Effects of low-dose cervical paraspinal lidocaine injections on cervicogenic dizziness–related outcomes: a randomized, sham-controlled, assessor-blinded trial

To determine whether low-dose cervical paraspinal intramuscular lidocaine injections improve dizziness-related disability and cervical sensorimotor outcomes in cervicogenic dizziness. In this randomized, sham-controlled, assessor-blinded trial, 81 adults with cervicogenic dizziness received bilateral C1–C7 paraspinal intramuscular injections (14 sites × 0.5 mL) of 0.5% lidocaine (local anesthetic injections, LAI; 35 mg/session; n = 41) or saline (sham injections, SI; n = 40) twice weekly for five weeks (10 sessions). The primary endpoint was change in Dizziness Handicap Inventory (DHI) total score. Secondary outcomes included DHI subscales, Neck Disability Index, neck pain, cervical range of motion, joint position error, posturography, kinesiophobia, anxiety, and depression. Analyses used intention-to-treat linear mixed-effects models. DHI total improved more with LAI than SI, with a between-group difference in change of −6.78 points (95% CI −8.21 to −5.36; p < 0.001; Cohen’s d = −1.16), large in standardized terms but below the 11-point anchor-based minimal important change. Twenty-one of 24 secondary endpoints remained significant after false discovery rate correction (|d| 0.30–1.13). Adverse events were infrequent and mostly mild. Lidocaine injections produced a modest short-term improvement in dizziness-related disability. Without verified participant blinding, long-term follow-up, or testing alongside rehabilitation, these findings require confirmation. Cervicogenic dizziness may involve an interaction between neck pain, cervical sensorimotor dysfunction, dizziness-related disability, and postural instability; clinical assessment should address both neck and balance function.In selected patients with cervicogenic dizziness, low-dose cervical paraspinal intramuscular lidocaine injections reduced dizziness-related disability more than sham injections in the short term, although the mean benefit remained below the anchor-based minimal important change of the Dizziness Handicap Inventory.Improvements in neck disability, neck pain, joint position error, and postural sway accompanied the change in dizziness-related disability, but their clinical relevance is uncertain.The injections were tested without concomitant rehabilitation; trials with long-term follow-up and formal assessment of participant blinding should test whether they add benefit to structured cervical and vestibular rehabilitation. Cervicogenic dizziness may involve an interaction between neck pain, cervical sensorimotor dysfunction, dizziness-related disability, and postural instability; clinical assessment should address both neck and balance function. In selected patients with cervicogenic dizziness, low-dose cervical paraspinal intramuscular lidocaine injections reduced dizziness-related disability more than sham injections in the short term, although the mean benefit remained below the anchor-based minimal important change of the Dizziness Handicap Inventory. Improvements in neck disability, neck pain, joint position error, and postural sway accompanied the change in dizziness-related disability, but their clinical relevance is uncertain. The injections were tested without concomitant rehabilitation; trials with long-term follow-up and formal assessment of participant blinding should test whether they add benefit to structured cervical and vestibular rehabilitation.