Blink and masseter inhibitory reflexes in Parkinson's disease

Abstract

Background/Aim. Idiopathic Parkinson's disease (PD) is a chronic, progressive, neurodegenerative disorder with prevalence from 60 to 187 per 100 000 persons in general population. The aim of the study was to determine the abnormalities of the blink reflex (BR) and the masseter inhibitory reflex (MIR) in parkinsonian patients, as indices of the functional status of brainstem neuronal network, and abnormality level dependence on disease progression. Methods. The investigation was conducted at the Clinic of Neurology, Clinical Center Nis, comprising a group of 60 subjects of both sexes, suffering from idiopathic Parkinson's disease in I-IV stages, according to the Hoehn and Yahr scale. The control group included 30 healthy subjects of both sexes and corresponding age. Testing of the patients was performed during the 'on' phase by registering MIR and BR. Results. Latency of polysynaptic R2 and R2' blink reflex responses and latency of polysynaptic S2 response, as well as a silent period of MIR, are linearly shortened in the subjects with PD, and more expressed in the subsequent stages of the disease compared to the control group. Conclusion. There is a positive correlation between the applied neurophysiological tests results and clinical stage of PD.Uvod/Cilj. Idiopatska Parkinsonova bolest (PB) je hronicno, progresivno, neurodegenerativno oboljenje sa prevalencijom od 60 do 187 na 100 000 stanovnika u opstoj populaciji. Cilj rada bio je utvrdjivanje abnormalnosti blink refleksa (BR) i maseter inhibitornog refleksa (MIR) kod obolelih od PB, kao pokazatelja funkcijskog statusa mreze neurona mozdanog stabla, i zavisnosti stepena abnormalnosti od progresije bolesti. Metode. Istrazivanje je obavljeno u Klinici za neurologiju, Klinickog centra u Nisu, u grupi od 60 osoba oba pola, obolelih od idiopatske PB u I-IV stadijumu bolesti, prema skali Hoehn-ove i Yahr-a. U kontrolnoj grupi bilo je 30 zdravih osoba oba pola, odgovarajuceg zivotnog doba. Testiranje bolesnika obavljeno je u 'on' fazi, registracijom MIR i BR. Rezultati. Latencije polisinaptickih R2 i R2' odgovora blink refleksa i latencije polisinaptickog S2 odgovora i perioda tisine maseter inhibitornog refleksa skracuju se linearno kod bolesnika sa PB, izrazenije u kasnijim stadijumima bolesti, u odnosu na kontrolnu grupu. Zakljucak. Postoji pozitivna korelacija izmedju rezultata primenjenih neurofizioloskih testova i klinickog stadijuma PB.