The bladder anatomy and its innervation are described. The bladder neck is composed of smooth muscle and elastic tissue and contains the internal urethral sphincter. Beyond this is the external urethral sphincter in the urogenital diaphragm. Micturition is controlled by the pontine micturition center and storage is maintained by sympathetic and somatic innervation. Neurogenic bladder dysfunction is classified based on the lesion level and includes uninhibited, reflex, sensory paralytic, motor paralytic, and autonomous bladders. Evaluation involves history, exam, labs, imaging of the upper and lower tracts, and urodynamics to assess filling and voiding functions.

1. DR. AJAY KUMAR SINGH
DNB Neurosurgery
VPIMS

2. ANATOMY OF BLADDER
 The lower part of the bladder neck
is also called the posterior
urethra because of its relation
to the urethra
 The smooth muscle of the bladder
is called the detrusor muscle

3.  The bladder neck (posterior
urethra) is a 2 to 3 cm long,
and its wall is composed of
detrusor muscle interlaced
with a large amount of elastic
tissue
 The muscle in this area is
called the internal sphincter
 Involuntary

4.  Beyond the posterior urethra,
the urethra passes through the
urogenital diaphragm, which
contain a layer of muscle called
the external sphincter of the
bladder
 Voluntary
 Tonicaly contracted normaly

5.  The bladder outlet: trigone, ureterovesical junction, bladder neck, and
proximal urethra.
 α-Adr receptors predominate in this area, and stimulation of
postganglionic α-adr receptors provides excitatory input to bladder outlet
that results in increased bladder outlet closure force.

6. Sphincteric mechanisms
 Proximal/internal (smooth muscle sphincter)‐formed by circular
smooth muscle fibers at bladder neck and proximal prostatic urethra.
 Distal/external (striated sphincter)‐
‐‐Slow twitch fibers responsible for baseline tonic activity
‐‐Fast twitch responsible for voluntary contractions

8. Innervation
 Parasympathetic innervation (pelvic nerve) mediates-
Detrusor muscle contraction (ACh, M3 muscarinic receptors)
Relaxation of IUS (NO)
 Sympathetic innervation (hypogastric nerve) mediates-
Relaxation of detrusor β3-adrenoceptors).
contraction of IUS (NA α1-adrenoceptors)
Somatic innervation:
Arises from the spinal motoneurones of Onuf’s nucleus(S2–S4).
During storage, pudendal nerve keeps the striated urethral sphincter closed.

9.  Preganglionic neurons (PGNs) of
 Parasympathetic----Sacral segment. Iintermediate grey matter (laminae
V–VII) of spinal cord.
 Sympathetic ---- Lumbar segment. Iintermediate grey matter (laminae V–
VII) of spinal cord.
 Parasympathetic PGNs send dendrites into the dorsal commissure and
into the lateral funiculus and lateral dorsal horn of the spinal cord and
exhibit an extensive axon collateral system that is distributed bilaterally in
the cord.

10.  The somatic motor neurons that innervate the EUS are located in the
ventral horn (lamina IX) in Onuf's nucleus.
 Interneurons in the lumbo-sacral spinal cord that are involved in LUT
function are located in the dorsal commissure, the superficial dorsal horn
and the parasympathetic nucleus.

11.  Some of these interneurons send long projections to the
brain, whereas others make local connections in the spinal
cord and participate in segmental spinal reflexes.

12.  In the brain, some neurons are specific for micturition:
 The neurons of Barrington's nucleus (also called the pontine
micturition centre (PMC)
 The periaqueductal grey (PAG),
 Cell groups in the caudal and preoptic hypothalamus.
 The neurons of several parts of the cerebral cortex, in particular the
medial frontal cortex.

13. Physiology of micturition
MICTURITION REFLEX.
 As the bladder fills with urine, the wall stretches, impulse are initiated by stretch
receptors in the bladder wall causing sensory signals to convey to the dorsal nerve
root S2,3,4 segments of spinal cord through pelvic nerves and then back to the
urinary bladder through parasympathetic fibres in the same nerve.
 During this reflex sympathetic effrents are reflexly inhibited.
In brain
 PONS: Facilitatory
 FRONTAL LOBE: Inhibitory

15. Storage reflexes
-Distention of bladder produces low-level
bladder afferent firing.
-This in turn stimulates the symp outflow
to outlet and pudendal outflow to EUS.
-These responses occur by spinal reflex
pathways and represent “guarding
reflexes,” which promote continence.
-Sympathetic firing also inhibits detrusor
muscle and transmission in bladder
ganglia.

