Widespread inter-ictal excitability changes in patients with temporal lobe epilepsy: A TMS/MEG study

Hsu, Wan-Yu; Kuo, Yi-Feng; Liao, Kwong‐Kum; Hsiang-Yu, Yu; Lin, Yung Yang

doi:10.1016/j.eplepsyres.2015.01.004

Cited by 10 publications

(5 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This could suggest that inputs from cortical and/or subcortical structures involved in and/or affected by the epileptic discharge may account for sympathetic imbalance in TLE . This hypothesis could be verified through noninvasive brain stimulation techniques and reflects recent insight from transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG) studies, which demonstrate that in TLE, cortical excitability alterations are distributed widely beyond the epileptic focus …”

Section: Discussionmentioning

confidence: 78%

“…24 This hypothesis could be verified through noninvasive brain stimulation techniques 25,26 and reflects recent insight from transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG) studies, which demonstrate that in TLE, cortical excitability alterations are distributed widely beyond the epileptic focus. 27,28 Present data exploring the interictal sympathetic control of HRV in untreated epilepsy are not consistent across studies. 7,9 Recently, a meta-analysis of HRV in epilepsy reported a lack of significant alterations of LF in epilepsy patients compared to controls; however, this parameter was found to be lower in patients with AEDs when compared to drug-free subjects.…”

Section: Effects Of Temporal Lobe Seizures On Hrv Parametersmentioning

confidence: 87%

See 1 more Smart Citation

Heart rate variability in untreated newly diagnosed temporal lobe epilepsy: Evidence for ictal sympathetic dysregulation

Romigi¹,

Albanese²,

Placidi³

et al. 2016

Epilepsia

View full text Add to dashboard Cite

Andrea Romigi is a clinical epileptologist and sleep specialist. SUMMARYObjective: To compare heart rate variability (HRV) parameters in newly diagnosed and untreated temporal lobe epilepsy (TLE) between the interictal, preictal, ictal, and postictal states. Methods: HRV parameters were extracted from single-lead electrocardiography data collected during video-electroencephalography (EEG) recordings from 14 patients with newly diagnosed TLE in a resting, awake, and supine state. HRV parameters in the time and frequency domains included low frequency (LF), high frequency (HF), standard deviation of all consecutive R wave intervals (SDNN), and square root of the mean of the sum of the squares of differences between adjacent R wave intervals (RMSSD). Cardiovagal index (CVI), cardiosympathetic index (CSI), and approximate entropy (ApEn) were also studied. Results: Frequency domain analysis showed significantly higher preictal, ictal, and postictal LF/HF ratio compared to the interictal state. Similarly, the LF component increased progressively and was significantly higher during the ictal state compared to interictal and preictal states. RR interval values were lower in the ictal state compared to basal and preictal states and in the postictal state compared to the preictal state. Interictal RMSSD was significantly higher compared to all other states, and ictal SDNN was significantly higher compared to all other states. Ictal CSI was significantly higher compared to preictal and interictal states, whereas preictal CVI was lower than in basal and ictal states. In addition, ictal ApEn was significantly lower than interictal and preictal ApEn. Interictal CVI was lower in left TLE compared to right TLE. In addition, in left TLE, ictal CVI was higher than interictal CVI, whereas in right TLE, CVI was lower in the preictal state compared to all other states. Significance: Our data suggest an ictal sympathetic overdrive with partial recovery in the postictal state. Higher sympathetic tone and vagal tone imbalance may induce early autonomic dysfunction and increase cardiovascular risk in patients affected by TLE.

show abstract

Section: Discussionmentioning

confidence: 78%

Section: Effects Of Temporal Lobe Seizures On Hrv Parametersmentioning

confidence: 87%

Heart rate variability in untreated newly diagnosed temporal lobe epilepsy: Evidence for ictal sympathetic dysregulation

