Bilateral eventration of sciatic nerve

Area of Science:

• Anatomy
• Neuroscience

Background:

• The sciatic nerve (SN) is the largest nerve in the human body, originating from the sacral plexus.
• Variations in the SN's anatomical course can lead to neurological symptoms and surgical complications.

Observation:

• During dissection, the two divisions of the sciatic nerve were found to be separate in the gluteal region bilaterally.
• The tibial nerve (TN) passed inferior to the piriformis muscle, while the common peroneal nerve (CPN) pierced it.

Findings:

• The study identified an anomalous passage of the sciatic nerve divisions through or below the piriformis muscle.
• This anatomical variation potentially predisposes nerves to compression, leading to conditions like piriformis syndrome.

Implications:

• Knowledge of these sciatic nerve variations is vital for surgeons managing piriformis syndrome, a common cause of leg pain.
• Abnormal SN pathways may also explain the high failure rate of popliteal nerve blocks.