Neuro Flashcards
Neuro portions of the exam
Lateral spinothalamic tract
Which category?
Role?
Where it crosses?
How to test?
Category: Ascending tract, SENSORY
Role: Pain and temperature
Where it crosses: Within spinal cord at level of innervation
How to test: Sharp/dull, hot/cold
Anterior spinothalamic
Which category?
Role?
Where it crosses?
How to test?
Category: Ascending tract, SENSORY
Role: Pressure and crude touch
Where it crosses: Within spinal cord at level of innervation
How to test: Light touch
Dorsal column (medial lemniscus)
Which category?
Role?
Where it crosses?
How to test?
Category: Ascending tract, SENSORY
Role: Proprioception, deep touch, discrimination, vibration, stereognosis
Where it crosses: pyramid motor (medulla) in brain stem, contralateral effected
How to test: tuning fork, 2 pt discrimination, kinesthesia, proprioception, stereognosis
Lateral corticospinal
Which category?
Role?
Where it crosses?
How to test?
Category: Descending tract, MOTOR
Role: MAIN motor path, motor fxn of limbs and digits musculature
Where it crosses: pyramid motor (medulla) in brain stem
How to test: Injury would result in UMNL presentation (hyperreflexia)
Anterior corticospinal
Which category?
Role?
Where it crosses?
How to test?
Category: Descending tract, MOTOR
Role: motor fxn for posture and axial musculature
Where it crosses: within spinal cord at level of innervation
How to test: no specific tests
Corticorubrospinal tract
What category?
Role?
Category: Descending, MOTOR
Role: similar to corticospinal (back up system)
Corticoreticulospinal tract
What category?
Role?
Category: Descending tract, MOTOR
Role: posture and locomotion, automatic functions (respiration, circulation, sweating, shivering, dilation, sphincteric muscles)
Vestibulospinal tract
What category?
Role?
Category: Descending tract, MOTOR
Role: Postural reactions, standing balance
Traumatic spinal cord injuries
Stats, how they occur
40% are cervical incomplete
Tetra and paraplegic common
MOI: hyperflexion, hyperextension, axial load, penetrating injuries, falls, transportation
Non-traumatic spinal cord injury causes
Cancer, infection, inflammation, motor neuron disorders, vascular diseases (spinal cord infarcts)
Most are paraplegic
Spinocerebellar tract
What category?
Role?
Crossing?
Category: Ascending, SENSORY
Role: non-conscious proprioception (walking)
Crossing: some crossed and some uncrossed (4 total tracts)
Spinal Cord Immediate Treatment
Goals
Prevent edema by using ice to reduce the chance of secondary injury (ischemia, hypoxia, necrosis)
Immobilized
Manage airways, breathing, circulation, injuries
Surgery: if need alignment changes, stabilization, reduce medical complications
Level of lesion
Most caudal segment of the spinal cord with normal sensory and motor function on both sides of the body
Motor level of ASIA scale
Most caudal segment with a grade >/= 3 with ALL segments above being grade 5
If T2-L1 then determined by intact sensory segment level
Sensory level of ASIS scale
Most caudal segment with bilateral score of 2 for both light touch and pin prick
Graded by 0 = absent, 1 = impaired, 2 = normal
ASIA A
No sensory or motor function is preserved in the sacral segments (S4-5)
ASIA B
Sensation but NOT motor is preserved below the neurological level and includes sacral segments
ASIS C = sensory incomplete
More than half of the key muscles below the NLI have a grade 3 or less
ASIS D = motor incomplete
More than half of the key muscles below the NLI have grade 3 or equal to 3
ASIA E = normal
Normal sensory and motor function
Uses with patients who have prior history of SCI
Deep anal pressure = what ASIA?
If present, ASIA B (sensory incomplete)
Voluntary Anal Pressure = what ASIA?
