Table 1.
Clinical characteristics of patients.
Table 2.
Protocols in which each individual patient participated at the different time points.
Table 3.
Protocols in which each individual control participated at the different time points.
Figure 1.
Assessing the dynamic modification range of LTP-LTD-like plasticity.
Different protocols of high frequency stimulation (HFS) are presented. In controls and patients HFSLTP, HFSLTP-LTD, HFSLTP-LTP protocols were investigated. The HFSLTD and HFSNO protocol in controls served as control condition. In the right panel the timing for each intervention is illustrated. Panel A: The R1 and R2 answers are illustrated. In the non-intervention protocol, no high frequency stimulation was applied. Panel B: The high frequency stimulation ended 5 ms before the expected R2 response to induce LTD like effects. Panel C: The HFS started with the onset of the R2 answer to induce LTP like plasticity.
Figure 2.
Probing the influence of BTX injections on homeostatic-like plasticity.
HFSLTP-LTD before, one, two and four weeks after Botulinum toxin (BTX) treatment was investigated in patients with blepharospasm.
Figure 3.
Electrode placement and examples of the R2 response.
Panel A: Placement of the electrodes around the orbicularis oculi and nasalis muscles. The right supraorbital nerve was stimulated. Panel B: Example of ipsilateral R1 and R2 responses after single pulse stimulation. Panel C: Example of HFSLTP protocol. High frequency stimulation was given at the onset of the R2 response to induce LTP-like effects. Panel D: Example of HFSLTD protocol. Here, HFS was applied before the onset of the R2 response to induce LTD-like effects.
Figure 4.
Presentation of normalized data for HFSLTP, HFSLTP-LTD, HFSLTP-LTP protocols.
Panels A–C show the normalized area under the curve of the ipsilateral R2 response after single pulse stimulation. HFSLTP, HFSLTP-LTD, HFSLTP-LTP were applied in patients and controls. In panels D, E, F the ipsilateral R2 area under the curve after paired-pulse stimulation are depicted. In panels G,H,I the % inhibition is shown. Here, inhibition was determined as percent change from the R2 response after paired-pulse stimulation relative to single pulse stimulation. Single pulse stimulation revealed a nonspecific decrease of the R2 response in all protocols and in both groups. After paired-pulse inhibition no changes were found, because the decrease of the R2 response was accompanied by a decrease of % inhibition (higher values indicate stronger inhibition). R2 area under the curve is given in µV/sec. Mean and standard error are shown. Open circles indicate controls, black diamonds patients.
Figure 5.
Presentation of normalized data for HFSLTD and HFSnon-intervention protocols in controls.
Panel A presents the results after single pulse, panel B after paired-pulse stimulation, and panel C % inhibition (higher values indicate stronger inhibition). R2 area under the curve is given in µV/sec. Mean and standard errors are shown. Circles indicate the HFSLTD, black diamonds the non-intervention protocol.
Figure 6.
R2 response of each individual subject at baseline and after HFSLTP.
Individual results of each subject before and immediately after HFSLTP for each protocol starting with HFSLTP (i.e. HFSLTP, HFSLTP-LTD, HFSLTP-LTP) are presented.
Figure 7.
R2 response of each control person at baseline and after HFSLTP, HFSLTD, and HFSnon-intervention.
In analogy to Figure 6, individual results of each control subject before and immediately after HFS for the HFSLTP, HFSLTD and non-intervention protocol are presented.
Figure 8.
HFSLTP-LTD before and after Botulinum Toxin Treatment.
Results of normalized data for HFS before and after Botulinum toxin (BTX) treatment in BEB patients are shown for HFSLTP-LTD. Panel A: Single pulse; Panel B: Paired-pulse. BTX had no effect on the HFSLTP-LTD protocol. Black line with circle = baseline; black, dashed line with square = one week after BTX injection; light grey line with diamond = two weeks after BTX; dark grey line with triangle = four weeks after BTX. R2 area under the curve is given in µV/sec. % inhibition is relative to single pulse measurements.
Table 4.
Differences in the methods used between the experiments.