Chapter 5: Spastic Dysarthria Flashcards
Spastic Dysarthria Definition
-Bilateral damage to both pyramidal (results in slow/weak mvmts) and extrapyramidal (weakness, increased muscle tone aka spasticity, abnormal reflexes) neural pathways.
What causes Spastic Dysarthria?
-ANY injury that causes bilateral damage to UMNs of pyramidal and extrapyramidal systems (e.g., strokes, degenerative diseases, TBI, infections of the brain tissue, tumors, cerebral anoxia, MS)
What is the most common cause of Spastic Dysarthria?
-Stroke will result in spastic dysarthria only when 2 or MORE strokes occur in certain combinations in the cerebrum or a single stroke occurs in the brainstem
What are degenerative diseases that result in Spastic Dysarthria?
- Primary Lateral Sclerosis (PLS)
- Amyotrophic Lateral Sclerosis (ALS) causes spastic dysarthria when UMN involvement is predominant. EVENTUALLY both UMNs and LMNs, resulting in mixed dysarthria (flaccid-spastic)
Traumatic Head Injury and Spastic Dysarthria
-Can result in widespread injury to brain, causes bilateral damage to pyramidal and extrapyramidal systems.
Spastic Dysarthria and Multiple Sclerosis
-Immunologic disorder resulting in inflammation of complete destruction of myelin sheath covering axons. W/ bilateral involvement to UMNs, it can result in spastic dysarthria.
What characteristics are shared between Spastic Paralysis and Spastic Dysarthria?
-Characteristics include spasticity, weakness of muscles, reduced range of mvmt, slowness of mvmt
What are speech characteristics of Spastic Dysarthria?
- Speech errors in spastic dysarthria are caused by spasticity, slowness, weakness in vocal-tract muscles.
- Components of speech that are impacted include: articulation, phonation, resonance, and prosody is usually affected MORE than respiration
What articulation errors are common with SD?
-Imprecise consonant production (most common error for SD but also common in ALL dysarthrias), and vowel distortions/errors
What phonation problems occur with SD?
-Harsh vocal quality due to air leaks through glottis (most common phonatory error), strained-strangled vocal quality (hyperadduction of VFs), and low pitch (increased muscle tone in larynx)
What resonance errors occur with SD?
-Hypernasality may result due to spasticity in velar muscles which slows & reduces range of soft palate mvmt & incomplete velopharyngeal closure during nonnasal speech sounds. Less severe than FD & usually does not feature nasal emission.
What are prosody changes occur with SD?
- Monopitch (tenseness of laryngeal muscles, reduce ability to contract/relax at normal rates to vary pitch)
- Monoloudness (increased muscle tone in laryngeal muscles resulting in difficultly modulating subglottic press for loudness)
- Short phrases
- Slow rate of speech (due to reduced speed & range of mvmt in the articulators)
What are respiration changes in SD?
-Problems of respiration do not play a major role in spastic dysarthria. Phonation/prosody problems more likely result from hyper adduction of VFs than respiratory problems.
What are additional characteristics of SD?
-Characteristics include: pseudo bulbar affect, drooling, or dysphagia
What are differences between Spastic Dysarthria and Flaccid Dysarthria?
- Bulbar palsy is typically seen with FD due to atrophy & weakness in muscles innervated through medulla, including tongue, velum, larynx, and pharynx. ***Caused by damage to LMNs.
- Pseudobulbar palsy is typically seen with SD due to weakness and slowness in same muscles.
- **Caused by damage to UMNs.
