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Biomedical subjects

B Laurent

Publications and source records attributed to B Laurent.

At least 37 records · Page 2Linked to original sources

Anaphylactoid reaction to etomidate: report of a case.

We report an anaphylactoid reaction to etomidate twice in a 60-year-old male with coronary artery disease and peripheral vascular disease. Following the first anaphylactoid reaction, the patient developed myocardial infarction. In addition, the patient's blood was moderately positive for latex antibodies, which made the differential diagnosis difficult. We concluded that the patient had anaphylactoid reaction to etomidate due to the temporal relationship to induction with the drug. The patient did not manifest similar reaction to other induction drugs used for other surgeries. The patient recovered from both incidents of anaphylactoid reaction to etomidate following intravenous administration of epinephrine and fluids.

Anaphylaxis↗

Treatment of hemorrhoids with circular stapler, a new alternative to conventional methods: a prospective study of 140 patients.

BACKGROUND: Surgical hemorrhoidectomy has a reputation for being a painful procedure. The aim of this study was to determine the efficacy and safety of a new procedure for surgical treatment of hemorrhoid disease. STUDY DESIGN: From April 1998 to August 1998, 140 patients (83 men and 57 women) with an average age of 43.8 years (range 19 to 83 years) underwent hemorrhoidectomy using a circular stapler. Operative times, pen- and postoperative complications, mean hospital stay, assessment of the postoperative pain, period of incapacity for work, and functional results were collected. All patients were evaluated at 2 weeks, 2 months, and 18 months after operation. RESULTS: The average length of the operation was 18 minutes (range 8 to 60 minutes). There were no perioperative complications. The postoperative complication rate was 6.4% (n = 9). Mean hospital stay was 36 hours (range 8 to 72 hours). Paracetamol was the only analgesic used. Eighty-three patients (59.3%) required analgesic for less than 2 days, 45 patients (32.1%) between 2 and 7 days, and 12 patients (8.6%) more than 7 days. No patients had anal wound care. One hundred four patients had professions. The period of incapacity for work was less than 3 days for 22 patients (21.1%), between 3 and 7 days for 13 patients (12.5%), between 7 and 14 days for 62 patients (59.6%), and more than 14 days for 7 patients (6.8%). At 18 months, 95.7% of patients were fully satisfied with the results, 3.6% were somewhat satisfied (n = 4), and 0.7% were unsatisfied. CONCLUSIONS: Treatment of hemorrhoids with a circular stapler appears to be safe, effective, and rapid, causing few postoperative complications and minimal postoperative pain. At 18 months, 95.7% of the patients were fully satisfied with the results.

Adult↗

[Headaches caused by abuse of symptomatic anti-migraine and analgesic treatment].

These daily or near-daily headaches result from the chronic overuse of all immediate relief antimigraine drugs: ergotamine, analgesics, and/or more recently triptans. Like for much chronic daily headaches, the International Headache Society diagnostic criteria for drug abuse headaches are difficult to apply. Generally, patients confuse primary headaches (usually migraines) with interparoxysmal tension-type headaches called "rebound headaches". Psychosocial factors may play a role. Insidiously, a compulsive automedication results, often in anticipation of headache. This headache syndrome resists symptomatic and prophylactic treatment. These headaches are frequent, very disabling and socioeconomically costly. They are still largely underdiagnosed. Drug-induced headaches may be restricted to those patients who are already headache sufferers. The pathogenesis is not clearly understood: it may involve a deficience of inhibitory pain modulation, a hyperactivation of nociceptive facilitatory systems, and the peripheral and central effects of the incriminating drugs. The withdrawal of all offending analgesic drugs and a multimodality approach are indispensable, but the therapeutic protocoles are actually very heterogeneous and poorly estimated. Non-drug means could be very helpful. Effective education of headache sufferers and regular follow-up are essential to avoid relapses. Prognosis factors have been evoked, but may not be significant for the long term outcome. The rate successfull of is actually estimated at 60 p. cent at five years. The benefits of an adequate management encourage early recognation of drug-induced headaches. This article has in view to take stock of the literature at the end of 1999, and to help physicians become mora aware of this problem and develp a more preventive attitude.

Analgesics↗

[IContribution of lexical recall in the Set Test in Alzheimer disease screening].

