Abstracts

Rationale: Ictal thirst has not yet been described as an ictal manifestation. There have been rare reports of periictal water drinking as an automatism but here we describe two cases of ictal thirst where patient asks for water specifically or chooses water everytime over other objects available and drinks it as if she is thirsty.Methods: The epilepsy-monitoring database (2002-2007) of the University of Nebraska Medical Center was searched for patients with a definite history of ictal thirst. All available data of the patients, particularly their original video and EEG data, were reviewed.Results: Out of over 200 monitored patients 2 were found to have thirst as an ictal manifestation. The first patient had 4 seizures during the monitoring, she asked for water during each one of these and drank water as if she was thirsty during ictal EEG discharge. The ictal EEG seizure onset was from the right temporal lobe. The MRI showed right mesial temporal sclerosis, as seen in figure 1 & 2. She is seizure free on 3 antiepileptic medications. Nine seizures were recorded in the second patient. She drank water in each one of them as if she was thirsty during ictal EEG seizure discharge. In 5 seizures she had other objects available to choose from but she always picked up the water jug and drank water. The ictal EEG seizure onset was from the right temporal lobe in every seizure. The MRI Brain showed a right medial temporal cystic lesion. The patient underwent a surgical resection of the lesion and has been seizure free for 25 months. Conclusions: Ictal thirst is an uncommon feature of temporal lobe seizures. It is not an automatism as the patient either asked specifically for water and drank it as if she was thirsty or chose a jug of water from myriad other objects available and then drank a significant amount of it as if quenching her thirst. It is likely that the thirst center lies outside the medial temporal area but the connections of the medial temporal area render it capable of influencing such behavior. A recent study of functional neuroimaging of thirst showed maximum thirst sensation evoked 13 highly significant activations and 9 deactivations in cingulate and parahippocampal gyri, insula, thalamus, amygdala, and mesencephalon. This does explain how thirst can be a manifestation of medial temporal lobe epilepsy. Recognition of such seizure manifestation is important in identifying seizures and aids in the correct localiztion of seizure focus.