CLINICAL AND NEUROIMAGING FEATURES OF KIMMERLE ANOMALY IN PATIENTS WITH SYMPTOMS OF VERTEBROBASILAR INSUFFICIENCY

Аннотация

Background. Kimmerle anomaly is an osseous variant of the posterior arch of the atlas in which complete or partial ossification of the posterior atlanto-occipital membrane forms an additional bony bridge over the vertebral artery groove. Its clinical relevance remains debated, because the anomaly may be asymptomatic or associated with vertebrobasilar insufficiency. 
Methods. A  retrospective  clinical  and  neuroimaging  study  included  82  patients  with radiographically confirmed Kimmerle anomaly. All patients underwent neurological examination, symptom stratification, cervical spine radiography, multislice computed tomography, and, when vascular symptoms were present, CT angiography or Doppler ultrasound of the vertebral arteries with functional head-rotation testing. Patients were grouped according to complete or partial bony arch, unilateral or bilateral involvement, and presence or absence of vertebral artery flow disturbance. 
Results. Complete Kimmerle anomaly was identified in 31 patients, partial anomaly in 51, unilateral involvement in 49, and bilateral involvement in 33. Vertebral artery flow reduction during testing was detected in 29 patients and was more frequent in complete and bilateral forms. Occipital headache, rotational dizziness, tinnitus, and postural instability were significantly more common among patients with hemodynamically relevant vertebral artery changes. 
Conclusion. Symptomatic Kimmerle anomaly should be interpreted as a clinico-radiological entity  rather than an incidental  skeletal  variant. Combined assessment of morphology, vascular dynamics, and symptom pattern improves diagnostic precision and supports personalized management of patients with vertebrobasilar insufficiency syndrome.
Keywords: Kimmerle anomaly, ponticulus posticus, arcuate foramen, atlas, vertebral artery, vertebrobasilar insufficiency, occipital headache, dizziness, multislice computed tomography, CT angiography, Doppler ultrasound, cervicogenic pain.