تاثير تحريك تالاموس بر پردازشهاي زباني و حافظه در بيماران پاركينسون

The Effect of Thalamic Stimulation on Memory and Language Processing in Parkinsonian Patients

Objective: Thalamic Deep Brain Stimulation (DBS) is reported to be successful in Parkinsonian patients with motor symptoms resistant to medication one of the treatment procedures. Despite evidence of cortico-subcortico-cortical circuit involvement in motor control, the role of this neural circuitry on higher cognitive functions such as language is still controversial. in particular, research evidence pertaining to the impact of ventrolateral thalamic stimulation on linguistic processing is scarce. This paper investigates the effect of right and left thalamus-DBS on memory and language processing in Parkinson patients. Materials & Methods: In this paper as a case series research, measured memory and language processing done in six Parkinson patients (2 left, 2right, 2 bilateral) who underwent implantation of deep brain stimulating electrode in ventrolateral thalamic nucleus. The data were collected in two "on" and "offʹ positions, with at least 40 days time interval in between. The patients were assessed using Wechsler memory test, verbal fluency and some sub-tests of Farsi version of Bilingual Aphasia Test (BAT). Results: The findings of this research are suggesting an improvement on grammar comprehension and a decline in sentence production and verbal fluency in "on" position versus "off" position, in both groups. The Wechsler memory scores in left thalamus group improved but declined in right thalamus group. Conclusion: The results indicate that thalamic DBS did not cause any deficit on grammar comprehension and even improved the level of comprehension. On the contrary a decrease in verbal fluency and sentence production, as two high level linguistic processing tasks, were observed. The results confirmed contemporary theories of thalamic participation on language processing, did not confirm a laterality effect on language. skills. Although observed difference after thalamic DBS between right and left group on memory score but confirmed laterality effect on memory.