Differential Diagnosis Among Acquired Dysarthrias

1. Differential Diagnosis Among Acquired Dysarthrias Oklahoma Speech-Language-Hearing Assoc. Sept. 30, 2010 Joe Duffy, Ph.D., BC-ANCDS Mayo Clinic Rochester MN

3. Why Attend To Motor Speech Disorders? They occur frequently Prevalence may increase They can be treated/managed They may announce neurologic disease

4. Why Differential Diagnosis of MSDs? Understanding nervous system organization for motor speech control Management decisions Localization & diagnosis of neurologic disease

5. “In what must be one of the best kept secrets of our time, both speech-language pathology and medicine have ignored certain incontrovertible facts of major importance to the differential diagnosis of human illness -- voice, speech, and language undergo audible and visible change when people fall prey to certain organic and psychiatric illnesses... such changes can be the first and only sign of a disease early in its evolution the manner in which speech becomes defective logically reflects the pathophysiology and psychodynamics of the illness… Aronson, ASHA, 1987

6. A Skilled Neurologist’s Thinking “I will ask our speech pathologist to evaluate her speech because I am not quite certain about what kind of dysarthria this is and I need as many clues as I can get to know how to proceed.”

7. Another Skilled Neurologist’s Thinking “I think it is important for the patient to visit with the speech consultants here. The two possibilities in my mind is that we are dealing with motor neuron disease or that we are dealing with a variant of multiple system atrophy. If …there is evidence of ataxia in his speech, then we may be dealing with MSA in which case it would be reasonable for the patient to undergo thermoregulatory sweat test and an autonomic reflex screen. However, if his speech is in keeping with motor neuron disease (ALS, ie flaccid or spastic dysarthria only) then I will have the patient undergo EMG… I think the diagnosis here will rest on the speech consultation.”

8. How Did We get Good At This? Darley, F. L., Aronson, A. E, & Brown, J. R. (1969a). Differential diagnostic patterns of dysarthria, Journal of Speech and Hearing Research, 12, 246-269. Darley, F. L., Aronson, A. E, & Brown, J. R. (1969b). Clusters of deviant speech dimensions in the dysarthrias, Journal of Speech and Hearing Research, 12, 462-496. Darley, F. L, Aronson, A. E, & Brown, J. R. (1975). Motor Speech Disorders, Philadelphia: WB Saunders.

9. Dysarthria A collective name for a group of MSDs associated with disturbed muscular execution or control of the speech mechanism due to CNS and/or PNS damage. May include abnormalities in strength, speed, range, tone or accuracy of speech movements. May affect respiration, phonation, resonance, articulation, & prosody.

10. Dysarthria…….. Includes several different types, each corresponding to damage to particular part(s) of the nervous system, & presumably each having different underlying neuropathophysiology. Each type has different auditory perceptual characteristics which can be distinguished clinically. Accurate identification has implications for localization; accurate description provides clues for management.

11. Dysarthria Types

12. Evaluation Tools Essential - Ears - Eyes - Hands Other - Flashlight - Tongue blade - Mirror - Stop watch - Audio/video recording - Acoustic & physiologic instrumentation

13. Clinical Evaluation History Oral mechanism exam (confirmatory signs) Vowel prolongation (quality, duration, pitch, loudness, steadiness) AMRs (speed & rhythm) SMRs (sequencing/programming) Contextual speech (all valves & components, prosody) Stress testing (fatigue)

14. Dysarthria Types

15. Flaccid Dysarthrias – Etiologies (N=154)

16. Flaccid Dysarthrias Neuromuscular Bases Weakness Reduced force of muscle contraction Reduced range of individual & repetitive movements Confirmatory signs Reduced muscle tone Reduced reflexes Atrophy Fasciculations (only seen with LMN lesions)

17. Confirmatory LMN signs associated with flaccid dysarthria Trigeminal (V) Jaw deviates to weak side on opening (unilateral) Jaw hangs open at rest (bilateral) Face (VII) Facial droop – flat nasolabial fold Reduced lip retraction, rounding, puffing Chin & perioral fasciculations Unilateral or bilateral

18. Confirmatory LMN signs associated with flaccid dysarthria Velopharyngeal (X, IX, XI) Hangs lower on weak side @ rest Elevates toward normal side on gag & phonation Reduced gag reflex Larynx (X) Weak cough & glottal coup

19. Confirmatory LMN signs associated with Flaccid Dysarthria Tongue (XII) Deviates to weak side on protrusion Fasciculations & atrophy

