Effect of constant-current pallidal deep brain stimulation for primary
dystonia on cognition, mood and quality of life: Results from a
prospective pilot trial
Objective: Knowledge on the effects of DBS on cognitive functions is
limited and no data exists on the effects of constant-current DBS
(CC-GPi-DBS), which appears to prevail over constant-voltage
stimulation. Our aim was to prospectively assess the effect of
Constant-Current-GPi-DBS, using an 8-contact lead, on cognition, mood
and quality of life.
Patients and Methods: Ten patients aged 27-49 underwent prospective
neuropsychological assessment using dedicated tests. Various cognitive
domains (intelligence, executive functions, memory, attention,
visuo-spatial perception, verbal intelligence) as well as emotional
state and quality of life were examined preoperatively and 1, 6 and 12
months after continuous constant-current DBS.
Results: Patients performed preoperatively below average on information
processing speed, phonemic verbal fluency and working memory. At
6-months there was an improvement in phonemic verbal fluency (p < .05),
which was retained at 12-months postoperatively (p = .05). Results also
showed marginal improvement in the Trail Making-A test (p = .051) and
the Stroop colour-word test (p < .05). Despite improvement in Quality of
Life (Physical and Mental Component improved by 32.42% and 29.46%
respectively), patients showed no discernible change in anxiety and
depression status.
Conclusions: CC-GPi-DBS for primary dystonia has no discernible negative
impact on cognition and mood. If anything, we noted an improvement of
certain cognitive functions
