Unilateral Transient Enhanced SEP during Integrated Multiparameter Neurophysiological Monitoring in a Newborn with Symptomatic Seizure

Round 1

Reviewer 1 Report

Giant SEPs are an esoteric topic, but is sufficiently rare for a case report to be considered.

1. The English language presentation leaves something to be desired.
a) In section 2 "Case description" the use of the present tense is unusual. It would be easier to read if it were in the past tense. This should apply through to the case presentation.
b) The sentence does not make sense: "An integrated multiparametric neurophysiological monitoring (IMNA) [1] lasting one hour is therefore required 24 hours after birth." The authors probably mean that an integrated multiparametric neurophysiological monitoring was clinically indicated.
c) "AngioRM" study - is "venous and arterial MRI angiography" meant?

The authors could add a reference and discussion to the literature on SEP in IOM. The SEP method should be described. Though it is unlikely, asymmetric scalp electrode positioning could partially explain the large amplitude.  In the new IOM SEP guidelines (MacDonald, Clin Neurophysiol 2019;131(1):161-179) it is shown that SEP amplitudes can vary with electrode positioning. The exact method for SEP recording should be described. 

The paper would be even better if a time series of SEP amplitude was presented. The magnitude of the change with phenobarbital administration would be easier to evaluate. They could indicate with an arrow in the chart when this was done.

The section on neurotransmitter imbalance is perhaps too long, as it is speculative and based on only one case. Could be shortened..

Author Response

1) The tense used in section 2 was changed. The propositions were subsequently clarified in more correct English.  

2) We have inserted the reference of SEP in IOM as rightly suggested. However, considering that electrodes disposition (according to the International 10-20 system) was carried out ensuring the maximum interhemispheric and interelectrode symmetry, we can establish that if the asymmetry was due to technical error, amplitude would be asymmetric from the beginning of the registration.  

We can also guarantee that the electrodes have not moved during the registration since they are kept adherent to the scalp by the use of elastic gauze, comfortable for the newborn but effective in keeping still the electrodes.  

3) Several traces of SEPs were performed during the monitoring, and we inserted the cascade, so that we can see when the potential returns to a normal amplitude (end of the seizure) and the moment of phenobarbital administration. 

Following this monitoring, others are carried out over time, which do not show other episodes. 

4) the section on the missing gaba-glutamate balance has been reduced. 

Reviewer 2 Report

The paper was well written. The findings are novel. The mechanisms were well addressed. 

Author Response

Thank-you for your comments