16. Voiding reflexes
At the initiation of micturition, intense
vesical aff activity activates
spinobulbospinal reflex pathway, then,
• Activation PMC via PAG, which inhibits
pudendal outflow to EUS and sympathetic
outflow to detrusor, and later it stimulates
parasympathetic outflow to detrusor and
urethra leading to voiding.

17. Neuroanatomy of bladder control
Cortical control
 Antero medial frontal lobes involved in voluntary initiation and
inhibition of micturition, delay of reflex voiding.
 Sends inhibitory signals to detrusor
 To avoid voiding till an appropriate location is found
 Has connection with pons; and corticospinal fibres synapse with motor
nuclei controlling striated sphincter

18. Pontine micturition centre
 At pontomesencephalic reticular formation (barrington nucleus)
 Dorsomedial tegmental region – center for micturiton ( M-region )
 Ventrolateral pontine tegmentum - center for storage (L-region)
 Affected by emotions, some people may experience incontinence when
they are excited or scared

19. Pontine Micturition Center
 Bladder filling  detrusor muscle
stretch receptors  signal to the
pons  Frontal lobe
 Perception of this signal (bladder
fullness) as a sudden desire to go
to the bathroom
 Normally, the brain sends an
inhibitory signal to the Pons to
inhibit the bladder from
contracting until a bathroom is
found.
 Urge to urinate disappears
 When urination appropriate,
brain sends excitatory signals to
the Pons, allowing voiding.

20. Spinal control
 Somatic (S2‐S4), Pudendal nerves(Excitatory to external sphincter)
 Parasympathetic (S2‐S4) (Excitatory to bladder)
 Sympathetic (T10‐L2)
--Hypogastric nerves to pelvic ganglia
--Inhibitory to bladder body, excitatory to bladder base/urethra

21. Neurogenic bladder dysfunction
This has been classified by Lapides into :
1. Uninhibited bladder
2. Reflex neurogenic bladder
3. Sensory paralytic bladder
4. Motor paralytic bladder
5. Autonomous bladder

22. Dysfunctions in Neurological Disorders
 Suprapontine lesions
 Spinal or Suprasacral lesions
 At or distal to Sacral lesion

23. Filling/Storage symptoms
 Urgency: “the complaint of a sudden compelling desire to void, which
is difficult to defer”
 Nocturia: when he/she wakes at night one or more times to void.
 Frequency: 8->8 void/24 hour
 Incontinence: inability to hold urine
 Urge incontinence: sudden, intense urge to urinate followed by an
involuntary loss of urine.

24. Voiding symptoms
 Hesitancy: difficulty in begining a urination reflex.
 Straining to void
 Dysuria

25. Lesion Older
terminolog
Newer
terminolgy
Pathogenesis Sens
ation
Tone &
cap
F/
U
H Residual
urine
Supraponti
ne
Uninhibited
bladder
Nuero
detrusor
overactivity
Loss of cortical inhibition of
reflex voiding
P Normal + Var
iabl
e
No
Infrapontie/
spinal
(UMN)
Reflex
neurogenic
bladder or
automatic
(spastic)
bladder
Neurogenic
D-
overactivity
w detrusor
dys-
synergia
Interruption of descending
autonomic tract and ascending
sensory pathway leading to reflex
and involuntary micturition
P/A (++)
Small
bladder
capacity
+ + ++
Conus, S2-4
roots in
cauda or N
(LMN)
Autonomus
bladder
Detrusor
areflexia
Interrutption of sensory and motor
supply leading to loss of reflex
and volutary control
A Reduced
(increasd
capacity)
No + +++
Sensory
root
ganglia,
post column
- Sensory
paralytic
bladder
Interruption of sensory supply A
(no
desie
to
void)
Reduced
(increasd
capacity)
No + +++
Dribbling
Motor nerve
root
- Motor
paralytic
Interruption of motor supply P Reduced
(variable)
No + +++

26. Mixed type A bladder: that damage the detrusor nucleus but spare the
pudendal nucleus.
 Renders the detrusor flaccid (also referred to as detrusor areflexia), while the
intact pudendal nucleus is spastic producing a hypertonic EUS.
 The bladder is large and has low pressure, so the spastic EUS produces
urinary retention.
Mixed type B bladder: that spare the detrusor n. but damage the pudendal n.
 Flaccid EUS and spastic bladder.
 The bladder capacity is low but vesicular pressures are usually not elevated
since there is little outflow resistance.

