Hans-Leo
2008-07-31, 14:05
Research done using www.movalyzer.com
Movement Disorders, 23, Suppl 1, p S126
372
Deep brain stimulation of STN improves some handwriting
movements in Parkinson’s disease patients
M.V. Alvarez, A.W. Van Gemmert, V.H. Evidente, J.N. Caviness,
E.D. Driver-Dunckley, M.H. Lyons, C.H. Adler
(Lackland AFB, Texas)
Objective: Evaluate the effect of deep brain stimulation (DBS) of
the subthalamic nucleus and dopaminergic medications on handwriting
movements in patients with Parkinson’s disease (PD).
Background: Studies of DBS as a treatment for PD have shown
that up to 80% of the patients have improved motor UPDRS scores.
Yet, there is little data regarding DBS effects on everyday used fine
motor tasks, such as handwriting.
Methods: Eight PD patients (4 female, 4 male, ages 64-82 years)
with UPDRS motor scores ranging between 7-66 in MedOff-StimOff
and 2-26 in MedOff-StimOn were studied. Patients performed a
handwriting task on a digitizer tablet using an inking pen. The handwriting
task consisted of cursive writing ‘‘lleelleellee’’, at a normal
and two-times-larger-than-normal size. Handwriting was performed
in the practically defined ‘‘off’’ state, before taking their morning
medications, with the stimulator off then switched on. Patients then
took their medications, and after 30-45 minutes they performed the
handwriting task again with the stimulator off and then on. The task
for each stimulator/medication condition was repeated 5 times. Six
dependent measures were extracted from the recordings (stroke duration,
stroke size, normalized jerk, peak acceleration, relative duration,
and ratio of size between the second ‘‘l’’ and the sixth ‘‘l’’).
Results: With the stimulator turned on the speed of handwriting
increased when patients were asked to write twice as large (duration
338 msec on, 391 off Z5-2.521, p50.012). Turning the stimulator
on also improved normalized jerk with 7/8 writing smoother (normalized
jerk from 27 on, 41 off; Z5-2.100, p50.036). Additionally,
peak acceleration show a trend towards improvement in 5/8 patients
when the stimulator was switched on (on 137 cm/s2, off 101 cm/s2,
Z51.680, p50.093). There was no change in handwriting performance
in the regular size writing when the stimulator was turned on.
Medication did not improve handwriting.
Conclusions: These data provide objective evidence for some
improvement in motor function from DBS of the STN. Handwriting
might be a useful outcome tool for adjusting DBS stimulator settings
in some patients.
Movement Disorders, 23, Suppl 1, p S126
372
Deep brain stimulation of STN improves some handwriting
movements in Parkinson’s disease patients
M.V. Alvarez, A.W. Van Gemmert, V.H. Evidente, J.N. Caviness,
E.D. Driver-Dunckley, M.H. Lyons, C.H. Adler
(Lackland AFB, Texas)
Objective: Evaluate the effect of deep brain stimulation (DBS) of
the subthalamic nucleus and dopaminergic medications on handwriting
movements in patients with Parkinson’s disease (PD).
Background: Studies of DBS as a treatment for PD have shown
that up to 80% of the patients have improved motor UPDRS scores.
Yet, there is little data regarding DBS effects on everyday used fine
motor tasks, such as handwriting.
Methods: Eight PD patients (4 female, 4 male, ages 64-82 years)
with UPDRS motor scores ranging between 7-66 in MedOff-StimOff
and 2-26 in MedOff-StimOn were studied. Patients performed a
handwriting task on a digitizer tablet using an inking pen. The handwriting
task consisted of cursive writing ‘‘lleelleellee’’, at a normal
and two-times-larger-than-normal size. Handwriting was performed
in the practically defined ‘‘off’’ state, before taking their morning
medications, with the stimulator off then switched on. Patients then
took their medications, and after 30-45 minutes they performed the
handwriting task again with the stimulator off and then on. The task
for each stimulator/medication condition was repeated 5 times. Six
dependent measures were extracted from the recordings (stroke duration,
stroke size, normalized jerk, peak acceleration, relative duration,
and ratio of size between the second ‘‘l’’ and the sixth ‘‘l’’).
Results: With the stimulator turned on the speed of handwriting
increased when patients were asked to write twice as large (duration
338 msec on, 391 off Z5-2.521, p50.012). Turning the stimulator
on also improved normalized jerk with 7/8 writing smoother (normalized
jerk from 27 on, 41 off; Z5-2.100, p50.036). Additionally,
peak acceleration show a trend towards improvement in 5/8 patients
when the stimulator was switched on (on 137 cm/s2, off 101 cm/s2,
Z51.680, p50.093). There was no change in handwriting performance
in the regular size writing when the stimulator was turned on.
Medication did not improve handwriting.
Conclusions: These data provide objective evidence for some
improvement in motor function from DBS of the STN. Handwriting
might be a useful outcome tool for adjusting DBS stimulator settings
in some patients.