06 May 2009
My initial thought --and here I reveal the depth of my ignorance-- was that since the tissues have been healing, the worsening allodynia isn't due to increased prostaglandins, bradykinin, leukotrienes, etc, released by the damaged muscle. Rather it's from dorsal horn wind-up, and neurogenic inflammatory factors like substance p and neurokinins A and B. It makes sense that those would continue to increase over time.
But that wouldn't explain why this doesn't seem to happen when I'm already in shape, even when a workout is much harder than usual.
Or is it just the obvious answer that the difference between relative inactivity and a moderate workout is less than the difference between a moderate workout and a really hard one?
05 May 2009
Medical News Today
For Cesarean Section, Regional Blocks Prove Superior To General Anesthesia
30 Apr 2009
General anesthesia (GA) is associated with an increased risk of infant intubation and low Apgar scores, relative to regional anesthesia. An analysis of 50,806 cesarean deliveries, published in the open access journal BMC Medicine, strongly supports guidelines that regional anesthesia is to be preferred over GA for most cesarean sections.
Charles Algert, from the Kolling Institute at the Royal North Shore Hospital, Sydney, was part of a team of researchers who studied births in the state of New South Wales, Australia, between 1998 and 2004. He said, "We have shown that general anesthesia poses significant risks to the neonate of both resuscitation requiring intubation and of a poor Apgar score at 5 minutes. The greatest relative risk of both adverse outcomes occurred in low-risk, planned, repeat cesarean deliveries under GA, but the greatest excess in risk attributable to GA was for emergency deliveries for fetal distress where the infant would already have been compromised to some extent".
Although current guidelines recommend regional blocks, GA was still used for 12.6% of cesareans across NSW in 2006. According to the NHS Maternity Statistics, 8.7% of cesarean sections in England in 2006-2007 were performed using GA. It is generally presumed that any harm caused by GA is short-lasting, with most studies focusing on resuscitation and the Apgar score at one minute. According to Algert, however, this may not be the case, "The increased rates of neonatal intubation after GA shown in this study represent harm in and of itself, and the persistence of low 5-minute Apgar scores suggests that deleterious effects may last longer than the immediate aftermath of delivery".
The authors conclude, "Clinicians considering the use of GA for a cesarean delivery should be aware of these possible consequences for the infant, for both planned and emergency sections".
Regional block versus general anaesthesia for caesarean section and neonatal outcomes: a population-based study
Charles S Algert, Jennifer R Bowen, Warwick B Giles, Greg E Knoblanche, Samantha L Lain and Christine L Roberts
BMC Medicine (in press)
Article available at journal website: http://www.biomedcentral.com/bmcmed/
Article URL: http://www.medicalnewstoday.com/articles/148091.php
02 May 2009
Medical News Today News Article: "FDA Requires Additional Labeling For Over-the-Counter Pain Relievers And Fever Reducers To Help Consumers Use Products Safely
29 Apr 2009
The Food and Drug Administration issued a final rule today that requires manufacturers of over-the-counter (OTC) pain relievers and fever reducers to revise their labeling to include warnings about potential safety risks, such as internal bleeding and liver damage, associated with the use of these popular drugs.
Products covered by the FDA action include acetaminophen, and a class of drugs known as the nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs include aspirin, ibuprofen, naproxen, and ketoprofen. Acetaminophen is in a class by itself. The revised labeling applies to all OTC pain relievers and fever reducers, including those that contain one of these ingredients in combination with other ingredients, such as in cold medicines containing pain relievers or fever reducers.
'Acetaminophen and NSAIDs are commonly used drugs for both children and adults because they are effective in reducing fevers and relieving minor aches and pain, such as headaches and muscle aches, ' said Charles Ganley, M.D., director, FDA's Office of Nonprescription Drugs in the Center for Drug Evaluation and Research. 'However, the risks associated with their use, need to be clearly identified on the label so that consumers taking these drugs are fully aware of the potential harm they can cause. It is important that they know how to take these medications safely to reduce their risk.'
Under the final rule, manufacturers must ensure that the active ingredients of these drugs are prominently displayed on the drug labels on both the packages and bottles. The labeling also must warn of the risks of stomach bleeding for NSAIDs and severe liver damage for acetaminophen.
Since 2006, some manufacturers have voluntarily revised their product labeling to identify these potential safety concerns. However, the voluntary changes to labeling do not address all of the labeling requirements in the new rule. For example, the new rule includes a warning on products containing acetaminophen that instructs consumers to ask a doctor before they are taking the blood thinning drug warfarin. The new rule requires all manufacturers to relabel their products within one year of today's date.
Safety data reported in medical literature indicate that people sometimes take more acetaminophen than the labeling recommends. Others unknowingly take multiple products containing acetaminophen at the same time. Exceeding the recommended dosage of acetaminophen may increase the risks for severe liver damage. Alcohol use can also increase the risk of liver damage with acetaminophen.
