The secret "spice": an undetectable toxic cause of seizure

Abstract

Neurologists and emergency department physicians are frequently involved in the comprehensive evaluation of a first generalized seizure. An important aspect of this evaluation is a detailed history which can identify a provoked seizure secondary to drug toxicity and hence avoid unnecessary treatment with antiepileptic drugs. "Spice" is an umbrella term for a variety of synthetic cannabinoid products whose inhalation has been associated with an increasing number of toxic side effects resulting in emergency department visits. These side effects (including psychosis, tachyarrhythmia, and seizures) are not typically seen with marijuana (Cannabis sativa) use. We report 2 patients with no prior history of neurological disease that experienced their first generalized tonic-clonic seizure after smoking Spice. The mechanism behind the possible proconvulsant effect of synthetic cannabinoids is not known, but it may be due to their effects at the cannabinoid receptor CB1. Although the US Drug Enforcement Administration placed 5 synthetic cannabinoids into schedule 1 for a 12-month period beginning March 2011, new Spice products containing different synthetic cannabinoids continue to emerge. Because synthetic cannabinoids are not detectable on commercial drug screens it is important that neurologists and emergency department physicians consider Spice inhalation in their differential diagnosis of a first generalized seizure.

Keywords: Spice; cannabis toxicity; first generalized seizure; marijuana toxicity; provoked seizure; synthetic cannabinoid; toxic seizure.

Figure 1.

Examples of currently legal Spice products. Note the physical similarity to marijuana and the “not for human consumption” and “incense” labelling.

Figure 2.

On the far left, the initial magnetic resonance imaging (MRI) of brain shows bilateral sulcal cerebrospinal fluid (CSF), fluid-attenuated inversion recovery (FLAIR) hyperintensity highlighted by the white arrows. In the middle, the initial T1 postcontrast shows diffuse pial and arachnoid enhancement, often seen in the setting of infection, postictal states, or drug reactions. On the right, the follow-up MRI brain T1 postcontrast obtained 2 weeks later, which shows resolution of the enhancement.