Question
A 19-year-old man is brought to the emergency department following a high-speed motor vehicle collision in which he was a restrained passenger. He complains of pelvic pain and involuntary loss of urine, with constant dribbling. Examination shows perineal bruising and there is pain with manual compression of the pelvis. Pelvic ultrasound shows a normal bladder. Injury to which of the following structures is most likely responsible for this patient’s urinary incontinence?
| A. |
Genitofemoral nerve
|
| B. |
Superior gluteal nerve
|
| C. |
Pelvic splanchnic nerves
|
| D. |
Obturator nerve
|
Show Answer
[ads id=”53026″]
|
Correct Answer � C
Explanation
|
|
Answer C) Pelvic splanchnic nerves
Pelvic splanchnic nerves
-
Pelvic splanchnic nerves originate from the sacral nerve roots S2–S4 and provide parasympathetic innervation to the rectum, erectile tissue, and detrusor muscle of the bladder.
-
Injury to these nerves (e.g., due to pelvic trauma, as seen in this patient) causes decreased activity of the detrusor muscle, which results in impaired bladder contractility (atonic bladder), overdistention, and decreased sensation of bladder fullness.
The resulting overflow incontinence typically manifests with involuntary loss of urine in the form of constant dribbling.
Genitofemoral nerve
-
Genitofemoral nerve injury can occur as a complication of laparoscopic surgery (e.g., hernia repair) or compression (e.g., psoas abscess). Injury to this nerve would cause sensory loss in the scrotal skin and the upper and anterior medial thigh, as well as a decreased cremasteric reflex.
-
Urinary incontinence would not be expected.
Superior gluteal nerve
-
The superior gluteal nerve innervates the gluteus medius and minimus muscles, which are responsible for abduction of the hip.
-
Injury to this nerve would result in a positive Trendelenburg sign but would not cause urinary incontinence.
Obturator nerve
-
Obturator nerve injury can also occur with pelvic trauma. Injury to this nerve would cause paralysis of the hip adductors and sensory loss in the medial thigh.
-
Urinary incontinence would not be expected.
Like this:
Like Loading...
