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Median nerve middle-long latency somatosensory evoked potentials in children with tactile evoked spikes
S Calzolari1, L Rozza, P De Marco
1Child Neuropsychiatry Unit, Santa Chiara Hospital, Trento, Italy.
Insights
Tactile evoked spikes (TES) and middle-long latency evoked potentials (MLSEPs) in children are the same neurophysiologic event. This finding helps understand brain responses to tactile stimulation in children, including those with EEG abnormalities.
Area of Science:
- Neurophysiology
- Pediatric Neurology
- Electroencephalography
Background:
- Hand tapping during electroencephalography (EEG) can trigger centrotemporal spikes in children aged 4-12.
- This phenomenon is observed in both healthy children and those with epilepsy.
- Children exhibiting these spikes also show giant middle-long latency evoked potentials (MLSEPs).
Purpose of the Study:
- To investigate the relationship between tactile evoked spikes (TES) and MLSEPs.
- To determine if TES and MLSEPs represent the same underlying neurophysiological event.
Main Methods:
- A neurophysiological study involving 50 children (25 with TES, 25 without EEG abnormalities).
- Performed MLSEP studies using both electrical and tactile stimulation.
- Simultaneously recorded digital EEG during stimulation.
Main Results:
- MLSEPs consistently displayed three negative peaks (NI, NII, NIII) and two positive peaks (PI, PII).
- Children with TES exhibited MLSEPs with significantly enlarged amplitudes.
- Analysis indicated that NII corresponds to the evoked spike and NIII to the subsequent slow-wave.
Conclusions:
- Tactile evoked spikes (TES) and middle-long latency evoked potentials (MLSEPs) are manifestations of the same neurophysiological event.
- The NII peak in MLSEPs represents the evoked spike, and the NIII peak represents the following slow-wave.
- This finding clarifies the nature of tactile-evoked brain responses in children.
Abstract:
It is known that hand tapping during electroencephalography (EEG) recording evokes centrotemporal spikes in some 4- to 12-year-old children. This phenomenon occurs in both healthy and epileptic children. The same children were reported to show giant middle-long latency evoked potentials (MLSEPs). To study the relationship between tactile evoked spikes (TES) and MLSEPs, we performed a neurophysiologic investigation in 25 children with TES and in 25 children without any EEG abnormality. Such an investigation included a MLSEP study after both electrical and tactile stimulation with simultaneous recording of digital EEG. MLSEPs consistently showed three negative (NI, NII, NIII) and two positive (PI, PII) peaks. Children with TES had MLSEPs of enlarged amplitude. The analysis of MLSEPs and TES characteristics led us to the conclusion that they are the same neurophysiologic event, with NII being the evoked spike and NIII the following slow-wave.