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Summary Background Conventional treatment for painful peripheral diabetic neuropathy is largely symptomatic and often ineffective, with unacceptable side-effects. We tested electrical spinal-cord stimulation for the management of chronic neuropathic pain. Methods Ten diabetic patients who did not respond to conventional treatment (mean age 51 [SD 9·3] years, six with type II diabetes, mean duration of diabetes 12 [6·3] years, mean duration of neuropathy 5 [2·1] years) were studied. The electrode was implanted in the thoracic/lumbar epidural space. Immediate neuropathic pain relief was assessed by visual analogue scale (VAS) after connecting the electrode, in a random order, to a percutaneous electrical stimulator or to a placebo stimulator. Exercise tolerance was assessed on a treadmill. Findings Eight subjects had statistically significant pain relief with the electrical stimulator (p Interpretation Electrical spinal-cord stimulation offers a new and effective way of relieving chronic diabetic neuropathic pain and improves exercise tolerance. The technique should be considered in patients with neuropathic pain who do not respond to conventional treatment.

Summary Background The use of opioid analgesics for chronic non-cancer pain is controversial. Some surveys report good pain relief and improvement in performance while others suggest a poor outcome with a propensity to psychological dependence or addiction. Methods We undertook a randomised double-blind crossover study to test the hypothesis that oral morphine relieves pain and improves the quality of life in patients with chronic regional pain of soft tissue or musculoskeletal origin who have not responded to codeine, antiinflammatory agents, and antidepressants. Morphine was administered as a sustained-release preparation in doses up to 60 mg twice daily and compared with benztropine (active placebo) in doses up to 1 mg twice daily over three-week titration, six-week evaluation, and two-week washout phases. Pain intensity, pain relief, and drug liking were rated weekly and psychological features, functional status, and cognition were assessed at baseline and at the end of each evaluation phase. Findings After dose titration in the 46 patients who completed the study, the mean daily doses of drugs were morphine 83·5 mg and benztropine 1·7 mg. On visual analogue scales, the morphine group showed a reduction in pain intensity relative to placebo in period I (p=0·01) and this group also fared better in a crossover analysis of the sum of pain intensity differences from baseline (p=0·02). No other significant differences were detected. Interpretation In patients with treatment-resistant chronic regional pain of soft-tissue or musculoskeletal origin, nine weeks of oral morphine in doses up to 120 mg daily may confer analgesic benefit with a low risk of addiction but is unlikely to yield psychological or functional improvement.

In many cases of whiplash injury symptoms persist and do not respond to treatment. There is uncontrolled evidence to suggest that intracutaneous injections of sterile water might help. Since that route may be unacceptable to patients the subcutaneous route is used in the randomised trial reported here. 40 patients with whiplash syndrome, mean age 46 years (24-73) were given subcutaneous injections of 0.3-0.5 ml sterile water or saline over tender and trigger points in the neck and shoulder. A maximum of three treatments were given during the first two months of the study and the patients were followed up for 8 months. The accidents had occurred 4-6 years previously. X-ray examinations revealed no traumatic spinal lesions. Neck mobility and pain levels were evaluated by a physiotherapist immediately before and after the first treatment and after 1, 3, and 8 months. After 3 months, the mean total mobility of the cervical spine had increased by 39 degrees in the sterile water group and 6 degrees in the saline group (p < 0.05). Minimum and maximum levels of pain in the weeks just before treatment were evaluated by a visual analogue scale from 0 to 10. After 3 months the minimum pain level had fallen from 2.2 to 1.4 in the sterile water group but was not reduced in the saline group (p < 0.02); the maximum had fallen from 8.1 to 3.8 in the sterile water group and from 8.3 to 7.5 in the saline group (p < 0.001). After 3 months, 19 of 20 patients in the sterile water group assessed their condition as generally improved but only 6 in the saline group felt that they had got better. After 8 months there were still significant differences for minimum pain score and for mobility but not for maximum pain or for self-assessment of improvement.

Misuse of opioids is associated with abnormalities of pituitary function. Patients with chronic pain frequently complain of fatigue and undergo endocrine testing. To test whether oral opioid treatment causes abnormal pituitary function we prospectively assessed pituitary function in 37 patients with chronic pain who were receiving either oral opioid analgesia or non-opioid analgesia. Oral opioid treatment was not associated with abnormal pituitary function although a few patients had abnormal results mainly related to obesity. Our results suggest that patients with chronic pain who have abnormal endocrine results should have a complete assessment, since abnormal test results cannot be attributed to their analgesia.

Profound and long-lasting analgesia (mean duration of pain relief 33.4 h, range 22.5--73.5 h) was produced by intrathecal administration of 3 mg synthetic beta-endorphin in all of 14 patients with intractable pain due to disseminated cancer. No respiratory depression, hypotension, hypothermia, or catatonia was observed.

Cryotherapy has been clinically applied to relieve pain using a new cryosurgical probe to block peripheral nerve function to achieve analgesia. Sixty-four patients with intractable pain were treated with cryoanalgesia. Fifty-two obtained relief of pain for a median duration of 11 days and a range of up to 224 days.

The intractable pain experienced by patients in the terminal stages of facial carcinoma poses difficult problems—nerve section, medullary tractotomy, or thalamotomy are not always suitable. In seven patients with advanced facial carcinomas who were in poor general health and severe pain, the technique of cisternal injection of hypertonic saline solution was tried. Between 6 and 20 ml. of saline solution was injected, the temperature ranging between 4 and 36°C and the osmolarity being greater than 1000 in all but one instance. Pain relief was immediate, but variable in duration (3-105 days). The injection was sometimes followed by transient vertigo, vomiting, or facial weakness.

In a consecutive series of twenty-seven patients referred to a pain-clinic for the treatment of severe pain, unrepeated nerve-blocks with bupivacaine ('Marcain') produced relief which was still present at 21 days in six out of fourteen patients with post-herpetic neuralgia, two out of six with pain from cancers, and four out of seven with pain from orthopaedic conditions. It is suggested that such nerve-blocks should be tried at an early stage in the management of intractable pain before impairment of the faculties occurs as a side-effect of potent analgesic drugs.

Twelve cases of intractable pain due to various lesions at different levels of the body have been treated by hypothermic subarachnoid irrigation. Worth-while relief has been obtained in seven patients, in five patients the effect was transient or unsuccessful. It is suggested that the unmyelinated C fibres are particularly susceptible to the permanent effects of cooling. No demonstrable sensory deficits and no bladder complications have been noted.