Fig. 1. Lower motor neuron injury of CN XII (a) A pathology affecting the CN XII nucleus may cause ipsilateral paralysis. (b) The segment in the hypoglossal canal may be damaged following traumatic injury causing fractures of the base of the skull. (c) Following its course, the nerve may be injured by a vascular pathology. (d) Injury to the neck segment may involve the cervical strap muscles.
