Cervical influence on dizziness and orientation

Sammanfattning: The overall aim of the work was to examine the influence of cervical biomechanical conditions on movement performance, to study musculoskeletal findings accompanying possible cervicogenic dizziness and to evaluate the influence of cervical proprioception on head orientation. Two devices, measuring cervical range of motion, were compared: Myrin, an inclinometer/compass method and Zebris®, a 3-dimensional ultrasound movement analyser. Both devices showed good reliability and agreement with less variability for the computerized method. The Myrin can be used in clinical routine work and the Zebris® adds information about 3-dimensional movements. (Study I). Cervical range of motion was examined in three dimensions in 120 neck-healthy subjects. Movement patterns of combined primary and coupled movements and the influence of age, gender and body mass index on these movements were investigated. Coupled movements are a natural part of cervical motion together with primary movements. Age affects the majority of primary and coupled cervical movements; the coupled movements of primary rotation and lateral flexion are especially changed with age (Study II). Twenty-two patients with dizziness of suspected cervical origin were examined with a structured physical examination and carefully examined to exclude other causes of dizziness. The effects of physiotherapy, based on these musculoskeletal findings, were evaluated directly after treatment and again long-term with questionnaires. Patients with suspected cervicogenic dizziness had some musculoskeletal findings in common, e.g., tenderness and tightness in the dorsal neck muscles, preserved cervical mobility and reduced cervico-thoracic mobility. Treatment based on these findings reduced both neck pain and dizziness. Some patients seem to need a maintenance strategy to avoid relapses in the long-term (Study III). Twenty neck-healthy subjects were examined before and after a unilateral neck muscle fatiguing task with head repositioning tests. An average overshoot before the fatiguing task decreased after acute muscle fatigue and the increased accuracy was significant and most pronounced for movements directed towards the fatigued side (Study IV). Eleven subjects with bilateral vestibulopathy were compared to fifteen healthy subjects in their ability to reproduce different head on trunk target positions. The subjects with bilateral vestibulopathy maintained their ability to recognize and fine-tune head on trunk movements (Study V). Cervical movement performance changed with increasing age. Treatment of cervical musculoskeletal findings reduced both neck pain symptoms and dizziness; diagnosis ex juvantibus supports the diagnosis of cervicogenic dizziness. Cervical proprioception is an important factor in sensing head on trunk movements. Lund University, Faculty of Medicine Doctoral Dissertation Series 2008:52