Lower back pain. The back pain of
cauda equina syndrome is usually more
severe than that which would be
expected of compression of a single
nerve root. The back pain is often
worsened by lying flat on the back, as
this increases local pressure on the
involved nerve roots. Pain is common
with most compressive causes of cauda
equina syndrome. Noncompressive (eg,
infiltrative) lesions may be less likely to
produce pain as an early symptom.9
Bladder dysfunction. Bladder dysfunction
is one of the characteristic
clinical features of cauda equina syndrome.
Symptoms of bladder dysfunction
include urinary retention, urinary
incontinence, and a decrease in urethral
sensation during urination. Urinary retention
usually precedes frank incontinence,
although incontinence might be
noticed first because it is much more
alarming.5 Rarely, urinary retention
without back pain or sciatica may be
the sole presenting feature of cauda
equina syndrome.10
Bowel dysfunction. Fecal retention
and incontinence are less common than
urinary symptoms, likely because urination
occurs more frequently than defecation
and, therefore, symptoms are
not immediately noticed.11 In cases of
severe compression, ‘‘double incontinence’’
of both bowel and bladder may
develop rapidly.
Sexual dysfunction. Possible symptoms
of sexual dysfunction in cauda
equina syndrome include erectile dysfunction,
urination during intercourse,
and dyspareunia. Patients are often
reluctant to report these symptoms
and, therefore, specifically inquiring
about them is important.