NEUROGENIC BLADDER.pptx

basic physiology

1. NEUROGENIC BLADDER Dr B Vinod Mch Neurosurgery Resident Gandhi medical college Hyderabad

2. INTRODUCTION Micturition is a process in which neural circuits in brain and spinal cord coordinate the activity of smooth muscles in bladder and urethra for storage and evacuation of urine. Healthy adult Bladder capacity about 500 ml , Micturition frequency 4 hours , Act of voiding 3 mins, Maximum time bladder is in storage mode

3. Functions and dysfunctions of bladder are discussed in following sections Neural control of micturition Types of neurogenic bladder Approach to lower urinary tract symptoms.

4. Functional unit of bladder Body Base External urethral sphincter.

5. I.NEURAL CONTROL OF MICTURATION Bladder receptors Motor innervation of bladder Bladder sensation Storage Voiding Periaqueductal grey-the switch Voluntary control of micturition.

6. Receptors 5 types efferent receptors Beta 3 adrenergic –Body Alpha 1adrenergic –base Muscarinic M3 -body and base P2X1 purinergic –body and base Nicotinic –external sphincter Storage of urine- by sympathetic system ( adrenergic) Voiding –Parasympathetic system ( Ach,ATP , Nicotinic, NO2)

7. MOTOR INNERVATION 3 sets of peripheral nerves Parasympathetic –Pelvic nerve (S3,4,5) Sympathetic - Mesentric &Pelvic nerve ( T11 –L2) Somatic - Pudendal nerve( S2,3,4)

8. BLADDER SENSATION Senstions are conveyed to spinal cord by hypogastric , pelvic and pudendal nerves. Afferent nerve components includes( . ( pelvic S2,3,4. Hypogastric T11-L2) Myelinated A-Delta (passive distention sensation) –conveys bladder filling sensation. Unmyelinated C fibres –generally insensitive to bladder sensation but responds to noxious stimulus ( irritation) Fibres terminates in spinal cord laminae I,V,VII , which project to periaqueductal grey ,then to sensory cortex. Bladder sensation are in series of First sense of filling First desire to void Strong desire to void Urgency

9. STORAGE OF URINE Storage centre at spinal cord level ( GUARDING REFLEX) Pontine continence centre ( storage centre ) which stimulates Onufs nucleus ,leads to contraction of EUS and pelvic musculature .

10. VOIDING OF URINE Voiding centre -brainstem ( spino -bulbar reflex) Two areas include mesencephalic periaqueductal grey & pontine micturition centre (M region)

11. PERIAQUEDUCTAL GREY-THE SWITCH The lateral & dorsal parts receives sensory from bladder, projects to pontine micturition centre . It also sends signal to higher centre ,receives inputs from & controls the primary input to pontine micturition centre . During bladder filling, higher centre (prefrontal cortex) can suppress the excitatory signal to pontine micturition centre ,thus preventing voiding. When voiding is desired it sends excitatory signals to pontine micturition centre .

12. Voluntary and higher control of micturation Centres include medial forebrain cortex, posterior cingulate cortex, parahippocampal complex. These areas maintains continence during storage and to enable voiding. During storage : when bladder sensations are low , it suppresses the activity of periaqueductal grey. During voiding : when patient has strong desire to void, it removes suppression on periaqueductal grey. Signals transmitted by bladder afferents create a desire to void,but the decision to void or to postpone voiding depends on the forebrain processing of the information like Enough urine in bladder In the right place and right time (socially appropriate)

13. II.TYPES OF NEUROGENIC BLADDER Un-inhibited neurogenic bladder Reflex neurogenic bladder(automatic bladder) Autonomous bladder Motor paralytic bladder Sensory bladder.

14. UN-INHIBITED BLADDER Lesion :above ponto -mesencephalic centre . Here cortical tonic inhibition of ponto -mesencephalic centre is lost. Results in hyperreflexic bladder which initiates contractions when the afferent inputs to periaqueductal grey area. Uninhibited bladder contracts and empties quickly and frequently. Coordination between the detrusor and the sphincter is maintained. Bladder emptying is complete and no residual urine. Affected individuals have urge incontinence.

15. REFLEX (AUTOMATIC) BLADDER Lesion: suprasacral cord lesions that disrupts bulbo -spinal reflex pathway. Disconnection of sacral cord from brainstem centre results in reflex detrusor , a sacral spinal reflex emerges that drives reflex bladder contractions. This local reflex is mediated by capsaicin-sensitive C fiber afferents . This reflex causes detrusor hyperreflexia and reflex detrusor contractions .

16. Pontine centre is needed for coordinated action between detrusor and spincter also for complete evacuation of urine. In cord lesions, here coordination is poor ,resulting in detrusor sphincter dyssynergia also incomplete emptying and residual urine..

17. AUTONOMOUS BLADDER Lesion : B/L destruction of S3,4,5 spinal cord segments, S3,4,5 pelvic nerves ,results in motor and sensory denervation of bladder. Here detrusor and sphincter both are hypoactive and sensations are lost. There is bladder filling without emptying. When pressure inside bladder exceeds sphincter then patient will experience overflow incontinence.

18. MOTOR PARALYTIC BLADDER Detrussor is de- efferented . Sensory and central pathway are intact. Detrusor and sphincter are hypoactive, results in retention of urine, but bladder sensations are normal.

19. SENSORY NEUROGENIC BLADDER Lesion : detrusor is deafferented from cord or the afferent tracts to brain Patient is unaware of bladder sensation, bladder gets distended without triggering a reflex contraction,results in retention of urine. Results in overflow incontinence.

