Biomedical subjects
D Bowsher
Publications and source records attributed to D Bowsher.
Responsiveness of chronic pain to morphine.
Explore the source record for details and available documents.
CSF enkephalins in diabetic neuropathy.
CSF methionine and leucine enkephalins were measured by high performance liquid chromatography and radioimmunoassay in diabetic patients with painful neuropathy (n = 22) and painless neuropathy (n = 5), and non-diabetic subjects with low back pain (n = 11). Wide variations in CSF enkephalin levels were found and they were often below the limit of detection (less than 0.1 pmol/l) in the diabetic and non-diabetic groups. The origin of CSF enkephalins is unknown and CSF levels may not reflect tissue concentrations. In conclusion, CSF enkephalin levels are difficult to interpret and do not provide useful information on the function of enkephalinergic pathways.
Weighted needle pinprick sensory thresholds: a simple test of sensory function in diabetic peripheral neuropathy.
A simple device is described, consisting of 12 weighted 23 gauge disposable needles (0.2 to 5.2 g), for testing sensation in busy diabetic clinics. The pinprick sensory threshold (PPT) is the lightest weighted needle which consistently elicits a sharp sensation. The subjects were 48 healthy controls (hospital staff), 44 diabetic patients without neuropathic symptoms, and 35 diabetic patients with chronic painful neuropathy. In the controls, the mean PPT from the right hand and foot obtained on two test occasions a week apart did not differ significantly. In diabetic patients without symptomatic neuropathy, the mean PPT in the right hand and right foot were significantly higher than in the controls. The diabetic patients with painful neuropathy had clearly increased mean PPT in the right hand and foot compared with controls. Marstock thermal limen in diabetic patients with painful neuropathy correlated significantly with PPT determinations. PPT and thermal thresholds probably give comparable information on small fibre dysfunction in diabetic patients with symptomatic neuropathy. Compared with thermal threshold determinations however, the weighted needle apparatus is inexpensive, simple, and rapid to use.
The location and function of respiratory fibres in the second cervical spinal cord segment: respiratory dysfunction syndrome after cervical cordotomy.
After high cervical percutaneous cordotomy for pain in malignant disease, 12 patients died during sleep at postoperative intervals between 1 and 8 days. Nine died after a first cordotomy and three after a second (contralateral) procedure. All except one had known pulmonary disease before operation. The operated segment of the spinal cord (C2) was studied histologically after death. Superposition of lesion outlines made it possible to determine those parts of the lesioned areas common to all unilateral and bilateral cases respectively. All cases dying of presumed respiratory dysfunction syndrome had lesions involving the region of the anterolateral funiculus in the C2 segment containing "pain" fibres activated from the second to fifth thoracic dermatomes. The fibres whose destruction appeared to be responsible for respiratory dysfunction syndrome were completely intermingled with ascending "pain" fibres. The possibility of these fibres being afferent in function is discussed.
Disturbances of C-fibre-mediated sensibility in lumbosacral disc disease.
Explore the source record for details and available documents.
Acute herpes zoster and postherpetic neuralgia: effects of acyclovir and outcome of treatment with amitriptyline.
This retrospective study was designed to assess the effects of acyclovir treatment of acute herpes zoster on subsequent postherpetic neuralgia, and to examine the effects of amitriptyline in the treatment of postherpetic neuralgia. Eighty seven patients with postherpetic neuralgia of three or more months' duration were studied: 24 of them had had their herpes zoster treated with oral acyclovir. At first presentation, only 25% of the 24 patients who had had their herpes zoster treated with acyclovir selected the word group containing burning on the McGill pain questionnaire compared with 76% of the 63 patients who had not received acyclovir. A higher proportion of patients who had had acyclovir than had not selected the word group which contains the word aching (63% versus 49%). Acyclovir thus appears to change the nature of postherpetic neuralgia. Postherpetic neuralgia was treated with amitriptyline, alone or in combination with distigmine and/or sodium valproate. There was a strong correlation between pain relief and the interval between the occurrence of herpes zoster and the initiation of treatment with amitriptyline--early treatment is almost twice as likely to be successful as late. Since conventional analgesics and sympatholytic drugs are of no benefit in the treatment of established postherpetic neuralgia, the sequelae of herpes zoster must, therefore, be recognized and treated with amitriptyline as soon as possible.
On "The effect of intravenous lidocaine on nociceptive processing in diabetic neuropathy" by Bach et al. in Pain, 40 (1990) 29-34.
Explore the source record for details and available documents.
Neurogenic pain syndromes and their management.
Neurogenic pain is defined as pain due to dysfunction of the peripheral or central nervous system, in the absence of nociceptor (nerve terminal) stimulation by trauma or disease. Other terms used to describe some (but not all) forms of neurogenic pain include neuropathic pain, deafferentation pain, and central pain; all these terms are subsumed into the wider expression 'neurogenic pain'. The clinical syndromes representing this type of disorder make up at least 25% of the patients attending most pain clinics. This is undoubtedly proportionately greater than its incidence in chronic pain as a whole, and is a measure of its intractability and of the therapeutic dilemma which it presents. However, neurogenic pain syndromes are much commoner than is perhaps generally recognized: when all categories are taken into account, there are probably more than 550,000 cases in the UK population of 56 million at any one time, i.e. a prevalence of about 1%.