20. Flaccid Dysarthrias RESPIRATORY-LARYNGEAL: Breathiness, hoarseness, diplophonia, stridor, monopitch, monoloudness, short phrases RESONANCE: Hypernasality, nasal emission ARTICULATION: Imprecision PROSODY: Monopitch, monoloudness DISTINCTIVE: Hypernasality, nasal emission, continuous breathiness, stridor, isolated muscle group involvement

21. Dysarthria Types

22. Spastic Dysarthria – Etiologies (N=144)

23. Major abnormalities associated with UMN lesions- Neuromuscular bases of spastic dysarthria -  Typically reflect combined effects of direct & indirect pathway involvement Spasticity Weakness Reduced range of movement Slowness of movement

24. Spastic Dysarthria Confirmatory signs Paresis/spasticity of other body parts Hyperactive reflexes (e.g., gag) Pathologic reflexes (e.g., suck, Babinski) Dysphagia, drooling Pseudobulbar affect Meaning = Bilateral UMN dysfunction

25. Spastic Dysarthria RESPIRATORY -LARYNGEAL: Strained-strangled voice, harshness, pitch and loudness variability, pitch, pitch breaks and voice stoppages, short phrases RESONANCE: Hypernasality ARTICULATION: Imprecise, vowels distorted PROSODY: rate, excess/equal stress, prolonged phonemes and intervals, short phrases DISTINCTIVE: harsh/strained voice quality, slow rate, slow/regular AMRs, reduced pitch & loudness variability

26. Dysarthria Types

27. Ataxic Dysarthria – Etiologies (N=166)

28. Ataxic Dysarthria Neuromuscular Bases Incoordination - Errors in speed, range, force, timing, & direction of movements Reduced tone Confirmatory Signs Hypotonia, slow voluntary movements, jerkiness, wide-based gait, intention tremor Meaning = Cerebellar dysfunction (paravermal, bilateral, or generalized)

29. Ataxic Dysarthria RESPIRATORY-LARYNGEAL: Monopitch, monoloudness, harsh voice RESONANCE: Normal to variable, including hyponasality ARTICULATION: Imprecision, irregular articulatory breakdowns, distorted vowels PROSODY: Slow rate, excess/equal stress, prolonged phonemes and intervals, inappropriate silences DISTINCTIVE: Irregular articulatory breakdowns, irregular AMRs, vowel distortions, excess/equal stress, dysprosody, excess loudness variations

30. Dysarthria Types

31. Hypokinetic Dysarthria – Etiologies (N=167)

32. Hypokinetic Dysarthria Neuromuscular Bases Slow individual movements Fast or slow repetitive movements Reduced range of individual & repetitive movements Reduced force Excessive tone (rigidity) Confirmatory Signs Rigidity False starts Decreased ROM Resting tremor (perioral tremulousness) Bradykinesia Masked facies Slow or fast repetitive movements Meaning = Basal ganglia control circuit dysfunction

33. Hypokinetic Dysarthria RESPIRATORY-LARYNGEAL: Breathiness, short phrases RESONANCE: hypernasality ARTICULATION: Imprecise PROSODY: Monopitch, monoloudness, short rushes, short phrases, variable rate, reduced stress DISTINCTIVE: Fast/accelerated rate, rapid/blurred AMRs, reduced loudness & stress, monopitch, monoloudness, breathiness, palilalia

