The Dysarthias — Distinguishing Features and Gestalts of Each of the Major Types

Abstract

A standard medical dictionary in America (U.S.) has defined dysarthria as articulation in speech. This definition is at once too narrow and too broad. It says nothing about aetiology seeming to implicate all aetiologies, but we don't use word that way. It singles out articulation and omits mention of phonation or resonance or respiration or prosody. (The 26th edition of American Illustrated Medical Dictionary has a new definition, a better one.) Lord Brain has defined articulation thus: the motor function whereby words are converted into sounds by movement of lips, tongue, vocal cords, palate and muscles of respiration. Now it's unusual to think of articulation as a process involving all that, but extension of term dysarthria to include those things is warranted. Professor William Peacher in U.S.A. suggested that a better term is dysarthrophonia, because we're dealing with articulation and phonatory problems. Professor Grewel in Amsterdam suggests term dysarthrophneumo­ phonia. Margaret Greene in her book Voice and Its Disorders emphasizes fact that in neurogenic impairment of communication there are combinations of impairments. She says, In more severe cases of paralysis, ataxia and hypermotoricity, palatal, pharyngeal, laryngeal and respiratory muscles may be involved. She reminds us as speech therapists not to concentrate upon one aspect of defective speech to neglect of another, but to treat problems of respiration, voice, and speaking as a wholistic entity. We like to use simply word dysarthria. We use it generically to cover a group of speech disorders of neurologic origin. The term encompasses co-existing motor disorders of respiration, phonation, articulation, resonance, and prosody. We also use term dysarthria to refer to a single process impairment. For instance, if there is a viral invasion of motor nucleus of XIIth cranial nerve and there is only a tongue problem, we still call that dysarthria even without an associate resonance or phonatory problem. If there is an isolated palato­ pharyngeal incompetence of neurologic origin, we include that. If there is unilateral vocal cord paralysis and nothing else, we include it too. We do not include dysJalias or stuttering. We don't include problems that are due to anatomical differences as in cleft palate and congenitally short palate. We don't include psychogenic aphonia or dysphonia. We refer to problems that are referable to damage of central or peripheral nervous system which implicate any or all of basic motor processes. There are many ways to classify dysarthria: we can do it according to age of onset, a congenital problem versus an acquired one. We can talk in terms of aetiologv: vascular, neoplastic, traumatic, infectious, toxic, metabolic, degenerative. We can talk about neuro-anatomical area of involvement: cerebral, cerebellar, or brain stem; or central versus peripheral. We can classify according to which cranial nerve is involved: V, VII, X. XII; or according to speech process involved: respiration, phonation, articulation, resonance, prosody. We could classifv by disease entity: parkinsonism, myasthenia gravis, amyotrophic lateral sclerosis, etc.