Lecture 2 - Cranial Nerves Flashcards
LMN Symptoms
Single limb paralysis
Flaccid muscle tone
Hyporeflexia
Muscular atrophy
Fibrillation/fasciculation
Symptoms of Cerebellar Syndrome
Incoordination/ ataxia
Dysmetria
Dysdiadochokinesis
Intention Tremor
Rebounding
Incoordination/Ataxia
A complex movement is decomposed
Dysmetria
Unable to measure distance or speed
Under- or Over-shooting
Dysdiadochokinesis
Alternate motion rate (pa pa pa)
Alternate sequential rate (pa ta ka)
Intention Tremor
Not resting tremor
Tremor when attempting to make an intentional movement
Rebounding
Inability to judge when the resistance has disappeared
Symptoms of Basal Ganglia Syndrome
Involuntary Movements:
Chorea
Dyskinesias
Hypokinesias
Athetosis
Rigidity
UMN Symptoms
Hemiplegia
Spastic tone
Resistance to passive movement
Hyperreflexia
Atypical Reflexes
- Babinski
No atrophy
No denervation
Muscles are paralyzed but they don’t die because they are hyper reflexive
Branchial Arches
There are 6 branchial arches that turned into muscles when we were born.
They are classified as Special Visceral Efferent even though they are under voluntary control
First Arch
Moror branch of the Trigeminal Nerve
Special Visceral Efferent
Muscles of mastication
Additional muscles:
Mylohyoid, ant. belly of digastric, tensor tympani, tensor veli palatini
Second Arch
Facial Nerve
Muscles of facial expression:
Buccinators, auricularis, frontalis, platysma, orbicularis oris, orbicularis occuli
Additional muscles:
stapedius, stylohyoid, posterior belly of digastric muscles
Third Arch
Glossopharyngeal Nerve
Innervates the stylopharyngeus muscle
- deals with swallowing
Fourth and Sixth Arches
Vagus Nerve
5th arch disappears
Superior and recurrent laryngeal nerves
Pharyngeal and laryngeal muscles:
cricothyroid, levator veli palatini
- deals with swallowing and phonation
Unnumbered Gill Structures
Spinal accessory nuclei in C1-C5
Sternocleidomastoid and trapezius muscle
Functional Classifications
****Put in Picture
Classification - General Somatic Efferent
General Somatic Efferent = innervation of the skeletal muscles (somite)
Includes: Ocular muscles (CNs Oculomotor (III), Trochlear (IV), Abducens(VI)
Lingual muscles (CN hypoglossal (XII) - All muscles of the tongue are somite
Classification - General Visceral Efferent
Synonym for Autonomic Nervous System
Smooth muscles to regulate pupillary reactions, gland secretion, and muscles of the heart, trachea, bronchi, esophagus, and viscera (ANS) :
Edinger-Westphal Nucleus (Oculomotor - III)
Superior Salivatory Nucleus (Facial - VII)
Inferior Salivatory Nucleus (Glossopharyngeal - IX)
Dorsal Motor Nucleus (Vagus - X)
Classification - Special Visceral Efferent
Branchial Efferent - muscles of face, mandible, pharynx, larynx, and neck. Includes:
Motor nucleus of the Trigeminal - V
Motor nucleus of the Facial - VII
Nucleus Ambiguous of Glossopharyngeal - IX, Vagus - X
Accessory motor nuclei (in upper cervical C1-C5 segments)
Motor nucleus of spinal accessory - XI
Classification - Special Somatic Efferent
Does not exist
Classification - General Somatic Afferent
Somesthetic input (pain, temperature, touch) from the skin and somatic muscles in the head, neck, and face includes:
Trigeminal - V sensory nerve
- chief sensory nucleus and spinal descending nucleus
Classification - General Visceral Afferent
General sensation, pain, and temperature from visceral structures from pharynx, palate, larynx, aorta, and abdomen includes:
Glossopharyngeal - IX
Vagus - X
Classification - Special Somatic Afferent
Special senses
Includes:
Optic - II (vision)
Vestibulo-acoustic - VII (audition and equilibrium) Also proprioception
Classification - Special Visceral Afferent
Gustation and smell (olfaction). Includes:
Olfactory - I
Facial - VII
Glossopharyngeal - IX
Vagus - X
Special has very special receptors/cells
General is pain and touch
Autonomic Nervous System
When the cell is outside the central nervous system its called a ganglia
Vital organs
Additional ganglion
- pre and post ganglionic positions
- cranial nerve nuclei
- corticonuclear tract
****Images clustered CN nuclei, coriconuclear tract
Innervation Pattern
HELP
** Image blue background white brain
Bilateral corticonuclear regulation of most CN LMNs
Exceptions:
- Lower face (VII)
- SCM/Trap muscles (XI)
- Lingual muscles (XII)
Ocular muscles - the gaze center
Coordination of both eyes - left frontal cortex to right center
R gaze center - right and left recti contraction
Why are CN’s so Complex?
