Neurofiziologija distonije

Cilj: U istraživanju su postavljena dva cilja: 1) Provesti preliminarno istraživanje kortikalnog perioda tišine registriranog u krikotiroidnom mišiću u zdravih ispitanika; 2) Provesti preliminarno istraživanje kortikalnog perioda tišine registriranog u krikotiroidnom i tireoartenoidnom mišiću te predstaviti rezultate farmakološkog pokušaja u liječenju osobe s aduktornom laringealnom distonijom. Metode i materijali:. Motorički evocirani potencijali (MEP) i kortikalni period tišine registrirani su u lijevom krikotiroidnog mišića kod devet zdravih ispitanika (prosječna dob 38,33 ± 9,43 godina). Transkranijalna magnetna stimulacija (TMS) aplicirana je u projekciji primarne motoričke kore za reprezentaciju laringealne muskulature lijeve (ipsilateralne) i desne (kontralateralne) hemisfere. Ispitanici sudjeluju u zadatku fonacije (voljna motorička aktivacija laringealne muskulature) te se aplicira supramaksimalni intenzitet stimulacije u odnosu na motorički prag za gornje ekstremitete. Provodi se analiza duljine trajanja kortikalnog perioda tišine izazvana ipsilateralnim i kontralateralnim TMS pobuđivanjem. U prikazu slučaja bolesnice s aduktornom laringealnom distonijom mapira se primarna motorička kora za reprezentaciju laringealne muskulature u cilju detekcije kortikalnog perioda tišine u krikotiroidnom i tireoartenoidnom mišiću. Uvodi se farmakoterapijsko liječenje s triheksilfenidil i klonazepam. Rezultati: Kortikalni period tišine uspješno je izazvan u osam zdravih ispitanika u krikotiroidnom mišiću podražajem kontralateralne (53,02 ± 4,53 ms) te u svih ispitanika podražajem ipsilateralne (53,76 ± 8,05 ms) laringealne motoričke kore. U prikazu slučaja bolesnice s laringealnom distonijom nije zabilježen kortikalni period tišine u krikotiroidnom i tireoaritenoidnom mišiću nakon registracije MEP odgovora. Farmakološko liječenje s triheksilfenidilom i klonazepamom nije bilo učinkovito u smanjivanju govorne/glasovne patologije u slučaju ispitanice s laringealnom distonijom. Zaključak: Preliminarno istraživanje pruža informacije o duljini trajanja kortikalnog perioda tišine u krikotiroidnom mišiću kod zdravih ispitanika. Rezultati istraživanja upućuju na nužnost provođenja budućih istraživanja kortikalnog perioda tišine kod ispitanika s laringealnom distonijom. Otkrivanje neurofizioloških mehanizama može pomoći u budućem dijagnosticiranju i liječenju osoba s laringealnom distonijom.

Objective: The study aimed to achieve two objectives: 1) Conduct a preliminary investigation of the cortical silent period recorded in the cricothyroid muscle in healthy individuals; 2) Perform a preliminary investigation of the cortical silent period recorded in the cricothyroid and thyroarytenoid muscles and present the results of a pharmacological trial in the treatment of a person with adductor laryngeal dystonia. Methods and Materials: Motor evoked potentials (MEPs) and cortical silent period were recorded in the left cricothyroid muscle of nine healthy participants (mean age 38.33 ± 9.43 years). Transcranial magnetic stimulation (TMS) was applied over the projection of the primary motor cortex for the representation of the laryngeal musculature of the left (ipsilateral) and right (contralateral) hemispheres. Participants were engaged in a phonation task (voluntary motor activation of laryngeal muscles), and supramaximal intensity stimulation was applied relative to the resting motor threshold for upper extremities. Analysis of the duration of the cortical silent period was performed following ipsilateral and contralateral TMS stimulation. In the single case study of a patient with adductor laryngeal dystonia, the primary motor cortex representing the laryngeal musculature was mapped to detect the cortical silent period in the cricothyroid and thyroarytenoid muscles. Pharmacotherapy with trihexyphenidyl and clonazepam was introduced. Results: The cortical silent period was successfully induced in the cricothyroid muscle of eight healthy participants by stimulating the contralateral (53.02 ± 4.53 ms) and all subjects by stimulating the ipsilateral (53.76 ± 8.05 ms) laryngeal motor cortex. In the case report of the patient with laryngeal dystonia, no cortical silent period was observed in the cricothyroid and thyroarytenoid muscles following MEP registration. Pharmacological treatment with trihexyphenidyl and clonazepam did not effectively reduce the speech/vocal pathology in the patient with laryngeal dystonia. Conclusion: The preliminary investigation provides information on the duration of the cortical silent period in the cricothyroid muscle in healthy individuals. The research results highlight the need for future studies on the cortical silent period in individuals with laryngeal dystonia. The identification of neurophysiological mechanisms can contribute to the future diagnosis and treatment of individuals with laryngeal dystonia.