Effects of pulse width variations in pallidal stimulation for primary generalized dystonia

L. Vercueil, J. L. Houeto, P. Krystkowiak, C. Lagrange, F. Cassim, A. Benazzouz, B. Pidoux, A. Destée, Y. Agid, P. Cornu, S. Blond, A. L. Benabid, P. Pollak, M. Vidailhet,
J Neurol. 2007-06-29; 254(11): 1533-1537
DOI: 10.1007/s00415-007-0578-8

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1. J Neurol. 2007 Nov;254(11):1533-7. doi: 10.1007/s00415-007-0578-8. Epub 2007
Jun 29.

Effects of pulse width variations in pallidal stimulation for primary
generalized dystonia.

Vercueil L(1), Houeto JL, Krystkowiak P, Lagrange C, Cassim F, Benazzouz A,
Pidoux B, Destée A, Agid Y, Cornu P, Blond S, Benabid AL, Pollak P, Vidailhet M;
Spidy GROUP (French Pallidal stimulation Group for dystonia).

Author information:
(1)Neurology and Neurosurgery, CHU Grenoble, 38043 Grenoble, France.

BACKGROUND: Various pulse widths (from 60-450 mus) have been used for bilateral
pallidal stimulation in generalized dystonia but, to date, no comparison of this
parameter’s effects is available.
OBJECTIVE: To provide an analysis of the differential effects of bilateral
short, medium and long stimulus pulse width (PW) on clinical improvement in
primary generalized dystonia.
METHODS: The most effective therapeutic stimulation parameters were recorded in
22 patients using bilateral pallidal stimulation. Six months after surgery, the
effects of bilateral pallidal short (60-90 micros), medium (120-150 micros) and
long (450 micros) PWs were studied in 20 of those patients. The effect of the
stimulation was assessed by reviewing videotaped sessions by an observer blinded
to treatment status (Burke-Fahn-Marsden movement score). Patients were tested on
separate days, in random order, for the stimulation conditions (acute effect
with the stimulation condition lasting 10 hours). The same contact was used for
each stimulation condition. All the electrodes were set at 130 Hz (monopolar
stimulation) and the intensity was set individually 10% below the side effect
RESULTS: Median PWs of 60 (short), 120 (medium) and 450 micros (long) were
compared,with a mean intensity of 4.46, 3.45 and 2.47 V, respectively. This
study failed to demonstrate any significant difference in the movement scale
dystonia mean scores depending on PW.
CONCLUSION: According to our findings, short duration stimulus PWs are as
effective as longer ones during a 10 hour period of observation. Confirmation of
this finding for chronic use could be of importance in saving stimulator energy.
Moreover, the use of smaller stimulus pulse widths are said to reduce charge
injection and increase the therapeutic window between therapeutic effects and
side effects.

DOI: 10.1007/s00415-007-0578-8
PMID: 17597333 [Indexed for MEDLINE]

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