Shared nuclei
- salivatory, solitarius, ambiguus
Shared CN functions - some CNs are doing more than one thing
- Ocular movement
- there are 3 CNs for eye movement
- Tongue sensation
- there are 2 CNs for tongue sensation, 2 for taste
Look up Summary Table 17-3
Trigeminal Neuralgia
AKA Tic Doulaureux
Loss of sensation due to damage to the trigeminal nerve
Stabbing pain
Trigger Point
Herpes Zoster
Caused by damage to the trigeminal nerve
Painful disorder along the nerve
Masticator Palsy
Caused by damage to the trigeminal nerve
Paralysis of the muscles of mastication
Unilateral UMN = mild paresis because of bilateral innervations; mild effect on muscle strength
Unilateral LMN = twitching, muscle atrophy, and jaw deviation to the side of the lesion
Bilateral (UMN/LMN) lesions = profound impact on chewing,
Bell’s Palsy
Due to damage to the Facial nerve
Ipsilateral Facial Paralysis
Sagging face
Loss of taste on anterior ⅔ of tongue
Cranial Nerve I
Olfactory
Function: Smell
Classification: SVA
Pathways:
Clinical Considerations:
- Anosmia = unilateral and bilateral lesions
- Caused by TBI, sinusitis, upper respiratory infections, orbital tumors
Assessment: Odor Identification
Speech Relevance: N/A
Cranial Nerve II
Optic
Function: Vison
Classification: SVA
Pathways:
Clinical Considerations:
- Blindness pattern
- Field of loss patterns
Assessment: Reporting on finger moving from periphery; reflexes
Speech Relevance: N/A
Cranial III
Oculomotor
Function: Eye Movement
Classification: GSE, GVE
Pathways:
Clinical Considerations:
- External ophthalmoplegia (ex. recti muscles are paralyzed)
- Diplopia
- Internal ophthalmoplegia (pupil is permanently dilated)
- Ptosis (droopy eyelid)
Assessment:
- Ocular movement
- Diplopia
- Pupillary response to light
Speech Relevance: N/A
Cranial Nerve IV
Trochlear
Function: Eye Movement
Classification: GSE
Pathways:
Clinical Considerations:
- Diplopia
- Peripheral Neuropathy
Assessment:
- Look for eyes moving in coordination
Speech Relevance: N/A
Cranial Nerve V
Trigeminal
Function:
- Receives pain/touch from skin and muscles in the face, orbit, nose, mouth, forehead, teeth, meninges, ant. ⅔ of tongue, ext. auditory meatus, and ext. surface of the tympanic membrane.