The risk for stomach bleeding may increase in people who use NSAIDs and who are taking blood-thinning drugs (anticoagulants) or steroids. Stomach bleeding risks also increase for people who take multiple NSAIDs at the same time, or in people who take them longer than directed. Alcohol use can increase the risk for stomach bleeding with NSAIDs use.
An FDA Advisory Committee meeting will be convened on June 29 & 30, 2009, to discuss further steps the FDA could take to reduce the risk of liver damage associated with acetaminophen overdoses.
To read the final rule on the relabeling of OTC pain relievers and fever reducers, go here.
To read the FR Notice announcing the FDA Advisory Committee meeting, see link.
Food and Drug Administration
Article URL: http://www.medicalnewstoday.com/articles/148085.php"
Medical News Today News Article: "Stroking The Skin Sends Signals Direct To The Brain, Deadens Pain Impulses
16 Apr 2009
The specialised nerve fibres in the skin are called CT nerves (C-tactile) and they travel directly to the areas in the brain that are important in the emergence of feelings.
'Basically the signals that tell the brain that we are being stroked on the skin have their own direct route to the brain, and are not blocked even if the brain is receiving pain impulses from the same area. In fact it's more the opposite, that the stroking impulses are able to deaden the pain impulses,' says Line Löken, postgraduate student in neurophysiology at the Sahlgrenska Academy.
Each individual nerve fibre is responsible for touch signals from roughly a square centimetre of skin. The research team used a specially-designed robot, which brushed over the exact area of skin for which a particular nerve fibre is responsible. The subjects were also asked to rate how pleasant or unpleasant they found the brushing.
'As the nerve signals that were sent in the CT nerves became more frequent, the subjects reported the experience as being increasingly pleasant. Of the skin nerves that we studied, it was only the CT nerves that had this strong link between the frequency of the signals and how pleasant it felt,' says researcher Johan Wessberg.
Journal: Nature Neuroscience
Title of the article: Coding of pleasant touch by unmyelinated afferents in humans
Authors: Line S. Löken, Johan Wessberg, India Morrisson, Francis McGlone, Håkan Olausson
The full text article is available on Nature Neuroscience's web page: http://www.nature.com/neuro/journal/vaop/ncurrent/abs/nn.2312.html
By: Elin Lindström Claessen
A 2003 study in Epilepsy and Behavior has some descriptions of the ecstatic seizures experienced by some patients with epilepsy.
They include intense erotic and spiritual experiences, feelings of become close to and blending with other people, and some sensations that couldn't be fully captured in words.
I've put some of the descriptions below because they sound absolutely wonderful:
The first seizure occurred during a concert when he was a teenager. He remembers perceiving short moments of an indefinable feeling. Such episodes recurred and a few months later evolved into a GTC [generalized tonic–clonic seizure]. He characterizes these sensations as ‘a trance of pleasure.’ ‘It is like an emotional wave striking me again and again. I feel compelled to obey a sort of phenomenon. These sensations are outside the spectrum of what I ever have experienced outside a seizure.’ He also describes cold shivering, increased muscle tension, and a delicious taste, and he swallows repeatedly. He enjoys the sensations and is absorbed in them in a way that he can barely hear when spoken to. When in a particular, relaxed mood, he can sometimes induce seizures by ‘opening up mentally’ and contracting muscles. He denies any religious aspects of the symptoms. ‘It’s the phenomenon, the feeling, the fit taking control.’ It lasts a few minutes and afterward he is tired with difficulties expressing himself for about 1 hour.
This man has a multifaceted symptomatology and a tendency to interpret bodily sensations as supernatural phenomena. Nevertheless, from the beginning of his forties, he experienced distinct, stereotypical attacks with a ‘change of concept of the surrounding world.’ He reports an ‘oscillating erotic sensation, like twinkling polar light’ in his pelvic region and down the inside of his thighs. This is described as different from sexual excitement, more like ‘an erogenous charge of the skin.’ He may also have a clairvoyant feeling of a ‘telepathic contact with a divine power.’ These sensations are of short duration and may be accompanied by faintness and followed by drowsiness. With carbamazepine treatment, the frequency of these attacks has been considerably reduced.
The attacks started in his first school year. The experiences are beyond what can be described in words. ‘I can sense the colours red and orange without seeing them. The feeling has an erotic aspect. It starts in the stomach and spreads upwards. It is pleasant, but not similar to ordinary joy. It is like an explosion.’ In the close presence of another person, he can feel a sort of peculiar unification. An intense déjà vu sensation, a queer taste, and ‘gooseflesh’ are also components of the seizures. As a child he was surprised that his friends denied having similar feelings, and he learned to keep them to himself. Sometimes these attacks evolved into CPSs with reduced consciousness and complex automatisms and afterward he had transient difficulties speaking. Before the diagnosis of epilepsy was made in his late teens, he was referred to a psychiatrist. A right-sided temporal lobe calcification was diagnosed by computed tomography at about 30 years, but he refused surgery. At 42, an expansion in the same region was found by MRI, and he was operated for an anaplastic oligodendroglioma. He was seizure-free for 6 years until recurrence of the tumor.
