The Spastic Sphincter

1. The Spastic Sphincter Hann-Chorng Kuo Department of Urology Buddhist Tzu Chi General Hospital

2. Function of urethral sphincter • Provide adequate urethral resistance at filling phase to prevent incontinence • Active relaxation during voiding phase for micturition • Inhibition of detrusor nucleus to postpone voiding before threshold • Release of inhibitory effect on detrusor nucleus at initiation of voiding (on-off switch)

3. Anatomy of male urethral sphincter

4. Anatomy of FemaleUrethral sphincter

5. Toilet training – A learning process influences voiding • Traditional voiding control by age 3 • CNS plasticity and adaptation to sensory input of micturition process • Retentive behavior of children • Parent pushing of toilet training • Behavioral stress to muscles and change in functional integrity of tissue

6. The overactive sphincter • Incorrect conditioning of voiding reflexes during CNS maturing • Symptoms ranging from incontinence to retention • Chronic LUT dysfunction is maintained by permanently up-regulated sacral reflex arcs • Dysfunctional voiding develops

7. The Pelvic Floor • Deep layer – Levator ani provide relaxation during micturition and defecation (S3,4), contraction to lift pelvic organ upward and compression • Transverse perinealis, ischeocavernous, bulbocavernous, urethral sphincter, anal sphincter muscles (S2) provide squeezing effect on pelvic organs

8. Anatomy of Pelvic Floor

9. Innervation of Pelvic Floor • Perineal skin sensation from S2 nerve • Skin sensation can be impaired unilaterally or bilaterally in S2 nerves • Loss of skin sensation often reflects a loss of urethral sphincter integrity • Deficits in S3,4 nerves are not associated with significant incontinence • Hypersensitivity of bladder is often mirrored hypersensitivity of the levator (S3,4)

10. Neuroregulation of sacral nerves in micturition reflex • Loss of pudendal afferent input can dampen the detrusor reflex • Enhanced afferent input to micturition center can augment detrusor reflex • Supraspinal inhibition or increased inhibitory input to micturition center can suppress detrusor reflex • Chronic anxiety or via behavioral pathway can cause loss of volitional or ability to relax the sphincter with void efforts

11. Pathophysiology of pelvic floor dysfunction • Changes in peptide release from nerve endings secondary to stress (supraspinal) • Enhanced release of inflammatory or neural-sensitizing peptides into tissue (local inflammation) • Inadequate pelvic floor control due to learned behavior (dysfunctional voiding)

12. Detrusor instability and Holding urine during involuntary DI

13. CNS Control of Pelvic floor • Medial part of dorsal pontine tegmentum (M-region) – sphincter relaxation and detrusor contraction • Lateral part of pontine tegmentum – sphincter contraction and detrusor inhibition • Onuf’s nucleus – spinal control center of pelvic floor – linkage to paraventricular nucleus

14. Micturition and Continence center in CNS

15. Central peptide pools linked to CNS centers regulating LUT function

16. Neurobiological background of pelvic floor dysfunction

17. Clinical assessment of a hypertonic pelvic floor • LUT Symptoms – frequency, urgency, suprapubic, perineal, deep pelvic pain, lower backpain, slow stream, intermittency, recurrent UTI, retention • Constipation or difficult defecation • Sexual dysfunction • Insomnia and other somatic complaints

18. Important past history

19. Hypertonic pelvic floor = hypertonic urethral sphincter? • Urethral sphincter and external anal sphincter are mainly innervated by S2 • Levator ani are innervated by S3,4 • Reflex coordination to bladder sensory input is synchronized in most of cases • Isolated denervation or impairment in conduction may occur

20. Hypertonic urethral sphincter Straining to initiate voiding

21. Hypertonic urethral sphincterStraining to open urethra

22. Hypertonic urethra = hyperactive urethra? • Hypertonic urethra indicates increased and sustained urethral pressure (tonic) during resting state • Hyperactive urethra indicates increased activity of urethral sphincter during voiding state • A spastic urethral sphincter causes difficulty in initiation of voiding

