Dysarthria is a motor speech disorder in which the ability to speak is affected as a result of central or peripheral nervous system damage, such as spasticity, flaccidity, incoordination or paralysis of the muscles that control the speech apparatus. This may include respiration, voicing, resonance, articulation and prosodic features, which may limit speech intelligibility. Dysarthria usually occurs due to various neuromotor problems such as vascular events, traumatic brain injuries, tumors, cerebral palsy, Parkinson's disease and can be seen in different types: spastic, flaccid, ataxic, hypokinetic, hyperkinetic and complex types. Assessment is usually done using imaging methods and computerized voice analysis systems, while treatment is aimed at maximizing communication skills.
In which diseases is dysarthria observed?
The source of neuromotor problems causing dysarthria can be vascular, traumatic, infectious, neoplastic, metabolic, etc. Different lesions and damages in the central and peripheral nervous system cause different types of dysarthria. The term dysarthria is generally used in the literature for acquired neurologic/neurogenic speech disorders that occur in adults due to brain injuries such as stroke and brain trauma. Neuromotor speech disorders observed in childhood are associated with cerebral palsy and are defined as "developmental dysarthria".
What are the diseases in which dysarthria can be seen?
1. Cerebrovascular events 2. Traumatic brain injuries 3. Tumors 4. Cerebral palsy 5. Progressive supranuclear palsy 6. Parkinson's 7. Huntington's disease 8. Amyotrophic lateral sclerosis 9. Multiple sclerosis 10. Myastania gravis
What are the Types of Dysarthria?
- Spastic dysarthria It is a type of dysarthria in which decreased vital capacity, scratchy, tense, harsh voice, low pitch, hypernasality, unclear consonant production, decreased emphasis, sometimes excessive or the same emphasis and slow speech are observed as a result of upper motor neuron (UMN) lesion (in degenerative diseases such as Cerebrovascular Events, Trauma, Progressive Supranuclear Palsy).
- Fluxide dysarthria: As a result of lower motor neuron (AMN) lesion (Bulbar palsy, Myasthenia Gravis, V., VII, XII. cranial nerve lesions) secondary to muscle weakness, decreased respiratory support, respiratory difficulty, faint voice in bilateral lesions, audible breathing, diphophonia, decreased pitch and intensity level, aphonia, hypernasality and nasal emission, unclear consonant production, unclear double lip, tooth-lip, tooth-lip, tooth-back tongue tip consonants or inability to produce these sounds, prosodic inadequacy, monotone speech.
- Ataxic dysarthria: It is a type of dysarthria in cerebellar system lesions in which speech characteristics such as low breathing, normal phonation or excessive variability in loudness, sudden bursts, cracking, scratching sound, monotony/monotony, unclear consonant production, distortions in vowel production, irregular vocalization, slow but exaggerated emphasis on almost every syllable, prolonged syllables, pauses after each syllable are observed.
- Hypokinetic dysarthria: In basal ganglia lesions (Parkinson's Disease), this type of dysarthria is characterized by decreased respiratory support, breathlessness in phonation, stiffness, tremor, decreased voice intensity, hypernasality in some cases, change in vocalization pattern, palilalia, single pitch, monotonous voice intensity, and short, clipped speech.
- Hyperkinetic dysarthria: In basal ganglia lesions; Myoclonia, Tourette Syndrome, Infection, Ballismus, Athetonia, regular tremor in pitch and volume, single pitch and pitch breaks, phrases at long intervals, variable ranges and monotony are observed. In dystonia and athetosis; weak respiratory support, scratchy, tense voice, audible inspiration, monotonous voice, variable and decreasing emphasis, long pauses in speech, inappropriate silence are observed, while in Chorea, sudden forced inhalation and exhalation, excessive variability in voice volume, panting, voice pauses due to involuntary movements, long pauses in speech, speech with short phrases and monotony are observed. In addition, hypernasality, variable vocalization, unclear consonant production and vowel distortion are other features of hyperkinetic dysarthria.
- Complex type dysarthria (Spastic-Flaxid): In diseases such as Amyotrophic Lateral Sclerosis in which upper and lower motor neuron lesions can be seen; poor respiratory support, hypernasality, unclear consonant production, prosodic inadequacy, decreased emphasis, monotony, UMN: single pitch, scratchy, tense voice with wet voice; AMN: faintness, monotonous voice intensity.
- Complex type dysarthria (Spastic-Athaxic): Poor respiratory support, impaired pitch control, harsh, breathy voice quality, sometimes hypernasality, impaired intonation, inadequate prosody, decreased emphasis and impaired pitch control are observed in UMN and cerebellar lesions (Multiple Sclerosis).
How is Dysarthria Assessment Performed?
The aim of the evaluation is screening and detection, diagnosis and planning the intervention method. The evaluation is based on the determination of damaged structures and their functions by imaging methods, direct observation of the movement and functions of structures for speech production with devices, and perceptual evaluation of speech production. In order to make more objective judgments, speech
Computerized voice analysis systems (CSL), video and voice recorders are used to evaluate acoustic properties.
What are the main goals of dysarthria therapy?
The general aim of the therapy is to maximize the patient's language use, speech intelligibility, rate, duration, naturalness, melody and prosodic features to enable the patient to participate in lifelong communication activities.
When is Alternative and Supportive Communication Systems (ASCS) needed?
In non-progressive and acute dysarthria, ADIS can be used until the patient can communicate again in intelligible speech. Chronic non-progressive dysarthric individuals may require long-term use of ADIS. In degenerative disorders, it can be used to support speech and then as a sole means of communication