27. SUPRAPONTINE LESIONS :
 Uninhibited bladder
 Decreased descend inhibitory input to pons.
 Coordinated activity of the sphincter and the
detrusor
 Urgency, frequency, nocturia, and
occasionally urge incontinence.
 Filling upto a normal threshold of 300‐350ml
 Bladder emptying too quickly and too often,
with relatively low volumes of urine.
 CVA, Brain tumors, Hydrocephalus.

28. SPINAL LESION
SPINAL CORD INJURY
3 types:
(1) above spinal segment T6,
(2) below T6 to the sacral cord
(3) distal to the sacral cord (cauda equina).
 Bladder contractility and reflex contraction are dependent on an intact
sacral cord and sacral reflex arcs, with injury to the sacral segments of the
spinal cord resulting in detrusor areflexia and fixed EUS tone.

29. Spinal shock:
 Initially, flaccid muscle paralysis and absent somatic activity as well as
suppressed autonomic activity below the lesion.
 Absence of sensation and motor function, loss of voluntary control and
sphincter compromise.
 The bladder is acontractile and areflexic.
 But, b/c of preservation of EUS tone, urinary incontinence is usually
secondary to poor emptying and overflow incontinence.

30. Suprasacral cord injury (UMN)
 Detrusor overactivity, smooth sphincter synergy (if below T6), and striated
sphincter dyssynergy.
 The dyssynergic striated sphincter causes a functional obstruction with
poor bladder emptying and high detrusor pressure.
 Smooth sphincter dyssynergy is present with lesions above T6.

31.  Functionally, the m/c problem in patients with suprasacral SCI is
failure of both filling/storage (because of detrusor overactivity) and
emptying (because of striated or smooth sphincter dyssynergia, or
both).

32. Autonomic dysreflexia.
 Lesions above the T6 sympathetic outflow tract, response to specific stimuli
can cause a massive disordered autonomic discharge.
 Pounding headache, hypertension, bradycardia, and flushing with sweating
above the zone of the lesion.
 Cervical injury.
 The stimulus for autonomic dysreflexia is most often distention or
manipulation of the bladder or rectum.

33. Neurospinal Dysraphism
 90% incidence.
 An areflexic bladder with an open bladder neck, inconsistent.
 There is a fixed EUS, with 10% to 15% of patients having detrusor–striated
sphincter dyssynergia.
 Patients usually suffer from incontinence as a result of filling pressures
overcoming the low fixed sphincter pressures and transient increases in
intra-abdominal pressure (stress incontinence).

34. DISEASED AT OR DISTAL TO SACRAL SPINAL CORD
SACRAL SPINAL CORD INJURY
 Detrusor areflexia
 Over time, decreased bladder compliance and elevated storage pressure
may develop.
 The bladder outlet is classically described as a competent but non-
relaxing smooth sphincter with a fixed EUS not responsive to voluntary
control.

35. EVALUATION OF NEUROLOGIC DISORDER
 History
 Neurologic examination
 Laboratory testing
 Radiologic studies
 Upper urinary tract imaging
 Lower urinary tract imaging
 Urodynamic testing of LUT
 CYSTOMETRY
 PRESSURE FLOW STUDIES AND UROFLOWMETRY
 ELECTROMYOGRAPHY
 VIDEOURODYANAMICS

36. Neurological examination:
Sensory examination of
 Anterior abdominal wall: thoracic
 Genitalia: sacral
 Lower extremities: lumbar lumbar nerve roots.
 The anterior portions of the scrotum and labia majora derive
innervation from the thoracolumbar spinal cord.
 The sacral nerve roots innervate the posterior portion.
 Saddle area of the perineum evaluate the afferent limb of pudendal n.

37. Basic motor and muscular tone—specifically, the tibialis anterior,
gastrocnemius, and toe extensors, innervated by the lower lumbar and
upper sacral nerves.
 P/R to evaluate the external anal sphincter is important for evaluation of
the pelvic floor musculature.
 Voluntary contraction of the external anal sphincter confirms
innervation of the pelvic floor and integrity of the corticospinal tract.
 Preserved sphincter tone in the absence of voluntary contraction is
consistent with a suprasacral lesion, whereas diminished tone is
consistent with a sacral or peripheral nerve abnormality.