We administered the Set Test to 128 control subjects and 82 patients with Alzheimer's disease. The subjects were to produce, within 15 seconds, items within specific categories: colors, animals, fruits and cities. Control subjects obtained a mean score of 40.3 +/- 3.6 and Alzheimer's disease patients a mean score of 2.7 +/- 4. We found a significant effect of item category, age and cultural level only in control subjects. There was an interaction between sex and item category in both groups. We observed a significant effect of the level of dementia as measured with the MMS only in the Set Test. The Set Test appears to require more attentional resources than fluency within two minutes.

Age Factors↗

Infection-related exposure of the lower anastomosis of femorodistal bypass: salvage through use of pedicle muscle flaps.

Wound dehiscence with exposure of the lower anastomosis is a limb- and life-threatening complication of femorodistal bypass. Plastic surgeons consider pedicle flaps to be unreliable in patients with arterial disease. Despite this opinion, we attempted to treat exposure complications using pedicle muscle flaps after careful study of vascularization on control angiography. The purpose of this report is to describe our results. From 1994 to 1997, infection-related exposure of the distal anastomosis was observed in three men and two women with a mean age of 76 years (range, 66 to 89 years). The exposed anastomosis was located on the dorsalis pedis artery in three cases, the anterior tibial artery in the upper third of the leg in one, and the anterior tibial artery in the lower third of the leg in one. The bypass material was a vein graft in three cases and a cuffed PTFE prosthesis in two cases. Bacteriological examination identified Staphylococcus aureus in three cases, Pseudomonas aeruginosa in one case, and both in one case. Two patients were diabetics and one was undergoing corticosteroid treatment. The anastomosis was covered with a pedicle muscle flap fashioned from the extensor digitorum in four cases and the lateral head of the gastrocnemius in one case. Our results showed that anastomoses on the anterior tibial artery and dorsalis pedis artery are at higher risk for infection-related exposure but this complication can be treated using pedicle muscle flaps. This alternative should be considered before bypass removal or amputation.

Aged↗

[Roles of arterial dysplasia, chronic ergotism and other factors in a case multiple spontaneous arterial dissections].

INTRODUCTION: Spontaneous dissection of cervical and visceral arteries are rare and usually associated with an underlying arterial disease. EXEGESIS: The authors report the unusual case of a 50-year-old woman with high blood pressure who presented spontaneous dissection of cervico-cephalic, renal and hepatic arteries and of the descending aorta. She had been taking ergotamine tartrate for ten years for migraine. She also suffered from Raynaud's syndrome worsened by treatment. CONCLUSION: The respective roles of arterial dysplasia, chronic ergotism, renovascular hypertension and migraine are discussed.

Aortic Dissection↗

Parietal and cingulate processes in central pain. A combined positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) study of an unusual case.

Parietal, insular and anterior cingulate cortices are involved in the processing of noxious inputs and genesis of pain sensation. Parietal lesions may generate central pain by mechanisms generally assumed to involve the 'medial' pain system (i.e. medial thalamic nuclei and anterior cingulate cortex (ACC)). We report here PET and fMRI data in a patient who developed central pain and allodynia in her left side after a bifocal infarct involving both the right parietal cortex (SI and SII) and the right ACC (Brodmann areas 24 and 32), thus questioning the schematic representation of cortical pain processing. No rCBF increase was found in any part of the residual cingulate cortices, neither in the basal state (which included spontaneous pain and extended hypoperfusion around the infarct), nor during left allodynic pain. Thus, as previously observed in patients with lateral medullary infarct, neither spontaneous pain nor allodynia reproduce the cingulate activation observed after noxious pain in normal subjects. Conversely, both PET and fMRI data argue in favour of plastic changes in the 'lateral discriminative' pain system. Particularly, allodynia was associated with increased activity anteriorly to the infarct in the right insula/SII cortex. This response is likely to be responsible for the strange and very unpleasant allodynic sensation elicited on the left side by a non-noxious stimulation.

Brain Mapping↗

Functional imaging of brain responses to pain. A review and meta-analysis (2000).

