L7: Spastic Dysarthria Flashcards
spastic dysarthria is caused by…
damage to the upper motor neuron which originates from primary motor cortex
there are indirect and direct pathways in UMN - in most cases both the indirect and direct paths are damage
bilateral UMN damage is generally required for…
permanent spastic dysarthria
unilateral UMN damage usually causes … what about when the internal capsule is damage unilaterally?
transient speech effects and more permanent limb effects (i.e. spastic hemiplegia)
when speech effects are permanent following unilateral damage (rare) a specific unilateral UMN dysarthria results, usually linked to damage of the internal capsule
in the case of unilateral UMN damage the following is observed
weakness in the lips (lower face) and tongue (unilateral innervation predominates)
no weakness in palate, jaw, pharynx, larynx, or upper face (bc bilateral innervation predominates)
what are the causes of spastic dysarthria (bilateral UMN damage)? what % of cases?
strokes and other vascular - 13%
traumatic brain injury and neurosurgical -4%
extensive brain tumour - 2%
undetermined (infections - encephalitis) - 11%
various progressive degenerative diseases - 58%
cerebral palsy and other congenital - 4%
what are the 5 major symptoms of spastic dysarthria?
loss of skilled movement
slowness
spasticity
weakness
hyperreflexia
loss of skilled movement refers to…
loss of fractionation of movements (loss of fine indv components of a movement)
reduced accuracy and range of movements
direction and rhythm of movement is retained
slowness is related to
loss of skill and inc spasticity
describe the spasticity seen in spastic dysarthria
passive stretch inc tone and resistance
rapid stretch inc spasticity (the more u stretch part of the body the more it will inc spasticity)
flexors in upper limbs, extensors in lower limbs
describe the weakness in SD
especially in distal limb muscles
lip, jaw, tongue, palate, pharynx, larynx, resp
describe hypereflexia
stretch reflex is hyperactive or exaggerated (i.e. jaw jerk, knee tap)
what other symptoms may we see in SD?
reduced facial experession
drooling
swallowing probs (94%)
etc
direct component (pyramidal) involves
direct corticospinal or corticobulbar path to LMN (pyramidal tract has large number of axons)
indirect component (extrapyramidal) involves
indirect and multisynaptic path from motor cortex to LMN (extrapyramidal tracts to red nucleus, retricular nuclei etc)
direct component (pyramidal) has 4 characteristics
loss of fine skilled movements (fractionization lost reflex)
dec tone
pos babinski, sucking reflex
weakness
indirect component (extrapyramidal) has 3 characteristics
spasticity
inc stretch reflex and gag
weakness
direct and indirect systems are _____ and ______ interconnected, usually see symptoms of _____ direct and indirect damage
overlapping and highly
(i.e. primary motor cortex and internal capsule)
both direct and indirect
it is possible but rare to see a dissociation bw ____ and ____ (i.e. pyramidal damage in medulla)
spasticity and weakness
what are the 5 most distinctive features of spastic dysarthria?
harsh voice
low pitch
slow rate (ALS)
strained/strangled
pitch breaks
resp impairment in SD causes what perceptual characs
short phrases
jerky irregular resp movements
clavicular breathing
how can we measure resp impairment in SD? What measures might we use?
strain gage pneumograph to record resp kinematics
reduced VC, reduced rate of exp flow, reduced lung volumes during speech, reduced abdominal contributions to speech breathing
laryngeal impairment in SD causes what perceptual characs
strained- strangled
monopitch
harsh voice
monoloudness
pitch breaks
low pitch
what did 2 studies find when measuring laryngeal impairment in SD?
laryngeal resistance, air pressure, and airflow –> half spastics had abnormally high laryngeal resistance, high air pressure and low airflow
acoustic measures –> lower pitch, reduced pitch range, and pitch variation, inc jitter and shimmer, dec H to N ratio
palatopharyngeal impairment in SD causes what perceptual charac
hypernasality
what did a study find when measuring palatopharyngeal impairment in SD?
noted initial velar elevation followed by progressive reduction in velar movement during continuous speech (i.e. counting) - uncertain cause (weakness or spasticity)
abnormal amount of nasalance
oral articulatory impairment in SD causes what perceptual characs
imprecise consonants, distorted vowels (centralized vowels, voiced for voiceless stop errors< spirantization of stops)
what did a study find when measuring force measures in oral articulatory impairments in SD?
rate of degeneration of force was impaired across all oral structures in patients w reduced speech intelligibility
what did a study find when measuring lip/tongue/jaw movement measures in oral articulatory impairments in SD?
lip movements slower than normal
tongue tip movements reduced and involve assistance from jaw movements
what did a study find when looking at consonant and vowel articulation in oral articulatory impairments in SD?
abnormally long syllable and word durations
reduced/abnormal vowel formants (F1 and F2)
slow and reduced formant trajectories during repeated diphthongs
weak and abnormal fricative spectra - less spectral tilt in /s/
longer vowels produced w slower (stair-step) formant trajectories
