November 2017

A 13-year-old male with lower extremity weakness | Sub-classification: Spine


A 13-year-old male presents with a six month history of difficulty walking. There is no history of trauma, malignancy, or other medical problems. He states that his legs feel “tight” and that the left leg is numb. He does not endorse upper extremity problems or incontinence of bowel or bladder.   


Cranial nerves II-XII are intact

DTRs – 3+ upper and lower extremities

Strength- 5/5

+ Clonus left lower extremity

Decreased sensation in left lower extremity

Mildly spastic gait


Figure 1

Figure 2


Please subit your answers to see the case explanation.


  • Zhao D, Wang S, Passias PG, Wang C.Craniocervical instability in the setting of os odontoideum: assessment of cause, presentation, and surgical outcomes in a series of 279 cases. Neurosurgery. 2015 May;76(5):514-21.
  • Weng C, Tian W, Li ZY, Liu B, Li Q, Wang YQ, Sun YZ. Surgical management of symptomatic os odontoideum with posterior screw fixation performed using the magerl and harms techniques with intraoperative 3-dimensional fluoroscopy-based navigation. Spine (Phila Pa 1976). 2012 Oct 1;37(21):1839-46.
  • Klimo P Jr, Kan P, Rao G, Apfelbaum R, Brockmeyer D. Os odontoideum: presentation, diagnosis, and treatment in a series of 78 patients. J Neurosurg Spine. 2008 Oct;9(4):332-42. doi: 10.3171/SPI.2008.9.10.332.
  • Arvin B, Fournier-Gosselin MP, Fehlings MG.Os odontoideum: etiology and surgical management.Neurosurgery. 2010 Mar;66(3 Suppl):22-31. 
  • Leng LZ, Anand VK, Hartl R, Schwartz TH. Endonasal endoscopic resection of an os odontoideum to decompress the cervicomedullary junction: a minimal access surgical technique. Spine (Phila Pa 1976). 2009 Feb 15;34(4):E139-43
  • Qiuhang Z, Feng K, Bo Y, Hongchuan G, Mingchu L, Ge C, Feng. Transoral endoscopic odontoidectomy to decompress the cervicomedullary junction. L.Spine (Phila Pa 1976). 2013 Jun 15;38(14):E901-6. ​

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