Neuro Flashcards
Why do parkinsons patient have OAB?
decreased dopamine, dopamine promotes detrusor relaxation
Name 3 malfunctions in neuro pathways that can lead to OAB
- M3 cholinergic receptors
-A-delta fibers to C- fibers
-C fibers convey increased pain and stretch. - B3 adrenergic receptor signals
-alternation leads to unchecked activation and inability to block parasympathetic signals which cause detrusor contraction - Abberant signals from S2-S4, peripheral nerve damage
MS patient presents. Wants to know her risk of having:
OAB:
detrusor sphincter dysynergia:
retetion:
overall bladder dysfunction in one’s lifetime:
OAB: 50%
detrusor sphincter dysynergia: 25%
retention: 25%
overall bladder dysfunction: 90% lifetime risk
Discuss the process of autonomic dysreflexia?
Exagerated reponse to a noxious stimili like bladder or bowel distention–>
triggers a sympathetic reflex (vasoconstriction/increased BP/ headache) and a parasympathetic surge (sweating, flushing).
Vitals show HTN and reflex bradycardia
above T6
Neuro physiology of the sigmoid and rectum
sympathetic input comes from what nerve?
What muscle does this control?
inferior and superior hypogastric chain
controls tone/relaxation of bowel smooth muscle
Neuro physiology of the sigmoid and rectum
parasympathetic input comes from what nerve?
What muscle does this control?
s2-s4 splanic nerves
activation causes rectal peristalsis/skeletal muscle change
What is the RAIR?
recto-anal inhibitory reflex
-autonomic control
triggered by distention of the rectum
-transient relaxation of internal anal sphincter coupled with contraction of the external anal sphincter
-allows you to pass air without solid or liquid
what nerves are particularly impacted by uncontrolled diabetes?
sacral nerve roots, pelvic nerve
Describe your work up for neurogenic bladder.
History
Physical
upper tract assessment - renal sono, KUB, 24hr Cr clearance, serum creatinine is not helpful.
lower tract assessment
Voiding diary
UDS (video or voiding cystogram)
Describe the 4 urodynamic classifications of the neurogenic bladder.
- failure to store due to bladder
-neurogenic detrusor overactivity
-poor compliance - failure to store due to outlet
-ISD - Failure to empty due to bladder
-detrusor arreflexia
-detrusor hypocontractility - Failure to empty due to outlet
-DSD
-sphincter bradykinesia (parkinsons everythign is slow)
At what DLPP should you be worried about upper tract damage?
> 40 cm H2O
Define detrusor sphincter dyssynergia.
involuntary contraction of the sphincter during an involuntary detrusor contraction
Patients with DSD are at increased risk for what conditions (4)
UTI, ureteral reflux, hydro, renal failure
Based on the level of the lesion, name the most likely type of neurogenic LUT dysfunction.
Above the level of the pons.
detrusor overactivity
Based on the level of the lesion, name the most likely type of neurogenic LUT dysfunction.
between Pons and sacral micturition center
detrusor overactivity with or without detrusor sphincter dyssynergia
Based on the level of the lesion, name the most likely type of neurogenic LUT dysfunction.
In the sacrum
areflexia
impaired contractility
sphincter dysfunction
What is spinal shock?
-initial period of detrusor areflexia, flaccid paralysis,
absent reflexes below the level of the lesion
this is followed by a recovery phase where there is return of detrusor activity
lastly, there is the stable phase-THIS IS WHEN YOU EVALUATE THEM. you can tell they are stable when their reflexes return
What are you looking for on video UDS?
-bladder contour to see diverticulae
-christmas tree shape instead of round
-bladder outlet
demylenation of which structures can cause urinary dysfunction in patients with MS?
pontine micturition center,
lateral cord (pain/stretch pathway)
cortex
sacral cord
Describe the filling phase.
Sympathetic nervous system promotes:
- Detrusor relaxation caused by activation of the beta 3 receptors via hypogatsric nerve and norepinephrine.
- contraction of the bladder neck caused by activation of the alpha receptors via hypogastric nerve and norepinephrine
Somatic nervous system-
- contraction of the external urethral sphincter caused by activation of the pudendal nerve releasing ACh at nicotinic receptors
Describe the voiding phase.
- detrusor stretch activates the mechanoreceptors to send signal to the pontine micturition center and periaquaductal grey via the pelvic nerve afferents.
- This sensory info is sent to the cerebral cortex.
- the cerebral cortex sends efferent signals to the PMC and lateral region of the pons.
- The PMC sends parasympathetic signals to release nitrous oxide to act on the nicotinic receptors to inhibit the pudendal nerve (somatic) to relax the external urethral sphincter
- PMC also activates the parasympathetic system via the pelvic nerve to release ACh which acts on M3 receptors and promote detrusor contraction and inhibits the sympathetic nervous system via the hypogastric nerve
Define neurogenic bladder
Abnormal bladder or urethral function in the context of clinically confirmed relevant neurologic disorders
Parasympathetic system
Where are the preganglionic neurons located?
Where do they synapse?
- intermediate gray matter of the sacral spinal cord (S1-3)
- in the pelvic ganglia
Describe the path of the sympathetic bladder innervation.
Where does it originate?
Where do they synapse?
How do the postganglionic axons get to the bladder?
- begins: intermediolateral nucleus of the lumbar spinal cord (L2-4)
Travels through lumbar splanchnic nerves.
- synapse: caudal mesenteric ganglion
- postganglionic axons run through the right/left hypogastric nerve and pelvic
