Case Reports ltal. J. NeuroL Sci. 18:217-220, 1997 Hypokaliemic with liquorice case rhabdomyolysis associated ingestion: report of an atypical Barrella M., Lauria G., Quatrale R., Paolino E. Clinica Neurologica dell'Universitg7 di Ferrara, Italy We here present an unusual case of hypokaliemic rhabdomyolysis, characterised by a sthenic deficit exclusively involving the distal muscles of the upper limbs and secondary to chronic glycyrrhizic acid intoxication, and by the absence of even ictal arterial hypertension. We discuss the etiopathogenetic bases and the risks related to the development of this secondary hypokaliemic syndrome, also in relation to other concomitant risk factors such as prolonged physical exercise and exposure to low temperatures. Key words: Rhabdomyolysis -- Myogtobinuria -- Liquorice -- Hypokaliemia. Introduction Alterations in the Na/K balance, the central nucleus of the bioelectrical activity of cell membranes, have an early effect on nervous tissue, cardiac and musculoskeletal metabolism. Hypokaliemia may have many causes, one of which is a primary or secondary alteration in the renin- angiotensin-atdosterone axis, the regulator of Na/K exchange at renal level. It is not entirely clear why serum potassium levels of 1.5 mEq/l should be accompanied by severe musculoskeletal effects in some subjects whereas, in others, a similar metabolic imbalance is dominated by cardiac rhythm disturbances. Regardless of the triggering causes, hypokaliemia can give rise to striate muscle fibre damage characterised by cellular effects that may vary from the transient formation of intracytoplasmic vacuoles to the complete disruption of cytoskeletal structures and consequent myofibrillar necrosis, as in the case of rhabdomyolysis [17]. Rhabdomyolyses are generally subdivided into genetically determined forms, which are sustained by a range of about 13 enzymatic defects [17] and are known as recurrent rhabdomyolyses, and secondary forms that have various predisposing and/or triggering factors, including hypokaliemia, exposure to low temperatures and physical exercise. One of the less frequent causes of hypokaliemic rhabdomyolysis is intoxication due to glycyrrhizic acid, a substance that is commonly found in liquorice-based products. It generally onsets in the form of a rapidly progressive muscle deficit, characterised by a prevalently proximal hyposthenia of the limbs associated with myatgias and cramps [17]. More severe cases may The study was supported in part by the Scuola di Specializzazionein Neurologia, Universit~t degti Studi di Ferrara. lead to acute renal failure and a subsequent malignant hyperthermia syndrome [17]. Hypokaliemic rhabdomyo- lysis is typically accompanied by high levels of myoglobinuria and marked increases in serum creatine phosphokinase (CPK). We here present an unusual case of hypokaliemic rhabdomyolysis characterised by a sthenic deficit exclusively involving the distal muscles of the upper limbs and secondary to chronic glycyrrhizic acid intoxication. Case study This 61-year-old male was brought to our attention two days after the appearance of a progressive sthenic deficit involving the distal muscles of the upper limbs, particularly the intrinsic muscles of the hands. The symptoms, which were initially characterised by a rapidly worsening burning sensation in the palms and prehension difficulties, first appeared while the man was shovelling snow and obliged him to stop what he was doing; they gradually and completely disappeared over a period of some hours. The following morning, not long after he had returned to shovelling snow, the symptoms reappeared in a much more pronounced manner, although they were still exclusively confined to his hand muscles. Although he rested, the sthenic deficit remained unchanged for the rest of the day and throughout the night. The patient did not present any signs of fever nor any alterations in diuresis. The anamnesis taken at the time of admission excluded the presence of any findings suggestive of familial neuromuscular diseases (investigated for three generations), and did not reveal any similar clinical Received 28 November 1996 - Accepted in revised form 30 May 1997 217