Brain responses to pain, assessed through positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) are reviewed. Functional activation of brain regions are thought to be reflected by increases in the regional cerebral blood flow (rCBF) in PET studies, and in the blood oxygen level dependent (BOLD) signal in fMRI. rCBF increases to noxious stimuli are almost constantly observed in second somatic (SII) and insular regions, and in the anterior cingulate cortex (ACC), and with slightly less consistency in the contralateral thalamus and the primary somatic area (SI). Activation of the lateral thalamus, SI, SII and insula are thought to be related to the sensory-discriminative aspects of pain processing. SI is activated in roughly half of the studies, and the probability of obtaining SI activation appears related to the total amount of body surface stimulated (spatial summation) and probably also by temporal summation and attention to the stimulus. In a number of studies, the thalamic response was bilateral, probably reflecting generalised arousal in reaction to pain. ACC does not seem to be involved in coding stimulus intensity or location but appears to participate in both the affective and attentional concomitants of pain sensation, as well as in response selection. ACC subdivisions activated by painful stimuli partially overlap those activated in orienting and target detection tasks, but are distinct from those activated in tests involving sustained attention (Stroop, etc.). In addition to ACC, increased blood flow in the posterior parietal and prefrontal cortices is thought to reflect attentional and memory networks activated by noxious stimulation. Less noted but frequent activation concerns motor-related areas such as the striatum, cerebellum and supplementary motor area, as well as regions involved in pain control such as the periaqueductal grey. In patients, chronic spontaneous pain is associated with decreased resting rCBF in contralateral thalamus, which may be reverted by analgesic procedures. Abnormal pain evoked by innocuous stimuli (allodynia) has been associated with amplification of the thalamic, insular and SII responses, concomitant to a paradoxical CBF decrease in ACC. It is argued that imaging studies of allodynia should be encouraged in order to understand central reorganisations leading to abnormal cortical pain processing. A number of brain areas activated by acute pain, particularly the thalamus and anterior cingulate, also show increases in rCBF during analgesic procedures. Taken together, these data suggest that hemodynamic responses to pain reflect simultaneously the sensory, cognitive and affective dimensions of pain, and that the same structure may both respond to pain and participate in pain control. The precise biochemical nature of these mechanisms remains to be investigated.

Analgesia↗

[Pain not associated with hypernociception. A physiopathologic, clinical and therapeutic approach].

It would be simplistic to consider the reality of pain as nothing more than heightened sensitivity to the pain. There are actually five types of pain, and it is often difficult to distinguish between them. Whereas hypernociceptive pain is mainly treated with analgesics belonging to one of the three categories as defined by the WHO, the mechanisms and treatment of the other four types of pain are very different It is obvious that close co-operation between the various healthcare professionals is indispensable in the treatment of these patients, while keeping in mind that the physician is "a symbol, an intermediary, a medicine that's better than medicine: the medicine works because it's a symbol - it's a symbol because it works". (P. Queneau and G. Ostermann.)

Humans↗

[Positron emission tomography to study central pain integration].

The study of pain integration, in vivo, within the human brain has been largely improved by the functional neuro-imaging techniques available for about 10 years. Positron Emission Tomography (PET), complemented by laser evoked potentials (LEP) and functional Magnetic Resonance Imaging (fMRI) can nowadays generate maps of physiological or neuropathic pain-related brain activity. LEP and fMRI complement PET by their better temporal resolution and the possibility of individual subject analyze. Recent advances in our knowledge of pain mechanisms concern physiological acute pain, neuropathic pain and investigation of analgesic mechanisms. The sixteen studies using PET have demonstrated pain-related activations in thalamus, insula/SII, anterior cingulate and posterior parietal cortices Activity in right pre-frontal and posterior parietal cortices, anterior cingulate and thalami can be modulated by attention (hypnosis, chronic pain, diversion, selective attention to pain) and probably subserve attentional processes rather than pain analysis. Responses in insula/SII cortex presumably subserve discriminative aspects of pain perception while SI cortex is particularly involved in particular aspects of pain discrimination (movement, contact.) In patients, neuropathic pain, angina and atypical facial pain result in PET abnormalities whose significance remain obscure but which are localized in thalamus and anterior cingulate cortices suggesting their distribution is not random while discriminative responses remain detectable in insula/SII. Drug or stimulation induced analgesia are associated with normalization of basal thalamic abnormalities associated with many chronic pains. The need to investigate the significance of these responses, their neuro-chemical correlates (PET), their time course, the individual strategies by which they have been generated by correlating PET data with LEP and fMRI results, are the challenges that remain to be addressed in the next few years by physicians and researchers. To advance our knowledge of the mechanisms generating both abnormal pain and analgesia (drugs and surgical techniques) in patients is the main motivation of such anexciting challenge.