Pain and allodynia in postherpetic neuralgia: role of somatic and sympathetic nervous systems.
The immediate effects of selective sympathetic and somatic blockades on pain and tactile allodynia in 12 patients with long-standing ophthalmic or high cervical postherpetic neuralgia were compared. For the duration of the somatic blockade, pain was completely abolished in 11 patients and allodynia in 8 patients. In contrast, during the sympathetic blockade only one patient reported total pain relief and three a marginal attenuation of pain while eight remained unchanged; and no patient reported clear alleviation of allodynia. After successful somatic blockade, pain and allodynia reappeared with tactile sensation while thermal sensation was still absent. Pain and allodynia appear to be related to sensory impulses travelling along the large rather than the small diameter fibres; and the sympathetic system may only have a limited role.
Octreotide, a long-acting somatostatin analogue, in diabetic neuropathic pain.
Explore the source record for details and available documents.
The diagnosis of reflex sympathetic dystrophy using an algometer.
Thirty-three patients with reflex sympathetic dystrophy were studied prospectively to ascertain the pressure-pain threshold of affected and unaffected limbs. The affected side had a lower threshold which was found to be statistically significant. In all 18 patients with upper limb involvement, the pain threshold was reduced on the affected side, but this applied to only 11 of the 15 with leg involvement. This difference may be because patients with lower limb symptoms had been referred later in the course of the syndrome. We showed by repeated tests that after an average of 49 days there was a slow return to normality. The estimation of pressure-pain thresholds may help in the earlier diagnosis of reflex sympathetic dystrophy.
Central pain.
Explore the source record for details and available documents.
Somatosensory findings in postherpetic neuralgia.
Somatic sensory perception thresholds (warm, cold, hot pain, touch, pinprick, vibration, two-point discrimination), allodynia and skin temperature were assessed in the affected area of 42 patients with unilateral postherpetic neuralgia (PHN) and 20 patients who had had unilateral shingles not followed by PHN (NoPHN), and in the mirror-image area on the other side. There was no difference between the two groups for age or length of time after the acute herpes zoster infection. The PHN group showed significant changes in all sensory threshold measurements when the affected area was compared with the mirror-image area on the unaffected side, while the NoPHN group exhibited no threshold changes. Mechanical allodynia was present in 87% of the PHN group; half of the 12 patients with ophthalmic PHN showed extension of allodynia to the maxillary distribution. No differences in skin temperature were recorded between affected and unaffected regions in either group. Our findings show a deficit of sensory functions mediated by both large and small primary afferent fibres and also suggest major central involvement in the pathophysiology of the condition. If PHN does not occur following acute herpes zoster, recovery of neural functions appears to be good.
Short term fluctuations in blood glucose concentrations do not alter pain perception in diabetic-patients with and without painful peripheral neuropathy.
Previous studies have suggested that acute hyperglycaemia may affect pain thresholds in non-diabetic subjects. We investigated the effects of acute fluctuations in blood glucose on the perception of pain in diabetic patients with and without painful diabetic neuropathy. Rapid swings in blood glucose concentration produced by IV glucose injection did not alter heat pain thresholds in diabetic patients without symptomatic neuropathy. Also, marked changes in neuropathic pain were not accompanied by significant alterations in blood glucose concentration in diabetic patients with painful neuropathy. Therefore, the alleged effects of acute hyperglycaemia on pain perception described in non-diabetic subjects are not reproduced in diabetic patients.
A case of tabes dorsalis with tonic pupils and lightning pains relieved by sodium valproate.
Explore the source record for details and available documents.
Intracranial stimulation of the trigeminal nerve in man. II. Reflex responses.
The reflex responses evoked by direct electrical stimulation of the intracranial portion of the trigeminal nerve have been studied in 16 subjects undergoing percutaneous retrogasserian thermocoagulation for the treatment of trigeminal neuralgia affecting the second or third division. In the obicularis oculi muscle, early and late responses similar to the R1 and R2 components of the blink reflex were recorded. The former could be evoked only by stimulation of the second division and its latency was consistent with intermediately fast afferents. A late reflex (50-70 ms) was occasionally recorded from the anterior belly of the digastric muscle. The response was sometimes followed by a later activity and showed the features of a polysynaptic reflex. No response was obtained in the jaw elevators when fully relaxed. With the subject voluntarily clenching his teeth, both an early "H-like" response and two silent periods in the background EMG were obtained. The second silent period was similar in the muscles ipsi- and contralateral to intracranial stimulation, while the first silent period was longer in the ipsilateral muscles. Possible mechanisms contributing to the inhibition following stimulation of the mixed portion of the nerve are discussed.
Pain laterality in relation to site of pain and diagnosis.
A retrospective study of pain laterality was performed on a sample of 1006 patients suffering from chronic pain attending the Centre for Pain Relief, Walton Hospital, Liverpool, U.K. 769 patients reported unilateral pain. There was no significant difference in the numbers presenting with right-sided and left-sided pain. When the data for different sites of pain were analysed separately a similar picture emerged. No statistically significant differences in the frequency of left- and right-sided pain were found at any site. Similarly, when the data for different diagnoses were examined, there were no significant differences in the laterality of the pain found in any diagnostic category. This study fails to support the general hypothesis that pain, when lateralised, occurs more frequently on the left.