JLE

Epileptic Disorders

MENU

Pupillary hippus in nonconvulsive status epilepticus Volume 14, issue 3, September 2012

Video

  • Pupillary hippus in nonconvulsive status epilepticus

Figures

See all figures

epd.2012.0521

Auteur(s) : David Schnell1, Laurent Arnaud1, Virginie Lemiale1, Stephane Legriel1,2 slegriel@ch-versailles.fr

1 Medical Intensive Care Unit, AP-HP, Hôpital Saint-Louis, University Paris-7 Paris-Diderot, UFR de Médecine, Paris

2 Medico-Surgical Intensive Care Unit, CH Versailles-Site André Mignot, Le Chesnay, France

Correspondence: Stephane Legriel Intensive Care Unit, CH Versailles-Site André Mignot Hospital, 177, rue de Versailles, 78150 Le Chesnay, France

Case study

A 47-year-old man was transferred to the intensive care unit for coma. On the day after admission, he experienced a generalised tonic-clonic convulsive status epilepticus. The seizures stopped after an intravenous clonazepam bolus combined with a 20-minute phenobarbital infusion. The patient then remained stuporous with spontaneous eye opening, dysconjugate gaze, leftward gaze deviation, and ongoing pupillary hippus (see video sequence). The EEG (figure 1) showed diffuse bilateral, non-reactive, rhythmic delta activity, predominating over the right hemisphere, indicating progression to generalised nonconvulsive status epilepticus (NCSE). The patient died due to multiple organ failure.

NCSE has been reported to develop in 13% (Legriel et al., 2010) to 20% (Treiman et al., 1998) of patients after convulsive status epilepticus. Autonomic symptoms frequently accompany seizure activity (Baumgartner et al., 2001). NCSE results from a dysfunction of the central autonomic network which involves the insula, the medial prefrontal cortex, and other regions of prefrontal cortex interactions (Baumgartner et al., 2001).

Pupillary autonomic manifestations during ictal activity can be summarised by bilateral mydriasis, which is a common manifestation during generalised tonic-clonic seizures, and rarely, by myosis or unilateral presentations. Pupillary hippus has been exceptionally reported to be associated with seizure activity. Pupillary hippus is defined as a continuous oscillation of pupillary diameter in the absence of light flux variations or other external stimuli (Thompson et al., 1971). Its pathophysiology remains under debate but seems to be related to dysregulation of pupillary motricity which is mediated by the Edinger-Westphal nucleus, the accessory parasympathetic cranial nerve nucleus of the oculomotor nerve, herein activated via the insula (Baumgartner et al., 2001; Centeno et al., 2011).

In addition, epileptic nystagmus is one of the hypotheses that should be formulated to explain dysconjugate gaze and leftward gaze deviation. The direction of nystagmus is usually contralateral to the epileptogenic hemisphere (Kellinghaus et al., 2008), which could explain in our case the leftward gaze deviation associated with a right-sided predominance of electroencephalographic ictal activity.

However, despite the variable presence of pupillary hippus during seizure activity, pupillary examination should be systematically performed in patients with status epilepticus. In this particular context, pupillary hippus may be a clinical sign alerting to the presence of NCSE and, therefore, an indication for performing an urgent EEG.

Disclosures

The authors have no conflicts of interest or financial support to disclose.

Legends for videosequences The patient presented ongoing pupillary hippus after control of generalised tonic-clonic seizure activity. Key words for video research on www.epilepticdisorders.com Syndrome: not applicable Etiology: not applicable Phenomenology: status epilepticus (convulsive) ; status epilepticus (non convulsive) Localization: not applicable