Lesions Of The Spinal Cord And Brainstem Flashcards
UMN
Weakness Mostly no atrophy (flaccidity is exception) No fasciculations Decreased reflexes in acute stage Increased reflexes in chronic stage Decreased tone in acute stage Increased tone in acute stage
LMN
Weakness Atrophy Fasciculations Decreased reflexes Decreased tone
ALS
Temperature Pain Touch Deep pressure Arranged lateral (coccygeal/sacral) to medial (cervical)
DCML
Joint sensation Vibration Pressure Discriminative touch Arranged medial (sacral) to lateral (cervical)
Arrangement of lateral Corticospinal tract
Same as ALS
Lateral (sacral) to medial (cervical)
When I say medial, you say:
Motor
Medial lesions are associated with ipsilateral motor deficits
When I say lateral, you say:
Sensory
At the level of CN8 and T10, what does the anterior spinal artery supply?
ALS and Corticospinal tracts (ventral)
At the level of CN8 and T10, what tract does the posterior spinal artery supply?
DCML
Is pure hemi-section of the spinal cord common?
No, very rare
Ipsilateral Corticospinal tract lesion
UMN
Loss of voluntary motor control
Ipsilateral DCML
Discriminative touch, pressure, proprioception, vibration
Contralateral ALS
Pain, temperature, crude touch
Lesion at a particular level
All sensation coming into dorsal horn would be lost
Motor nerve exiting ventral horn (LMN) lost
Ventral (anterior) horn cell lesion (or disease)
Spinal muscular atrophy
Polio
PMN involvement
Amyotrophic lateral sclerosis
Ventral horn and CST involvement producing UMN and LMN signs
Anterior cord syndrome
Anterior spinal artery ischemia or infarct
Loss of voluntary motor control and loss of pain, temperature and crude touch below infarct
Discriminative touch, pressure, proprioception spared
More rostral = more dysfunction
Commissural syndrome of the spinal cord
Lesion to ventral white commisure
Bilateral symmetric loss of pain and temperature in dermatomal distribution of spinal cord segments
Not typical but likely a precursor to central cord syndrome
Central cord syndrome
- bilateral damage of central part of spinal cord
- loss of sensation and voluntary motor control in the area of peripheral distribution of more rostral spinal cord segments
- sacral sparing: due to somatotopic organization; Rostand neurons more medial
Medial brainstem lesions of midbrain
- oculomotor nerve LMN: same side damage = ipsilateral eye down and out
- Corticospinal tract: opposite limbs with spastic paresis
Medial brainstem lesions in pons
- Abducens nerve LMN: same side damage = ipsilateral eye addicted
- Corticospinal tract: opposite limbs with spastic hemiparesis
Medial brainstem lesions in medulla
- hypoglossal nerve LMN: same side damage = tongue protrudes toward affected side
- Corticospinal tract: opposite limbs with spastic hemiparesis
Lateral brainstem lesion in mid pons
- CN V motor and sensory loss on same side
- pain and temp lost on same side of face
- opposite side of body pain and temperature loss
Lateral brainstem lesion in caudal pons
- mostly AICA
- CN VII motor LMN
- CN V sensory
Lateral brainstem lesion rostral medulla
- palatial arches and uvula: sensory CN IX and motor CN X
- uvula deviates away from side of LMN lesion
Lateral brainstem lesion in midbrain
- no motor symptoms
- face/ body pain, temp, touch all lost on contralateral side
- spinothalamic, medial lemniscus, trigeminothalamic all crossed
