Clinical significance of the redundant nerve roots of the cauda equina documented on magnetic resonance imaging.
OBJECTIVE
Previous reports of redundant nerve roots (RNRs) of the cauda equina have been limited to evaluations based on myelography. Neither the imaging nor the clinical features of RNRs in relation to magnetic resonance (MR) imaging have been elaborated. The MR imaging characteristics of RNRs were evaluated using the Japanese Orthopaedic Association score before and after the surgery.


METHODS
There were 44 patients with L4-5 spondylolisthesis in which a complete blockage was demonstrated on myelography. All patients underwent posterior L4-5 interbody fusion. Based the myelographic and MR imaging findings, the patients were stratified into the following three groups: RNRs recognized on both myelographic and MR imaging (Group A); RNRs recognized on myelography but not very evident on MR imaging (Group B); and RNRs not recognized on either myelographic or MR imaging (Group C). Among these three groups, pre- and postoperative clinical symptoms were compared.


RESULTS
There were 16 patients in Group A, 14 in Group B, and 14 in Group C. In terms of preoperative clinical symptoms, there was a significant difference between Groups A and C in the incidence of leg pain and tingling sensation. Significant differences were also noted between Groups A and C and between Groups B and C in ambulatory ability. Evaluation of postoperative clinical symptoms showed a significant difference between Groups A and C in ambulatory ability.


CONCLUSIONS
Patients with MR imaging evidence of RNRs presented with more severe clinical symptoms. It is believed that the RNR features derived from MR images represent important findings.
Ono
Atsushi
A
Department of Orthopaedic Surgery, Hirosaki University School of Medicine, Japan. atsu-ono@cc.hirosaki-u.ac.jp
Suetsuna
Futoshi
F
Irie
Tomoyuki
T
Yokoyama
Toru
T
Numasawa
Takuya
T
Wada
Kanichiro
K
Toh
Satoshi
S
D000368:Aged; D002420:Cauda Equina; D000013:Congenital Abnormalities / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006801:Humans; D007866:Leg; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009192:Myelography; D010146:Pain / Q000209:etiology; D011184:Postoperative Period; D012678:Sensation Disorders / Q000209:etiology; D012720:Severity of Illness Index; D013123:Spinal Fusion; D013126:Spinal Nerve Roots / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology*; D013168:Spondylolisthesis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D016138:Walking