chapter 5 Flashcards
neurologic basis of spastic dysarthria
bilateral damage to umn tracts
umns are in the
CNS
-descending motor tract, terminates at level of brainstem
role of umn in spastic dysarthria
-bilateral damage to umns of pyramidal/extrapyramidal neural pathways
pyramidal system damage spastic
can result in weak/slow skilled movements
extrapyramidal system damage spastic
can result in weakness, increased muscle tone (spasticity), and abnormal reflexes
onset may mimic
flaccid dysarthria, however very quickly spasticity sets in
significance of bilateral damage
damage must be bilateral, affecting both left and right tracts of pyramidal and extrapyramidal systems
-weakness and slowness, particularly in tongue and lips
-spasticity most noticeable in laryngeal muscles
-abnormal reflexes (primitive reflexes)
causes of spastic dysarthria
strokes, degenerative diseases, traumatic head injury, infections of brain tissue, tumors
stroke
most common cause of spastic; will only result in spastic when two or more strokes occur in certain combos in the cerebrum or a single stroke occurs in the brainstem (before the cranial nuclei)
amyotrophic lateral sclerosis (ALS)
degenerative neurologic disease of unknown cause; terminal, average life expectancy 22 months from time of onset, causes spastic when UMN involvement predominant
traumatic head injury
can produce widepsread injury to brain, causing bilateral damage to pyramidal and extrapyramidal systems
multiple sclerosis
suspected immunological disorder resulting in inflammation or complete destruction of myelin sheath covering axons - bilateral involvement of umns results in spastic
other causes
brainstem tumor, cerebral anoxia, viral infection in cerebral tissue, bacterial infection in cerebral tissue
speech characteristics of spastic dysarthria
-speech errors are a result of spasticity, slowness, weakness in vocal-tract muscles
respiration less effected in spastic because
the phrenic nerve