34. Dysarthria Types

35. Hyperkinetic Dysarthrias – Etiologies (N=141)

36. Hyperkinetic Dysarthrias Deviant characteristics are product of abnormal involuntary movements that occur on continuum of: rhythmic irregular & unpredictable rapid slow. Present in any or all components of speech -- prominent effects on rate & prosody. Abnormal movements sometimes activated only during speech (e.g., SD - focal, speech induced dystonia). Highly variable across individuals as a function of Type of abnormal movement Loci of abnormal movement(s) Invol movements reflect “Impaired inhibition of competing motor patterns” (Mink, 2007, Arch Neurol). Hyperkinetic mvt disorders due to presumed reduction of the normal inhibitory BG output. Chorea – frequent, brief, sudden, twitchlike movements that flow from body part to body part in a chaotic manner, but often resembles fragments of normal movements; the invol movements are sometimes converted into motor patterns that appear voluntary. It exists as a spectrum of movements that can be proximal or distal, large or small in amplitude, and intermittent or nearly continuous. It is assoc w abn in striatum or STN. At present, not know if activity driving choreatic mvts originates in BG or in thalamocorticval or brainstem motor pattern generators. Dystonia – invol spasms producing twisting postures in different body parts. Assoc w focal lesions in putamen, GP, or thalamus. May reflect relative dopamine deficiency or dopamine type 2 receptor dysfunction. Abnormal cocontraction of agonist and antagonist muscles usually exacerbated by movement. Current hypothesis is that it results fro incomplete suppression of competing motor patterns due to insufficient surround inhibition of competing motor pattern generators. Deficient surround inhibition may also lead to “overflow” contraction of adjacent muscles. Decreased efficacy of the surround with or without expansion of the center causes inappropriate disinhibition of unwanted muscle activity. Invol movements reflect “Impaired inhibition of competing motor patterns” (Mink, 2007, Arch Neurol). Hyperkinetic mvt disorders due to presumed reduction of the normal inhibitory BG output. Chorea – frequent, brief, sudden, twitchlike movements that flow from body part to body part in a chaotic manner, but often resembles fragments of normal movements; the invol movements are sometimes converted into motor patterns that appear voluntary. It exists as a spectrum of movements that can be proximal or distal, large or small in amplitude, and intermittent or nearly continuous. It is assoc w abn in striatum or STN. At present, not know if activity driving choreatic mvts originates in BG or in thalamocorticval or brainstem motor pattern generators. Dystonia – invol spasms producing twisting postures in different body parts. Assoc w focal lesions in putamen, GP, or thalamus. May reflect relative dopamine deficiency or dopamine type 2 receptor dysfunction. Abnormal cocontraction of agonist and antagonist muscles usually exacerbated by movement. Current hypothesis is that it results fro incomplete suppression of competing motor patterns due to insufficient surround inhibition of competing motor pattern generators. Deficient surround inhibition may also lead to “overflow” contraction of adjacent muscles. Decreased efficacy of the surround with or without expansion of the center causes inappropriate disinhibition of unwanted muscle activity.

37. Hyperkinetic Dysarthrias---Neuromuscular bases & confirmatory signs Too Much Movement Chorea Dystonias Tremor Palatopharyngolaryngeal myoclonus

38. Chorea Involuntary, rapid, nonstereotypic, unpatterned random, purposeless movements of a body part at 1 or multiple levels at rest, during sustained postures, & during speech.

39. Chorea--Speech Characteristics Phonation - Respiration: sudden forced insp./exp.; excess loudness var.; strained-strangled voice; voice stoppages; transient breathiness; grunts Resonance: intermittent hypernasality & weak pressure Cs Articulation: distortions/irregular breakdowns; distorted vowels; slow & irregular AMRs; smacking noises Prosody: prolonged intervals & phonemes; inappropriate silences; variable rate; excess/insufficient/variable stress

40. Dystonia Relatively slow waxing/waning involuntary postures resulting from excessive cocontractures of antagonist muscles Tend to be slow & sustained but there may be superimposed quick movements Can involve: only one body segment Contiguous regions (segmental) Generalized Can be present at rest or during sustained postures or can be movement induced (e.g., spasmodic dysphonia)

41. Dystonia--General Primary complaints: effortful; inability to get it out; involuntary movements; dysphagia Nonspeech orofacial findings: Normal size, strength, symmetry, reflexes Occasional drooling, dysphagia, blepharospasm Relatively slow waxing/waning movements @ 1 or multiple levels @ rest & during sustained postures, but sometimes only during speech Occasional improvement with sensory tricks

42. Dystonia--Speech Characteristics Phonation-Respiration: voice stoppages; strained-harsh voice; audible inspiration; excess or alternating loudness; unsteady, tremor-like voice Resonance: intermittent hypernasality Articulation: distortions & irregular breakdowns; distorted vowels; slow & irregular AMRs; noises Prosody: inappropriate silences; excess loudness variation; excessive-inefficient-variable stress

43. Neurogenic Spasmodic Dysphonia (SD) Technically a hyperkinetic dysarthria because many SDs associated with tremor or dystonia (e.g., Meige syndrome, focal cranial dystonias, torticollis) Adductor, abductor, or mixed in character Onset at 20-80 years (M ~ 45-50) M:F ~ 1:1 - 1:4 Begins insidiously; remission rare when neurologic

44. Neurogenic SD (cont.) Often associated with flu-like illness &/or psychologic stress, even when neurologic (worsened by stress, fatigue) Singing, laughter, “emotional” speech may be normal Usually speech induced ? secondary to basal ganglia or cerebellar control circuit pathology

