367 - Lumbosacral Plexopathy Secondary to Retroperitoneal Hematoma

Case Diagnosis: Lumbosacral plexopathy is a condition characterized by pain, weakness, and sensory disturbances in the lower back, pelvis, and lower extremities. It is relatively less common compared to brachial plexopathies due to the relatively better protected anatomy of the lower back and pelvis, however it remains of clinical importance due to its impact on an individual patient’s mobility and quality of life. Lumbosacral plexopathies can result from various causes, with retroperitoneal hematoma being a significant, often iatrogenic, factor.

Case Description: We present the case of a 64-year-old Caucasian male with a history of hypertension, hyperlipidemia, tobacco use, and a family history of aortic dissection, who presented to the Emergency Department with severe lower back pain, numbness, and weakness in his right leg. A CTA scan revealed a ruptured infrarenal abdominal aortic aneurysm. He subsequently underwent aorto-uni-iliac stent grafting and femoro-femoral bypass, initially experiencing relief of symptoms in his lower back and right leg, but later developing new numbness and weakness in the left leg. Follow-up imaging showed the left retroperitoneal hematoma resolving. After eight days, he was transferred to in-patient rehabilitation for physical therapy, showing clinical improvement. He was eventually discharged home continuing with outpatient physical therapy. Over three months, he continued to improve, with EMG studies indicating acute, incomplete left upper lumbosacral plexopathy. Repeat electrodiagnostic studies are recommended at eight months post-injury, along with continued home exercises.

Discussions: This case underscores the importance of understanding the complex interactions between vascular issues, anatomical structures, and neurological consequences. It is essential for clinicians to recognize the possibility of nerve injury early. An adequate exam, neurodiagnostic imaging, and nerve conduction studies can help differentiate lumbosacral plexopathies from similar presenting neuropathies and radiculopathies.

Conclusions:
This case illustrates a classic presentation of lumbosacral plexopathy secondary to retroperitoneal hematoma and the resulting functional impairment and potential for long-term neurological complications.