Confusion and excitability of initially undetermined cause in the course of poisoning with deadly nightshade in attempted suicide: symptoms, differential diagnosis, toxicology and physostigmine treatment of an anticholinergic syndrome

History and admission findings: After a walk in a wood a 55-year-old teache r was admitted to the emergency unit of a university hospital because of so mnolence and excitability. Her rectal temperature was 37.8 degreesC, she ha d sinus tachycardia (rate of 130/min)but no other significant findings. Investigations: With the exception of C-reactive protein (10 mg/dl), MCV(10 1 fl), MCH (34 pg) and arterial blood gases (pH 7.483, pCO(2) 35.5 mmHg, ba se excess 5.1 mmp/l) laboratory tests were within normal limits. Qualitativ e screening of serum for benzodiazepines, barbiturates and antidepressives was negative. Neurological examination, including lumbar puncture and crani al computed tomography were noncontributory. Treatment and course: 10 hours after admission the patient developed signs of an anticholinergic syndrome with mydriasis, dry mouth, tachycardia, hot skin and an atonic bladder. Ph ysostigmine 2 mg completely reversed the neurological and mental symptoms. After gas chromatography, mass-spectrometry of a urine sample showed an atr opine molecular fragment with a molecular weight of 271. At intervals of 3 to 5 hours the recurrence of confusion and excitability required 4 further i.v. injection of physostigmine. The patient subsequently became accessible to psychiatric examination and reported that during the walk she had swall owed 8-10 berries of deadly nightshade with suicidal intent. Conclusion: In case of excitability and confusion as well as somnolence or coma of uncertain aetiology an anticholinergic syndrome caused by ingestion of atropine-containing plants or psychoactive drugs (phenothiazines, butyr ophenones, tri- or tetracyclic antidepressants) should be included in the d ifferential diagnosis. If there are suggestive clinical findings (tachycard ia, somnolence, coma or threatened respiratory arrest, physostigmine should be given if there are no contraindications.