nerves Flashcards
cranial nerves
CN I – Olfactory CN II – Optic CN III – Oculomotor CN IV – Trochlear CN V – Trigeminal CN VI – Abducens CN VII – Facial CN VIII – Vestibulocochlear CN IX – Glossopharyngeal CN X – Vagus CN XI – Accessory CN XII – Hypoglossal
CN V - function
- mastication
- facial sensation
- somatosensation from anterior 2/3 of tongue
CN V - facial sensation - divisions
- ophthalmic
- maxillary
- mandibular
CN VII - function
- facial movements
- taste from anterior 2/3 of tongue
- lacrimation
- salivation
- eyelid closing
- stapedius muscle of the ear
CN VII vs parotid gland
nerve courses through the parotid gland, but does not innervate it
CN IX - function
- taste and somatosensation from posterior 1/3 of tongue
- swallowing
- salivation
- monitoring carotid body and sinus chemo and baroreceptors
- elevates pharynx and larynx
CN X - function
- taste from epiglottic region
- swallowing
- soft palate elevation
- midline uvula
- talking
- coughing
- parasympathetics to thoracoabdominal viscera
- monitoring aortic arch body and chemo and baroreceptors
- tongue movement
tongue - main muscles (and innervation)
- hyoglossus (XII)
- genioglossus (XII)
- styloglossus (XII)
- palatoglossus (X)
(12 +10)
cranial nerve reflex?
- corneal 2. lacrimation 3. jaw jerk
4. pupillary 5. Gag
corneal nerve reflex - afferent and efferent
afferent - V1 opthalmic (nasociliary branch)
effernt - VII (temporal branch - orbicullaris oculi)
Gag reflex - afferent and efferent (only CN)
afferent - IX
effernt - X
pupillary reflex - afferent and efferent (only CN)
afferent - II
effernt - III
Lacrimation reflex - afferent and efferent (only CN)
afferent - V1
effernt - VII
jaw jerk reflex - afferent and efferent (only CN)
afferent - V3 (sensory - muscle spindle from masseter)
effernt - V3 (motor - maseter)
CN X lesion - appearance
uvula deviates AWAY from side of lesion. Weak side collapses and uvula points away
CN XII lesion - appearance
tongue deviates toward side of lesion (“lick your wounds”) due to weakened tongue muscles on affected side (LMN lesion)
vertebra disc hernitation?
nucleus polposus (soft central disc) herniates through annulus fibrosus (outer ring) usually posterolaterally
spinal cord tracts?
- dorsal column
- lateral spinothalamic
- anterior spinothalamic
- lateral corticospinal tract
- anterior corticospinal tract
spinal cord - dorsal column transfers
- pressure
- vibration
- fine touch
- propioception
spinal cord - lateral spinothalamic tract transfers
pain
temperature
spinal cord - anterior spinothalamic tract transfers
crude touch (απροσδιόριστη) pressure
cavernous sinus syndrome present with
- variable ophthalmoplegia
- decreased corneal sensation
- Horner syndrome
- decreased maxillary sensation (occasionally)
….passes through cavernous sinus
- CN III, CN IV, CN V1, CN VI
- occasionaly V2
- postganglionic sympathetic pupillary fibers
- carvenous portion of internal carotid artery
ALS pathophysiology
defect in superoxide dismutase 1 –> combined UMN and LMN deficits with NO sensory, occulomotor deficits, bowel, bladder or sensory deficits
ALS - deficits
combined UMN and LMN deficits with no sensory or occulomotor deficits
NO SENSORY OR BOWEL BLADDER DEFICITS
ALS - treatment
Riluzole
spinal cord lesions - complete inclusion of anterior spinal artery
spares dorsal columns and Lissaeuer tract
watershed area of anterior spinal cord (why)
upper throracic ASA territory, as Adamkiewicz artery supplies ASA below T8
Adamkiewicz artery supplies ASA … (area)
below T8
tabes dorsasis - spinal cord lesion?
