Mystery case: hypoglossal nerve palsy in occipito-temporal pneumatization.

A 47-year-old man, with a 25-year history of frequent scuba diving, presented with a right-sided hypoglossal palsy 2 days after occipital head trauma. CT showed excessive occipito-temporal and atlas pneumatization, soft tissue emphysema, right-sided opacification of mastoid air cells, and a right-sided hypoglossal canal fracture (figures 1 and 2). Hypoglossal palsy resolved spontaneously 10 days later. Four months later, mastoid fluid collection disappeared on CT, and other abnormalities were stable. Repetitive positive pressure phenomena (e.g., Valsalva maneuver) are often associated with cranial bone pneumatization.1,2 The preexisting cranial bone pneumatization probably placed the patient at risk for cranial bone fracture of the thinned bone in the setting of minor head trauma.