To the Editor:
A 13-year-old female, with a history of migraine, was admitted with a Glasgow coma score (GCS) of 11 at the emergency. Before the onset of confusion, the patient complained of a headache. When admitted, she was febrile (38°C) with slow and depressed respiration (8 breaths per minute). Pulse rate was of 80 per minute and blood pressure of 111/60 mmHg. She had no neck stiffness. Osteotendinous reflexes were all absent. Physical examination was normal. Brain computed tomography was unremarkable. Electrocardiogram and biological tests, including arterial blood gas, blood tests and CSF study were normal. Immunological screening in blood and urine for barbiturates, tricyclic antidepressants, benzodiazepines, opiates and cannabinoids was negative, no chromatographic screening was performed. The diagnosis of encephalitis was suspected and the patient was intubated and received intravenous ceftriaxone and aciclovir. Finally, a detailed interrogation of the parents found that about 1 hour before the onset of confusion, the patient had drunk an infusion (about 30 g in 250 ml) of a plant to treat a migraine headache. All drugs were immediately stopped and the plant brought later by the family was identified by a botanist as Delphinium peregrinum. Patient's clinical outcome was favorable: After about 24 hours, the patient was conscious but remained disorientated, the fourth day she totally recovered and was thus discharged from the hospital. Clinical examination after 1 and 3 months was unremarkable.
Delphinium peregrinum is an endemic plant in some Moroccan regions and characterized by dark violet flowers. No therapeutic use of this plant is known in the Moroccan traditional pharmacopoeia.Citation1 The genus Delphinium has been long known for its toxicity in mammals.Citation2 This toxicity is variable depending on species, growth stages and concentration of toxic substance. Over 40 norditerpenoid alkaloids are found in Delphinium species. The methylsuccimidoanthronyllycoctonine (MSAL) group of alkaloids is the most toxic. The lycoctonine group of alkaloids, found in Delphinium peregrinum, has a moderate toxicity.Citation3 The mechanism of toxicity of this class of alkaloids is neuromuscular paralysis; they compete as post-synaptic inhibitors of the neurotransmitter acetylcholine, specifically, acting at the α1 nicotinic sites in the muscle and brain,Citation4 causing muscular fatigue, depressed respiration and other curare-like symptoms. Thus, clinical signs of intoxication in cattle include muscular weakness and trembling, straddled stance, periodic collapse into sternal recumbency, and finally, death from respiratory failure while in lateral recumbency.
Human delphinium poisoning is exceptional; the only case in the literature was reported in 1996: After the intake of one gram of Delphinium root, a teenager presented ventricular tachycardia and convulsion.Citation5 Our patient was admitted with a GCS of 11, depressed respiration and areflexia. These symptoms had already been described in literature in cases of cattle, mouse and rat and were caused by the curare-like effect of alkaloids. The lack of human clinical cases does not allow us to compare these symptoms to other studies.
No specific treatment is available. Physostigmine is known to reverse toxicosis from larkspur in cattle and has been used as an emergency treatment for animal poisoning.Citation2 The treatment of our patient was symptomatic with endotracheal intubation for the depressed respiration. The clinical outcome was favorable, and the recovery of neuromuscular function had been totally achieved 4 days after admission probably related to the elimination of toxins.
The first aid treatment of human poisoning must be rapid and efficient with respiratory assistance because of curare-like effect of toxins. Generally, it is not easy to diagnose plant poisoning due to the lack of specific detection methods and variability of clinical symptoms. The only way that remains is the detailed anamnesis and clinical examination.
Acknowledgments
We are very grateful to Professor Taleb Abdelkader from Hassan II Agronomic and Veterinary Institute, Rabat, Morocco, for his help to identify the plant.
Declaration of interest: The authors report no conflict of interes. The authors alone are responsible for the content and writing of the paper.
References
- Charnot A. La toxicologie au Maroc. Mémoire de la Soc. Sci. Nat. du Maroc, Rabat, n° XLVII, Nov 1945: 308.
- Pfister JA, Panter KE, Manners GD, Cheney CD. Reversal of tall larkspur (Delphinium barbeyi) poisoning in cattle with physostigmine. Vet Hum Toxicol 1994; 36:511–514.
- Manners GD, Panter KE, Pelletier SW. Structure-activity relationships of norditerpenoid alkaloids occurring in toxic larkspur (Delphinium) species. J Nat Prod 1995; 58:863–869.
- Dobelis P, Madl JE, Pfister JA, Manners GD, Walrond JP. Effects of Delphinium alkaloids on neuromuscular transmission. J Pharmacol Exp Ther 1999; 291:538–546.
- Tomassoni AJ, Snook CP, Mc Conville BJ, Siegel EG. Recreational use of delphinium; an ancient poison revisited (abstract). J Toxicol Clin Toxicol 1996; 34:598.