Romigi¹,

Albanese²,

Placidi³

et al. 2016

Epilepsia

View full text Add to dashboard Cite

show abstract

“…In TLE, while most seizures originate in the hippocampus [66], the epileptogenic network has been shown to often extend to entorhinal, lateral temporal, and inferior frontal cortices as well, together with subcortical nuclei, such as the amygdala and medial thalamus [61,62]. Offering a synoptic view on brain dynamics at a millisecond scale, electrophysiological studies employing electroencephalography (EEG) and magnetoencephalography (MEG) not only have been of high utility in characterizing changes at seizure onset but also could reveal chronic changes in local and distributed activity [67,68]. Notably, studying statistical relationships between time series has been used to evaluate dynamic changes in interregional connectivity; moreover, electrophysiological techniques provide a range of spectral (i.e., frequency-dependent) markers that have the potential to probe tissue epileptogenicity in vivo.…”

Section: Evidence Justifying the Study Of Tle As A Network Disordermentioning

confidence: 99%

Network analysis for a network disorder: The emerging role of graph theory in the study of epilepsy

Bernhardt

Bonilha

Gross

2015

Epilepsy & Behavior

229

181

View full text Add to dashboard Cite

“…54 Another study evaluating the excitability patterns in the motor, auditory, and somatosensory cortices in TLE patients using magnetic stimulation and magnetoencephalography (MEG) showed that focal epilepsy led to permanent changes in the cortical excitability beyond the focus of epilepsy, which correlated with the frequency of seizures. 55 By another magnetic stimulation study, there were significant changes in both inhibition and excitation on the asymptomatic hemisphere after epilepsy surgery, which indicated that changes in the excitability in patients with focal epilepsy were indeed the result of a generalized functional problem. 56 Theoretically, if the focus of the seizure is active for a long time, that focus produces a permanent secondary focus in the relevant cortical areas of the contralateral hemisphere via commissural connections, which is called the mirror focus.…”

Section: Discussionmentioning

confidence: 97%

The Thalamic and Intracortical Inhibitory Function of Somatosensory System Is Unchanged in Mesial Temporal Lobe Epilepsy With Hippocampal Sclerosis

Akıncı

Gündüz

Özkara

et al. 2021

Journal of Clinical Neurophysiology

View full text Add to dashboard Cite

Purpose: In mesial temporal lobe epilepsy with hippocampal sclerosis, there is parietal atrophy and cognitive involvement in related domains. In this context, we hypothesized that inhibitory input into somatosensory cortex and thalamus may be increased in these patients, which could improve after epilepsy surgery. Thus, we analyzed the inhibitory function of somatosensory system by studying surround inhibition (SI) and recovery function of somatosensory evoked potentials in patients with mesial temporal lobe epilepsy with hippocampal sclerosis.Methods: Nine patients with unoperated mesial temporal lobe epilepsy with hippocampal sclerosis, 10 patients who underwent epilepsy surgery, and 12 healthy subjects were included. For SI of somatosensory evoked potentials, we recorded somatosensory evoked potentials after stimulating median or ulnar nerve at wrist separately and after median and ulnar nerves simultaneously and calculated SI% in all participants. For recovery function of somatosensory evoked potentials, paired stimulation of median nerve at 40-and 100-millisecond intervals was performed. We compared the findings among groups. As a secondary analysis, we determined the outliers in the patient group and analyzed the relation to the clinical findings.Results: The mean SI% or recovery function was similar among three groups. However, there were five patients with SI loss on normal side in the patient group, which was related to the antiseizure drugs. Conclusions:In contrast to our hypothesis, both intracortical (SI) and thalamic/striatal (recovery function) inhibitory modulation of the somatosensory cortex was not altered in mesial temporal lobe epilepsy with hippocampal sclerosis and did not differ in surgical and nonsurgical groups.

show abstract

Widespread inter-ictal excitability changes in patients with temporal lobe epilepsy: A TMS/MEG study

Cited by 10 publications

References 55 publications

Heart rate variability in untreated newly diagnosed temporal lobe epilepsy: Evidence for ictal sympathetic dysregulation

Heart rate variability in untreated newly diagnosed temporal lobe epilepsy: Evidence for ictal sympathetic dysregulation

Network analysis for a network disorder: The emerging role of graph theory in the study of epilepsy

The Thalamic and Intracortical Inhibitory Function of Somatosensory System Is Unchanged in Mesial Temporal Lobe Epilepsy With Hippocampal Sclerosis

Contact Info

Product

Resources

About