Fig 1.
BS-EEG from a patient with EME, showing alternative periods of slow waves of high amplitude (the burst) and periods of so called flat EEG (the suppression).
Table 1.
Demographic and clinical Data of the patients.
Fig 2.
Pooled power spectrum showing a clear peak at the 1–4 Hz frequency range in all these patients for both the burst and suppression phases
Fig 3.
Grand avarage of DICS and RPDC results during burst phases.
A. Grand average of the sources described by DICS analysis during burst phase. The source of the strongest power in the frequency band 1–4 Hz was detected bilaterally in precuneus in all 13 patients. The 2nd source was detected bilaterally in the somatosensory cortex in all patients. The 3rd source was detected in prefrontal regions bilaterally; Subsequent sources were detected in the thalamus (4th source) bilaterally and the last coherent source was found in the brainstem, in all 13 patients. B. RPDC during burst phase: showing significantly (p = 0.003) stronger information flow from the precuneus (source 1) towards the somatosensory cortex (p = 0.001) (second source) and the prefrontal cortex (third source) (p = 0.004) as well as from the brainstem (source 5) towards the thalamus (p = 0.004) and from the thalamus to the precuneus (p = 0.004) rather than vice versa. Also, stronger RPDC (p = 0.002) was detected from the somatosensory cortex towards the prefrontal cortex.
Fig 4.
Grand avarage of DICS and RPDC results during suppression phases.
A. Shows DICS results for the suppression phases. The source of the strongest power in the frequency band 1–4 Hz was detected bilaterally in the precuneus in all 13 patients (first source) and was very similar to the strongest sources during burst phases. The 2nd strongest sources were found bilaterally in the occipital cortex in 11 patients and unilaterally on the left side in two patients. The 3rd source was detected in the somatosensory cortex bilaterally. The last sources were detected bilaterally in the prefrontal cortex, similar to the third source during the burst phases. No deep sources were discovered during the suppression phases. B. RPDC during suppression phases showed no significant differences in information flow between sources. Connections between the sources: 1 and 2 (p = 0.49), 1 and 3(p = 0.52), 1 and 4 (p = 0.32), 2 and 3 (p = 0.29), 2 and 4 (p = 0.42), 3 and 4 (p = 0.29).
Fig 5.
The source absolute power for the first source during both phases showing higher absolute power during burst phases than during the suppression phases.