degeneration (DEMYELINATION) of dorsal columns and roots
Argyll Robertson pupils
are bilateral small pupils that reduce in size on a near object (accommodate) they do not “react” to light
tabes dorasil - clinical examination
- absence of Deep Tendon Reflexes
- Romberg sign (+)
- Argyll Robertson
- Stroke without hypertension
Syringomyelia - symptoms (and area) / seen with
bilteral loss of pain and temperature
usually C8-T1 –> cape - like
seen with Chiari I malformation
vitamin B12 deficiency - spinal cord lesions
sabacute combined degeneration –> demyelination of dorsal column, lateral corticospinal tracts, and spinocerebellar tracts
poliomyelitis - death of … cells
LMN
poliomyelitis - signs and symptoms
- signs of infection –> malaise, headache, fever, nausea
2. LMN lesion signs –> weakness, hypotonia, flaccid paralysis, fasciculations, hyporeflexia, muscle atrophy
poliomyelitis - labs
- CSF: increase WBCs and slight increase of protein, no change of glucose
- virus recovered from stool or throat
poliomyelitis - glucose in CSF
no change
Spinal mascular atrophy (Werding-Hoffman disease) - pathophysiology / mode of inheritance
congenital degeneration of anterior horns of spinal horn –> LMN lesion AR
Spinal mascular atrophy (Werding-Hoffman disease) - common appearance
floppy baby with marked hypotonia and tongue fasciculations
Spinal mascular atrophy (Werding-Hoffman disease) - prognosis
infantile type –> median age of death of 7 months
Poliomyelitis vs Spinal mascular atrophy (Werding-Hoffman disease) according to weakness
polio –> asymmetric
SMA –> symmetric weakness
Friedreich’s ataxia - gene / action of this gene
FRATAXIN –> iron binding protein
Friedreich’s ataxia leads to (mechanism and findings)
problem of frataxin (iron binding protein) –> impairment in mitochondria functioning–> ROS –> degeneration of multiple spinal cord tracts –> muscle weakness, loss of DTRs, vibratory sense and proprioception
Friedreich’s ataxia - symptoms/presentation
- Staggering gait 2. frequent falling 3. nystagmus
- dysarthria 5. per cavus 6. hammer toes
- diabetes mellitus 8. hypertrophic cardiomyopathy
- kyphoscoliosis (childhood)
- Loss of DTRs
Friedreich’s ataxia - gait
Staggering gait
Friedreich’s ataxia - appearance of foot (and definition of that
- per cavus: foot is distinctly hollow when bearing weight
2. hammer toes: toes that are bent permanently downwards
Brown-Sequard syndrome findings
- ispilateral UMN signs below the level of lesion
- ipsilateral loss of tactile, proprioception, vibration below the level of lesion
- contralateral pain and temperature loss below the level of lesion
- Ipsilateral loss of all sensation AT LEVEL OF LESION
- ispilateral UMN sign at the level of lesion
- Horner syndrome (if lesion above T1)
Landmark dermatomes - C2
Landmark dermatomes - C3
Landmark dermatomes - C4
Landmark dermatomes - C6
C2: posterior half of a skull cap
C3: high turtle-neck shirt
C4: low-collar shirt
C6: upper limb (includes thumbs)
Landmark dermatomes - T4
Landmark dermatomes - T7
Landmark dermatomes - L1
Landmark dermatomes - L4
T4: at the nipple
T7: xiphoid process
L1: at the inguinal ligament
L4: includes the kneecaps
Landmark dermatomes - S2, S3, S4
erection and sensation of penile and anal zone
Landmark dermatomes - T10
at the umbilicus
clinical reflex - mc and nerves
bicepts - C5, C6
tricepts - C7, C8
patella - L3, L4
achlles - S1, S2
cremaster reflex - to check
L1, L2 (testicle move)
anal wink reflex - to check
S3, S4
anal wink reflex - mechanism
contraction of the external anal sphincter upon stroking of the skin around the anus
penis dermatome
S3