Postgrad Med J 1997; 73: 254-255 (© The Fellowship of Postgraduate Medicine, 1997 Letters to the Editor Postgrad Med J: first published as 10.1136/pgmj.73.858.254 on 1 April 1997. Downloaded from Hereditary essential tremor and movement disorders. Alternatively, it may be two to three years. Although some countries restless legs syndrome indicative of an underlying link. The differing accept haemachromatosis sufferers as paid pharmacological responsiveness of the two blood donors, asymptomatic patients in the disorders argues against a shared pathophy- UK may not perceive any tangible benefit Sir siological mechanism. A linkage at the genetic from their weekly hospital visit and are Essential tremor is usually considered to be a level would therefore seem more likely. Like excluded from blood donor panels.2 Venesec- monosymptomatic disorder with variable clin- hereditary tremor, restless legs syndrome has tion is inconvenient and noncompliance can ical expression, about half of all cases demon- been reported to present in childhood and be a problem. strating an autosomal dominant pattern of adolescence as an hereditary condition with Ancylostoma duodenale is a nematode para- inheritance.' Possible associations with other probable autosomal dominant transmission.6 site of the human gut. The adult worms are movement disorders have been described, It may be that in this family, genes for 8-11 mm long, and attach to the mucosa of including Parkinson's disease.2 We report a essential tremor and restless legs have co- the upper small intestine with a set of cutting patient with hereditary essential tremor and segregated. In such families, identification of mouthparts. They live on blood and plasma the restless legs syndrome. the genetic locus for one condition may thus protein sucked from the lamina propria, each A 71-year-old woman complained of a facilitate definition of the other. worm consuming 0.2 ml of blood (about tremor in her right upper limb. This had 0.09 mg of iron) per 700- affected her writing since her teens but had day. Worldwide, ANDREW J LARNER 900 million become worse in recent also people harbour hookworms, months, affecting CMC ALLEN making this infection second to men- the left arm. The tremor was exacerbated only by Department ofNeurology, struation as the major global cause of iron anxiety and fatigue; alcohol had no relieving Addenbrooke's Hospital, deficiency. effect. Tremulousness of the voice had made Cambridge CB2 2QQ, UK The therapeutic potential of hookworms it increasingly difficult for her to sing in the for church choir. She also complained of dis- haemachromatosis is obvious. To attain a comfort in the legs when sitting, unrelieved by Correspondence to Dr AJ Lamer, Department of daily blood loss equivalent to 450 ml per massage but improved by getting up and Neurology, St Mary's Hospital, Praed Street, week, 300-400 worms would be required, walking about, and by taking a hot bath. She London W2 INY, UK depending on the amount of iron resorbed. A duodenale lives for one to six years and 'could not relax' because of an uncontrollable Accepted 21 August 1996 urge to move her legs when at rest. Although autoinfection does not occur so blood loss is present throughout the day, this was particu- predictable. A three- or six-monthly blood larly evident at night and often prevented her 1 Bain PG, Findley LJ, Thompson PD, et al. A count, albumin and ferritin would be used to study of hereditary essential tremor. Brain 1994; monitor therapy. Commonly prescribed from falling asleep. This symptom had also 117: 805-24. drugs been present since childhood when she had 2 Lang AE, Kierans C, Blair RDG. Family history would not kill the worms during their been labelled a 'fidget' at school because of of tremor in Parkinson's disease compared with residence but once iron stores had returned those of controls and patients with idiopathic to normal a two-day course of mebendazole her restlessness in class. A significant exacer- dystonia. In: Yahr MD, Bergmann KJ, eds. bation of these symptoms occurred during Parkinson's disease. Advances in Neurology, vol 45, should eradicate them. Hookworms are well pregnancy. Both her father and paternal New York: Raven Press, 1986; pp 313-6. adapted and, apart from anaemia, morbidity grandfather had been troubled by a similar 3 Aldrich MS, Allen R, Ancoli-Isreal S, et al. from natural worm infection is minimal. The Toward a better definition of the restless legs practicalities of experimental human infection tremor of the arms. Moreover, her father had syndrome. Mov Disord 1995; 10: 