Bilateral compressive lumbosacral plexopathy due to internal iliac artery aneurysms

Sciatica: An Extremely Rare Complication of the Perianal Abscess

Background

Sciatica has been classically described as pain in the back and hip with radiation in the leg along the distribution of the sciatic nerve, secondary to compression or irritation of the sciatic nerve. Spinal abnormality being the most common etiology, is one of the most common indications for MRI of the lumbosacral spine. Here we describe imaging findings secondary to a supralevator perianal abscess causing irritation of the sciatic nerve, which was diagnosed on MRI of the lumbosacral spine.

Case Report

A 47-year-old male patient presented to the emergency department with severe acute pain in the right hip and right leg which was aggravated by limb movement. Clinically, a possibility of sciatica was suggested and MRI of the lumbosacral spine was ordered. The MRI did not reveal any abnormality in the lumbosacral spine; however, on STIR coronal images, a right perianal abscess with air pockets was seen. The perianal abscess was extending above the levator ani muscle with and was seen tracking along the sciatic nerve, explaining pain along the distribution of the sciatic nerve. The abscess was surgically drained, followed by an antibiotic course. The patient was symptomatically better post-surgery. Post-operative scan done 3 days later revealed significant resolution of the infra- and supralevator perianal abscess. The patient was discharged from hospital on post-operative day 3 on oral antibiotics for 7 days. On 15^th post-operative day, the patient was clinically completely asymptomatic with good healing of the perianal surgical wound.

Conclusions

Extra-spinal causes are rare and most often overlooked in patients with sciatica. While assessing patients with sciatica, extra-spinal causes for the radiation of pain along the distribution of the sciatic nerve should always be looked for if abnormalities in the MRI of the lumbar spine are not found. Inclusion of STIR sequences in the imaging of the lumbosacral spine, more often than not, helps to identify the extra-spinal cause of sciatica when MRI of the lumbosacral spine does not reveal any abnormality.

An unusual case of acute foot drop caused by a pseudoaneurysm

Lower extremity neurologic symptoms are a common presenting problem. Here we report the case of a 73-year-old man who developed acute right foot pain and foot drop. History, physical examination, and electrodiagnostic studies were consistent with a lumbosacral plexopathy. Imaging studies revealed an internal iliac artery pseudoaneurysm, a rare cause of acute foot drop.

CT and MRI in the evaluation of extraspinal sciatica

Sciatica is the most frequently encountered symptom in neurosurgical practice and is observed in 40% of adults at some point in their lives. It is described as pain of the hip and the lower extremity secondary to pathologies affecting the sciatic nerve within its intraspinal or extraspinal course. The most frequent cause is a herniating lumbar disc pressing on the neural roots. Extraspinal causes of sciatic pain are usually overlooked because they are extremely rare and due to intraspinal causes (lumbar spinal stenosis, facet joint osteoarthritis, fracture, and tumors of the spinal cord and spinal column) being the main consideration. Early diagnosis of sciatica significantly improves the likelihood of relieving symptoms, as well as avoiding any additional neurologic injury and unnecessary surgery. We evaluate histolopathologically confirmed extraspinal causes of sciatica cases, accompanied by their presented computed tomography and/or magnetic resonance imaging findings.

Aneurisma de artéria ilíaca interna roto: relato de caso

Aneurismas isolados da artéria ilíaca interna são raros, acometem 0,1% da população e correspondem a 1% dos aneurismas aorto-ilíacos. Na maioria das vezes, os pacientes são assintomáticos, mas podem apresentar dor abdominal, massa pulsátil no hipogástrio ou na fossa ilíaca, sintomas compressivos urinários, gastrointestinais ou neurológicos. Podem ocasionar quadro de abdome agudo, principalmente quando há ruptura. O diagnóstico precoce dos aneurismas isolados de artéria ilíaca interna é incomum, sendo identificados quando mais volumosos ou rotos, o que aumenta significativamente sua morbimortalidade e torna seu prognóstico mais reservado. Dessa forma, representam um desafio terapêutico. A ligadura cirúrgica tem sido o tratamento mais comum, entretanto a cirurgia endovascular tem mostrado bons resultados, inclusive nos aneurismas rotos. É relatado caso de aneurisma de artéria ilíaca interna isolado roto diagnosticado durante laparotomia para abordagem de abdome agudo.

Aneurysm of the common iliac artery presenting as a lumbosacral plexopathy

We describe a case of lumbosacral plexopathy caused by an isolated aneurysm of the common iliac artery. The patient presented with worsening low back pain, progressive numbness and weakness of the right leg in the L2-L4 distribution. This had previously been diagnosed as sciatica. A CT scan showed an aneurysm of the right common iliac artery which measured 8 cm in diameter. Despite being listed for emergency endovascular stenting, the aneurysm ruptured and the patient died.

It is important to distinguish a lumbosacral plexopathy from sciatica and to bear in mind its treatable causes which include aneurysms of the common and internal iliac arteries.