Dysarthria is a motor speech disorder of neurological origin (cf. dysphonia due to primary laryngeal pathology), causing impaired motor control (articulation) of the speech musculature. There is no language disturbance (cf. aphasia, although the two may coexist).
There are various syndromes of dysarthria, which have been classified as follows:
- Flaccid or nasal dysarthria:
- hypernasal, breathy, whining output, as in bulbar palsy, myasthenia gravis.
- Spastic dysarthria:
- slow, strained ("strangled") output, monotonous, as in pseudobulbar palsy; may coexist with Broca’s aphasia.
- Ataxic or cerebellar dysarthria:
- altered rhythm of speech, uneven irregular output, slurred speech (as if inebriated), improper stresses; seen in acute cerebellar damage due to asynergia of speech muscle contractions (cf. scanning speech).
- Hypokinetic dysarthria:
- monotonic pitch, hypophonic volume, as in parkinsonism.
- Hyperkinetic dysarthria:
- several varieties are described, including choreiform (as in Huntington’s disease), dystonic (as in tardive dyskinesia, and other dystonic syndromes), tremulous (tremor syndromes), and the dysarthria with vocal tics (including coprolalia) in Gilles de la Tourette syndrome.
- Mixed dysarthria:
- combination of any of above.
Treatment of the underlying cause may improve dysarthria (e.g., nasal dysarthria of myasthenia gravis). Baclofen has been suggested for dysarthria of upper motor neurone type. Speech and language therapy may provide symptomatic benefit.
Darley FL, Aronson AE, Brown JR. Motor speech disorders. Philadelphia: Saunders, 1975
LaMonte MP, Erskine MC, Thomas BE. Approach to the patient with dysarthria. In: Biller J (ed.). Practical neurology (2nd edition). Philadelphia: Lippincott Williams & Wilkins, 2002: 236-243 Murdoch BE (ed.). Dysarthria. A physiological approach to assessment and treatment. Cheltenham: Stanley Thornes, 1998
Anarthria; Aphasia; Asynergia; Broca’s aphasia; Bulbar palsy; Coprolalia; Dysphonia; Fatigue; Lower motor neurone (LMN) Syndrome; Parkinsonism; Pseudobulbar palsy; Scanning speech; Upper motor neurone (UMN) syndrome