An upper cervical spine injury producing paraesthesia in the distribution of the mandibular division of the trigeminal nerve.

A case is reported of a 37-year-old man who developed paraesthesia in the distribution of the mandibular division of the trigeminal nerve following an injury to the upper cervical spine during a game of rugby. The central pathways of the trigeminal nerve are discussed and it is proposed that mandibular fibres descended beyond their expected level in the spinal trigeminal nucleus, and that it was these fibres which were compressed in the unstable dislocation at the atlanto-axial joint producing the paraesthesia described. Other remote anatomical explanations for the paraesthesia are considered.