Surgical Experience in Cases of L5 and S1 Symptoms Caused by Upper Lumbar Spinal Stenosis of L2–L3 and L3–L4

Abstract

Object: Previous reports have indicated that the level of lumbar spinal canal stenosis (LSCS) often differs from that diagnosed from neurological symptoms, and L5 nerve roots are often affected by stenosis at the L2–L3 or L3–L4 level; however, few cases have been described. Decompression surgery for upper lumbar spinal canal stenosis (LSCS) of L2–L3 and L3–L4 causing L5 and S1 symptoms was investigated. Methods: Eight patients with a diagnosis based on L5 or S1 symptoms, but whose MRI or CT-myelography showed only one level of stenosis at L2–L3 or L3–L4 were studied. The level of stenosis was determined by the most narrowing lesion, such as total or subtotal block on CT-myelography and MRI. Selective nerve root block was performed to determine which nerve root was the origin of the pain in these patients. One-level decompression surgery at L2–L3 or L3–L4 was performed in 8 patients. Results: There were 2 cases of stenosis at L2–L3 and 6 cases at L3–L4. The level involved suggested by neurological symptoms was L5 in 6 cases and S1 in 2 cases. L5 symptoms were most often affected by L3–L4. Symptoms in all patients disappeared after one-level decompression surgery. Conclusions: Degenerative stenosis of upper levels such as L2–3 and L3–4 involved damage in lower nerve roots such as L5 or S1, and L5 symptoms were most often affected by L3–L4. Decompression surgery for upperlevel stenosis improved symptoms in all patients. Physicians should be aware that upper-level stenosis can cause radiculopathy at a lower level.