title: Clinical Presentation of Cervical Myelopathy at C1-2 Level.
abstract: METHODS
  Single-center retrospective study.
  
  
  OBJECTIVE
  To clarify the clinical features of cervical myelopathy at the C1-2 level.
  
  
  BACKGROUND
  Methods for distinguishing the affected level based on myelomere symptoms or dysfunction of the conducting pathway were established. However, no symptoms have been identified as being specific to the C1-2 level segment.
  
  
  METHODS
  We evaluated 24 patients with cervical myelopathy due to spinal cord compression at the C1-2 level. Preoperative neurological assessment were investigated and compared with the rate and site of compression of the spinal cord using computed tomography-myelography.
  
  
  RESULTS
  Impaired temperature and pain sensation were confirmed in 18 of the 24 patients with that localized to the upper arms (n=3), forearm (n=9), both (n=2), and whole body (n=4). Muscle weakness was observed in 18 patients, muscle weakness extended from the biceps brachii to the abductor digiti minimi in 10 patients, and in the whole body in 8 patients. Deep tendon reflexes were normal in 10 patients, whereas hyperactive deep tendon reflexes were noted in 14 patients. The rate of spinal cord compression was significantly higher in patients with perceptual dysfunction and muscle weakness compared with those with no dysfunction. However, no significant difference in the rate and site of compression was identified in those with dysfunction.
  
  
  CONCLUSIONS
  Perceptual dysfunction and muscle weakness localized to the upper limbs was observed in 58% and 42% of patients, respectively. Neurological abnormalities, such as perceptual dysfunction and muscle weakness, were visualized in patients with marked compression.
authors: Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors: Yasutaka
authors: Y
authors: Murahashi
authors: Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors: Tsuneo
authors: T
authors: Takebayashi
authors: Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors: Yoshinori
authors: Y
authors: Terashima
authors: Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors: Hajime
authors: H
authors: Tsuda
authors: Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors: Mitsunori
authors: M
authors: Yoshimoto
authors: Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors: Toshihiko
authors: T
authors: Yamashita
keywords: Atlantoaxial joint; Cervical spine; False localizing sign; Myelopathy; Spondyloarthropathy