45. Neurogenic SD -- Adductor Primary Complaints: ?’d speaking effort & fatigue; ETOH responsive; tight, strained, voice & chest Nonspeech Oral Mechanisms: normal unless tremor or dystonia elsewhere; abnormal laryngeal exam during phonation; jerky, arrhythmic thoracic/abdominal movements & facial grimacing secondary to laryngospasm

46. Neurogenic SD -- Adductor (cont.) Speech Characteristics Continuous or intermittent strained, jerky, squeezed, effortful voice Voice arrests Tremor Occasional hypernasality Inappropriate silences, slow rate

47. Neurogenic SD -- Abductor Primary Complaints: ?’d speaking effort & fatigue; ETOH responsive; “run out of air” Nonspeech Oral Mechanism: similar to adductor SD but “spasms” are abductor Speech Characteristics Brief, breathy or aphonic segments at utterance onset or in VL environment Occasional hypernasality Short phrases secondary to glottal air wastage

48. Tremor Rhythmic (periodic) movement of a body part The most common involuntary movement Can be resting, postural, action or terminal Essential tremor occurs with sustained posture and action, usually in upper limbs, head, or voice (probably related to cerebellar control circuit dysfunction).

49. Organic (Essential) Voice Tremor A focally manifest hyperkinetic dysarthria Present in ~ 20% with essential tremor (Jankovic ‘90) 50% familial Locus ? cerebellorubrothalamocortical circuit Onset usually gradual; patient may be unaware of presence Worse with stress/fatigue; may improve with ETOH Often accompanied by head/extremity tremor but can be isolated

50. Organic Voice Tremor (cont.) Primary Complaints: shaky, jerky voice; worse with fatigue; ETOH responsive Physical Findings: rhythmic vertical laryngeal movements & adductor/abductor oscillation of cords in synch with voice tremor; tremor possible in other speech structures Speech Characteristics: Quavering, rhythmic waxing/waning tremor (4-7 Hz) Voice arrest possible Articulation normal but rate may be slow Restricted pitch/loudness variability

51. Palatopharyngolaryngeal Myoclonus Abrupt, rhythmic/semirhythmic unilateral or bilateral movements of palate, pharynx, larynx (& occasionally nares, lips, tongue, respiratory muscles) Locus: Guillain-Mollaret triangle (dentate n., red n., inferior olive) Etiology: Usually brainstem or cerebellar stroke Other: tumor, MS, TBI, encephalitis, degenerative CNS disease Onset can be delayed following acute insult Can be benign

52. Palatopharyngolaryngeal Myoclonus Primary Complaints: earclicks; often unaware of movements Nonspeech Orofacial Findings: abrupt, rhythmic/semirhythmic unilateral or bilateral movements of palate, pharynx, larynx (& occasionally nares, lips, tongue, respiratory muscles)

53. Palatopharyngolaryngeal Myoclonus - Speech Characteristics Phonation-Respiratory: myoclonic “beats” @ ~ 1-4 Hz; voice arrests when severe Resonance: occasional intermittent hypernasality Articulation-Prosody: Usually normal* but brief silent intervals if myoclonus interrupts respiration, phonation, or articulation *But usually assoc. with spastic, ataxic, or flaccid dysarthria

54. Dysarthria Types

55. Unilateral UMN – Etiologies (N=98)

56. Unilateral Upper Motor Neuron Dysarthria Neuromuscular bases Weakness Incoordination Spasticity Lesion foci Frontal lobe Corona radiata Internal capsule Brainstem

57. Unilateral Upper Motor Neuron Dysarthria (cont.) Confirmatory signs Hemiparesis/plegia Central face weakness Central tongue weakness

58. Unilateral UMN Dysarthria (cont.) Primary speech characteristics Imprecise articulation Irregular articulatory breakdowns Slow (-1) & ? irregular AMRs Hoarseness Reduced loudness

59. Dysarthria Types

60. Mixed Dysarthrias – Etiologies (N=406)

61. Mixed Dysarthrias Most Common Mixes (300 Mayo patients) flaccid-spastic - 42% ataxic-spastic - 23% hypokinetic-spastic - 7% ataxic-flaccid-spastic - 6% hypokinetic-hyperkinetic - 3% other - 19%

62. Mixed Dysarthrias Disease & Type (examples) ALS - spastic-flaccid M.S. - spastic, ataxic* Wilson’s disease - hypokinetic, spastic, ataxic* * Shy-Drager syndrome - hypokinetic, spastic, ataxic, flaccid* * Progressive supranuclear palsy - hypokinetic, spastic, ataxic** * any type possible * * one or more possible