Beware of Neurotoxins in Common Plants: Water Hemlock Poisoning Presenting as Convulsive Status Epilepticus.

BACKGROUND: Pediatric status epilepticus occurs in about 44/100.000 children per year with an unknown cause in about a third of patients. One cause can be the ingestion of plants containing toxins that target the central nervous system. Here we describe an ingestion of water hemlock resulting in a status epilepticus. METHODS: We studied in detail the clinical, laboratory, electrophysiological, and radiological features of a patient with status epilepticus. RESULTS: A 9-year-old boy presented to the pediatric emergency department for sudden onset of nausea, vomiting, and status epilepticus approximately one hour after the patient had bitten into the root of a water plant in an inner-city park. Bilateral tonic-clonic seizures could only be terminated after administration of midazolam, lorazepam, and finally propofol. Cranial MRI, cerebrospinal fluid, and EEG findings were largely unremarkable. The ingested plant was identified as water hemlock through a detailed search with the help of a drawing issued by the patient with the help of the medical team. The specific toxicological analysis for water hemlock verified the presence of cicutoxin and cicudiol in the blood sample. The patient was discharged, levetiracetam was weaned off four weeks later, and he has remained seizure free since. CONCLUSIONS: Given the considerable percentage of cases of unknown etiology in new-onset pediatric status epilepticus, it is important to consider plant intoxication as a possible cause.

Poisoning due to water hemlock.

INTRODUCTION: Water hemlock, which encompasses a range of species divided across two genera (Cicuta and Oenanthe), are regarded as being among the most poisonous plants both in North America and in the United Kingdom. Despite their toxicity, the literature consists almost entirely of case reports. AIM: The aim of this review is to summarize this literature by covering all aspects of taxonomy and botanical characterization, principal toxins, basic pharmacology including mechanisms of toxicity, and the clinical features, diagnosis, and management of poisoning. MECHANISMS OF TOXICITY: The principal toxins, cicutoxin and oenanthotoxin, belong to a group of C17 conjugated polyacetylenes. They act as (noncompetitive) gamma-aminobutyric acid antagonists in the central nervous system (CNS), resulting in unabated neuronal depolarization that can lead to seizures. Ingestion of even a small amount of plant matter may result in severe intoxication. FEATURES: After ingestion, the patient is most likely to experience CNS stimulatory effects including seizures that, in the absence of aggressive supportive care, can result in death. Other features include nausea, vomiting, diarrhea, tachycardia, mydriasis, rhabdomyolysis, renal failure, coma, respiratory impairment, and cardiac dysrhythmias. MANAGEMENT: Treatment consists mainly of prompt airway management and seizure control, plus decontamination if achieved early and after stabilization. In the event of renal failure, the use of hemodialysis has been employed successfully. CONCLUSIONS: The ingestion of water hemlock can lead to serious complications that may be fatal. Prognosis is good, however, if prompt supportive care is provided.

Plant exposures: wilderness medicine.

This article discusses poisonous plants, the symptoms that might arise if they are ingested, and the treatments that should be administered to patients.