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Biomedical subjects

D Bowsher

Publications and source records attributed to D Bowsher.

At least 55 records · Page 3Linked to original sources
PubMed1992

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.

Acute Disease↗
PubMed1991

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%.

Amitriptyline↗
PubMed1991

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.

Aged↗
PubMed1991

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.

Arm↗
PubMed1990

Central pain.

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Central Nervous System Diseases↗
PubMed1990

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.

Aged↗
PubMed1990

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.

Adult↗
PubMed1986

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.

Electric Stimulation↗
PubMed1985

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.

Chronic Disease↗
PubMed1984

Classification of neurons by dendritic branching pattern. A categorisation based on Golgi impregnation of spinal and cranial somatic and visceral afferent and efferent cells in the adult human.

Neurons from adult human brainstem and spinal cord, fixed by immersion in formalin, were impregnated by a Golgi method and examined in sections 100 micron thick. Objective numerical criteria were used to classify completely impregnated neurons. Only the parameters mentioned below were found to be valid. Neurons in 100 micron sections were classified on the basis of (i) the primary dendrite number, indicated by a Roman numeral and called group; (ii) the dendritic branching pattern, comprising the highest branching order seen, indicated by an Arabic numeral and called category; the lowest dendritic branching order observed in complete neurons, indicated by an upper case letter and called class; and the number of branching orders seen between the two preceding, indicated by a lower case letter and called subclass. On the basis of the above characteristics, all neurons seen in the grey matter of the spinal cord and cranial nerve nuclei could be classified into thirteen 'families'. The results of other investigations (Abdel-Maguid & Bowsher, 1979, 1984) showed that this classification has functional value.

Adult↗
PubMed1984

Interneurons and proprioneurons in the adult human spinal grey matter and in the general somatic and visceral afferent cranial nerve nuclei.

Using the classification of Abdel-Maguid & Bowsher (1984), interneurons of the dorsal horn of the grey matter of the human spinal cord and medulla oblongata were found to belong to only three 'families' of neurons, out of a possible thirteen. This is in itself one of the justifications for the method of classification. Functional identification of these human neurons has been made on the basis of topological, morphological and projectional comparison with known cells in other mammalian species. Among the cells identified are gelatinosal interneurons and Renshaw cells of laminae VII and VIII. Neurons belonging to the same 'family' as Waldeyer cells of lamina I continue around the outer edge of the grey matter, their dendrites forming a part of the boundary between grey and white matter. Interneurons with small and very small dendrite fields lie on interlaminar boundaries and have mediolaterally oriented dendrites, in contrast to the craniocaudally oriented dendritic field of most dorsal horn neurons. If such dendrites lying along interlaminar boundaries are also found to exist in other species, it may explain the abrupt change in physiological characteristics which is found on passing an electrode from one lamina to another.

Adult↗
PubMed1984

Superficial dorsal horn of the adult human spinal cord.

Golgi studies in the adult human spinal cord reveal 10 cell types in the first three laminae. Five are Golgi Type II or ipsilateral proprioneurons of short or long range--the latter including Waldeyer cells. Several of the cells in this group have dendrites that help to form interlaminar boundaries on the gray-white boundary. Two of the four cell types in Lamina II have dendritic fields that correspond exactly to the primary afferent terminal axonal fields described in the cat by Rethelyi (1977). Three cell types, one in each lamina, can be tentatively homologized with monkey spinothalamic cells described by other authors. Our previously described classification method based on dendritic patterns suggests that the Golgi Type II interneurons and ipsilateral proprioneurons belong to two different cell families (and Waldeyer cells to a third), whereas the putative spinothalamic neurons are all different cell types.

Animals↗