Effects of COVID-19 lockdown on chronic drug-resistant pain patients treated using brain stimulation approaches

Chronic pain often shows insufficient response to pharmacological treatments. Non-invasive brain stimulation (NIBS) of the motor cortex has been proposed as an alternative therapeutic approach [1,2]. This therapeutic intervention requires repeated NIBS sessions once-daily for 1 or 2 weeks followed by a maintenance protocol [2e4]. In our hospital, we usually apply ten NIBS daily sessions (two weeks, Monday to Friday); we will refer to this period as induction phase. After the induction phase, responsive subjects enter into the maintenance phase. Maintenance phase consists of one NIBS session every two weeks (for some patients this interval is shortened to 7e10 days). We used both repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS). In our lab, pain relief is similarly obtained with the two techniques. Currently, approx. 90% of our patients are receiving tDCS. A very small number of patients receiving tDCS are treated at home. In these cases, the caregiver is trained to apply the tDCS and we follow the patients remotely. Mid of March 2020, 74 patients were included in the maintenance phase of tDCS treatment at the Hospital and 7 patients were in the same phase but at home. Due to COVID-19 pandemic lockdown, we were not allowed to receive the patients at the Hospital to minimize the risk of contagion. Here, we present and analyse the effects of one-month lockdown on these patients and the estimated cost of starting again in the next future. We telephonically interviewed both the patients that habitually received tDCS at the Hospital (so that were forced to discontinue the treatment) and the patients that were receiving tDCS at home before the lockdown (they did not discontinue the treatment). During the phone interview, we asked to quantify the pain they have on a numeric rating scale (NRS) from 0 to 10, so we have the possibility to compare it with the pain rating of the last tDCS session they received (we use to collect this info at every hospital visit or at home NIBS session). We observed pain worsening of patients that discontinued the treatment (N 1⁄4 74; female 1⁄4 49; mean age 52.3 ± 12.0; NRS: last evaluation before lockdown 5.0 ± 2.4 and after 6.7 ± 1.7, paired t-test, p < 0.0001), but not of patients that did not (N 1⁄4 7; female 1⁄4 4; mean age