Post-traumatic priapism is a myth…
Specifically I looked into priapism after trauma. I always thought priapism after spinal cord injury was a myth. On every course in trauma management I attended lately, there is always a comedian with a carrot in his trousers that is supposed to emulate priapism which, in turn, always seems to be pathognomic of complete spinal cord transection. I always thought that was a bit silly as I, during my ten years of being exposed to trauma patients, have never seen a single case of priapism.
Granted, I mostly work in remote arctic fishing towns. Reindeer (and even more so, fish) are more common than young male accident-prone adults. After asking around, I found that none of my colleagues have seen priapism after spinal injury, but all of them seem to have heard of other colleagues who had seen it. Right. Hence, I came to the conclusion it was all a myth. Just like the anecdotal alcoholic in the waiting room who never got a c-spine collar and then woke up a tetraplegic.
Not a myth after all…
Not so. A year ago I saw my first case of post-traumatic priapism. A young man was admitted to our ED after having an motor vehicle accident. He was found lying on the side of the road, complaining of back pain, was generally bruised and … had a pathetic ,flappy, persisting priapism.
Unlike in the training scenarios, our patient could move all his limbs so his spine wasn´t completely transected. On the CT he had stable thoracic and lumbar fractures. Interestingly, the MRI came out blank. There were no signs of any spinal cord injury or spinal swelling whatsoever. The patient had no other penile nor pelvic injuries that could explain his priapism.
Eventually, our patient made a full recovery without any neurological deficits. The priapism spontaneously resolved after five or six hours. As no other explanation was found, his priapism was attributed to a transient spinal shock.
So, post-traumatic priapism exists after all, but it doesn´t always mean severe spinal injury.
Very brief literature review
Priapism, in itself, is a reasonably common presentation in a variety of diseases. It can be divided into ischaemic- or non-ischaemic types. Ischaemic, ´low flow priapism´can be thought of as a compartment syndrome were blood flow out of the penis is obstructed. It is commonly caused by drugs, haematological disorders like leukaemia, sickle cell anemia or pelvic malignancies causing outflow obstructions. If you sample blood from the corpora it will turn out venous on blood gasses and on appearance. Typically the erection is firm and painful to the touch.
´High flow priapism´is a lot more uncommon. This time, priapism is caused by uncontrolled blood flow into the penis. The erection is commonly painless and sample blood will be arterial on appearance and on blood gas. Unlike the ischaemic type, ´high flow priapism´is mostly caused by injury to the perineum or spinal cord.
The Literature on priapism after spinal cord injury is very restricted, almost non-existent. I could find only 12 cases detailed in three papers. 9 of those patients had complete spinal cord transection while the remaining three had only partial lesions. The priapism in these case is attributed to loss of sympathetic input to the pelvic vasculature resulting in uncontrolled arterial inflow into the penile synods. That sympathetic outflow arises from the lowest levels of the spinal cord so any lesion, from the brainstem to the conus, can result in post-trauamtic priapism. Also, several authors mention transient priapism secondary to spinal shock but for obvious reasons there are no case reports or data as far as I can tell.
On the other hand there are numerous, hundreds, of papers describing priapism secondary to pelvic or penile injury. Most commonly high flow priapism is caused by rupturing the cavernous artery or one of it´s branches. Some reviewers also suggest trauma to pelvic or penile arteries can cause dysregulation of their blood flow resulting in priapism.
Priapism is a rare consequence of trauma.
If you see it, it is more likely to be caused by pelvic or penile injury.
Spinal cord injury can cause priapism, but judging by the literature it is incredibly rare.
Priapism does´t necessarily mean significant spinal cord injury.
Transient priapism can be caused by transient spinal shock.
The only review I could about priapism in spinal cord injury…..
Management of recurrent priapism in a cervical spinal cord injury patient with oral baclofen therapy. Vaidyanathan S, Watt JW, Singh G, Hughes PL, Selmi F, Oo T, Soni BM, Sett P. Spinal Cord. 2004 Feb;42(2):134-5
Arch Phys Med Rehabil. 1998 May;79(5):494-6. Side effects of chronic intrathecal baclofen on erection and ejaculation in patients with spinal cord lesions. Denys P1, Mane M, Azouvi P, Chartier-Kastler E, Thiebaut JB, Bussel B.
This one isn´t available to me but it sounds exciting. Priapism is reported in association with judicial hangings…