title: Lumbar Disc Herniation Presented with Contralateral Symptoms.
abstract: OBJECTIVE
  This study aimed to unravel the putative mechanism underlying the neurologic deficits contralateral to the side with lumbar disc herniation (LDH) and to elucidate the treatment for this condition.
  
  
  METHODS
  From January 2009 to June 2015, 8 patients with LDH with predominantly contralateral neurologic deficits underwent surgical treatment on the side with LDH with or without decompressing the symptomatic side. A retrospective review of charts and radiological records of these 8 patients was performed. The putative mechanisms underlying the associated contralateral neurological deficits, magnetic resonance imaging (MRI), electromyography (EMG), and the adequate surgical approach are discussed here.
  
  
  RESULTS
  MRI revealed a similar laterally skewed paramedian disc herniation, with the apex deviated from the symptomatic side rather than directly compressing the nerve root; this condition may generate a contralateral traction force. EMG revealed radiculopathies in both sides of 6 patients and in the herniated side of 2 patients. Based on EMG findings and the existence of suspicious lateral recess stenosis of the symptomatic side, 6 patients underwent bilateral decompression of nerve roots and 2 were subjected to a microscopic discectomy to treat the asymptomatic disc herniation. No specific conditions such as venous congestion, nerve root anomaly or epidural lipomatosis were observed, which may be considered the putative pathomechanism causing the contralateral neurological deficits. The symptoms resolved significantly after surgery.
  
  
  CONCLUSIONS
  The traction force generated on the contralateral side and lateral recess stenosis, rather than direct compression, may cause the contralateral neurologic deficits observed in LDH.
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Korea.
authors.forename: Pius
authors.initials: P
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Korea.
authors.forename: Chang Il
authors.initials: CI
authors.lastname: Ju
authors.affiliation: Department of Neurosurgery, Suwon Nanoori Hospital, Suwon, Korea.
authors.forename: Hyeun Sung
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, College of Medicine, Chosun University, Gwangju, Korea.
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Kim
keywords: Contralateral; Herniated disk; Lumbar