2LT Medical Student San Juan Bautista School of Medicine US Army Guaynabo, Puerto Rico, United States
Abstract Body : Abstract
Piriformis syndrome is a condition where the piriformis muscle compresses the sciatic nerve, leading to pain, tingling, or numbness in the buttocks which often radiates down the posterior portion of the ipsilateral lower limb. It differs from sciatica, which is often caused by nerve compression at the spine. This case report discusses sciatic nerve and piriformis muscle variation and potential clinical manifestations associated with the like.
Introduction
Anatomical variations of the sciatic nerve can influence the exacerbation of piriformis syndrome. The sciatic nerve runs beneath the piriformis muscle, but variations in its course can make it more susceptible to compression. Anatomical changes to the piriformis muscle itself may also change the clinical presentation in a patient with piriformis syndrome. If the piriformis muscle is different than described as normal as per the American Association for Anatomy, it may more easily compress or irritate the sciatic nerve. These anatomical variations can make certain individuals more predisposed to developing piriformis syndrome.
Discussion
In a female cadaveric specimen (ID: 039-22D) the right sciatic nerve is absent because the tibial and common fibular nerves never connect. The common fibular nerve passes through the two bellies of the piriformis muscle. The inferior gluteal nerve arises from the common fibular nerve which then innervates the gluteus maximus muscles. Further dissection of the specimen demonstrates the piriformis muscle behaves similarly to a biceps-type muscle in that it is divided into two muscle heads- one superficial and one deep muscle head. The superficial head is in a posterior superior position related to the deep head. Both heads are inserted in a common tendon at the greater trochanter area. The tibial nerve passes inferior to the deepest piriformis muscle belly.
Clinical Case Presentation
Due to the anatomical variations found in this specimen, they likely suffered from piriformis syndrome. Compression of the common fibular nerve can cause muscle weakness and pain in the back of the thigh, which may radiate down the ipsilateral leg. In severe cases, compression of the common fibular nerve may cause foot drop, where the individual has difficulty performing dorsiflexion of the foot. Altered sensations, such as peripheral neuropathy also occur.
Conclusion
Piriformis syndrome is a condition characterized by pain, numbness, or tingling in the buttock, hip, or upper leg, resulting from the piriformis muscle compressing the sciatic nerve. It can be caused by anatomical variations in the sciatic nerve or the piriformis muscle. In cases where anatomical variations to the sciatic nerve or the piriformis muscle are present, there is an increased risk of suffering from piriformis syndrome.
