No evidence that 43.2 Hz trains use lower reported SEEG effect currents than 50 Hz trains

We compared the stimulation current that caused a clinical effect for 43.2 Hz alternating-polarity trains and for 50 Hz trains. We used the metadata of 143 SEEG stimulations in 38 patient entries (37 persons) from OpenNeuro ds006519 (negative motor responses) and ds005169 (visual percepts). No patient received both train types, so the unit of inference is the patient median of log2 current. In ds006519, the 50/43.2 Hz ratio of patient medians was 1.61 (95% CI 0.71-3.65, exact p = 0.19, 12 vs 6 patients). In ds005169, the ratio was 0.82 (95% CI 0.58-1.50, exact p = 0.70, 3 vs 17 patients). The pooled test, stratified by dataset, gave a ratio of 1.22 (permutation p = 0.41). When we adjusted for age and dataset, the frequency term was -0.06 log2 (permutation p = 0.86). Thus, these data give no evidence that 43.2 Hz alternating-polarity trains need less current. The data do not prove equivalence. Frequency is confounded with era, clinician and region, and the currents are clinical values, not titrated thresholds. The package contains numpy-only code, the metadata copies, the per-stimulation and per-patient tables, and a figure.

SEEG · intracranial electrical stimulation · alternating-polarity stimulation · stimulation current · negative motor response · visual percept · between-patient comparison