Day-Of Study Notes for neuro test Flashcards
Relating to bladder function: The pons inhibits the ________ + __________
The pons controls the __________ which use ______ fibers to activate the bladder wall
pelvic floor muscles and external sphincter
Sacral urination center which uses parasympathetic fibers that activate the bladder wall
The _________ inhibits the pons when it’s not a good time to peepee
Frontal cortex
What tract releases seratonin?
What tract released Norepinephrine to help with tonic facilitation?
Raphespinal
Ceruelospinal
Flexor nerve are usually more _____ to extensor nerves
Distal nerves are usually more ______ to proximal nerves
distal
Lateral
What tract has to do with anticipatory postural changes?
Reticulospinal
The anterior spinocerebellar and the rostrospinal are both __________ and ________
Single fiber
Internal feedback
The rostrospinal is an (ipsi/contralateral) feedback tract from spinal levels ____
Ipsilateral
C1-T1
Subconcious temperature info is transmitted to the ________
Reticular formation and thalamus
The slow medial nocieption tract uses what fibers?
C fibers
What is the destination of the anterior/lateral spinothalamic tract?
Primary and secondary association somatosensory cortex
The anteriolateral spinothalamic 1st and 2nd order neurons synapse in the….
Substantia gelitanosa
What spinal levels control reflexive bladder function
T11-L2
+
S2-S4
During Hemi-cord syndrome (Brown-Sequard)
You typically see (contralateral/ipsilateral) absence of anteriolateral spinothalamic senses
and (contralateral/ipsilateral) of motor/DCML
Contralateral anteriolateral
Ipsilateral motor/DCML
_____ cord syndrome typically stretches the anterior c artery
Anterior cord syndrome
What tract functions are usually unaffected by anterior cord syndrome?
DCML
Central cord syndrome is usually caused by….
Extension/trauma
In central cord syndrome (usually cervical)
Small lesions usually cause ____
whereas large lesions _____
Small: nociceptive
& pain impaired at the
level of the lesion
Large: additionally
see upper limb motor
impairments
True or false: In Cauda Equina syndrome, complete lesion of cauda equina are common
False
True or false: In Cauda Equina syndrome, you typically see spasticity and hyperreflexia
False, they are abscent
Stretch injuries of the spinal cord or cauda equina during
child development/growth spurts can cause….
Tethered cord syndrome
In tethered cord syndrome
Stretching of the spinal cord causes ____
whereas damage to cauda equina causes ____
Upper motor neuron signs
Lower motor neuron signs
Tethered cord associated with ________
spina bifida
myelomeningocele (L4, L5, S1)
Damage to the lumbar
and/or sacral spinal roots
Sensory impairments
Flaccid paresis/paralysis of
lower limb muscles,
bladder, & bowels
These describe what?
Cauda equina syndrome
Spinal shock lasts at least 24 hours and may last ____
2-3 weeks
The end of spinal shock is marked by return of ____ reflexes
Anal reflexes
With a spinal cord injury, Spinal neurons can become __________ , developing ___________ as
neuroplasticity develops new synapses in reflex pathway
Hyperexcitable, hyperreflexia
Somatic reflexes are gone
Autonomic reflexes of smooth muscles are impaired or lost
Autonomic regulation of blood pressure is impaired
Temperature regulation is lost (sweating and goose bumps)
These are symptoms of…
Spinal Shock
Injury at S2-S4 or related nerve roots causes flaccid areflexive bladder
What does this cause and how can it be treated in males?
Overfilling and leaking of bladder
Condom catheter
Injury above S2-S4 interrupts descending tracts causing ________ and _______ bladder
hypertonic, hyperreflexive bladder
Injury above S2-S4 interrupts descending tracts will require…..
Intermittent catheterization or indwelling catheter required
Note: Spasticity of bladder wall can potentially force urine back to kidneys
Lesion between S2 and S4 reflex circuit in males causes….
Impotinence, genitial has no sensation
(worst one)
Males with lesion between L2 and S2 will likely have what sexual function?
Normal sexual function due to intact L1-L2 aswell as parasympathetic nerves in S2-S4 being intact.
Genitial sensation is abscent however
Males with a SCI above T12 will have what sexual function?