- Proprioception of jaw
- Controls jaw movement
Classification: GSA, SVE
Pathways:
Clinical Considerations:
- Loss of sensation - Tic Doulaureux
- Herpes Zoster
- Masticator Palsy
Assessment:
- Symmetry during rest and action
- Jaw movements
Speech Relevance:
- Dental sounds
- Bilabial sounds
Cranial Nerve VI
Abducens
Function:
- Lateral Eye movements
- Abducts eye via activation of the lateral rectus muscle
Classification: GSE
Pathways:
Clinical Considerations:
- Medial Strabismus = no gaze to affected side
- Diplopia
Assessment : Impaired Ocular movements
Speech Relevance: N/A
Cranial Nerve VII
Facial
Function:
- Regulates secretions from the lacrimal and mucosal glands of the nasopharynx and salivary secretion from sublingual and submaxillary glands
- Mediates taste sensation from anterior ⅔ of tongue and palate
- Innervates muscles of facial expression, scalp, and stapedius
Classification: GVE, SVA, SVE
Pathways:
Clinical Considerations:
- Unilateral facial paresis
- Secretions
- Taste
- Bell’s Palsy
- Hyperacusia
Assessment:
- Oral Secretion
- Taste Sensation
- Facial Symmetry
- Ability to smile
Speech Relevance:
- Bilabial Sounds
- Labiodental sounds
- Sagging face
- Drooling of food
- Loss of taste
Cranial Nerve VIII
Auditory
Function: Hearing, Equilibrium
Classification: SSA
Pathways:
Clinical Considerations:
- Hearing Impairments
- Disequilibrium
Assessment:
- Repetition of words with masking
- Weber Test
- Rinne (Mastoid Placement)
Speech Relevance: Hearing
Cranial Nerve IX
Glossopharyngeal
Function:
- Mediates gag and respiratory reflexes
- Regulates salivary secretion
- Transmits taste from posterior ⅓ of tongue
- Contributes to swallowing reflex
Classification: GVE, SVA, SVE
Pathways:
Clinical Considerations:
- Palatal sensation
- Gag reflex (afferent)
- Swallowing
- Taste (posterior ⅓)
- Cutaneous senation
Assessment:
Speech Relevance:
- Can’t form bolus (swallowing)
- Loss of taste
- No gag reflex
Cranial Nerve X
Vagus
Function:
- Sensation from pharynx, larynx, thorax, carotid body, abdomen
- Regulates Nausea, oxygen intake, and respiratory reflex
- Innervates glands, cardiac muscles, trachea, bronchi, esophagus, stomach and intestine
- Taste sensation
- Controls muscles of larynx, pharynx, and soft palate
Classification: GVE, SVA, SVE
Clinical Considerations:
Assessment:
- phonation
- voice quality
- swallowing quality
- resonance quality
Speech Relevance:
- Swallowing
- Sensation
- Dysarthria
- Palatal Movement
- Gag reflex
- Pitch
Cranial Nerve XI
Spinal Accessory
Function:
- Controls head position by controlling trapezius and sternocleidomastoid muscles
Classification: SVE
Pathways:
Clinical Considerations:
- UMN - Contralateral Weakness
- LMN - ipsilateral paralysis = dropped shoulders, deviated head
Assessment:
- Shrugging/Shoulder movement
- Head turn against resistance
Speech Relevance: N/A
Cranial Nerve XII
Hypoglossal
Function: Controls motor movements of the tongue
Classification: GSE
Pathways:
Clinical Considerations:
- Unilateral LMN = ipsilateral paralysis
- Bilateral LMN = loss of speech, swallowing, chewing
- Unilateral UMN = contralateral muscle weakness with gradual recovery
- Bilateral UMN = complete paralysis
Assessment:
- Visual appearance
- Tongue movement against resistance
- Alternate motion rate
Speech Relevance:
- Lingual sounds
- Dental sounds
- Swallowing
Multiple Nerve Innervation
Ocular Muscles
Lingual Muscles
Pharyngeal Muscles
Cranial Nerve Mediated Reflexes
Pupillary Reflex
Corneal Reflex
Gag Reflex
Sneeze Reflex
Pupillary Reflex
Constriction
