This document provides an overview of neurourological anatomy and physiology. It discusses the central nervous system centers that control bladder function, including the pons, cortex, basal ganglia and cerebellum, as well as spinal cord centers. It describes the arcs and loops involved in bladder control, including supra spinal, sympathetic, parasympathetic and pudendal arcs and loops. It also covers spinal tracts, basic concepts of neurourological function, reflexes, types of neurogenic bladder dysfunction, and pharmacological management options.

2. OVERVIEW
 Anatomy and physiology
 CNS centers
 Arcs and loops
 Spinal tracts
 Basic concepts of neurourological
function
 Reflexes
 Dysfunction
 Pharmacological management

3. Anatomy and physiology
 Upper urinary tract dysfunction is rare
due to neurological disease
 Lower urinary tract is richly supplied
with both autonomic and somatic
nervous system

4. Bladder anatomy
 Three anatomical layers
 Inner mucosal layer
 Muscular middle layer
○ Outer and inner longitudinal layer
○ Middle circular layer
 Outer adventitial layer
 Functinally bladder is divided in to parts
 Body
 Trigone

6. Receptors of the bladder
 Parasympathetic (musacrinic)
 Sympathetic
 Dual action
 Beta adrenargic
 Alpha adrenergic

8. CNS centers
 PONS
 Pontomesencephalic reticular formation
 Afferents from bladder receptors of
distension
 Sphincter detrusor synergesia
 Reticulospinal tracts spincter and detrusor
centers of the spinal cord

9.  Cortex, basal ganglia and cerebellum
 Paracentral lobule involved in voluntary
initiation of micturition and inhibition of reflex
voiding
 Lesions results in frequency and urgency
 Direct control of voluntary micturition
influencing the onufs nucleus through CST
 Pontine micturition center

11.  Spinal cord centers
 Sympathetic anteriomediolateral gray
column thoracolumbar cord T9-L1
 Parasympathetic nuclei intermediolateral
region of sacral cord S2-S4
 Onuf’s nucleus anterior horn of sacral cord

12. Arcs and Loops
 Supra spinal arc
 Parasympathetic afferent input from tension
receptor in the bladder wall to pontine
micturition centers
 Reticulospinal tracts to centers to sacral
cord
 3 to 4 yrs of age voiding is a reflex process
 Lesions above the brain stem manifested
clinically by frequency and urgency with
preserved detrusor sphincter synergesia

14.  Sympathetic nervous system arc
 Efferent sympathetic innervation T9-L1
through ventral routes, sympathetic ganglia
in the para vertebral chain preaortic and
parvertebral chains
 Touch, pain, and temperature from bladder
through spinothalamic tract

17.  Parasympathetic nervous system arc
 Efferents originate in the sacral cord travels
throgh ventral spinal roots and pelvic nerves
and joins with sympathetic nerves to create
a large autonomic plexus
 Proprioceptive information of bladder
sensation and pain through posterior
columns and spinothalamic centers to PMC
and supraspinal centers

19.  Pudendal system arcs
 Efferent somatic innervation of ext sphincter
from the onufs nucleus through pudendal
nerves
 Afferent carry exteroceptive and
proprioceptive sensation from pelvic floor
 Afferent fibers from the ext sphincter and
pelvic floor synapse with pudendal motor
neurons in ventral horns of the spinal cord
and helps in voluntary and reflex activity

21. LOOPS
 Loop 1
 Pathways between frontal cortex, basal
ganglia, thalamic nuclei, cerebellum and
pontomesencephalic reticular formation
 Predominantly inhibitory
 Interruption leads to loss of volitional control of
micturition reflex – uninhibited detrusor
 CVA, brain tumor, head injury, multiple
sclerosis, Parkinson’s disease.

23.  LOOP 2
 Sensory afferent neurons from detrusor –
posterior and lateral columns, ‘’long routing’’ in
spinal cord - pontomesencephalic portion in
brain stem
 Efferent neurons from micturition center travel
down in reticulospinal tract ‘’long routing’’ to
detrusor without any synapse in spinal cord
 Required to establish an adequate magnitude
and duration of detrusor reflex to accomplish
complete bladder emptying

24. contd
 Interruption – hyper-reflexic detrusor –
unable to produce a voluntary voiding
contraction
 Spinal cord trauma, multiple sclerosis, spinal
cord tumor, arachnoiditis

26.  LOOP 3
 Detrusor and pudendal motor nuclei and
their interneurons in sacral cord
 Coordination between detrusor contraction
and striated urethral sphincter relaxation
during voiding

28.  LOOP 4
 Motor cortex in frontal lobe – traverse via
pyramidal tract in lateral columns of spinal
cord, synapse on pudendal sphicter nucleus.
 Voluntary control over striated muscle of the
urethral sphincter during bladder storage
and voiding

