Favorable response to intrathecal, but not oral, baclofen of priapism in a patient with spinal cord injury

Spine (Phila Pa 1976). 2009 Feb 1;34(3):E127-9. doi: 10.1097/BRS.0b013e31818d04ff.

Abstract

Study design: Case report.

Objective: To retrieve data about the utility of intrathecal baclofen for the treatment of otherwise refractory priapism that may occur in patients with spinal spasticity.

Summary of background: Baclofen exerts well-known inhibitory effects on sexual function both in animals and humans. This observation led to the introduction of oral baclofen in the treatment of refractory and recurrent idiopathic priapism.

Methods: We report a 41-year-old male patient who sustained a severe traumatic spinal cord injury in a motor vehicle accident. On clinical examination he presented with tetraplegia (motor level C3). Initial cervical magnetic resonance imaging showed a C3 to C4 lesion with a herniated disc and compression of the dural sac. One month later the patient developed priapism episodes.

Results: He received oral baclofen with only minimal beneficial effect on priapism. Eight months postinjury the patient underwent a test-trial with intrathecal baclofen bolus, which caused absence of priapism for 10 hours. One month later, an intrathecal pump system was implanted, leading to absence of priapism episodes.

Conclusion: In the present case report, reduction of supraspinal control on the spinal cord may have induced an up-regulation of GABAB receptors, which are involved in penile tumescence. The trauma induced also liberation of penile reflexes with episodes of priapism. Normal full blood count and color duplex ultrasonography of the penis excluded a vascular genesis of priapism. This is the first report about the utility of intrathecal baclofen for the successful control of otherwise untreatable priapism in a patient with severe spinal spasticity. Hence, evaluation of intrathecal baclofen should be considered in patients suffering from severe and/or frequent priapism when oral baclofen and/or hormonal therapy are ineffective. The beneficial effect of intrathecal, but not oral baclofen, in our patient suggests a dose-dependent effect.

Publication types

  • Case Reports

MeSH terms

  • Administration, Oral
  • Adult
  • Baclofen / administration & dosage*
  • Brain / physiology
  • Cervical Vertebrae / injuries
  • Cervical Vertebrae / pathology
  • Dose-Response Relationship, Drug
  • Efferent Pathways / drug effects
  • Efferent Pathways / injuries
  • Efferent Pathways / physiopathology
  • GABA Agonists / administration & dosage*
  • GABA-B Receptor Agonists*
  • Humans
  • Injections, Spinal
  • Intervertebral Disc Displacement / etiology
  • Intervertebral Disc Displacement / pathology
  • Intervertebral Disc Displacement / physiopathology
  • Male
  • Penile Erection / drug effects
  • Penile Erection / physiology
  • Priapism / drug therapy*
  • Priapism / etiology*
  • Priapism / physiopathology
  • Receptors, GABA-B / metabolism
  • Secondary Prevention
  • Spinal Cord / drug effects*
  • Spinal Cord / metabolism
  • Spinal Cord / physiopathology
  • Spinal Cord Compression / complications
  • Spinal Cord Compression / physiopathology
  • Spinal Cord Injuries / complications*
  • Spinal Cord Injuries / physiopathology
  • Treatment Outcome

Substances

  • GABA Agonists
  • GABA-B Receptor Agonists
  • Receptors, GABA-B
  • Baclofen