Unexpected Right-Sided Nerve Root Variant During L4–L5 Microdiscectomy and Decompression: A Case Report Highlighting Diagnostic and Intraoperative Challenges

Abukar Abdi Nor,1,2 Abdiweli Mohamed Abdi,1,3 Nur Abdullahi Karshe,4 Dayib Hussein Mohamed,1,5 Ayub Omar Adam,4 Mohamed Ismael Iman,1 Nor Haji Osman,1,3 Osman Mohamed Mohamud,6 Abdirahman Mohamed Jimale31Department of Medicine, Faculty of Medicine and Surgery, Al Hayat Medical University, Mogadishu, Somalia; 2Department of Inpatients, Horyaal Hospital, Mogadishu, Somalia; 3Department of Policy and Planning, Health Information Systems Section, Directorate of Health and Human Services, Mogadishu, Somalia; 4Department of Neurosurgery, Horyaal Hospital, Mogadishu, Somalia; 5Department of Emergency, Horyaal Hospital, Mogadishu, Somalia; 6Department of Medicine, Faculty of Medicine and Surgery, Zamzam University of Science and Technology, Mogadishu, SomaliaCorrespondence: Abdiweli Mohamed Abdi, Email cabdiwalishiikh@gmail.comAbstract: Lumbosacral nerve root variants may complicate anatomical identification and decompression during lumbar spine surgery. We report a 45-year-old woman with progressive lower limb numbness and paresthesia predominantly affecting the right leg, intermittent low back pain, and right-sided radiating pain aggravated by standing and walking. Examination showed preserved motor strength and sensory impairment in a predominantly right L4 distribution. Preoperative magnetic resonance imaging (MRI) demonstrated an L4–L5 disc bulge with thecal sac indentation, bilateral L5 nerve root abutment, and mild bilateral foraminal narrowing; no nerve root anomaly was reported. During L4–L5 microdiscectomy and decompression, two distinct right-sided neural structures were unexpectedly identified under microscopic visualization and interpreted as suspected duplication of the exiting L4 root. Both structures were preserved during decompression. Retrospective MRI review did not confirm the variant, and intraoperative electrophysiological identification was not feasible. During five months of monthly telephone follow-up, the patient reported improvement in radicular pain, walking tolerance, and sensory symptoms, without reported neurological deterioration. Follow-up neurological examinations and standardized outcome measures were unavailable. This case highlights the importance of recognizing and characterizing unexpected neural anatomy when clinical, imaging, and operative findings do not fully correlate. Definitive anatomical classification and objective postoperative recovery remain uncertain.Keywords: nerve root anomaly, suspected nerve root duplication, lumbar microdiscectomy, lumbar decompression, magnetic resonance imaging, case report