Neurogenic Speech Disorders Unit 1

CN V

Trigeminal - Origin: Pons

Motor - muscles of mastication

Sensory - Sensation of the face, mouth, and jaw

Effect of lesion: paresis or paralysis, atrophy, of the masticatory muscles on the paralyzed side

CN VII

Facial - Origin: Pons

Motor - muscles of facial expression and stapedius muscle

Sensory - Submandibular, sublingual, and lacrimal glands; taste on anterior 2/3 of tongue

Effect of lesion: facial muscle paralysis based on location of lesion

CN IX

Glossopharyngeal - Origin: Medulla

Motor - stylopharyngeus, and upper constrictor muscles of the pharynx

Sensory - Sensation for phayrnx, tongue, posterior 1/3 taste

Effect of lesion: Reduced pharyngeal sensation

CN X

Vagus - Origin: Medulla

Three branches: Pharyngeal, Superior Laryngeal, Recurrent Laryngeal

Effect of lesion: Dysphagia

CN X - Pharyngeal Branch

Motor - muscles of pharynx and soft palate

Sensory - sensation for pharynx and soft palate

CN X - Motor for voice

Recurrent laryngeal nerve (left and right) - motor innervation for all intrinsic muscles of larynx except for cricothyroid

Superior laryngeal nerve (external branch) - motor innervation for cricothyroid

CN X - Sensory for Larynx

Superior laryngeal nerve (internal branch) - sensation above VF

Recurrent laryngeal - sensation below VF

CN X - Additional innervation

Motor and sensory functions for the thoracic and abdominal viscera

Taste information from the epiglottis

CN XI

Spinal Accessory - Origin: Medulla and spinal cord

Motor - Cranial portion - pharynx, uvula, levator veli palatini

Motor - Spinal portion - Neck muscles

Effect of lesion: Can weaken head rotation towards opposite side of lesion

CN XII

Hypoglossal - Origin: Medulla

Motor - intrinsic and extrinsic muscles of tongue (except palatoglossus), neck muscles

Effect of lesion: Damage can lead to atrophy, weakness, and fasciculations of the tongue on the side of the lesion.

Spinal nerves

Phrenic - 3rd, 4th, and 5th cervical nerves combine in the cervical plexus to form the paired phrenic nerves which each innervates ½ of the diaphragm

Motor Speech Processes

Cognitive-linguistic processes

Motor speech planning and programming

Neuromuscular execution

Types of dysarthria

ArMFUlS - HH

Ataxic, ( r ), Mixed, Flaccid, UUMN, ( l ), Spastic, Hypokinetic, Hyperkinetic

Ataxic

Localization: cerebellum (control circuit)

Neurogenic characteristic: Incoordination

Mixed

Localization: More than one

Neurogenic characteristic: More than one

Flaccid

Localization: Lower motor neuron (LMN)

Neurogenic characteristic: weakness

UUMN

Localization: Unilateral UMN

Neurogenic characteristic: weakness, incoordination, or spasticity

Spastic

Localization: Bilateral Upper motor neuron (UMN)

Neurogenic characteristic: spasticity

Hypokinetic

Localization: Basil ganglia control circuit

Neurogenic characteristic: ridgidity or reduced range of motion

Hyperkinetic

Localization: Basil ganglia control circuit

Neurogenic characteristic: abnormal movements

Major anatomical levels of the nervous system and possible MSDs that can occur at each level

Supratentorial - Apraxia; Dysarthria: UUMN, Spastic, Hypokinetic, Hyperkinetic

Posterior Fossa - Dysarthrias: Ataxic, Flaccid, UUMN, Spastic, Hyperkinetic

Spinal - Dysarthrias: Flaccid

Peripheral - Dysarthrias: Flaccid

Types of apraxia

Oral apraxia - difficulty planning sequence of oral movements

Verbal apraxia - difficulty with sequential ordering of movements in the correct spatial and temporal relation to each other

Conditions that could be mistaken for a MSD

Fluency disorder, voice disorder, aphasia

Normal speech changes due to aging

• Fundamental Frequency (Pitch)

• Voice Quality

• Vocal Stability

• Intensity (Loudness)

• Speech breathing patterns

• Rate

• Prosodic variations

MSDs are characterized by:

Age of onset, course, site of lesion, neurologic diagnosis, pathophysiology

MSDs are characterized by: Age of onset

Congenital, developmental, acquired

MSDs are characterized by: Course

Congenital, chronic (stationary), improving, progressive (degenerative), and exacerbating-remitting

MSDs are characterized by: Site of lesion

NM junction, peripheral or cranial nerves, brainstem cerebellum, basal ganglia, pyramidal or extrapyramidal pathways, cerebral cortex

MSDs are characterized by: Neurologic diagnosis

Degenerative, inflammatory, toxic-metabolic, neoplastic, traumatic, vascular

MSDs are characterized by: Pathophysiology

Weakness, spasticity, etc.