Hyperpneumatisation of the craniocervical bones: an emerging aetiological pattern

Abstract

Background: Hyperpneumatisation of the skull base and upper cervical vertebrae is a very rare condition of uncertain aetiology and pathophysiology. Case report: A case of extensive hyperpneumatisation of the craniocervical junction and upper three cervical vertebrae is described, in a patient who habitually performed the Valsalva manoeuvre to relieve the symptoms of a patulous eustachian tube. Reported symptoms of ear, neck and shoulder pain deteriorated after minor head trauma. There was a drastic radiological and clinical improvement after ceasing to perform the Valsalva manoeuvre. Discussion: All reported cases of craniocervical bone hyperpneumatisation have in common a history of raised middle-ear pressure, minor trauma or both. We therefore suggest that chronically raised middle-ear pressure leads to destruction of bony tissue and pneumatisation, and that this process is able to cross joints into the cervical spine, either via micro-fractures following trauma, or as a result of congenital assimilation of the craniocervical junction.

Post-traumatic temporal bone pneumatocele presenting after aggressive Valsalva

“…The patient in our case had a habit of performing Valsalva manoeuvres to blow his nose, and he also had a patulous eustachian tube. In a case reported by Fussey et al , a patient with a patulous eustachian tube developed a habit of Valsalva manoeuvres to reduce his autophony symptoms 9. Fussey writes, ‘It is plausible that his repeated Valsalva maneuvers eventually produced a eustachian tube mucosal fold which acted as a ball-valve, preventing dissipation of raised middle-ear pressure; over time, this positive pressure led to the development of hyperpneumatization’.…”

“…In many of the cases we reviewed, hyperpneumatisation of the temporal bone is observed without prior trauma, and the air space is initially contained within the bone. The defect often does not present clinically until a pneumatocele forms in adjacent soft tissue,1 5 7 9 10 12–15 17 or the thinning bone fractures 2 4 6 11. Both of these manifestations have been attributed to minor trauma in several cases 2 6 7 10–12.…”

“…In many cases of cranial hyperpneumatisation, the reversal of pneumatisation has been achieved by non-invasive measures such as instructing the patient to cease any form of Valsalva manoeuvre,2 4 6 9 12 14 or performing a myringotomy 1 13. We did not feel that these were appropriate approaches to address a bony defect as large as what was presented, due to a concern for progressive encephalocele formation in a young patient 18.…”

“…The mastoid part of the temporal bone is normally air-filled, and its antrum is in communication with the middle ear space. Eleven of the 17 cases referenced above reported an association between hyperpneumatisation and increased middle ear pressure or frequent Valsalva manoeuvres 1 2 5–7 9 11–15. However, no cases of pneumatisation at the site of a prior mastoid bone fracture have been reported.…”

“…Pneumoceles more commonly present in the paranasal sinuses,2 but at least 17 cases of mastoid sinus origin have been reported 1 2 4–17. The mastoid part of the temporal bone is normally air-filled, and its antrum is in communication with the middle ear space.…”