lesions Flashcards
Dorsal horns have CB of ______ neurons
sensory
Ventral (anterior) horns have CB of ________ neurons
motor
Spinothalamic tract (ALS) Info: Cross:
Pain, temperature, crude touch Crosses: After it ascends or descends via Lasseurs tract, on the dorsal horn
DCML Info: Cross:
Propioception, tactile information, vibration Enters dorsal root -> ipsilateral dorsal column (fasciulus cuneatus or gracilis) - > projects up Crosses: caudal medulla (nucleus cuneatus or gracilis) via internal arcuate fibers -> medial lemniscus tract
damage to hypoglossal nerve
tongue deviates to lesion
damage to vagus nerve
uvula will deviate to contralateral side
damage to vestibular cochealr of vestibular nuclei
N/V, nystagmus
hemiparesis
weakness on one side of the body
Webers syndrome
Damage to the midbrain: CB, corticospinal and CN 3 1. Corticospinal: contralateral UMN; hemiparesis 2. CB: uvula will go to ipsilateral side, tongue will go away from the lesion (because above where it branches), exaggerated gag reflex
Oculomotor palsy (CN3)
dialated pupil Eye is down and out eye
What are the rule of 4s?
- 4 CN: A. Above the midbrain (1, 2, 3, 4) B. Pons (5, 6, 7, 8) C. Medulla (9, 10, 11, 12) 2. 4 CN that divide into 12 have motor nuclei in the midline: (CN 3, 4, 6, 12) 3. the 4 that do not divide by 12 are all located laterally: 5, 7, 9, 11. 4. 4 midline columns that all start with M: A. Medial lemniscus B. Motor nucleus of 3, 4, 6, 12 C. MLF D. Motor pathway (corticospinal tract) 4. 4 lateral (side) columns that start with S A. Spinothalamic B. Sympathetic C. Spinal trigeminal (sensory to face) D. Spinocerebellar
This will allow you to tell:
- Is the lesion medial or lateral: which tracts are affected? Then, we can ask: 2. Midbrain, pons or medulla: which CN is affected?
medial medullary sundrome can be d/t
occlusion of anterior spinal a.
Damage to CN 4 (trochlear):
Eye cannot look down when looking at nose
Damage to CN5 (trigeminal)
ipsilateral facial sensory loss
Damage to CN6 (abducens)
ipsilateral eye abduction weakness (eye cant abduct)
Damage to CN7 (trigeminal)
?
Damage to CN8 (ipsilateral )
ipsilateral deafness
Damage to CN 9 (glossopharyngeal)
ipsilateral pharyngeal sensory loss
Damage to CN 10 (vagus)
ipsilateral palate weakness
Damage to CN 11 (spinal accessory)
ipsilateral shoulder weakness
Damage to CN 12 (hypoglossal)
ipsilateral weakness of tongue
Damage to motor tract (corticospinal) in BS
contrlateral hemiparesis (weakness); UMN signs
Damage to medial leminscus in BS
contralteral loss of propioception and vibration
Damage to nucleus and nerve
ipsilateral motor loss of 3, 4, 6 ,and 12
Damage to spinocerebellar path in BS
ipsilateral ataxia
Damage to spinothalamic tract in BS
Contrlateral pain/temp/ crude touch loss in body
Damage to sensory nucleus of V (face)
ipsilateral pain/temp loss in face
Damage to sympathetic pathway
ipsilateral Homers syndrome
If we see : “lost of sensory (pain and temp to the left face”, what do we conclude
ipsilalateral sensory (trigeminal) V tract dysfunction -> Left sided lesion DO NOT USE CN 5 TO LOCALIZE TO PONS, BC CN 5 TRAVELS THROUGHOUT ALL BS
only use ______ to pick deficit is CN __
8
If cranial nerve is involved, the lesion must be located where?
BRAINSTEM!
What causes medial medullary syndrome?
Anterior spinal A.
In the midbrain, what a is most responsible for damage?
Posterior cerebral A.
In the pons, what as are responsible for damage?
Medial: paramedial branches of basilar (CN6) Lateral: long circumferential branches of basilar a (CN 5, 7, 8)
In the medulla, what as are responsible for damage?
Medial: Anterior spinal A (damages CN 12) Lateral: PICA (damages CN 9, 10, 188)
Sx: R sided weakness L eye is down and out. Use rules to figure out whats wrong?
- R sided weakness-> corticospinal tract -> medial lesion 2. L eye is down and out -> oculomotor palsy -> located in the midbrain Left medial midbrain lesion (webers) d/t PCA.
Left eyelid droop (ptosis) and small pupil (miosis) ->
L Horners syndrome
Loss of pain and temp to left face ->
damage to CN 5
Loss of gag reflex in left throat
CN 9 (glossopharnygeal)
Palate raised to the right side
CN 10
hoarse voice
damage to CN 10
corneal reflex
CN 5
corneal reflex
CN 5
facial spasms is d/t
CN 7
How do rule of 4:
- Look for involvement of midline CN: 3,4,6, 12-> indicate a midline damage
- All other CN involvement indicate a lateral involvement
- Look for involvement of M tracks -> medial side involvement
- Look for involvement of S tracks -> lateral side involvement
Complete transection of posterior columns in the cervical region would produce what impairment(s)?
Damage the fascilulus cuneatus and fasciulus gracilis -> complete loss of propioeption, vibratory, tactile info from cervical down
ipsilateral
no change
decrease/loss of function
decrease/ loss of function
Contralateral
no change
no change
loss of function
- contralateral
- no change
- no change
- loss of function
lesion to
anterior horn
ipsilateral LMN paralysis
damage to Lateral corticospinal tract
ipsilateral spastic paralysis
Posterior ______ sulcus is present throughout the entire SC.
Posterior _____ sulcus separates the cuneate fasiculus and the gracile fasiculus and disappears.
________ column is only present in the thoracic area
Posterior lateral sulcus is present throughout the entire SC.
Posteior intermediate
Lateral column
