The clinical significance of neuropsychological changes following bilateral subthalamic nucleus deep brain stimulation for Parkinson's disease

• Published in: Journal of clinical and experimental neuropsychology 2009-01, Vol.31 (1), p.65-72
• Main Authors: Higginson, Christopher I., Wheelock, Vicki L., Levine, Dawn, King, David S., Pappas, Conrad T. E., Sigvardt, Karen A.
• Format: Article
• Language: English
• Subjects: Adult and adolescent clinical studies; Aged; Analysis of Variance; Biological and medical sciences; Clinical significance; Cognition - physiology; Cognitive function; Deep brain stimulation; Deep Brain Stimulation - methods; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Female; Humans; Learning - physiology; Male; Medical sciences; Middle Aged; Motor Activity - physiology; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Neuropsychological Tests; Organic mental disorders. Neuropsychology; Parkinson Disease - physiopathology; Parkinson Disease - therapy; Parkinson's disease; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Reliable change index; Stereotaxic Techniques; Subthalamic nucleus; Subthalamic Nucleus - physiology
• ISSN: 1380-3395; 1744-411X
• DOI: 10.1080/13803390801982734

Despite the clinical importance of the question, a number of methodological issues have limited firm conclusions regarding the cognitive safety of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD). Amongst these issues, studies have generally failed to consider the postoperative changes that occur within individual patients. This study utilized reliable change indices (RCIs) derived from a PD sample to determine the frequency of clinically significant postoperative decline on a battery of neuropsychological measures. This approach addresses measurement reliability, potential practice effects, and disease progression. The proportion of patients experiencing clinically significant postoperative decline on measures of list learning and verbal fluency was greater than expected based on disease progression; however, the majority of patients (55%) did not experience a significant decline in performance on any of the cognitive tests administered, and only one experienced decline on more than one test. Therefore, the statistically significant declines on measures of list learning and verbal fluency observed in the sample as a whole were the result of clinically significant declines experienced by a minority of participants.