title: Spontaneous migration of a redundant nerve root accompanied by absorption of lumbar disk herniation. A case report.
abstract: A redundant nerve root is defined as a large, elongated and tortuous nerve root commonly associated with severe lumbar spinal canal stenosis. Elongation of nerve roots as a result of mechanical trapping at stenotic level is assumed to be a possible mechanism. Here we present a case in a patient who showed a redundant nerve root above the level of a lumbar canal stenosis caused by disk herniation and redundancy spontaneously migrating to a lower lumbar stenosis level accompanied by absorption of the herniated disk as shown by magnetic resonance imaging (MRI). A 67-year-old Japanese woman presented with bilateral thigh/leg pain and intermittent claudication. A midsagittal T2-weighted MR image of the lumbar spine revealed severe spinal canal stenosis at the L3-4 and L4-5 levels. At the L3-4 level, central disk herniation compressed the dural tube. An MR image revealed redundant nerve roots just cranial to the severely compressed L3-4 level. A follow-up MRI study revealed regression of disk herniation at the L3-4 level. In contrast, there was no significant change of the stenosis at the L4-5 level. Sagittal T2-weighted MR imaging at follow-up revealed redundant nerve roots just cranial to the L4-5 level, whereas the redundant nerve roots cranial to the L3-4 level had disappeared. The MRI findings of the present case support the "squeeze" hypothesis as causative of redundant nerve roots.
authors.affiliation: Department of Orthopedic Surgery, Chiba Aoba Municipal Hospital; Chiba, Japan - masaokod@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Koda
authors.forename: T
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authors.lastname: Rokkaku
authors.forename: C
authors.initials: C
authors.lastname: Mannoji
authors.forename: Y
authors.initials: Y
authors.lastname: Okamoto
authors.forename: T
authors.initials: T
authors.lastname: Kon
authors.forename: M
authors.initials: M
authors.lastname: Murakami
authors.forename: T
authors.initials: T
authors.lastname: Furuya
authors.forename: M
authors.initials: M
authors.lastname: Yamazaki