634-42. always been 'fidgety' and unable to settle. Her 4 Bomstein B. Restless legs. Psychiat Neurol have been studied previously.3'4 Side-effects only sibling, a non-identical twin sister, was (Basel) 1961; 141: 165-201. include pruritus at the site of cutaneous 5 Jankovic J. Essential tremor and other movement penetration, mild laryngeal and pulmonary unaffected, likewise her only son (aged 47). disorders. In: Findley LJ, Koller WC, eds. On symptoms during pulmonary passage and examination, the patient had a distal Handbook of tremor disorders. New York: Marcel http://pmj.bmj.com/ tremor in the upper limbs, accentuated by Dekker, 1995; pp 245-61. occasionally, upper gastrointestinal discom- 6 Ekbom KA. Restless legs syndrome. Neurology fort. In the UK there is no danger of posture. Writing showed intrusion of tremor 1960; 10: 868-73. and drawing of a spiral was impaired. Head transmission to others (except in the special titubation ('no-no') was also evident, and case of miners working in warm damp holding a single note revealed vocal tremor. tunnels) because the soil dwelling stage Otherwise neurological examination was en- Hookworms to treat haemachro- requires a high ambient temperature. The tirely normal; in particular, there were no matosis? main problem is likely to be patient consent. dystonic features nor evidence of a peripheral There is a natural aversion to the idea of neuropathy. Investigations (urea, creatinine, Sir intestinal parasites and blood sucking crea- on September 25, 2021 by guest. Protected copyright. thyroid function tests, full blood count, serum Biological control strategies can be used to tures, and the knowledge that one was vitamin B12 and red cell folate) were normal. tackle ecological problems and plant diseases. harbouring them could colour subsequent Treatment with propranolol (40 mg bid) For example, hydrocarbon-metabolizing bac- perception of abdominal symptoms. For marginally improved her postural tremor, teria are used to degrade oil spills and long-term maintenance therapy only a little but had no effect on her restless legs. gardeners use parasitic organisms like the blood loss is required, so biannual venesec- Clinically this patient had unequivocal wasp Encarsia formosa, which preys on green- tion would be used. In conclusion, we feel hereditary essential tremor.1 Furthermore, house whitefly. However, living organisms are that despite current enthusiasm for alternative she fulfilled the suggested diagnostic criteria rarely used for treatment of human disease, and 'natural' medicine, the possibilities of for restless legs syndrome.3 Previous accounts although Wagner von Janregy won a Nobel hookworm therapy for haemachromatosis of an association between hereditary essential prize in 1927 for his work with malaria have been overlooked. tremor and restless legs are few. Bornstein therapy for syphillis, now superseded by reported a pedigree in which restless legs and penicillin, and leeches are still valued by D SIMON C ROSE hereditary tremor coincided in three patients plastic surgeons. We should like to propose Department ofHistopathology, University College over two generations, with a similar time of hookworms for the treatment of haemachro- London, Medical School, Rockefeller Building, onset in each patient, and opined that the matosis. University Street, London WClE 6JJ, UK syndromes were 'somehow associated'.4 Bain Idiopathic haemachromatosis is an auto- et al found restless legs in three of 93 patients somal recessive inborn error of iron metabo- BEGONiA A BOVILL with hereditary essential tremor; restless legs lism with accumulation of 20-40 g of iron Department ofHaematology, Whittington and tremor were found to co-segregate.1 resulting in multi-organ damage and death Hospital, Highgate Hill, London Nl9 5NF, UK Jankovic has reported encountering several from cardiac failure or liver disease (normal patients with the restless legs syndrome and body iron content is 3-4 g). Removal of Accepted 21 August 1996 an essential tremor-like tremor but gives no excess iron reverses many of the biochemical further details.5 and functional abnormalities.' Treatment 1 Finlayson NDC. Hereditary (primary) haema- The association between essential tremor chromatosis. BMJ 1990; 301: 350-1. includes weekly venesection of 450 ml of 2 Wormwood M, Darke C, Trenchard P. Heredi- and restless legs in our patient could be the whole blood (equal to 0.2 g of iron) until tary haemacbromatosis and blood donation. chance concurrence of two relatively common iron stores return to normal, which may take BMJ 1991; 302: 593.