One of the striking things about epilepsy is how different each person's experience of having a seizure can be.
While it is stereotypically assumed to be a negative experience, some aspects can be remarkably beautiful.
The Russian author Dostoyevsky famously said of his epilepsy 'I would experience such joy as would be inconceivable in ordinary life - such joy that no one else could have any notion of. I would feel the most complete harmony in myself and in the whole world and this feeling was so strong and sweet that for a few seconds of such bliss I would give ten or more years of my life, even my whole life perhaps.'
There are several more case descriptions in the article, all of which have some aspect which touch at least the edge of ecstasy, if not the very heart of the experience.
(Via Mind Hacks.)
Privation Theories of Pain
Most modern writers accept that a privation theory of evil should explicitly account for the evil of pain. But pains are quintessentially real. The evil of pain does not seem to lie in an absence of good. Though many directly take on the challenges this raises, the metaphysics and axiology of their answers is often obscure. In this paper I try to straighten things out. By clarifying and categorizing the possible types of privation views, I explore the ways in which privationists about evil are—or should or could be—privationists about pain’s evil.
International Journal for Philosophy of Religion (2009)
The traditional accounts of pain’s intrinsic badness assume a false view of what pains are. Insofar as they are normatively significant, pains are not just painful sensations. A pain is a composite of a painful sensation and a set of beliefs, desires, emotions, and other mental states. A pain’s intrinsic properties can include inter alia depression, anxiety, fear, desires, feelings of helplessness, and the pain’s meaning. This undermines the traditional accounts of pain’s intrinsic badness. Pain is intrinsically bad in two distinct and historically unnoticed ways. First, most writers hold that pain’s intrinsic badness lies either in its unpleasantness or in its being disliked. Given my wider conception of pain, I believe it is both. Pain’s first intrinsic evil lies in a conjunction of all the traditional candidates for its source. Pain’s second intrinsic evil lies in the way it necessarily undermines the self-control necessary for intrinsic goods like autonomy.
Utilitas Vol. 21 No. 2 June 2009
May I have your attention please?
STOP DENYING CANCER PATIENTS THE MEDICINE THEY NEED.
Thank you for your attention
Br J Cancer. 2009 Apr 28;
Apolone G, Corli O, Caraceni A, Negri E, Deandrea S, Montanari M, Greco MT
Most patients with advanced or metastatic cancer experience pain and despite several guidelines, undertreatment is well documented. A multicenter, open-label, prospective, non-randomised study was launched in Italy in 2006 to evaluate the epidemiology, patterns and quality of pain care of cancer patients. To assess the adequacy of analgesic care, we used a standardised measure, the pain management index (PMI), that compares the most potent analgesic prescribed for a patient with the reported level of the worst pain of that patient together with a selected list of clinical indicators. A total of 110 centres recruited 1801 valid cases. 61% of cases were received a WHO-level III opioid; 25.3% were classified as potentially undertreated, with wide variation (9.8-55.3%) according to the variables describing patients, centres and pattern of care. After adjustment with a multivariable logistic regression model, type of recruiting centre, receiving adjuvant therapy or not and type of patient recruited (new or already on follow-up) had a significant association with undertreatment. Non-compliance with the predefined set of clinical indicators was generally high, ranging from 41 to 76%. Despite intrinsic limitations of the PMI that may be considered as an indicator of the poor quality of cancer pain care, results suggest that the recourse to WHO third-level drugs still seems delayed in a substantial percentage of patients. This delay is probably related to several factors affecting practice in participating centres and suggests that the quality of cancer pain management in Italy deserves specific attention and interventions aimed at improving patients' outcomes.British Journal of Cancer advance online publication, 28 April 2009; doi:10.1038/sj.bjc.6605053 www.bjcancer.com."
(Via HubMed - pain.)
Exp Brain Res. 2009 Apr 29;
As volunteers can easily communicate quality and intensity of painful stimuli, human pain models appear to be ideally suited to test analgesic compounds, but also to study pain mechanisms. Acute stimulation of nociceptors under physiologic conditions has proven not to be of particular use as an experimental pain model. In contrast, if the experimental models include sensitization of the peripheral or central pain processing they may indeed mimic certain aspects of chronic pain conditions. Peripheral inflammatory conditions can be induced experimentally with sensitization patterns correlating to clinical inflammatory pain. There are also well-characterized models of central sensitization, which mimic aspects of neuropathic pain patients such as touch evoked allodynia and punctate hyperalgesia. The main complaint of chronic pain patients, however, is spontaneous pain, but currently there is no human model available that would mimic chronic inflammatory or neuropathic pain. Thus, although being helpful for proof of concept studies and dose finding, current human pain models cannot replace patient studies for testing efficacy of analgesic compounds."
(Via HubMed - pain.)