Deep brain stimulation and cognitive functions in Parkinson's disease: A three-year controlled study.

There is debate over the cognitive and behavioral effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD). To evaluate these effects, we performed a prospective, naturalistic controlled, 3-year follow-up study. A total of 65 PD patients were enrolled, of whom 32 underwent STN-DBS (PD-DBS) and 33, even though eligible for this treatment, declined surgery and chose other therapeutic procedures (PD-control). Motor and neuropsychological functions were assessed in all the subjects at baseline (T0) and 36 months (T36). The PD-DBS patients were also evaluated at 1, 6, 12, and 24 months after surgery (T1, T6, T12, and T24). At T1, compared with T0, the PD-DBS patients recorded worse logical executive function task and verbal fluency (FAS) scores, whereas their performance of memory tasks remained stable. At T12, their cognitive profile had returned within the pre-DBS range, thereafter remaining stable until T36. FAS scores at T36 were significantly worse in the PD-DBS compared with the PD-control patients. This is the first long-term naturalistic controlled study of cognitive functions in PD patients submitted to STN-DBS. Our results confirm previous reports of a worsening of verbal fluency after DBS, but show that STN-DBS seems to be relatively safe from a cognitive standpoint, as the short-term worsening of frontal-executive functions was found to be transient.

Zangaglia R ，Pacchetti C ，Pasotti C ，Mancini F ，Servello D ，Sinforiani E ，Cristina S ，Sassi M ，Nappi G ... -  《-》

The effects of bilateral subthalamic nucleus deep brain stimulation (STN DBS) on cognition in Parkinson disease.

Heo JH ，Lee KM ，Paek SH ，Kim MJ ，Lee JY ，Kim JY ，Cho SY ，Lim YH ，Kim MR ，Jeong SY ，Jeon BS ... -  《JOURNAL OF THE NEUROLOGICAL SCIENCES》

Neuropsychological changes 1-year after subthalamic DBS in PD patients: A prospective controlled study.

This study aimed at investigating the neuropsychological effect of DBS of the Subthalamic Nucleus in patients with advanced Parkinson's disease (PD). A standardized neuropsychological test battery, assessing reasoning, memory and executive functions, was administered to 27 PD patients who underwent DBS-STN (DBS group) and to a matched control group of 31 PD patients under optimal medical treatment (MED group). Patients were evaluated at baseline and at the end of 1 year. Change score analysis (T1 minus T0 scores) demonstrated a significant decline in phonemic verbal fluency in the DBS group compared with the MED group (p < 0.005), while there were no significant changes between the two groups for the other cognitive tests. Single cases analysis by means of multivariate normative comparisons revealed that 4 out of 27 DBS patients (15%) showed cognitive deterioration one year post surgery. These patients were significantly more compromised from a motor standpoint (UPDRS, section III) than the 23 DBS PD patients who had no cognitive decline post surgery. Results of this prospective controlled-study showed that phonemic verbal fluency declined one year after DBS-STN, while the other cognitive domains did not change significantly. Nevertheless, single case analysis highlighted the fact that a subgroup comprising 15% of DBS-STN patients (4/27) showed significant cognitive decline 1 year after surgery.

Castelli L ，Rizzi L ，Zibetti M ，Angrisano S ，Lanotte M ，Lopiano L ... -  《-》

Deep brain stimulation of the subthalamic nucleus improves intrinsic alertness in Parkinson's disease.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a treatment option for patients with Parkinson's disease (PD) in the advanced stage. Besides motor improvement, DBS of the STN may also modulate cognitive and attentional functions of the basal ganglia. In our study, 13 patients with PD and bilateral DBS of the STN were assessed with DBS switched on and off by the use of a wide range of neuropsychological tasks. This included reasoning, cognitive flexibility, phonemic and semantic word fluency, verbal and nonverbal short-term memory, learning, delayed verbal memory recall, and stimulus-response incompatibility. Special emphasis was put on basic attentional functions, in particular intrinsic and phasic alertness as well as visual search. DBS significantly improved intrinsic alertness, whereas phasic alertness and other neuropsychological domains were not affected. Additionally, the effects on intrinsic alertness were independent of motor improvements by DBS. The findings suggest that DBS modulates the fronto-parietal network of alertness.

Fimm B ，Heber IA ，Coenen VA ，Fromm C ，Noth J ，Kronenbuerger M ... -  《-》

Risk factors for executive dysfunction after subthalamic nucleus stimulation in Parkinson's disease.

Daniels C ，Krack P ，Volkmann J ，Pinsker MO ，Krause M ，Tronnier V ，Kloss M ，Schnitzler A ，Wojtecki L ，Bötzel K ，Danek A ，Hilker R ，Sturm V ，Kupsch A ，Karner E ，Deuschl G ，Witt K ... -  《-》