Pelvic neurological disorders

Question 1

What are the different locations and related disorders

Answer 1

Suprapontine
- stroke
- PD
- tumours
- trauma
- dementias

Spinal (top near brain)
- MS
- Trauma
- tumour

Sacral/ infrasacral (lower/mid sc)
- disc prolapse
- tumour
- pelvic nerve injury
- small fibre neuropathy

Question 2

Types of innervation

Answer 2

Autonomic
- bladder (detrusor, sphincter, urethra)

Somatic

Conus medullaris
- sacral spinal cord

Cauda equina
- sacral roots

Sacral plexus

Peripheral nerve
- pudendal nerve

Question 3

Patients with urogenital symptoms, what is next ?

Answer 3

Patient presenting with unexplained symptoms

• lower urinary tract symptoms e.g. urinary incontinence, retention and voiding difficulties
• sexual symptoms
• bowel symptoms
• sensory symptoms

Once urological causes have been excluded, could there be an underlying neurological cause

Some disorders can present with urogenital symptoms
- Initially
- Predominantly

Question 4

Predominantly pelvic neurological disorders

Answer 4

Brain
- neurodegenerative MSA
- normal pressure hydrocephalus

Spinal cord and clonus
- tumour
- transverse myelitis (e.g MOGAD)
- anteriovenous malformations

Sacral roots (cauda equina)
- lumbosacral canal stenosis - degeneration
- spinal dwarfism
- tumour
- inflammatory (CMV, herpes simplex)

Peripheral nerve
- small fibre neuropathies
- pure autonomic failure

Question 5

History taking for diagnosis

Answer 5

Standard uro-neurology
- neurological and autonomic symptoms

Sensory symptoms - pelvic floor/ organs
- LUT - urethro-vesicle sensations
- lower bowel- ano- rectal sensations
- genital - loss of somatic or erogenous sensations
- pain
- persistent genital arousal

Motor symptoms:
- deterioration of pelvic floor squeeze
- spasms

Drug use and uro-genital dysfunction
- SSRI = sexual dysfunction
- dysfunction may remain after coming off of medication

Question 6

Neurological examinations

Answer 6

Motor examinations

Digital rectal/ internal examination
- small sphincter
- Levator muscles
- tone, strength, endurance, exhaustion, pain

Reflex testing
- bulbocavernous reflex s2-4
(Pinch balls, catheter tug)
- anal reflex s2-5
()

Question 7

Methods of investigation

Answer 7

MRI (pelvic pain)
- lumbosacral spine (axial and sagittal cuts through sacrum)
- lumbosacral plexus
- Pelvis

Other:

• urethral sphincter EMG
• anal sphincter EMG
• Bulbocavernosus reflex

Question 8

Assessment peripheral innervation

Answer 8

Visceral nerves
Indirect assessment: urodynamics

Somatic nerves
(Voluntary bladder, lower bowel + vagina)
Direct assessment : pelvic neurophysiology tests

Question 9

Sacral roots

Answer 9

Pure motor (s4)
- nerves to perenium and levator ani

Mixed (s3/2)
- pudendal nerve (sphincter nerves)

Pure sensory (s3/2/1)
- perforating cutaneous nerve
- posterior femoral cutaneous nerve

Question 10

EMG assessment of pelvic floor muscles

Answer 10

EMG

Superficial:
- Tonically active muscles (anal sphincter, urethral sphincter) (stops incontinence)
- Silent at rest (Bulbocavernosus)

Deep:
- Levator ani (puborectalis) (silent at rest, activated by contraction)

Concentric needle EMG:

Anal sphincter EMG
- evaluate nerve injury affecting the lower spinal cord (sacral cord), sacral S1-5 nerve roots, pudendal nerve
- neurogenic changes of reinnervation/ denervation

Urethral sphincter EMG
- Young women presenting with urinary retention
- abnormal EMG findings - CRDs and decelerating bursts.

Somatosensory evoked potentials (SEPs)
- provide peripheral stimulus, transcutaneous electrical stimulation
- scalp electrodes pick up electrical potentials generated in the cortex

Dermatomal SEPs
- S2/3/4 sensory roots (apply here to get a recording)

Pudendal SEP stimulation parameters
- filter settings, rate of stim and montages
- stimuli strength not more than 3 times the threshold
- usually 10-15 mA sufficient to get good pudendal SEP
- BMI doesn’t interfere with pudendal SEP

Question 11

Pelvic neurophysiology testing types

Answer 11

Sensory pathway:

1. Pudendal SEP
2. Sacral dermatomal SEPs - s2/3/4 roots
3. Dorsal Penile nerve conductions
4. Bulbocavernosus reflex

Motor pathway:

1. Pudendal motor terminal latencies
2. Pelvic floor EMG - sphincter, bulbospongiosus, puborectalis

Autonomic:

1. Perineal sympathetic skin response

Question 13

When to suspect neurological cause in unexplained urogenital complaints

Answer 13

• multipelvic organ involvement
• perineal sensory complaints
• urinary retention
• presence of other neurological symptoms; forgetfulness, dexterity, unsteadiness