30. Spinal tracts
 Corticospinal tract
 Reticulospinal tract
 Spinothalamic tract
 Posterior columns

31. Basic concepts of
neurourological function
 Two phases
 Low pressure insensanate filling and storage
of urine
 Efficient evacuation under voluntary control
 Filling and storage of urine
 Passive filling phase initial phase occurs till
proxim al urethral pressure > exceeds the
bladder
 Continence reflex phase bladder pressure >
urethral pressure

32.  Frontal micturition center by bladder
distension enhances sympathetic activity
and external sphincter
 Micturition
 Normal urinary voiding is voluntary
disinhibition of pontine and sacral reflex
activity in response to bladder distension

33. REFLEXES
 Superficial anal reflex
 Anal reflex or anal wink consists contraction
of anal sphincter in response to stroking or
pricking the skin of perianal region
 Inferior haemarhoidal nerve (S2-S5)
 Caudaequina or conus medullaris lesions
 Bulbocavernosus reflex
 Stimulating the skin of glans or penis
response is felt by placing a gloved finger in
rectum

34. Neurogenic bladder dysfunction
5 types (2 UMN; 3LMN)
 Uninhibited
 Reflex
 Autonomous
 Motor paralytic
 Sensory paralytic

35. Nomenclature
 Urgency is the complaint of a sudden and
compelling desire to pass urine that is
difficult to defer.
 Urge incontinence is the complaint of
involuntary leakage accompanied by
urgency. Leakage may range from drops to
soaking
 Retention bladder is unable to empty itself
to a point that there is over 100 cc's (3.5
ounces) of urine left over in the bladder
after urinating*

36. Uninhibited bladder
 Lesion affecting the second frontal gyrus
and the pathways leading from it down
to the pontine centre
 Frontal lobe tumours, parasagittal
meningiomas, anterior communicating
artery aneurysms, normal perssure
hydrocephalus, Parkinson’s disease and
multisystem atrophy

37. Uninhibited bladder
Features are:
 Urgency at low bladder volumes
(detrusor hyperreflexia)
 Sudden uncontrollable evacuation
 No residual urine - little risk of infection
 If severe intellectual deterioration occurs
urine may be passed at random, without
appropriate concern.

38. Spinal bladder
 Damage to spinal cord by trauma, tumor, multiple
sclerosis
 Fullness is not appreciated
 Intravesical pressure may only be indicated by
sweating, pallor, flexor spasms, dramatic rise in
blood pressure
 Reflex emptying without warning
 Incomplete evacuation may improve with practice
and may be performed at will if massaged and
suprapubic pressure applied
 Detrusor – sphincter dyssynergia .
 Evidence of bilateral pyramidal lesion – enhanced
reflexes and extensor plantar response
 Bladder is small and contracted, can hold
maximum of 250ml

39. Autonomous bladder(subsacral
lesions)
 Damage to sensory and motor
components in cauda equina or pelvis
 Cauda equina lesions, Pelvic
surgery, pelvic malignant lesions, spina
bifida and high lumbar disc lesions
 MRI or myelogram is obligatory to
exclude high disc lesions

40. Autonomous bladder(subsacral
lesions) contd
Features
 Continual dribbling incontinence
 Considerable residual urine with high
infection risk
 No sensation of bladder fullness- large
atonic bladder
 May be associated with perineal
numbness and loss of sexual function

41. Sensory bladder
 Similar to autonomous bladder
 Anatomical explanation is uncertain
 Primary problem is sensory denervation
 Ultimately overdistension, myogenic
damage and contractile failure
 Rare disorders : Tabes dorsalis, SACD
and Multiple sclerosis, Diabetes mellitus

42. Sensory bladder contd..
Features :
 Massive retention of urine in litres – high
risk of infection
 Dribbling incontinence of sufficiently
large volumes
 Voiding possible with considerable
straining but evacuation is incomplete

43. Motor paralytic
 Areflexic detrusor
Marked by painful distention
Inability to initiate urination
Difficulty initiating
urination, straining, decreased size and
force of stream, interrupted stream, and
recurrent urinary tract infection.

44. Pharmacological methods
 Urinary retention
 Cholinergic agents to increase detrusor
motor function
○ Bathnechol improves detrusor funtion
particularly in denervation and
selectively affects bladder and gut
 Alpha adrenergic blockers such as
prazosin

45.  Urinary incontinence
 Inhibition of detrusor activity and increase
functional capacity of bladder
 Anticholinergics such as propanthaline
 Anticholinergic with smooth muscle
relaxing properties such as oxybutinin
 TCA such as imipramine with
anticholinergic activity

46. Thank u