Dacrystic seizures: demographic, semiologic, and etiologic insights from a multicenter study in long-term video-EEG monitoring units.

Purpose: To provide an estimate of the frequency of dacrystic seizures in video-electroencephalography (EEG) long-term monitoring units of tertiary referral epilepsy centers and to describe the clinical presentation of dacrystic seizures in relationship to the underlying etiology.

Methods: We screened clinical records and video-EEG reports for the diagnosis of dacrystic seizures of all patients admitted for video-EEG long-term monitoring at five epilepsy referral centers in the United States and Germany. Patients with a potential diagnosis of dacrystic seizures were identified, and their clinical charts and video-EEG recordings were reviewed. We included only patients with: (1) stereotyped lacrimation, sobbing, grimacing, yelling, or sad facial expression; (2) long-term video-EEG recordings (at least 12 h); and (3) at least one brain magnetic resonance imaging (MRI) study.

Key Findings: Nine patients (four female) with dacrystic seizures were identified. Dacrystic seizures were identified in 0.06-0.53% of the patients admitted for long-term video-EEG monitoring depending on the specific center. Considering our study population as a whole, the frequency was 0.13%. The presence of dacrystic seizures without other accompanying clinical features was found in only one patient. Gelastic seizures accompanied dacrystic seizures in five cases, and a hypothalamic hamartoma was found in all of these five patients. The underlying etiology in the four patients with dacrystic seizures without gelastic seizures was left mesial temporal sclerosis (three patients) and a frontal glioblastoma (one patient). All patients had a difficult-to-control epilepsy as demonstrated by the following: (1) at least three different antiepileptic drugs were tried in each patient, (2) epilepsy was well controlled with antiepileptic drugs in only two patients, (3) six patients were considered for epilepsy surgery and three of them underwent a surgical/radiosurgical or radioablative procedure. Regarding outcome, antiepileptic drugs alone achieved seizure freedom in two patients and did not change seizure frequency in another patient. Radiosurgery led to moderately good seizure control in one patient and did not improve seizure control in another patient. Three patients were or are being considered for epilepsy surgery on last follow-up. One patient remains seizure free 3 years after epilepsy surgery.

Significance: Dacrystic seizures are a rare but clinically relevant finding during video-EEG monitoring. Our data show that when the patient has dacrystic and gelastic seizures, the cause is a hypothalamic hamartoma. In contrast, when dacrystic seizures are not accompanied by gelastic seizures the underlying lesion is most commonly located in the temporal cortex.