Assess through:
Shining light in eye
CN III Efferent fibers
CN II afferent fibers
Corneal Reflex
Eye blink
Assess through corneal touch
CN VII efferent fibers
CN V afferent fibers
Gag Reflex
Effort to vomit
Assess through pharyngeal touch
CN X efferent fibers
CN IX, X afferent fibers
Sneeze Reflex
Sneeze
Assess through nasal irritation
CN X efferent fibers
CN V afferent fibers
Cranial Nerve Syndromes
Weber Syndrome
Millard-Gubler Syndrome
Locked-in Syndrome
Wallenberg Syndrome
Dejerine Syndrome
Weber Syndrome
Midbrain
Structures = corticospinal fibers, Oculomotor nerve
Symptoms:
Contralateral hemiplegia
Ipsilateral ocular paralysis
Lateral eye deviation
dilated pupil
Possible ptosis
Millard-Gubler Syndrome
Lower Pons
Coricospinal nerves, facial nerve, abducens,
Contralateral hemiplegia
Medial strabismus due to ocular paralysis
Ipsilateral facial paralysis
Strabismus
Eyes don’t look in the same direction at the same time
Locked-in Syndrome
Bilateral Basal Pons
Motor fibers and Cranial Nerve VI
Quadriplegia
Preserved vertical eye movements
Intact sensation and comprehension
Wallenberg Syndrome
Lateral Medulla
Trigeminal spinal tract, nucleus ambiguous, spinal lemniscus
Ipsilateral pain sensation loss from face
Contralateral pain sensation loss from body
Dysarthria
Dejerine Syndrome
Medial Medulla
Hypoglossal Nerve, pyramidal fibers
Contralateral hemiplegia
Contralateral hemianesthesia - loss of sensation
Dysarthria due to ipsilateral lingual paralysis
Neurological Motor Speech Assessment - Purpose
Identify the following:
Nature of oral deficit
Facial adequacy for speech
Severity of disorder
Implications for treatment
Neurological Motor Speech Assessment - Patient History
Ask:
Onset and course
Associated deficit:
- dysphagia and dysarthria
- fatigue
- unintelligibility
Perception of deficit by self and/or others
Cognitive ability
Neurological Motor Speech Assessment - Salient Motor Features
Muscle Strength
Movement speed
Movement range
Movement accuracy and steadiness
Muscle tone
Assessment of Muscle Strength
Strength Dysfunction:
- Failure to reach or sustain a level
- Strength fall with sustained act
- Inaccurate/excessive/lesser strength
Implications:
- respiration (incompetence)
- Laryngeal (incompetence)
- Palatopharyngeal (emission)
- Articulatory (precision)
Assessment of Speed
Speed Dysfunction:
- slow start
- slow course & slow delay
- slow movements with limited range
Implications for speech, prosody, and resonance
Assessment of Range
Range Disturbance:
- limited for single/repetitive movement
- inaccurate and variable range
Implications for speech:
- prosodic dysfunctions
- weak articulation
Assessment of Movement Accuracy
Accuracy Disturbance:
- Over/Under shooting
Implications:
- random breakdown in speech
- prosodic variations
Assessment of Movement Steadiness
Steadiness Disturbance:
- Tremor
- Chorea
- Involuntary Movements
Implications:
- Articulatory fluctuation
- Unsustained articulation
- Premature articulations
- Random Prosodic interruptions
Assessment of Confirmatory Signs of Motor Dysfunction - Non-Speech Symptoms
Gait:
- Clumsy - with wide-based gait
- Standing - body swaggering from side to side
- Not walking from heel to toe or in a straight line
Pathological Reflexes
Palsy:
- Single or multiple sets of muscles
Slow and awkward movement
Object dropping
Foot dropping while walking
Unexplained fatigue
Assessment of Confirmatory Signs of Motor Dysfunction - Speech Symptoms
Sound distortions
Slurred and imprecise speech
Impaired resonance
Slow rate of speech:
