SUMMARY Nine patients are described with unilateral wasting of the hand muscles associated with elongated C7 transverse processes or with rudimentary cervical ribs. In three patients there was selective wasting of the lateral part of the thenar pad, accompanied by mild weakness of the other hand muscles. In four patients all the hand muscles were wasted, but this was more marked in the lateral part of the thenar pad than elsewhere. In two patients wasting was uniformly distributed throughout the hand. Weakness and wasting in the forearm was only present in four patients and was relatively mild. Sensory loss, when present, affected mainly the inner side of the forearm. Nerve conduction studies revealed no abnormality in the distal part of the median nerve, but some patients had reduced or absent sensory action potentials when the fifth finger was stimulated. In all nine patients a sharp fibrous band was found at operation, which extended from an elongated C7 transverse process or from a rudimentary cervical rib to the region of the scalene tubercle on the first rib. The fibrous band caused angulation of the C8 and TI roots in five patients, and of the lower trunk of the brachial plexus in three. Pathological changes were frequently visible in affected nerves at the site of angulation. Division of the fibrous band relieved pain and paraesthesiae in eight patients and atrested muscle wasting and weakness in nine patients. There was, however, only slight recovery of power in affected muscles; wasting in the hand appeared to be unchanged after periods of up to eight years.

SUMMARY A technique is described for the quantitative assessment of peripheral nociceptive C fibre function by measurement of the axon reflex flare. Acetylcholine, introduced by electrophoresis, is used to stimulate a ring of nociceptive C fibre endings at the centre of which the increase in blood flow is measured with a laser Doppler flowmeter. This flare (neurogenic vasodilatation) has been compared with mechanically or chemically stimulated non-neurogenic cutaneous vasodilation. The flare is abolished by local anaesthetic and is absent in denervated skin. The flare has been measured on the sole of the foot of 96 healthy subjects; its size decreases with age in males, but not in females.

. (1976). British Journal of Industrial Medicine, 33, 65-71. Accidental exposure to isocyanate fumes in a group of firemen. A total of 35 firemen involved in fighting a fire in a factory in which polyurethane foam was made were exposed to fumes of toluene di-isocyanate from two large storage tanks which were damaged during the fire, resulting in massive spillage. Most of the men experienced symptoms during the fire or during the three weeks after it. The symptoms were mainly gastrointestinal, respiratory, or neurological. Altogether 15 men described gastrointestinal symptoms which subsided within two days of onset. Respiratory symptoms were described by 31 men and were most pronounced during the three days after the fire, thereafter tending to improve. The neurological findings are described separately. When the men were reviewed at six months there was a suggestion that some of them might have sustained long-term damage to the respiratory tract, and almost four years later 20 men had persistent respiratory symptoms. Serial measurements of ventilatory capacity revealed a marked decline in the first six months although this was not sustained.A fire occurred in November 1967 at a factory manufacturing polyurethane foam, during which 35 firemen were exposed to chemical fumes including toluene di-isocyanate (TDI). The men were part-time firemen with the exception of five full-time officers. The fire started in a part of the factory where finished blocks of foam were stored and, because of the highly inflammable nature of the foam, the fire spread rapidly to the production section where several tanks of TDI and other chemicals used in the manufacturing process were stored (Table 1).The flexible polyurethane foam was manufactured by reacting toluene di-isocyanate and a propylene glycol, together with various additives. In the factory were several tanks each containing 13 500 litres TDI. When the fire had been in progress for

SUMMARY A technique is described for stimulating and recording from nerves in the finger using surface electrodes. A decrease in amplitude and velocity was found with increasing age. In control subjects the digital potential was approximately one and a half times larger than the potential recorded at the wrist. In patients with carpal tunnel syndrome there was some reduction in amplitude and velocity of the digital potential, but the changes were more marked at the wrist. In diabetic patients more uniform changes were found in the two segments. The Casey (1971). McLeod (1966) pointed out that the measurement of conduction velocity over short conduction distances in the finger is of particular value in patients with neuropathies when slowing and dispersion of the volley is of such a degree that an action potential cannot be recorded over the longer conduction distance between the finger and the wrist. A further advantage is that a distal part of the peripheral nervous system can be studied, which may be useful in investigating dying back neuropathies. For example, the technique has proved valuable in demonstrating a distal lesion in alcoholic neuropathy (Casey and Le Quesne, 1972). METHODS HEALTHY SUBJECTSNinety-four healthy subjects whose ages ranged from 20 to 80 years were examined. None had symptoms or signs of neuromuscular disease. Seventy-five subjects were examined when the digital skin temperature was 35-36°C. This group consisted of 39 females and 36 males. When examining seriously ill patients, it was not always possible to attain or maintain this temperature. A number of results in such patients were obtained when the skin temperature was only 30-32°C. In order to assess these findings a further 19 healthy subjects were examined when the skin temperature of the finger was between 30 and 320 C.