Changes in Bladder Function after Neurological Injury Flashcards
Type of muscle lining the Bladder
Smooth muscle
Function of Detrusor mm
relax to close
contract to void
Possible complication that may occur with a bladder dysfunction secondary to SCI
UTI or kidney infection if the ureter is overly filled and back flow.
How does the bladder performs its function?
Micturition reflex (stretch reflex)
When bladder is filled, the pressure increases
smooth muscle stretch
parasympathetic input contracts the detrusor to void.
If pressure raises too high, external sphincter relaxes and urination occurs (~400-450mL)
If the patient lacks ____ control, they are unable to overwrite the micturition reflex and voiding occurs regardless
cortical
Segmental Innvervation of the bladder
Parasympathetic (S2-S4): contract detrusor mm
Sympathetic fibers (T12-L2): relax detrusor mm
Pudental nerve (S2-S4): somatosensory innervation of External urethral sphincter and pelvic floor (needed for volitional voiding)
Importance of Bladder management for our patients
Prevention of kidney damage
Autonomic Dysreflexia (injuries above T6)
Minimize skin breakdown
psychosocial effects
Reasons for CVA/TBI to have loss of bladder control
- change in mental status
- damage to cortex/brain stem which controls external sphincter and detrusor
- unable to volitionally control bladder
- Dec. sensation/awareness
- Post indwell catheter, detrusor mm
Note: physically get there might be an issue so dont wait until too full
Neurogenic bladder
disruption of the parasympathetic and sympathetic pathways in the SC (can be a complete or iSCI)
Disruption of corotical control over micturition reflex
leads to either failure to store urine or release urine
“reflexive” or “areflexive bladder”
How much bladder control does a SCI patient have
Depends on the type & level of injury
Complete: disruption of voluntary and reflex control
incomplete: voluntary and reflex control may be intact
UMN Lesions & blader control
Failure to empty
occurs at: cervical/thoracic lesions
S2-S4 intact
no cortical input to bladder
sacral reflexes are intact (parasympathetic & sympathetic)
bladder can empty reflexively (tapping on abdomen above symphysis pubis/stroking inner thigh)
“reflexive bladder”
Reason of incontinence in UMN lesion (reflexive bladder)
occurs due to reflex emptying:
hyper-reflexic
Detrusor dysynergia
Lumbar lesions and Bladder control
Mix UMN/LMN
loss of cortical input
sacral reflexes are partially intact (parasympathetic & sympathetic)
bladder can empty reflexively only partially
need Intermittent cath to fully empty
LMN lesion & Bladder control
failure to store
S2-S4 affected
Loss of cortical input
sacral reflexes are disrupted (areflexic)
Bladder/EUS is flaccid
require use of catheter
When can areflexic bladder occur?
spinal shock 3-6 weeks post injury
urine will leak out of bladder
