motor speech diso wk 1

speech equation

cogntive-linguistic + motor speech (plan, program) + neuromuscular (exec and control)

motor speech disorder

speech disorders resulting from neurologic impairments affecting the planning, programming, control, or execution of speech

other speech disturbances (not MSD)

acquired neurologic stuttering

palilalia

echolalia

pseudoforeign accent syndrome

aphasia

musculoskeletal defects

non-neuro/psychogenic voice disorders

pychogenic/non-organic disorders

dysarthria

collective name for group of neurologic speech disorder resulting from abnormalities in the strength, speed, range, steadiness, tone, or accuracy of mvmnts required for breathing, phonatory, resonatory, articulatory, or prosodic aspects of speech production

responsible pathophysiology

CNS or PNS abnormalities

most often weakness, spasticity, incoord, involunary mvmnt, excessive/variable muscle tone

perceptual classification of MSD

perceived by the ear, "gold standard"

also acoustic and physiologic methods

DAB approach

based on presumption of underlying pathophysiology and lesion localization

identified 6 types of dysarthria, and apraxia

now added 2 more dysarthrias: UUMN and undetermined

apraxia of speech

neurologic speech disorder reflecting and impaired capacity to plan/program sensorimotor commands necessary for directing mvmnts that result in phonetically and prosodically normal speech, can be in absence of physiologic disturbances and absence of disturbances in any component of lang

central nervous system

brain, spinal cord

cerebrum, cerebellum, brainstem

spinal cord

transmits nerve signals toward and away from brain to/away from other organs and muscles

processes sensations and form appropriate motor response in absence of brain input

peripheral nervous system

transmits sensory information to brain

carries out motor commands from brain

cells of nervous system

neurons

glial (supporting)

synapse

gap btwn end of axon and another neuron

gray matter

high concentration of nerve cell bodies

white matter

high concentration of myelinated axons

myelination contains the electrical current within (like a charging cord)

sensory

afferent

from body to brain

motor

efferent

from brain to body

motor speech system divisions

final common pathway

direct activation pathway

indirect activation pathway

control circuits

final common pathway

last link in the chain of neural events that lead to execution and motor activity

includes cranial and spinal nerves

stimulates muscle contraction and mvmnt

aka lower motor neurons

damage to final common pathway

reduction/extinction of reflexes (peripheral sensory pthwy), weakness, atrophy, fasiculations

responsible for speech characteristics of flaccid dysarthria

direct activation pathway

crucial to voluntary motor activity, especially consciously controlled skilled, discrete and often rapid voluntary mvmnts

aka UMN system, direct motor system, pyramidal tracts

inclused corticobulbar tracts and corticospinal tracts

damage to direct activation pathway

unilateral: contralateral weakness, minor effect on speech, normal reflexes, unilateral UMN dysarthria

bilateral: bilateral weakness, mild-severe effect on speech, spasticity, spastic dysarthria

indirect activation pathway

mediates subconscious, automatic muscle activities (posture, mucsle tone, supporting voluntary mvmnt)

aka extrapyramidal system, indirect motor system, UMN system

damage to indirect activation pathway

usually bilateral, decorticate/decerebrate posturing, mild-severe effects on speech, spasticity, hyperactive reflexes, dysphagia, disinhibition of physical expression of emotion, spastic dysarthria

basal ganglia control circuit

plans and programs postural and supportive components of motor activity (start and stop)

extrapyramidal system

dopamine plays an important role

damage to basal ganglia control circuit

hypokinesia: hypokinetic dysarthria (rigidity, slow, stiff mvmnts)

hyperkinesia: hyperkinetic dysarthria (rapid, involuntary mvmnts)

cerebellar control circuit

integrates and coords execution of smooth and directed mvmnts

damage to cerebellar control circuit

truncal ataxia, gait ataxia, limb ataxia, intention tremor, incoord, ataxia dysarthria

mayo clinic system

uses a 7 point scale of severity

38 perceptual characteristics divided into 7 categories: pitch, loudness, voice quality, respiration, prosody, artic, resonance

additional ratings include intelligibility and bazarreness

there's a modified version of this

methods for studying motor speech diso

perceptual (gold standard)

acoustic (instrumental)

physiologic (instrumental)

visual imaging (instrumental

some assessments

Mayo clinic system for differential diagnosis of dysarthria

Frenchay dysarthria assessment (FDA)

Bogenhausen dysarthria scales (BoDyS)

goals of examination

understand patient's problem (diagnosis, severity, prognosis)

determine beginning level of treatment

6 salient features

muscle strength

speed of mvmnt

range of motion

accuracy of mvmnt

motor steadiness

muscle tone

lower motor neuron damage

affects whole side of face

upper motor neuron damage

affects only a part of a half of the face (i.e. the upper part only)

assessment of intelligibility in dysarthric speakers (AIDS)

standardized test for intelligibility

quantifies intelligibility of single words and sentences

provides an estimate of communication efficiency examines rate of intelligible words per minute in sentences

sentence intelligibility test (SIT)

intelligibility test

word accuracy- count the number of correct words and divide by the total number of words to get the word intelligibility percentage

diagnosis of dysarthria

presence of perceptible speech deficits

confirmatory signs: provide additional clues regarding lesion localization (ex: pseudobulbar affect, fasciculations, muscle atrophy, related neurological signs)