20. UNINHIBITED REFLEX AUTONOMOUS MOTOR SENSORY Site of lesion Above ponto -mesencephalic centre Suprasacral spinal cord Sacral cord/S3,4,5 roots/pelvic nerves. Motor supply to bladder Sensory pathway to bladder Bladder Hyper-reflexive Hyper-reflexive Hypo- reflexic Hypo- reflexic Normal contractability Detrusor-Sphincter synergy synergy Dysynergic Hypo- reflexic Hypo- reflexic Normal Residual urine absent present Large volume Present Present Urge present present absent Present Absent Symptoms urgency hesitency Overflow incontinence Overflow incontinence Overflow Incontinence Frequency increased increased Very frequent Very frequent Very frequent Urine volume/evacuation less less less less less Bladder volume normal small large large Large Urine stream normal poor poor poor Poor

21. URODYNAMIC CLASSIFICATION OF BLADDER DYSFUNCTION Urodynamics are a means of evaluating the pressure –flow relationship between bladder and urethra. Types of urodynamic dysfunction seen in neurogenic bladder. Hyperreflexic detrusor Hyporeflexic detrusor Hyperreflexic sphincter Hyporeflexic sphincter

22. Madersbacher urodynamic classification Based on functional status of detrusor and sphincter : Detrusor hyperreflexia with hyperreflexive sphincter Detrusor hyporeflexia with hyporeflexic sphincter Detrusor hyporeflexia with hypereflexic sphincter(mixed type A neurogenic bladder) Detrusor hyperreflexia with hyporeflexic sphincter(mixed type B bladder)

23. Detrusor hyperreflexia with hyperreflexive sphincter Characteristic of uninhibited and reflex bladder Due to detrusor sphincter dyssynergia (both contract synchronously) Uninhibtted bladder has a hyperreflexic and coordinated detrusor ,sphincter Reflex bladder has hyperreflexic detrusor and sphincter with detrusor sphincter dyssynergia.

24. Detrusor hyporeflexia with hyporeflexic sphincter Seen in autonomous bladder in conus cauda lesions.

25. Detrusor hyporeflexia with hypereflexic sphincter(mixed type A neurogenic bladder) Damage of detrusor nucleus renders detrusor flaccid, while the intact pudendal nucleus produces a hypertonic external urinary sphincter. Spastic sphincter produces retention .

26. Detrusor hyperreflexia with hyporeflexic sphincter(mixed type B bladder) Characterized by flaccid external sphincter due to pudendal nucleus lesion while bladder is spastic due to disinhibited detrusor nucleus. Leads to continuous dribbling of urine incontinence. Most common seen in tethered cord syndrome which exerts traction over the lumbosacral cord.

27. III.LOWER URINARY TRACT SYMPTOMS Classified as Storage Voiding Post- micturation

28. Storage symptoms : Incontinence Urgency Nocturia Voiding symptoms Hesitency Straining to void Intermittency Slow stream Splitting /splaying Terminal dribble. Post-micturition symptoms Feeling of incomplete smptying Post micturition dribble

29. INCONTINENCE Defined as involuntary leakage of urine due to detrusor hyperreflexia or sphincter hyporeflexia. Types of incontinence

30. Urge incontinence It is an inability to suppress the urge to delay the voiding at an appropriate place and time. Usual site of lesions include: Forebrain lesions Pontine continence centre Supra sacral cord lesions sparing senstions Local bladder diseases.

31. Forebrain lesions ,especially medial frontal lesions ,remove the tonic inhibitory control over periaqueductal grey and pontine centre producing uninhibited bladder with detrusor over activity. Pontine lesions will result in inhibitory at sphincter and urine is expelled. Bulbospinal reflex pathway involvement in cord lesions with preserved sensations. Local bladder conditions like cystitis.

32. INCONTINENCE WITHOUT URGE Bladder evacuation without sensation. Five types Social incontinence Reflex incontinence Overflow incontinence Dribbling incontinence Stress incontinence

33. Social: In forebrain lesions results in evacuation of large volume urine in socially inappropriate places , mimics bladder evacuation of an infants. Reflex: In supraspinal lesions with ascending and descending fibres involved (UMN) ,local reflex contractions produces sudden onset small volume,short interval leakage without urge. Overflow: S3,4,5 segments/roots . Dribbling : mixed type B bladder ,( MMC and tethered cord ) Stress : leakage of urine with excertion , sneezing,coughing etc . It indicates weakness of external sphincter and usually seen in multiparous women.

34. URGENCY Sudden compelling desire to pass urine which is difficult to defer. Seen in uninhibited bladder in lesion above ponto -mesencephalic lesions.

35. NOCTURNAL ENURESIS Nocturnal continence is due to Normal bladder compliance Closed outlet Decreased urine production at night Nocturnal enuresis is any unintended voiding during night time sleep.

36. VOIDING SYMPTOMS Retention , hesitancy, straining of voiding and poor stream are common voiding symptoms. Voiding symptoms are manifestations of bladder hyporeflexia or sphincter hyperreflexia. Seen in spinal cord lesions and obstructive urological diseases. Hesitency :is difficulty in initiating micturition resulting in delay in the onset of voiding after individual is ready to pass urine is due to, Poor central drive from pontine micturition centre on detrusor (Bulbospinal pathway involved) Detrusor hyporeflexia (Motor bladder) Sphincter hyperreflexia. Straining to void :The muscular effort used to either initiate ,maintain or improve the urinary stream.

37. POST MICTURATION DRIBBLE Involuntary loss of urine immediately after individual finishes passing urine, usually after leaving the toilet in males or after raising from toilet in females. Cause :weakness of pelvic floor muscles.