38. Neurological examination: to evaluate the integrity of sensorimotor
pathway known as the segmental reflex arcs

39. Laboratory testing
 Serum Creatinine
 Urine routine
 Urine culture and sensitivity
 Serum electrolytes
 Input-Output chart

40. Radiologic
Upper UTI
 Hydronephrosis
 Chronic pyelonephritis
 Renal scarring
 Vesicouretric reflux
 Renal calculi
Lower UTI
 Cystoscopy : detrusor overactivity as trabeculation and diverticula, urethral
strictures and prostatic obstruction.
 Voiding cystourethrogram: vesicoureteric reflux morpholgic changes

41. Urodyanamic testing: Non invasive
 Assesment of PVR and urolflowmetry
 No absolute volume above which PVR is
universally considered to be abnormal.
(<100ml), ideally <50 ml.
 PVR indicates poor bladder contractility or
BOO or both,

42. Uroflowmetry: provides the data on the
rate of urinary flow over time from the
urethra.
 A low flow rate indicates poor bladder
contractility or BOO or both.
 Normal uroflow rate : 25ml/sec
 Obstructed : < 5ml/sec
 Reliable only when voided volumes is
200‐400ml

43. Cystometry
 Invasive
 Evaluate the compliance of bladder
during filling and voiding.
 Detrusor pressure is measured.
 At 50 and 100 ml/min.
 1st sensation: 100 ml
 Full: b/w 400 and 600 ml

44. Normal
• Low detrusor pressures at initiation
• Normal bladder sensations
• No detrusor contraction during filling
• Rapid rise in detrusor pressure just prior to voiding
• Voiding at detrusor pressure below 40 cm in males & 20 cm in females.
3 Voiding States
 Low detrusor pressure and high flow rate (unobstructed)
 High detrusor pressure and low flow rate (obstructed)
 Low detrusor pressure with low flow rate (poor detrusor contractility).

45. Electromyography.
 Sphincter EMG is used to record bioelectric potentials generated by the
striated sphincter complex during bladder filling, storage, and micturition.
 It provides information on voluntary control of the pelvic floor
musculature and coordination between the detrusor and pelvic floor.
 During bladder filling, EMG activity should gradually increase and reach a
maximum before voiding.
 This so-called guarding reflex is also present during the Valsalva
maneuver, coughing, or other maneuvers that increase abdominal
pressure.

46. TREATMENT
Failure to store urine
 Management of detrusor overactivity or impaired
compliance
 Timed voiding and pelvic floor exercises
 Medications
 Sacral neuromodulation
 Augmentation cystoplasty

47. Timed voiding and pelvic floor exercises
 Decreased fluid intake
 Avoidance of dietary irritants such as caffeine, bowel regulation and
avoidance of constipation and timed voiding.
 Bladder retraining and pelvic floor muscle exercises

48. Medications:
Anticholinergic: Oxybutynin (5mg TDS), Flavoxate, tolterodine.
By blockage of muscarinic Ach receptors to inhibit unstable detrusor
contraction.
 Detrusor inastability
 Incontinence
 Urgeny
 Cathter induced bladder spasm,

49. Beta agonist: Mirabegron
Activation of beta-3 adrenargic receptors relaxes the detrusor smooth muscle
during the storage phase.
Alpha blocker: BOO. Phenoxybenzammine (10-20 mg BD), prazocin (0.5-2 mg BD
Tricyclic antidepressant: imipramine
Anticholinergic and sympathetic action
Decrease bladder contractality and increase sphincter resistance
Botulinum toxin A: (blocks NMJ presynaptic vesicle fusion, which prevent Ach
release. Ideopathic or neurogenic detrusor overactivity (200 U) and decreased
bladder compliance(100 U).

50. Management of outlet deficiency
Intrinsic sphincter deficicncy, poorly functioning EUS, bladder outlet
injury.
Iinjectable bulking agents
Sling procedure
Artificial urinary sphincters
Bladder neck closure
Urinary diversion

51. Failure to empty urine
 Managment of detrusor acontractility
 Clean intermittent catheterization
 Indwelling catheters
 Voiding with valsalva maneuvers
 Cholinergic agonists
 Sacral neuromodulation
 Urinary diversion

52. Management of detrusor-external sphincter dyssynergia
 External spincterotomy
 Urethral stenting
 Botulinum toxin A injection
Management of Detrusor-internal sphincter dyssynergia
 Alpha adrenargic blocker
 Cystoscopic incision with electrocautery

53. THANK YOU

54.  Urgencey : sudden urge to urinate
 Frequency: frequent urination (> 8 voids/24 hour) or > 1 void in night.
 Nocturia:
 Hesitency: difficulty in beginning the voiding reflex
 Urge incontinence: sudden urge to micturate
 Incontinence: involuntary loss of urine per urethra
 Overflow incontinence: frequent dribbling
 Dysuria: painful sensation of micturition