Lumbosciatalgia Due to Pyramidal Syndrome

Piriformis syndrome is a poorly known cause of sciatica and there are few cases reported in the international literature where sciatica is the form of presentation. It is caused by compression or entrapment of the sciatic nerve due to piriformis muscle pathology. A 65-year-old Caucasian man was admitted in Department of Neurology because he suffered from sciatica and weakness of the left lower limb, so initially a disc herniation was suspected. Upon physical examination, he presented marked gluteal muscle atrophy, mild quadriceps muscle atrophy and paresis of the left lower extremity with distal dominance. Electroneuromyography provided evidence of left sciatic nerve injury of severe intensity and profuse signs of active denervation present. MRI lumbar plexus revealed asymmetrical enlargement of the left piriformis muscle that obliterated the ipsilateral greater sciatic foramen, compressing the left sciatic nerve. As a result, secondary atrophy of the gluteus maximus and medius can be observed on this side. Due to the severity of the symptoms, surgery was performed to release the nerve. Piriformis syndrome rarely occurs as sciatica. The diagnosis is usually delayed because of the absence of further pathognomic testing and established diagnostic criteria, which are based on clinical manifestations. This syndrome is often confused with lumbar-sacral or hip disease. So, in a disease such as the case presented, the piriformis syndrome should be considered. We think that it is very interesting to know that a piriformis syndrome can debut as a lumbosciatalgia and it can be confused with lumbar disc pathology, so this may delay the diagnosis and cause further suffering to the patient. J Med Cases. 2016;7(6):248-251 doi: http://dx.doi.org/10.14740/jmc2503w