Therapeutic Effects of Transcranial Alternating Current Stimulation Targeting the Left Dorsolateral Prefrontal Cortex in Patients with Persistent Postural-Perceptual Dizziness: A Preliminary Study

Abstract Background Persistent postural-perceptual dizziness (PPPD) is a chronic vestibular disorder often refractory to standard pharmacotherapy. Transcranial alternating current stimulation (tACS) offers a non-invasive approach to modulate cortical activity. This prospective study aimed to evaluate the therapeutic potential and safety of multi-session tACS targeting the left dorsolateral prefrontal cortex (DLPFC) in patients with PPPD. Methods Ten patients with definite PPPD received a 2-week intervention consisting of 10 Hz, 1.5 mA tACS targeting the left DLPFC. Dizziness handicap, anxiety, and depressive symptoms were evaluated at baseline, immediately post-treatment, and at 1-month follow-up using the Dizziness Handicap Inventory (DHI), Hamilton Anxiety Scale (HAMA), and Beck Depression Inventory (BDI), respectively. Results Repeated-measures ANOVA demonstrated significant overall treatment effects across all time points for DHI (F(2, 18) = 30.19, p < 0.001), HAMA (F(2, 18) = 12.80, p < 0.001), and BDI (F(2, 18) = 6.34, p = 0.008). Post-hoc analysis showed immediate post-treatment reductions in DHI (p = 0.038), with the most pronounced improvements observed across all scales at 1-month follow-up (DHI: p < 0.001; HAMA: p = 0.003; BDI: p = 0.010). Adverse events were mild, transient, and self-limiting, with mild paresthesia being the most frequent (30%). Conclusion Multi-session tACS over the left DLPFC significantly alleviated dizziness, anxiety, and depressive symptoms in PPPD patients, with therapeutic benefits sustained at 1-month follow-up. These preliminary findings suggest tACS as a safe, feasible alternative intervention for PPPD.