and Functional Use of Denervated Muscle”, J Biomed Eng,
Vol. 6, pp. 205-11, 1984
[2] T. Mokrusch, B. Neundörfer,
“Electrotherapy of Permanently Denervated Muscle – Long-Term Experience with a
New Method”, PMR, Vol. 4, pp. 166-173, 1994
[3] T. Mokrusch, A. Engelhardt, K.F. Eichhorn, G. Prischenk, H. Prischenk, G. Sack, B. Neundörfer, “Effects of Long Impulse Electrical Stimulation on Atrophy and Fibre Type Composition of Chronically Denervated Fast Rabbit Muscle”, J Neurol, Vol. 237, pp. 29-34, 1990