- articulatory duration
- increased pauses
Reduced loudness
Altered phonation
Examination of Motor Speech
Symmetry is very important in the brain
Testing Conditions:
- Rest
- Non-speech motor activity
- Sensation
- Speech activity
Assessment - Face
Rest Condition: Check for symmetry of - eyes - nasolabial fold - mouth angle - philtrum and its ridges - cheek curve - forehead wrinkles - facial bulk
Assessment of Facial Signs of Weakness
Masked face
Sagging face/lip
Lack of wrinkles
Absence of nasolabial fold
Wide pallbearer fissure
Flat philtrum
Asymmetric facial contours
Assessment of Facial Muscles - MN Involvement
Facial muscles are needed for speech and non-speech tasks
Sensation of oral facial muscles
Unilateral UMN – no problem, the patient should be able to make expressions
(the other side will take over)
Bilateral UMN – nothing can do, expression less, very few movements
Unilateral LMN – one side is affected
Bilateral LMN (both facial nerves are damaged)– patient cannot do anything, both sides of the face are affected
**profound affects with bilateral
Assessment of Mandibular Muscles
At rest condition:
- manidble asymmetry and bulk
- bilateral jaw sagging
Non-speech activities:
- jaw opening/closing with or without resistance
- lateral jaw movement against force
- bulk during jaw clenching
- holding tongue depressor
Sensation Assessment
Speech Tasks
LMN/UMN/Bilateral involvement
- Bilateral = big issue
Assessment of Tongue
At rest condition:
- Symmetry
- Fibrillations at edges
Non-Speech Motor Activities:
- Protrusion
- Movements
- Movements against resistance
Sensation:
- 3 CNs for tongue sensation =
Speech Tasks
UMN/LMN/Bilateral Involvement
UMN - unilateral = contralateral problem with tongue
LMN = ipsilateral problem with the tongue
Bilateral = devastating
Assessment of Palatopharyngeal Port
At rest condition:
- Symmetry of arch while saying “ah”
- Unilateral palatal asymmetry (deviates to good side)
- Bilateral palatal asymmetry (affects gag reflex because whole palate comes down
Sensation
Speech Tasks
- Produce “ah” and “ga”
- Deviation to good side
- Lower excursions
LMN/UMN/Bilateral Involvement:
Unilateral UMN = asymmetry, but minimal
Unilateral LMN = vagus or trigeminal nerve; one side will go down, ipsilateral
Bilateral = whole thing comes down
Assessment of Larynx
At rest condition:
- Position of head and shoulders
Sensation
Non-speech tasks:
- Coughing/Throat clearing
Speech tasks:
- Roughness, hoarseness, breathiness
UMN/LMN/Bilateral Involvement:
Unilateral UMN (ALWAYS CONTRALATERAL): no profound impact because of bilateral innervation
Bilateral UMN – profound impact on vocal folds (present the same as bilateral LMN)
Uni LMN = ipsilateral, LMN (ALWAYS IPSILATERAL): one vocal fold would be fixed in para-medium position (hoarseness, diplophonia, breathiness)
Bilateral LMN: both vocal folds would be fixed in para-medium position
Assessment of Respiratory Capacity
At rest condition:
- Posture - changed or abnormal posture
- Shortness of breath
- Abnormal breathing patterns - chest breathing
Speech tasks:
- Water glass manometer (bubble generation)
Assessment of Speech Quality
Contextual Attributes of Spontaneous Speech:
- Intelligibility
- Intensity
- Resonance characteristics
- Naturalness
Intelligibility and naturalness go when there is any kind of dysarthria
Additional Aspects of Assessment
Stress reading
- Need to read with lots of energy/stress
Vowel Prolongation
- Duration, steadiness, loudness
Sequential Motion Rate =
Alternate Motion Rate =
Speed and regularity of movements