23. Hyperactive urethral sphincterduring initiation & voiding

24. SCI with type 1 DESD and low detrusor contractility

25. States of dysfunctional voiding due to spastic sphincter

26. Clinical assessment of pelvic floor muscle function • Uterine prolapse or cystocele • Sensation of perineal skin • Anal tone measurement • Volitional contraction of pelvic floor • Search for inflammatory sources (hemorrhoid, prostatitis, vaginitis) • Focal neurological findings (Bulbocavernous reflex, deep tendon reflex)

27. Digital rectal examination of Pelvic floor muscles • Deep and superficial sphincter muscle tone, weak, high, or normal? • Hypersensitivity or tenderness of the levator or urethral sphincter • Motor identity of sphincter muscles or levator ani muscles • Voluntary repetitive contractions of sphincter and levator muscles

28. Tentative diagnosis of pelvic floor hypertonicity • Spastic urethral sphincter – a chronic hypertonic urethral sphincter causing functional bladder outlet obstruction • Poor relaxation of pelvic floor muscles – inadequate relaxation during voiding causing hesitancy, low intermittent flow • Non-relaxing pelvic floor or urethral sphincter –-- no relaxation during voiding efforts by abdominal straining or Valsalva maneuver

29. Diagnosis based on initial investigations • LUT symptoms • Negative urinalysis or urine culture • High pelvic floor muscle tone • Low maximal flow rate and obstructive intermittent flow pattern • No evidence of BPH or other pathology • Voiding diary verified LUTS

30. VUDS Analysis in 112 Non-obstructive Men with LUTS • Normal bladder & urethra 25 (22.3%) • Hypersensitive bladder 17 (15.2%) • Detrusor instability 6 (4.5%) • Detrusor failure 3 (2.7%) • Poor relaxed external sphincter 61(54.5%)

31. Urodynamics • Uroflowmetry & EMG • Cystometrogram & EMG • Pressure flow study • Videourodynamic study • Urethral pressure profilometry • Pudendal nerve latency time • Evoke potential study

32. Intermittent Flow

33. Relaxation of urethral sphincter at initiation of voiding

34. Poor relaxation of urethral sphincter during voiding

35. Intermittency due to poor relaxation of ES

36. Pseudodyssynergia in CVA causing high voiding pressure

37. Inhibition of detrusor contraction by urethral sphincter during voiding

38. Stop test – volitional sphincter contraction and inhibition of voiding

39. Guarding reflex – during uninhibited detrusor contractions

40. Coordinated sphincter activity during filling phase in Enterocystoplasty

41. Increased sphincter activity causing isolated obstruction in detrusor areflexia

42. DHIC and increased sphincter activity during filling

43. Detrusor overactivity and overactive sphincter & pelvic floor

44. Type I DESD in C5,6 SCI

45. Type II DESD in Thoracic SCI

46. Urethral sphincter v Pelvic floor muscles – analogue?

47. Discoordinated urethral sphincter in dysfunctional voiding

48. Chronic pelvic floor spasticity – A cause of pelvic pain? Increased muscle tone of pelvic floor muscles Spasticity of urethral sphincter Spasticity of external anal sphincter Hypertonicity of pyriformis muscles Fascitis of pubococcygeus or coccygeus muscles Physiotherapy and medication for pelvic floor spasticity can relieve pelvic pain Should search for tendered points or infection

49. Chronic prostatitis syndrome • Symptoms of frequency, urethral irritation, hesitancy, intermittency, residual urine sensation, perineal pain and lower back pain • Spastic urethral sphincter might be a cause of chronic prostatitis or reflux abacterial prostatitis • Treated as spastic sphincter may work

50. Spastic urethral syndrome and constipation • Chronic constipation causes hypertonic anal sphincter and hence, pelvic floor muscles • Poor relaxation of pelvic floor muscles results in inhibition of detrusor contractions during voiding • Concomitant treatment of constipation can relieve voiding symptoms