Brain↗

[Multidisciplinary treatment of neurologic pain and indications for antalgic surgery].

We present our multidisciplinary approach systematically adopted for patients with resistant pain. All the anatomic, pathophysiological, clinical, radiographical, electrophysiological and psychological aspects of pain should be considered before deciding on treatment indication. These principles are illustrated by a description of different available medical and surgical techniques for the treatment of paraplegic pain. We emphasize the importance of pain centers in caring for these patients. All possibilities for antalgic treatment can be considered in such centers, providing a better approach to all aspects of pain.

Humans↗

[Mini-Mental State Examination:a useful method for the evaluation of the cognitive status of patients by the clinician. Consensual French version].

A PRACTICAL TOOL: Screening for cognitive deficiency has been considerably improved by the use of a standardized tool, the Mini-Mental State Examination (MMSE). The MMSE only takes a few minutes and furnishes quantitative data for comparison between patients and to follow the evolution of a given patient. AN IMPORTANT ROLE: The MMSE is particularly useful for screening for dementia and states of mental confusion. It should be used systematically for elderly subjects, not only in the neurology setting, but also in geriatrics, psychiatrics and internal medicine. INTERPRETATION: The global score gives an assessment of the subject's performance level, taking into account for age, affective status and cultural situation. The MMSE cannot alone provide the diagnosis of dementia which requires a complete neurological examination. THE CONSENSUAL FRENCH VERSION: Diverse French versions have been developed with considerable differences in scoring schemes. For this reason, the Working Group on Cognitive Evaluations (GREC) has established a consensual version of the MMSE in French.

Cognition Disorders↗

Midazolam effects on implicit and explicit memory processes in healthy subjects.

RATIONALE: Studying midazolam-induced amnesia offers an interesting approach to the organization of normal memory processes, since memory performance can be studied in the same subject in "on" and "off" drug conditions. OBJECTIVE: The present study investigated the effect of midazolam on skill learning. The task and the experimental design we used also allowed us to assess the effect of midazolam on priming and explicit memory. METHODS: Eighteen patients who underwent minor ear surgery and who were anaesthetized with intravenous midazolam, and 18 matched control subjects participated in a mirror reading task on 2 separate days. Patients were tested under midazolam on day 1 and without any medication on day 2. The mirror reading task was made of French words, some of which repeated across trial blocks, others being new. RESULTS: Patients under midazolam read new mirror written words faster with practice, which attested for intact skill learning. Moreover, they read repeated words faster than new words with practice, which was interpreted as reflecting intact priming abilities. These spared implicit memory capacities were observed along with severe explicit memory impairments. Learning for both new and repeated mirror written words on day 2 was similar in patients and in controls, which was interpreted as suggesting that the implicit learning that occurred on day 1 under midazolam was normal. CONCLUSIONS: The quality of skill learning, both in terms of speed of and lasting effect, was normal under midazolam in the task we used. In the context of the present task, midazolam offers an interesting, reversible model of amnesia.

Adult↗

Procedural learning in Parkinson's disease: intact and impaired cognitive components.

Two experiments were carried out to study procedural learning in Parkinson's disease (PD) patients. In Experiment 1, ten patients and their normal controls participated in a classical mirror reading task and in an inverted reading task where word-stimuli made of non inverted letters had to be processed from right to left (e.g., ygoloruen). In both tasks, reading times for new stimuli were compared to reading times for stimuli that repeated over blocks. Although PD patients and their controls exhibited learning for repeated words in both tasks, PD patients did not respond faster with practice for new words in the inverted reading task. In Experiment 2, PD patients and their controls were presented with an original dot counting task in which participants were asked to process a horizontal series of black and white dots from right to left and to indicate whether a dot that had been designated by a number at the beginning of each trial was black or white. Results showed that PD patients, in contrast to controls, did not exhibit learning in this task. Results are discussed in terms of the cognitive components involved in these tasks. It is suggested that PD patients are impaired in the acquisition of a right-to-left visual scanning skill that could be studied directly in Experiment 2.

Case-Control Studies↗