Tremor syndrome associated with a fungal toxin: sequelae of food contamination

The man was first to develop symptoms. He reported feeling slightly shaky as the bus arrived at the shops at about 13:00. He had difficulty getting off the bus, his legs felt “wobbly” and he had to sit down. He developed uncontrollable shaking throughout the body, and felt sticky and sweaty. Initial assessment by ambulance officers at about 13:10 was that he had severe muscle tremors and was unable to walk, and that it was difficult to understand his speech. He had no nausea or vomiting, and his abdomen was soft. He was diaphoretic, with blood pressure 160/76 mmHg, pulse rate 80 beats/min, respiratory rate 32 breaths/min, and Glasgow Coma Score 15 out of 15. His oxygen saturation level was 85%, improving to 97% with high-flow oxygen.

Subsequent assessment in hospital at 13:40 revealed that the patient’s Glasgow Coma Score had fallen to 11. Although his speech was incomprehensible, he was able to obey commands; he also displayed generalised weakness and intention tremor. He remained hypertensive and diaphoretic, but was afebrile. He later recounted (to P R L) that he had thought he was going to die. All symptoms, apart from the intention tremor, had subsided by 16:30.

The patient’s medical history included chronic airway limitation, asthma, hypertension, episodic atrial fibrillation, osteoarthritis, a left total hip replacement, and an essential tremor. He had no known allergies. His medications included verapamil, digoxin, aspirin, salbutamol, tiotropium bromide, salmeterol xinafoate, quinine bisulfate prn, paracetamol and rofecoxib prn. His essential tremor remained untreated because of the contraindicated use of β-blockers in asthma.

A chest x-ray was unremarkable, but electrocardiography revealed a right bundle branch block. A computed tomography brain scan showed generalised volume loss with no intracranial haemorrhage or early changes of infarction; a small low-density focus present in the right basal ganglia region was consistent with chronic lacunar infarction.

The results of haematological and biochemical tests were within normal limits, except for urea (8.7 mmol/L; reference range [RR], 2.5–6.4 mmol/L), white cell count (11.2 × 109/L; RR, 4.0–11.0 × 109/L), and haemoglobin (128 g/L; RR, 130–165 g/L) (red cells were normocytic and normochromic). The patient’s blood glucose level (measured by glucometer) was 7.3 mmol/L (RR, 3.5–8.0 mmol/L). Pseudocholinesterase (13.5 U/mL; RR, 7.0–19.0 U/mL) and serum digoxin (1.5 nmol/L; RR, 1.3–2.6 nmol/L) levels were within normal limits. No urine screen for drugs was carried out.

The patient was admitted for observation and investigation. The following day he was lethargic, exhausted, and displayed minimal tremor. He was eventually able to mobilise with the aid of a walking stick, as usual.

The woman had a similar presentation. She complained of feeling dizzy and shaky, but had no nausea or vomiting. Ambulance officers described her as being anxious, diaphoretic, and with uncontrollable shaking. Her blood pressure was not palpable because of severe shaking, but she was well perfused. She was tachycardic (pulse rate, 110 beats/min, taken from electrocardiographic monitoring), with a respiration rate of 20 breaths/min, temperature 36.5ºC, Glasgow Coma Score of 15, and blood glucose level (measured by glucometer) 7.0 mmol/L (RR, 3.5–8.0 mmol/L). Although she was no longer tachycardic on admission to hospital, she remained anxious and diaphoretic, with a generalised tremor that increased with stimuli (eg, being questioned). Her oxygen saturation level on room air remained above 95%. All symptoms, apart from the intention tremor, subsided by 16:30.

The patient’s medical history included a left nephrectomy for calculi, right renal calculi and lithotripsy, chronic airway limitation, asthma, hypertension, and a left-eye cataract. Her medications included hydrochlorothiazide, frusemide, nitrofurantoin, aspirin, trimethoprim, salbutamol prn, beclomethasone dipropionate, quinine bisulfate prn, paracetamol prn, and Macu-Vision tablets (containing ascorbic acid, vitamin E, zinc oxide and cupric oxide).

A chest x-ray and electrocardiogram were normal. A computed tomography brain scan showed no abnormality apart from a polypoid density in the inferior maxillary sinus.

The results of haematological and biochemical tests were normal, except for urea (9.1 mmol/L; RR, 2.5–6.4 mmol/L) and creatinine (0.13 mmol/L; RR, 0.06–0.12 mmol/L). The level of pseudocholinesterase was within normal limits (18.7 U/mL; RR, 7.0–19.0 U/mL). A urine screen conducted for drugs of abuse (including amphetamines, methamphetamines, benzodiazepines, cocaine, opiates and cannabis) was negative.

The patient was admitted for observation, and gradually improved the following day.

Both patients were discharged 2 days after admission with a very slight residual intention tremor. When assessed by their general practitioner 2 weeks later, the man had only a mild increase in his usual essential tremor and the woman’s tremor had completely resolved.