Nodding syndrome, a mysterious neurological disorder, typically affects 5-15y old children in subregions of sub-Saharan Africa, including northern Uganda. Although various investigations into the possible causes were performed very recently, the cause still remains obscure. Therefore, children can only be treated symptomatically (seizure control), this with older generation anti-epileptic drugs. As observations (Masterthesis Velghe, 2013) have already indicated that treatment can be substantially improved by implementing (small) changes, therapeutic drug monitoring (TDM) could be very useful to gain a better understanding of the adequacy of the treatment. For this purpose, dried blood spots are highly suitable as they are minimally invasive, without posing difficulties with respect to sample handling, storage and transport. Furthermore, dried urine matrices will be used in an attempt to get a better insight into the cause of Nodding syndrome, by investigating the levels of different biomarkers.