J Neurocrit Care.  2023 Jun;16(1):46-50. 10.18700/jnc.230019.

Unexpected epileptogenic effect of lethal doses of pentobarbital: a case report

• Giudicelli-Bailly A
• Badia CD
• Augsburger M
• Quintard H
• Giraud R
• De Stefano P

• KMID: 2543393
• DOI: http://doi.org/10.18700/jnc.230019

Abstract

Background
Barbiturate poisoning is rare but potentially fatal.
Case Report
We reported a case of barbiturate poisoning in a 28-year-old woman who recovered from lethal pentobarbital deliberate self-poisoning. The initial blood pentobarbital concentration was 61 mg/L, corresponding to a potentially lethal dose. Despite the ingestion of a high dose of pentobarbital, the electroencephalogram revealed an unattended pattern compatible with possible nonconvulsive status epilepticus. Following resuscitation maneuvers, appropriate care, and antiseizure medication, the patient awakened after 7 days. The evolution was excellent without neurological deficits at 2 months.
Conclusion
Despite the expected and known effects of high-dose pentobarbital in reducing and suppressing cortical activity in the brain, the present case demonstrates that lethal dose of pentobarbital may have an epileptogenic effect. Our hypothesis was that the mechanism of the origin of such a picture is a relatively abrupt decrease in toxic doses of pentobarbital, resulting in a withdrawal phenomenon.

Keyword

Pentobarbital; Status epilepticus; Nonconvulsive status epilepticus; Ictal–interictal continuum; Forensic science

Figure

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  Fig. 1. The image shows 20 seconds of 25-channel electroencephalogram (EEG) in bipolar longitudinal montage. Distance between bold vertical grey bars: 1 seconds electrocardiogram. (A) Rhythmic and periodic patterns with morphology of 2 Hz spike-wave and/or and 2–3 Hz generalized rhythmic delta activity+sharp) frontally predominant, unreactive to pain stimulus, compatible with possible nonconvulsive status epilepticus in coma, day 3 from intoxication. (B) Generalized slow activity on a sub-continuous background (delta band predominant). EEG improved after parenteral anti-seizure medication, 36 hours after status epilepticus onset. STIM, stimulus.

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  Fig. 2. Pentobarbital’s plasma level (mg/L) during intensive care unit stay. EEG, electroencephalogram; NCSE, nonconvulsive status epilepticus. H0, zero hours (time of injection); H+2, 2 hours after injection.

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  Fig. 3. Brain magnetic resonance imaging on day 4 from intoxication revealing no abnormalities. (A) Horizontal section of diffusion-weighted imaging. (B) Fluid-attenuated inversion recovery.

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