An epidemiological study of wastage among racehorses was conducted in 1982 and 1983 among six stables, five of which were in Newmarket. The basis of the survey was the inability of horses to take part in cantering exercise as a result of injury or disease. The greatest number of days lost to training was caused by lameness (67.6 per cent) and respiratory problems (20.5 per cent). Conditions of the foot (19 pe cent), muscle (18 per cent), carpus (14 per cent), fetlock joints (14 per cent), tendons (10 per cent) and sore shins (9 per cent) were the major reasons for training days being lost in 198 cases in which a positive diagnosis of the site of lameness was made. The results confirm a previous investigation by Jeffcott and others (1982) and suggest that the diagnosis, therapy and prophylaxis of lameness merit a high priority in research efforts to reduce wastage among young racehorses.

3 Strupp M, Brandt T, Muller A. Incidence of post-lumbar puncture syndrome reduced by reinserting the stylet: a randomised prospective study of 600 patients. J Neurol 1998;245:589-92. 4 Greene HM. Lumbar puncture and the prevention of post puncture headache. JAMA 1926;86:391-2. 5 Evans RW. Complications of lumbar puncture. Neurol Clin North Am 1998;16:83-105. 6 Carson D, Serpell M. Choosing the best needle for diagnostic lumbar puncture. Neurology 1996;47:33-7. 7 Muller B, Adelt K, Reichmann H, Toyka K. Atraumatic needle reduces the incidence of post-lumbar puncture syndrome. J Neurol 1994;241:376-80. 8 Kleyweg RP, Hertzberger LI, Carbaat PAT. Significant reduction in post-lumbar puncture headache using an atraumatic needle. A double-blind, controlled clinical trial. Cephalalgia 1998;18:635-7. 9 Braune HJ, Huffman G. A prospective double-blind clinical trial, comparing the sharp Quincke needle (22G) with an "atraumatic" needle (22G) in the induction of post-lumbar puncture. Acta Neurol Scand 1992;86:50-4. 10 Flaatten H, Krakenes J, Vedeler C. Post-dural puncture related complications after diagnostic lumbar puncture, myelography and spinal anaesthesia. Acta Neurol Scand 1998;98:445-51. 11 Lybecker H, Moller JT, May O, Nielsen HK. Incidence and prediction of postdural puncture headache. A prospective study of 1021 spinal anesthesias. Abstract Objectives To assess the ability of patients with binocular 6/9 or 6/12 vision on the Snellen chart (Snellen acuity) to read a number plate at 20.5 m (the required standard for driving) and to determine how health professionals advise such patients about driving. Design Prospective study of patients and postal questionnaire to healthcare professionals.

SUMMARY A 45-year

We analyzed the medical records of 103 patients with familial adult motor neuron disease (MND). In the 72 families, 329 members were known to be affected. Observations were compared with the sporadic and Mariana forms of MND. Clinical and laboratory examinations of all three forms were similar in clinical course and findings, but there were minor variations in age at onset, sex ratio, survival, and the frequency with which onset occurred in the lower extremities. Recognition of the familial form still depends on diagnosis of the disease in more than one member of a family.

Thyroid nodules are present in up to 50 percent of adults in the fifth decade of life. Patients are often treated with thyroxine in order to reduce the size of the nodule, but the efficacy of thyrotropin-suppressive therapy with thyroxine remains uncertain. In this study, 53 patients with a colloid solitary thyroid nodule confirmed by biopsy were randomly assigned in a double-blind manner to receive placebo (n = 25) or levothyroxine (n = 28) for six months. Before treatment, pertechnetate-99m thyroid scanning showed that 22 percent of the nodules were functional, 25 percent hypofunctional, and 53 percent nonfunctional. High-resolution (10-MHz) sonography was used to measure the size of the nodules before and after treatment. Suppression of thyrotropin release was confirmed in the levothyroxine-treated group by the administration of thyrotropin-releasing hormone; thyrotropin release was normal in the placebo group. Six months of therapy did not significantly decrease the diameter or volume of the nodules in the levothyroxine group as compared with the placebo group. We conclude that the efficacy of levothyroxine therapy in reducing the size of colloid thyroid nodules is not apparent within six months, despite effective suppression of thyrotropin.