Kimmerle's Anomaly as a Possible Causative Factor of Chronic Tension-Type Headaches and Neurosensory Hearing Loss: Case Report and Literature Review

Abstract

Kimmerle's anomaly also known as ponticulus posticus is a common anatomical variation of the atlas, the first cervical vertebra. It is the product of the complete or incomplete ossification of the posterior atlanto-occipital membrane over the vertebral artery groove resulting in the formation of a foramen (arcuate foramen) containing the vertebral artery and the posterior branch of the C-1 spinal nerve. This variation has been associated with vertebro-basilar insufficiency symptoms, various types of headaches, and acute hearing loss. The aim of the present study is to substantiate whether Kimmerle's anomaly is the possible cause of chronic tension-type headaches and neurosensory-type hearing loss in a patient with a known history of headaches and accompanied unilateral hearing loss. The headaches demonstrated the characteristics of the chronic tension-type; the audiometric investigation concluded the hearing loss to be of the neurosensory type; whereas, the imaging examinations revealed the existence of a partial osseous bridge, that is an incomplete arcuate foramen (ponticulus posticus or Kimmerle's anomaly) on the upper surface of atlas. Both the clinical and the radiological findings of this case are indicative of a possible connection between Kimmerle's anomaly and the manifestation of chronic tension-type headaches and neurosensory-type hearing loss.

Ponticulus Posticus on the Posterior Arch of Atlas, Prevalence Analysis in Symptomatic and Asymptomatic Patients of Gulbarga Population

“…The audiometric investigation concluded the hearing loss to be of the neurosensory type, whereas, the imaging examinations revealed the existence of a partial osseous bridge, that is an incomplete arcuate foramen on the upper surface of atlas. Both the clinical and the radiological findings of this case were indicative of a possible connection between Kimmerle's anomaly and the manifestation of chronic tension-type headaches and neurosensory-type hearing loss [12]. However, in contradiction to above mentioned study in which they found symptoms only in patients with partial or incomplete forms of PP, in our study, we found that patients with both the forms of ponticulus posticus had symptoms of tension type headache and migraine in the age group of 16-45 years.…”

Prevalence and Morphologic Characteristics of Ponticulus Posticus: Analysis Using Cone-Beam Computed Tomography

“…[49][50][51] The PP is generally regarded as a simple anatomical variant. However, the compression of the nervous and vascular structures passing through the foramen (vertebral artery, periarterial plexus, and suboccipital nerve) may result in a combination of symptoms such as cervical migraine 49 ; neurosensory-type hearing loss 52 ; neck pain; vertigo; shoulder-arm pain; and, in some instances, even loss of postural muscle tone, consciousness, and vertebrobasilar insufficiency syndrome. 17 Severe headache is present in 56% to 90% of subjects.…”

Study of Arcuate Foramen of Atlas Vertebrae

“…Kimmerle's anomaly can be a cause for manifestation of chronic tension type headaches and neurosensory type hearing loss [13] and also for acute cerebrovascular disorders in vertebro basilar field [14] and can be an extravasal factor in respect of the vertebral artery causing a compression-stenosing -irritative effect. [15] Cushing KE et al have reported that presence of an arcuate foramen can cause tethering of the vertebral artery in the foramen and dissection can occur from repetitive trauma with movement of the neck [16].…”