Plant-induced seizures: reappearance of an old problem

Abstract

Several plant-derived essential oils have been known for over a century to have epileptogenic properties. We report three healthy patients, two adults and one child, who suffered from an isolated generalized tonic-clonic seizure and a generalized tonic status, respectively, related to the absorption of several of these oils for therapeutic purposes. No other cause of epilepsy was found, and outcome was good in the two adult cases, but the course has been less favorable in the child. A survey of the literature shows essential oils of 11 plants to be powerful convulsants (eucalyptus, fennel, hyssop, pennyroyal, rosemary, sage, savin, tansy, thuja, turpentine, and wormwood) due to their content of highly reactive monoterpene ketones, such as camphor, pinocamphone, thujone, cineole, pulegone, sabinylacetate, and fenchone. Our three cases strongly support the concept of plant-related toxic seizure. Nowadays the wide use of these compounds in certain unconventional medicines makes this severe complication again possible.

Ada çayı yağının ağızdan kullanımına bağlı süt çocuğunda konvülziyon

“…These substances are epileptogenic and caused intoxication pictures characterized by convulsion at much lower doses compared to other herbal drugs in an investigational study (7). The fact that inadvertent oral intake of a dessert spoon of garden sage caused intoxication with convulsion during infancy in our case seems to be compatible with the investigational study mentioned.…”

Chemical Composition of Vintage Preban Absinthe with Special Reference to Thujone, Fenchone, Pinocamphone, Methanol, Copper, and Antimony Concentrations

“…Wormwood, hyssop, and fennel oil were considered to be convulsant essential oils with epileptogenic components (27). Essences of hyssop have caused poisoning of humans and were found to possess a convulsant action of central origin in animals.…”

Plantas usadas como medicinais no município de Ipê, RS, Brasil

“…Torna-se necessário, no entanto, chamar a atenção de que plantas como o funcho e a camomila, apesar do uso tradicional e da confirmação científica de suas atividades farmacológicas, não podem ser consideradas como isentas de efeitos colaterais. Para o funcho já foram relatadas dermatites de contato em humanos (LEUNG, 1980), sendo que o óleo volátil obtido dos frutos pode causar convulsões epileptiformes (BURKHARD et al, 1999) e depressão do sistema nervoso central (GIRRE, 1985;WENIGER e ROBINEAU, 1988). Para a camomila, também, já foram relatadas dermatites de contato em seres humanos, desenvolvidas pelo contato repetido com a planta (SIMÕES et al, 1986, PAULSEN e ANDERSEN, 1993.…”