Biological base of stuttering

Mucanje je poremećaj govora kojeg obilježavaju ponavljanje slogova, prolongacija zvuka i blokade u govoru, kao i sekundarna ponašanja poput tenzija mišića i vrata. Javlja se između treće i šeste godine života, s visokom stopom oporavka. Mucanje je češće kod muškaraca nego žena, s omjerom 4:1 u odrasloj dobi. Postoje 3 tipa mucanja: razvojno, psihogeno i neurogeno. Razvojno mucanje je najčešće i razvija se tijekom razvitka jezika i govora djeteta. Osobe koje mucaju znaju što žele reći, no imaju problema u inicijaciji govora. Različite grane znanosti poput psihologije i lingvistike su pokušale objasniti uzroke mucanja, no najvažnija saznanja pruža neuroznanost. Identificirane su regije u mozgu povezane s mucanjem i strukturne abnormalnosti tih područja, kao i promjene u njihovoj povezanosti. Kao najvažniji neuroprijenosnik povezan s mucanjem izdvaja se dopamin, a identificirani su i geni uključeni u patogenezu mucanja. Do sada je napravljeno puno studija, no daljnje istraživanje je potrebno, ponajviše dugotrajne studije koje bi omogućile nove uvide u terapijske mogućnosti.Stuttering is a speech disorder characterized by repetition of sylablles, prolongation of sound and blockages in speech, as well as secondary biheviours like tension of face and neck muscles. It occurs between age of three and six with a high rate of recovery. Stuttering occurs more often in males than females, with a ratio of 4:1 in adults. There are 3 types of stuttering: developmental, psycogenic and neurogenic. Developmental stuttering is most common and occurs during the child's development of language and speech. Persons who stutter know what they want to say, but have difficulties in initiation of speech. Various science disciplines like psychology and linguistics have tried to explain causes of stuttering, but neuroscience provides the most important findings. Regions of brain involved in stuttering and their structural abnormalities have been identified, as well as changes in their interconnections. The most important neurotransmitter implicated in stuttering is dopamin. Also, several genes involved in patogenesis of stuttering have been identified. A lot of studies have been conducted so far, but additional investigation is necessary. Longitudinal studies are the most needed in order to provide new therapeutic opportunities