Reviewer's report
Title: Prediction of Seizure Control in Non-ketotic Hyperglycemic Induced
Seizures
Version: 1 Date: 4 June 2009
Reviewer: Nagaendran Kandiah
Reviewer's report:
Major Revisions
Methods, Para 2, line 5-please explain why the CT/MRI needs to be negative.
Often in hyperglycemia there can be T2/DWI changes and this is not
inconsistent with hyperglycemic seizures. What do the authors mean by
“negative”? They need to list the specific CT/MRI features that were evaluated
for. Exclusion of patients with CT/MRI poses a significant selection bias.
We intended to exclude other causes of focal seizures such as brain
infarction. MRI was not done in of our cases were done. The T2 changes
might be a possible explanation of focal seizure.
Methods, Para 3-Why did the authors exclude patients with sepsis, shock,
CNS infections etc? Sepsis is often associated with acute hyperglycemia and
will need to be studied as a potential predictive factor for seizure control.
Similarly for CNS infections, shock, calcium, magnesium, etc.
We would like to exclude all other causes of focal seizure. In addition,
NKHS is rarely found in sepsis patients.
Results, Para 1, line 2-As authors do not intend to study MRI/CT parameters,
there is no need to exclude patients without brain imaging. However if the
records indicate another potential cause for seizures in these patients, then
there is grounds for exclusion.
We would like to exclude all other causes of focal seizure. The diagnosis
of NKHS should be made only if there is no other possible causes of focal
seizure such as cerebral infarction, abscess, or tumor.
Results, Para 3, line 1-how were the number of seizure attacks ascertained.
Was there a “seizure chart”? If the number of seizures was an estimate based
on recall, then there will be serious concern of significant recall bias and
accuracy of data in this paper. This needs to be clearly stated.
The frequency of seizure was counted by patients and relatives. The
number might not be exactly accurate. However, the seizure is intermittent
and does not cause unconsciousness. In addition, we asked patients about
number of clusters of seizure, not the total numbers of seizure.
Discussion, Para 4, line 4-the authors state that the seizures may be
explained by abnormal foci in the brain. As such exclusion of patients with
abnormal MRI/CT may not be justifiable
The abnormal MRI in NKHS might be an explanation of focal seizure.
None of our cases had an MRI. However, according to the diagnostic criteria,
NKHS should be diagnosed only if seizures are concurrent with
hyperglycemia without any other apparent causes such as brain infarction or
sepsis [2-4].
Discussion, Para 4-were EEG done? Did the patients have EEG changes
during the partial seizures? Were movement disorders such as hyperglycemic
choreoathethosis excluded?
No subjects had an EEG during the seizure attack. In addition, we did
not include subjects with abnormal movement.
Minor Revisions
Background-Needs significant rephrasing and use of correct tense
Methods,Para 4-the whole paragraph should not be under the section of
statistical analysis.
We moved that part to method part.
Methods, Para 5-Please provide all the variables studied under univariate
analysis and their significance values.
We have provided all study variables on Table 1.
Results, Para 1, line 4-Authors need to provide the list of abnormal findings on
brain imaging in the 11 patients that were excluded. Unless there were
specific findings such as large strokes or tumours, there may not be a need to
exclude these patients
10 patients had cerebral infarction and one patient had
encephalomalacia.
Results, Para 4, line 2-what was the range for “time prior to admission”.
6-336 hours.
Results, Para 5, line 4-was there any follow-up post discharge? What was the
average period patients were reviewed post discharge. Authors need to
provide more information on how they established that none of their patients
required long-term AEDs.
We have followed up all subjects for years and none of them neither has
seizure attack again nor required anti-epileptic drugs.
Discussion, Para 1, line 1-reference required to substantiate the higher
prevalence of NKHS in Asia
We have deleted this sentence.
Discussion, Para 2, line 1-4 –the authors use the term “mental status” and
“consciousness” interchangeably, this requires clarification.
We changed to consciousness at both sentences.
Discussion, Para 2, line 6-The authors state that in their series there were no
obvious precipitating factors. This may be an overstatement as they have
excluded patients with sepsis, shock, etc.
In our experience, NKHS rarely has occurred in sepsis. We did not
intend to conclude that but just want to show this observation.
Level of interest: An article of limited interest
Quality of written English: Not suitable for publication unless extensively
edited
An English native speaker has already preliminarily edited our revision
manuscript.
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests