Ataxic Dysarthria Flashcards
Ataxic Dysarthria: Overview
Associated with damage to the cerebellar control circuit
Can manifest in any/all of the speech production levels but is most prominent in articulation and prosody.
Predominately reflects problems of motor control; breakdown in timing and coordination
Ataxic Dysarthria: Characteristics
Reflects the effects of incoordination and reduced muscle tone, the products of which are slowness and inaccuracy in force, range, timing and direction of speech movements.
Localization of Speech in the Cerebellum
Different areas of the cerebellum contribute to different aspects of speech planning and control.
Cerebellum is active in both covert and overt speaking.
Severe ataxic dysarthria is often associated with bilateral cerebellar damage, whereas speech often quickly improves when lesions are unilateral.
Clinical Characteristics of Cerebellar Lesions and Ataxia / Cerebellar Disease
- Difficulty standing and walking are the most common signs of cerebellar disease; stance and gait are often broad-based and truncal instability may lead to falls.
- Steps may be irregularly paced, legs lift too high and slap to the ground.
- Ataxic movements are halting, imprecise, jerky, lacking in speed.
- Cognitive disturbances may be present; executive function, visuospatial, and language deficits may occur.
- Titubation
- Nystagmus
- Hypotonia
- Dysmetria
- Dysdiadochokinesis
Titubation
A rhythmic tremor of the body or head that can occur with cerebellar disease.
Usually manifests as rocking of the trunk or head forward/back, side to side, or in a rotary motion.
Nystagmus
The most common abnormal eye movement associated with cerebellar disease.
Rapid back and forth, jerky eye movements at rest or with lateral or upward gaze.
Hypotonia
Can occur in cerebellar disease and can be associated with excessive pendulousness, which is a function of decreased muscle tone or decreased resistance to movement.
Dysmetria
A common sign in cerebellar disease, it’s a disturbance in the trajectory of a moving body part or inability to control movement range.
Characterized by over- or under-shooting targets.
Dysdiadochokinesis
A manifestation of decomposition of movement due to errors in timing and speed which results in poor coordination.
Abnormalities in rate, rhythm, amplitude, and precision.
Etiologies
Any process that damages the cerebellum or cerebellar control unit can cause ataxic dysarthria.
- Degenerative
- Vascular
- Traumatic
- Demyelinating
- Neoplastic or cancer-related
- Toxic/Metabolic
- Inflammatory
Degenerative Diseases
- Can occur sporadically and without known cause, but a hereditary basis is increasingly recognized.
- Hereditary ataxias can be fatal or not and can begin in childhood or adulthood.
- Degenerative changes in the BG, cerebral cortex, spinal cord, and peripheral nerves can occur; associated clinical features of parkinsonism, dementia, pyramidial and ophthalmologic signs, and bulbar/psuedobulbar palsy.
Friedrich’s Ataxia
The most common degenerative disease causing ataxia.
Begins before 20, evolves to incapacitation and death over the course of approx. 20 years.
Cardinal features:
- Limb and gait ataxia
- Dysarthria
- Absent muscle stretch reflexes in lower limbs
- Sensory loss
- Signs of corticospinal tract involvement
Vascular Disorders
Vascular lesions can affect the cerebellum but it isn’t super common.
Lesions most often caused by stroke, hemorrhage, aneurysms, or arteriovenous malformations.
Von Hippel-Lindau Disease
An inherited autosomal dominant condition characterized by blastomas of the cerebellum and retina and visceral cysts and tumors.
Trauma
TBI is frequently associated with limb ataxia and ataxic dysarthria.
Anoxia secondary to TBI is often a cause of cerebellar deficits.
CTE: Ataxic dysarthria is possible.
