CODI 555 Motor Speech Disorders
Lecture 6:  Multiple Lesion Sites: Mixed Dysarthria & Other Neurogenic Speech Disorders

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 Mixed Dysarthrias: Common Etiologies

•  ALS - flaccid-spastic (?ataxic)
•  MS -  spastic-ataxic (variable could have all other types mixed in)
•  Shy-Drager - spastic-ataxic-hypokinetic
•  PSP - spastic-hypokinetic
•  Parkinson’s Disease - hypokinetic-hyperkinetic
•  Wilson’s Disease - spastic-ataxic-hypokinetic

 Neurogenic Mutism

•  Patient may be mute i.e. complete lack of speech for a number of reasons
•  Most common include:
•  Severe dysarthria (anarthria)
•  Severe apraxia of speech
•  Aphasia
•  Cognitive/affective disorders

 Anarthria

•  Most have spastic, hypokinetic or a mixed dysarthria with both spastic and hypokinetic symptoms
•  Most frequent etiology of above are vascular lesions especially brainstem CVA
•  Also associated with rare conditions
•  Locked in Syndrome
•  Bi-opercular Syndrome

 Apraxia of Speech

•  Not unusual, but often lasts for only a few days post-onset
•  Mutism often resolves into vocal apraxia (whisper phonation)
•  Characteristics of vocal apraxia
•  Difficuly initiating and/or sustaining vocalization
•  Prosodic problems (pitch variation)
•  Difficulty controlling volume
•  Respiratory effort
•  Deviations of voice quality

 Aphasia

•  Mutism not uncommon in acute period
•  Persistent mutism (even in global aphasia) is uncommon
•  May be more common with subcortical aphasias (lesions in thalamus and basal ganglia)

 Cognitive/Affective Deficits

•  Group of disorders of arousal reflecting damage to reticular activating system (RAS)
•  Include such disorders as:
•  Persitent vegetative state
•  Akinetic mutism
•  Has been suggested that “aphasic” mutism reflects dysfunction in frontal lobe activation mechanisms -diagnosis of aphasia may not be accurate

 Other Neurogenic Speech Disorders

•  Include an ecclectic group of disorders that do not reflect problems with motor control but that produce disorded speech that resembles an identifiable motor speech problem
•  Included are:
•  Neurogenic (cortical) stuttering
•  Palilalia & echolalia
•  Pseudoforeign accent
•  Aphasia & aprosodia

 Neurogenic stuttering

•  Stuttering-like behavior that appears after damage to nervous system
•  Some cases have history of developmental stuttering which either reemerges or remits with onset or progression of neurological disease
•  Characteristics - pg 299
•  Co-occurance with aphasia, AOS & dysarthria (hypokinetic)
•  Etiology
•  Primary are CVA & TBI
•  Diseases & side-effect of drugs

 Palilalia

•  Compulsive repetition of utterance (usually words/phrases) with increasing rate and decreasing loudness
•  Reiterations occur in conversation, narratives & ellicited speech
•  Patients are aware but show no struggle, do not try to inhibit them, but are agitated by them
•  Etiology
•  Variety of neurogenic diseases- notably Parkinson’s
•  Bilateral basal ganglia pathology

 Pseudoforeign accent

•  Very rare disorder - as of 1990 only 25 documented cases
•  Person adopts arctic/prosody changes folloiwng CNS damage that give the impression of a foreign accent
•  Changes are not entirely consistent with any known language
•  Co-occurrance with mild aphasia and/or AOS is common as is right hemiparesis &right central facial weakness
•  CVA & TBI most common etiologies

 Aphasia

•  NOT a motor speech problem but verbal output can be deviant with respect to phonemic accuracy & prosodic features of speech
•  Speech of non-fluent pts is often slow & produced with an abnormal prosodic pattern
•  Pts with word retreival deficits may use delays (filled or unfilled) that give speech a halting, hesitant sound
•  Dysfluencies that are suttering-like may also occur in these pts
•  Fluent pts may make phonologic errors that mimic articulatory deficits in AOS

 Right-hemisphere Lesion Aprosodia

•  Deficit in the production & interpretation of the variations in speech that convey emotion, emphasis and linguistic information
•  Similar in nature to deficits found in many dysarthrias, cognitive affective disorders & pyschiatric conditions
•  Output or speech deficits summarized pg 311
•  Assessment relies on appearance of prosodic abnormalities in extended spontaneous conversation