Abstracts

Rationale: PIWD is very rare seizure semiology caused by seizure onset zone (SOZ) in the non-dominant temporal lobe. Propagation of epileptiform activity into a hypothalamus may activate water seeking as an attempt to satisfy a motivational drive. This hypothesis has not been confirmed in human. We aimed to report a pathophysiology and expand the clinical spectrum of PIWD.Methods: We identified 3 patients with PIWD between March 2003 and March 2013. Only seizures confirmed by definite video-EEG recordings (vEEG) were included. None of these patients underwent resective epilepsy surgery. All PIWD were observed during seizure or within 60 seconds after the offset of seizures. Results: None of our patients had abnormal interictal drinking, compulsive water drinking or water intoxication syndromes. Patient 1: AV was an 11-year-old-left-handed male with neurofibromatosis 2, intellectual disability, spastic quadriparesis and intractable epilepsy. Brain MRI showed left mesial temporal and hypothalamic lesion. During a vEEG, he developed a brief hypermotor seizure lasting for 14 seconds. He made noises, cried, tuned head to the left side, choked and had violent movement of the right arm without alteration of awareness or postictal confusion. He developed PIWD 9 sec after the seizure offset. EEG showed poorly lateralized ictal EEG activity in the left hemisphere. Seizures had been well controlled with clobazam, oxcarbazepine and levetriacetam (LVT). Patient 2: CP was a 17-year-old-left-handed male with a history of intractable epilepsy since 7 years of age, probable caused by focal cortical dysplasia in the left frontal-temporal-insular region. Four PIWD were captured during the vEEG. All PIWD occurred between 2 and 55 sec after the seizure offset. Ictal SPECT during one of the seizure showed hyperperfusion in the left frontal-temporal with some spreading into insular and thalamus/hypothalamus regions. Seizures had been partially controlled with VNS, LVT and valproate (VPA). Patient 3: OG was an 11-year-old female with intractable epilepsy with myoclonic absence and normal intelligence. During hyperventilating procedure she developed generalized irregular 2.5-Hz-spike-and-wave discharges. Clinically, she had urinary urge, panic attack and PIWD during the ictal EEG activity. She had no loss of consciousness during the seizure. Brain MRI was normal. Her seizures had been poorly controlled with lamotrigine and VPA. Conclusions: The MRI (hypothalamic lesion) and ictal SPECT (ictal hyperperfusion) abnormalities in Patients 1 and 2 confirm that either functional or anatomical hypothalamic dysfunction may be involved in the PIWD. The generalized epilepsy in Patients 3 has been well known for the thalamic involvement. These case series are the first to confirm the role of hypothalamus in PIWD and to expand the clinical spectrum of PIWD in that PIWD can also be seen in generalized epilepsy. In addition, this is the first report case of PIWD seen in generalized epilepsy. Ictal panic attack supported the simultaneous involvement of Papez circuit, controlling emotion and autonomic function, during the PIWD.