1: J Neurol Neurosurg Psychiatry. 2007 Oct 26 [Epub ahead of print]

Cognitive declines following bilateral subthalamic nucleus deep brain stimulation
for the treatment of Parkinson's disease.

York MK, Dulay M, Macias A, Levin H, Grossman R, Simpson R, Jankovic J.

Baylor College of Medicine, United States.

BACKGROUND: We investigated the cognitive and psychiatric outcome 6-months after
bilateral subthalamic nucleus deep brain stimulation (DBS) for the treatment of
Parkinson's disease (PD) using a disease control group. METHODS: Twenty-three DBS
patients were compared to 28 medically-treated PD patients at baseline and
6-months on neuropsychological measures. In addition to the group outcomes, we
report reliable change indices (RCI) and a dementia caseness analysis. RESULTS:
The DBS patients demonstrated a significant decline in verbal memory compared to
the control group (p < 0.003), and trends for decline on oral information
processing, including verbal fluency, timed transcription, and word naming. DBS
patients demonstrated declines in attention, set shifting, and semantic fluency,
however, these changes were similar to the PD groups' rate of decline. RCI
indicated that DBS patients demonstrated clinically significant declines in
verbal fluency (p <0.01) and inhibition of a dominant response (p <0.003), with
trends for declines in set shifting (p<0.02) and verbal long-term recall (p
<0.08), indicative of frontostriatal dysfunction. DBS patients did not
demonstrate significant changes in depression, anxiety, or psychological distress
scores. The caseness analysis revealed that one of the DBS patients (4%)
converted to dementia over 6-months compared to none of the PD controls.
CONCLUSIONS: Our findings demonstrate that DBS patients experience declines in
verbal recall and trends for declines in oral information processing 6-months
following surgery even when good motor outcome is achieved. Potential candidates
should be counseled about the risk of mild frontostriatal cognitive declines
following DBS to weigh the risks and benefits of the surgery.


PMID: 17965146 [PubMed - as supplied by publisher]