[Early postoperative assessment of cognitive functions after stereotactic pallidotomy in patients with primary dystonia - preliminary results].

BACKGROUND AND PURPOSE

The newest studies notify that globus pallidus, besides the motor control, plays an important role in cognitive functioning of: memory, attention, linguistic skills, visuospatial ability, and executive functions. Stereotactic pallidotomy (the lesion of the motor region of the globus pallidus) is one of the surgery options that is used in the treatment of the primary dystonia. Motor region is located in the postero-ventral part of the internal globus pallidus. The goal of the study was to assess of the influence of pallidotomy on cognitive functioning in the group of patients suffering from the primary dystonia.

MATERIAL AND METHODS

Eighteen patients diagnosed with primary dystonia were treated by stereotactic pallidotomy and they were investigated neuropsychologically. The study was performed between March 2004 and February 2005. Neuropsychological assessment was conducted 1-2 days prior to operation and 2 days following the surgery. The clinical course of the cognitive functions and emotional status were assessed by the following neuropsychological tests: Mini Mental State Examination (MMSE), Trail Making Test A and B (TMT A and B), Stroop Color-Word Interference Test, N-back Test, Auditory Verbal Learning Test (AVLT), Benton Visual Retention Test (BVRT), Wisconsin Card Sorting Test (WCST), Beck Depression Inventory (BDI), Montgomery-Asberg Depression Rating Scale (MADRS).

RESULTS

The statistically significant differences have been obtained between the results before and after the surgery in the depression scales: BDI (p<0.02) and in MADRS (p<0.01). None of the neuropsychological tests revealed significant differences between the results before and after the surgery. The only trend (p=0.06-0.07) was noted between results of AVLT before and after the surgery. The average results were worse after the surgery in the first, fifth and sixth attempt of the reply.

CONCLUSIONS

Stereotactic pallidotomy has not significantly changed cognitive functions in the patients suffering from primary dystonia. Whereas, the emotional state has significantly improved in consequence of the applying surgery. Stereotactic pallidotomy in primary dystonia seems to be a treatment option safe for the patients' cognitive functions.