If present, ASIA C (motor incomplete)
Zone of Partial Preservation (ZPP)
Might be dermatomes present below sensory level and myotomes below motor level that remain partially innervated
Most caudal segment with sensory defines extent of ZPP
ONLY FOR ASIA A
Pin prick prognostication
Pin prick (LE and sacral) within 72 hours is good indicator of motor function and ability to walk
Central cord syndrome
Most common
Damage to central cord
Hyperextension of neck, usually in elderly who fall
More loss in UE than LE
Associated with spinal canal stenosis
Brown Sequard Syndrome
Compression of one side of the spinal cord or hemisection
Typically seen after knife/penetrating injury
ISPILATERAL loss of motor
CONTRALATERAL loss of sensation
Anterior Cord Syndrome
Rare
Occlusion of blood supply to the anterior cord (pain and temperature) below injury level
Conus Medullaris Syndrome
Conus medullaris where spinal cord terminates (L1-L2)
CM lies close to nerve roots and can result in UMN and LMN features (spasticity)
May spare sacral reflexes
Cauda equina
Damage to lumbar and sacral nerve roots (L2 and below)
LMN injury
Loss and flaccid bowel and bladder
Affects more than just one nerve root
Surgical emergency
Usually bilateral leg pain/numbness, sacral root problems, urinary retention, stool incontinence, absent reflexes
Spastic bladder
Injuries ABOVE conus medullaris
Messages still travel between bladder and spinal cord
Tapping may trigger emptying
Bladder can be trained to empty on its own
Catheters or condom/foley drainage
Flaccid bladder
Injuries below conus medullaris
Messages do not travel between bladder and spinal cord
Loses ability empty reflexively
MUST be catheterized
Autonomic System: Sympathetic NS
Fight or flight response
Thoracic and lumbar portions of the spinal cord
Increase blood flow to muscles
Relaxes bronchial muscles for increase in O2
Autonomic System: Parasympathetic NS
Rest and digest
Cranial and sacral nerves
Restores energy and maintains bodily fluids
Decrease HR
Increase blood flow to smooth muscle
Contracts bronchial muscles
Autonomic NS dysfunction in SCI
With SNS dysfunction (T6 and above)
- Decrease HR: vagus nerve still intact from PSNS so lower heart rate… not a good way to track exercises
- Decrease BP: altered HR control and decreased muscle tone in LE contribute to this
- Poor regulation of body temperature: will go up and down with environmental temperature, messages about temperature are blocked by NLI, ensure proper hydration during session
Reasons for dizziness in SCI population
Autonomic dysreflexia, orthostatic hypotension, hypoglycemia
Autonomic dysreflexia
AT or ABOVE T6
Noxious stimuli below the NLI causes sympathetic response (blood vessels restrict)
Causes sharp rise in BP is controlled by the vagus nerve ABOVE the NLI leaving below to still be in sympathetic response
Above the NLI: sweating, flush, bradycardia
Below the NLI: chills, pale, cool, clammy, dizzy, nausea
Response to autonomic dysreflexia
If standing, sit them down
DO NOT lay flat
Try to find noxious stimuli - check bladder/catheter, bowel impairment (bladder irritation 75-85% of cases)
If above 150 BP then pharmacological management
If left untreated, can lead to hemorrhage, retinal detachment, seizures or death
Spinal shock
Cause
S/S
Time frame
Cause: acute SCI
S/S: suppression of all reflex activity below the NLI
Time: Last days - months
Neurogenic shockCause
S/S
Time frame
Cause: acute SCI, T6 and above ONLY
S/S: loss of sympathetic vascular tone and unopposed parasympathetic response… 1) bradycardia, 2) hypotension, 3) hypothermia
Time: within 30 minutes of injury and can last 6 weeks
Can be life-threatening if not treated
SCI Health Risks
- Pressure sores/wounds
- Poor secretion clearance
- DVT and PE = lack of muscle pump action
- Heterotrophic ossification (avoid forced PROM and serial casting) = treat within tolerable limits
- Osteoporosis
- Post traumatic Syringomyelia = formation of abnormal tubular cavity in the spinal cord