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Patients who had experienced a recurrence were then advised to give themselves at most two subcutaneous injections of sumatriptan per day. The second injection could be given when needed (at a clear symptom) provided at least an hour had passed since the first injection and provided they had perceived headache relief after that injection. At the second follow-up these patients, as previously, reported recurrence of headache but now they had been able effectively to treat the recurrence with a second injection. Only 1 patient had an additional recurrence within 24 h. In a randomised, double-blind, placebo-controlled, parallelgroup clinical trial2 in 639 patients, 34-38% of those treated subcutaneously with sumatriptan reported a recurrence compared with 18% of those on placebo. These high percentages of recurrence may arise simply because of the short half-life (about 2 h) of sumatriptan. In most cases, however, recurrences can be overcome by a second injection. Until further clinical data are available, the use of more than two injections per day is not recommended. Gothenburg Migraine Clinic, Sociala Huset, S-411 17 Gothenburg, Sweden

CARL DAHLÖF

1 Anon. Sumatriptan from molecule to man. Eur Neurol 1991; 31: 279-344 2. Subcutaneous Sumatriptan International Study Group. Treatment of attacks with sumatriptan. N Engl J Med 1991; 325: 316-21.

migraine

Manganese intoxication during total parenteral nutrition SiR,—Trace elements, including manganese (Mn), are usually given intravenously to patients on long-term total parenteral nutrition (TPN).l,2 However, little is known about Mn supplementation in TPN. 2,3 A 62-year-old man was admitted to hospital with gait disturbance that had been worsening slowly over the previous 16 months. He had been on TPN for 31 months because of short-bowel syndrome developing after massive bowel resection for superior mesenteric artery occlusion. Essential trace elements, including Mn 2-2 mg daily (an amount not more than three times American Medical Association guidelines’) had been added to the TPN solution for a total of 23 months. The cumulative Mn dose was 15 g. His whole blood Mn had been 3-0-5-6 Ilg/dl (normal 0-4-20), and his serum and plasma Mn had never been above the normal range. On admission, he was alert and well-oriented and scored 29/30 on Japanese version of the mini-mental-state test.4He had parkinsonism, with dysarthria, mild rigidity, hypokinesia with masked face, a halting gait, and severely impaired postural reflexes. Laboratory findings were normal except for slight renal dysfunction. A 1 ’5 T magnetic resonance scan (MRI) during the third hospital week revealed symmetrical high-signal intensity on Tl-weighted images in the basal ganglia, especially globus pallidus, tectum, and tegmentum of midbrain and pons (figure). These regions were not enhanced by gadopentetate dimeglumine; nor did they show changes on T2-weighted images. In the second week trace element supplementation was discontinued. Biperiden and levodopa were given intravenously and his parkinsonism gradually regressed. 15 weeks after Mn cessation whole-blood Mn had fallen to 0-5 )g/dl. The high intensity of basal ganglia and brainstem on MRI decreased 15 weeks after supplementation had stopped and was much reduced at 22 weeks (figure), though the globus pallidus retained some hyperintensity. This patient had a unique combination of parkinsonism, a high signal intensity in basal ganglia and brainstem on MRI, and a history of intravenous Mn adminstration. Mn is known to cause parkinsonism,s radiologically it shortens spin-lattice relaxation times via its paramagnetism and increases signal intensities on Tl MR images. Mirowitz et al6 observed high intensity in the globus pallitus on Tl-weighted MRI in all nine patients on TPN; monkeys given Mn showed similar changes, the intensity declining after Mn discontinuation.7 In a necropsy case, Yamada et all’ reported that Mn intoxication caused degeneration of the basal ganglia with predominant gliosis of the globus pallidus. Basal ganglia, and the globus pallidus especially, seem vulnerable to Mn. Mn

MRI

scans in third hospital week (upper) and 22 weeks (lower) after withdrawal of Mn. Axial section including pons High signal intensity of pontine tegmentum arrowed (upper) T1-weighted images (TR=500 ms, TE = 90 ms)

homoeostasis in plasma depends on rapid tissue distribution and enterohepatic circulation. Experiments in rats9 show that Mn concentrations in brain are greater after intravenous than after oral administration. Careful attention should be paid to the intravenous administration of manganese. Department of Neurology, Institute of Brain Diseases, and Department of Radiology, Tohoku University School of Medicine,

Sendai 980, Japan, and Department of Surgery, Sendai Red Cross Hospital

1. Expert

AKIKO EJIMA TORU IMAMURA SHOZO NAKAMURA HIROSHI SAITO KO MATSUMOTO SATOSHI MOMONO

Panel, AMA Department of Foods and Nutrition Guidelines for essential element preparation for parenteral use. JAMA 1979; 241: 2051-54

trace

CR. Trace element metabolism in adult patients requiring total parenteral nutrition. Am J Clin Nutr 1989, 49: 573-79. 3. Shike M, Ritchie M, Shils ME, Alock N, Fombaun C. Manganese status in long-term home TPN patients. Clin Res 1986; 34: 804A (abstr). 4. Mon E, Mitani Y, Yamadori A. Usefulness of a Japanese version of the mini-mental state test in neurological patients. Jpn J Neuropsychol 1985; 1: 82-90. 5. Huang CC, Chu NS, Lu CS, et al. Chronic manganese intoxication. Arch Neurol 1989; 46: 1104-06. 6. Mirowitz SA, Westrich TJ, Hirsch JD. Hyperintense basal ganglia on T1-weighted MR images in patients receiving parenteral nutrition. Radiology 1991; 181: 117-20. 7. Newland MC, Ceckler TL, Kordower JH, Weiss B. Visualizing manganese in the primate basal ganglia with magnetic resonance imaging. Exp Neurol 1989; 106: 251-58. 8. Yamada M, Ohno S, Okayasu I, et al. Chronic manganese poisoning: a neuropathological study with determination of manganese distribution in the brain Acta Neuropathol 1986; 70: 273-78. 9. Kabata H, Matuda A, Yokoi K, Kimura M, Itokawa Y. The effect of the dosage and route of manganese administration on manganese concentration in rat brain. Jpn J Hyg 1989; 44: 667-72. 2.

Fleming

Manganese intoxication during total parenteral nutrition.

426 Patients who had experienced a recurrence were then advised to give themselves at most two subcutaneous injections of sumatriptan per day. The se...
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