Spastic Dysarthria Cerebral Palsy
About Spastic Dysarthria
The way it appears in:
- Spastic Hemiplegia
- Spastic Paraplegia
- Spastic Diplegia
- Spastic Quadriplegia
- Dyskinetic syndromes
- Athetoid Syndrome
Cerebral Palsy Spastic Dysarthria
Dysarthria is a condition in which it is difficult for a person to articulate words due to either to emotional stress, paralysis, or spasticity of the muscles used in speaking. The word derives from two phrases, (‘dys’ meaning ‘having a problem with’); (‘arthr’ meaning ‘articulating’). Any of the speech subsystems (respiration, phonation, resonance, prosody and articulation) can be affected, which can result in difficulties in intelligibility, audibility, naturalness, and efficiency of vocal communication. In cerebral palsy spastic dysarthria, the condition results from the neurological damage caused by the C.P. hindering control over the tongue, throat, lips or lungs. Swallowing problems can also be present.
While the effects of dysarthria can be present in all the forms of cerebral palsy (spastic, dyskinetic [athetosis] and ataxic) it is most commonly found in the spastic syndrome. Spastic C.P. is most commonly associated with low birth weight, hypoxia, and ischemia (reduced cerebral blood flow during labor). Of the various types of spastic C.P., (hemiplegia, paraplegia, diplegia,) the condition is most pronounced in spastic hemiplegia.
- Arm and leg on one side of the body have clasp-knife spastic weakness or paralysis.
- Corticospinal track (the primary pathway that carries the motor commands that control voluntary movement)is affected.
- Deviation of the tongue to the side of the body opposite the cerebral lesion.
- When dysarthria is present, bilateral control of the speech musculature permits rapid resolution of the condition.
- There may be mild phonologic (the organization of sounds in speech) delay, language and cognitive problems.
- When there are early left-hemisphere lesions, language functions are assumed by the right hemisphere which may leave visual-spatial functions of right hemisphere partially damaged.
- In left hemiplegia, language is not affected but there may be residual right-hemisphere damage.
Ordinarily affects the legs only without impinging on speech and language.
- All extremities are affected, but lower limbs are more impaired than upper.
- Respiratory muscles may be affected.
- Severity of dysarthria: can range from mild to severe and can affect all muscles (respiratory, laryngeal, articulatory, and palatopharyngeal.
- Dysphagia (difficulty in swallowing) and drooling may be present.
- Cognitive abilities may be affected.
- Flexion (bending) and adduction of the hips and scissoring (crossing of the legs during walking, a widely known clinical sign of child spasticity), toe walking.
- The most severe of all the spastic syndromes, generally equal motor impairment in all four limbs.
- In most cases both corticospinal and corticobulbar fibers are affected.
- Normally respiratory, laryngeal, articulatory and palatopharyngeal muscles are involved.
- Dysphagia (difficulty in swallowing), drooling, can be accompanied by lower facial paralysis and sensory loss of the lips and chin.
- A significant degree of cognitive impairment and speech and language delay: some may be cognitively intact.
Dyskinetic syndromes are less common than spastic syndromes. Athetosis is the most common dyskinetic syndrome in cerebral palsy. It may manifest in pure form or mixed such as choreoathetosis or dystonic athetosis. Athetosis, often with choreoathetosis is now predominantly caused in cerebral palsy by perinatal loss of oxygen.
- Hypotonia (decreased muscle tone. … Infants with hypotonia seem floppy and feel like a “rag doll” when held) and slow motor development. Hypotonia may progress to normal tone or a mixed hypertonic-athetoid condition with maturity.
- Failure to achieve balance in a sitting position.
- The MORO reflex and the asymmetric tonic neck reflex (ATNR) are abnormal.MORO reflex: (also known as the startle reflex), an involuntary response present at birth which normally disappears within 6 months of age. When an infant is startled by a loud noise or other stimulus or feels that he or she is falling, the Moro reflex causes the baby to extend his or her arms, legs and fingers and arch their back.
ATNR reflex is an involuntary response present at birth which normally disappears within 6 months of age. It is also commonly referred to as the fencing reflex because the position of the infant’s arms and head resembles that of a professional fencer. When the infant’s face is turned to one side, his or her arm and leg on that side extend, while the limbs on the opposite side bend.
The presence of the ATNR reflex beyond six months can indicate that the baby has developmental delays. In CP children, the effects of ATNR often remain and become even more pronounced. As an abnormal reflex, the ATNR can cause problems as the child grows. The ATNR impedes activities such as rolling, bringing the hands together, and bringing the hands to the mouth. The ATNR can cause damage to the child’s joints and bones, curvature of the spine, and dislocation of the thighbone.
- Dysphagia (difficulty in swallowing) and drooling: chronic dysphagia and dysarthria are common; In general, severity of the dyskinetic involvement of the limbs occurs in direct proportion to the severity of the speech mechanism.
- Cognitive deficits do not necessarily accompany the motor disability.
Causes of Athetoid Dysarthria
Conventional wisdom found in speech and neurologic literature attribute dysrthria of athetosis in CP to variable, irregular, sometimes random involuntary movements of the speech muscles. However more recent research proposes that a pattern of abnormal voluntary motor commands for speech is generated by athetoids and not involuntary movements. These inappropriate commands occur in athetosis because cerebral lesions prevent normal sensorimotor integration to generate appropriate speech motor commands. This disruption of the internal sensorimotor feedback system for appropriate motor commands causes faulty movements that are perceived by others as involuntary. Thus the dysarthria appears to result of faulty programming of voluntary movements rather than random involuntary movements.
Children with spastic CP are less likely to suffer from respiratory and articulatory problem than those suffering from athetosis. Childhood dysarthrias caused by cerebral palsy are the most common motor speech disability.