cauda equina syndrome

Question 1

what is the most common cause of cauda equina syndrome

Answer 1

lumbar disc herniation at L4/5 and L5/S1

which causes compression of the lumbosacral nerve roots in the distal dural sac (beyond L1)

Question 2

what is it

Answer 2

compression of the cauda equina (the nerve roots which extend beyond the termination of the spinal cord at level L1)

Question 3

what are other causes of cauda equina syndrome

Answer 3

neoplasms
abscesses
iatrogenic (spinal anaesthesia)

Question 4

what are the clinical features of cauda equina

Answer 4

lower back pain - with alternating or bilateral radicular pain and saddle anaesthesia (cannot feel toilet paper when wiping)

bladder and bowel disturbance - constipation/retention/incontinence

Question 5

management of cauda equina

Answer 5

for spinal compression:
urgent whole spine MRI - lumbar and sacral
surgically decompress within 48 hours

for malignancy:
administer dexamethasone 16mg daily + PPI

Question 6

A 72 year old man presents with acute back pain, bilateral leg weakness and lower abdominal pain. Examination reveals flaccid paralysis of both legs, with a sensory level of L3 on both sides of the midline. Abdominal palpation reveals a grossly distended bladder with no other organomegaly or lymphadenopathy. MRI scan of his spine shows an L3 vertebral body fracture with compression of the cauda equina. The radiologist comments that the L3 vertebral body, as well as several other vertebral bodies have sclerotic areas within them. What is the underlying diagnosis?

Answer 6

metastatic prostate cancer

prostate cancer frequently metastasises to bone and causes sclerotic lesions

Question 7

what nerve roots are responsible for dorsiflexion of the foot

Answer 7

L4/5