I read the symptoms.
The case has got complicated by trauma,convulsions,speech disorder
and later ataxia.
I would suggest to do blood gases study for now.also know the pO2, pCO2 Ph of blood. bicarb level and base excess.
Also c reactive protein
Also i would ask for a deeper history of hypoxia, anoxia, suffered any time during the seizure and brain injury
a decreased po2 at that time for 4 minutes is enough to damage the brain and keep the pupils reacting and dilated.
A decreased serum sodium would suggest hyponatraemia now
However sub clinical gram negative infection must also be ruled out, esp tuberculosis
and meningitis.( its not always with a neck rigidity