Abnormal cancellation of the vestibulo-ocular reflex (VOR) after mild head and/or neck trauma

Dizziness and/or feeling of unsteadiness are frequent symptoms of post-concussion syndrome and may last for months or even years. Because of the ill-defined nature of these symptoms and the difficulty to localize the site of the lesion, the patient is frequently diagnosed as psychoneurotic. Since an abnormal cancellation of the vestibulo-ocular reflex (VOR) by fixation and tracking can be responsible for dizziness, we evaluated it by a simple clinical test. Patients complaining of dizziness who underwent a head and/or neck trauma were compared with healthy controls and with patients suffering from a known vestibulo-cerebellar pathology. Abnormal cancellation of VOR was found in the post-traumatic patients and in those with a vestibulo-cerebellar pathology and can explain their complaints.