Loss of psychogenic erection, no sensation, reflexive erection/ ejaculation possible
Sexual function:
Males after a SCI will have ____
Females after a SCI will have ____
Males: Low spermcount/fertility
Females:
Fertility returns to normal after
SCI
However, pregnancy can be
high risk due to lack of
sensation, muscle contractions
and may require Ceasarian
section
Urination/defecation problems
Reduced or lost sensation in “saddle” area
LBP
Unilateral/B sciatica
LE weakness and sensory deficits
Reduced LE reflexes
These are symptoms of _______
cauda equina lesions
What are 2 mechanisms for UMN overactivity?
Absence of corticospinal/ DORSAL reticulospinal inhibition
OR
Brain stem UMN overactivity
What is clasp-knife phenomenon
Catch is build up of resistance to stretch initially
Basically initial rigidity followed by relaxation during PROM
Spasticity arises when pyramid tract is interrupted at: ____ ____ ____
Cortex, Corona Radiata, Internal Capsule
Lesions must include the _______ to produce spasticity
Pre-motor cortex
What tract is found in the genus of the internal capsule?
Corticobulbar
Where does the cortico-reticular tract arise?
Premotor and supplementary motor areas
Where does the cortico-reticular tract go?
Medial and lateral/dorsal reticulospinal
What is the ventromedial reticular formation?
Inhibitory area in medulla, dorsal to pyramids
Controlled by pre-motor cortex
INHIBITS SPINAL STRETCH REFLEX via dorsal/lateral reticulospinal tract
The excitatory system of the extrapyramidal tracts facilitates ______ and inhibits ____
Facilitates: Spinal stretch reflex, extensor tone
Inhibits: flexors
(Note: under less cortical control than inhibitory system)
True or false: Lesions of ventromedial reticular formation or the dorsal/lateral reticulospinal tract will produce spasticity
True
What are the different kinds of spinal segmental inhibition?
1a presynaptic inhibition
1a reciprocal inhibiton
1b autogenic inhibiton
Renshaw cell inhibition
1a presynaptic inhibition is mediated by the release of ________
GABA-ergic neurotransmitters that decrease efficacy of 1a afferent transmitters release
Renshaw cells inhibit homonymous muscles and _____
Synergistic muscles
Note: they also inhbiit both gamma MN and 1a neurons
Recurrent neurons excite renshaw cells using what neurotransmitter?
AcH
What is the most common measurement of spasticity?
Modified Ashworth scale
Patient in relaxed position (generally supine)
Passively move joint rapidly through available PROM
Graded 0-4
Describe the pathway of the consensual blink response
1st order neuron – trigeminal ganglion
2nd order neuron – spinal trigeminal nucleus
To interneuron in reticular formation
To B CN VII facial n to B orbicularis oculi to blink both eyes
What nerve innervates the “Stapedius of ear”
Facial N
Vestibular system considered central and peripheral .
what is the Peripheral part?
Peripheral part = peripheral vestibular n and vestibular apparatus
True or false: Damage to 1 spinal segment or root cannot completely paralyze any limb muscle
True, due to the plexus
Traumatic axonopathy:
If Schwann cells and connective tissues intact, can regrow at rate of __________
Occurs after crush injury or closed fracture
1mm/day
Carpal tunnel syndrome is example of…
Traumatic myelinopathy
Traumatic myelinopathy
Repeated mechanical pressures impair blood flow and cause changes to connective tissue of nerve
Myelin becomes damaged and with sensitization of nociceptors the n becomes excessively sensitive to mechanical or chemical stimuli
Can have full recovery
How does polyneuropathy progress?
Distal to proximal (stocking glove)
The first symptoms of polyneuropathy tend to be….
First symptoms tend to be sensory loss/dysfunction
Small fiber symptoms: pain, temperature, numbness, dysthesias
Large fiber symptoms: sensory ataxia, proprioception and vibration sense
Guillain-Barré Syndrome
Inflammatory demyelinating syndrome that typically occurs after viral infection causing more motor than sensory problems, distal to proximal progression
Urgent need to seek medical help due to risk of respiratory failure
Sig # require ventilator support
Prognosis good for recovery for classical form; some rarer variants cause axonal injury
CNS injuries vs PNS injuries on a NCV test
CNS injuries have normal nerve conduction velocity whereas PNS injuries have decreases velocity and amplitude
What has faster muscle atrophy? A CNS injury or a PNS injury?
PNS
