Topical gabapentin gel alleviates allodynia and hyperalgesia in the chronic sciatic nerve constriction injury neuropathic pain model

Background: Systemic gabapentin is a mainstay treatment for neuropathic pain though there are side effects. Localized therapy may curtail such side effects so a topical gabapentin dermal application was examined in the chronic constriction injury (CCI) model of neuropathic pain. Methods: Partial denervation CCI was achieved by rat sciatic nerve ligation. Gabapentin gel (10% w/w) was applied three-times daily on the ipsilateral or contralateral plantar surface of the hind-paw while in a concurrent systemic study, gabapentin was intraperitoneally administered daily (75 mg/kg) for 30 days. Tests for static- and dynamic- mechano-allodynia (paw withdrawal threshold [PWT] to von-Frey filament application and latency [PWL] to light brushing), coldallodynia (paw withdrawal duration [PWD] to acetone), heat- (PWL and PWD) and mechanohyperalgesia (PWD to pin-prick) were utilized to assess pain while effects on locomotion (open field) and motor balance (rotarod and footprint-analysis) were measured on days 5-30 postsurgery. Results: Topical application of gabapentin gel ipsilaterally but not contralaterally alleviated CCI-induced static- (days 10-30) and dynamic-allodynia (days 15-30), suppressed cold-allodynia (days 10-30), heat- (days 15-30) and mechano-hyperalgesia (days 5-30) indicating a local action. Systemic gabapentin exhibited similar pain profiles but was associated with motor impairment. The gabapentin gel formulation afforded desirable neuropathic pain alleviating effects devoid of unwanted systemic side-effects. Conclusions: These outcomes disclose an expedient pharmacological validation of the effectiveness of topical gabapentin gel against an extensive range of nociceptive stimulus modalities utilizing the CCI-induced neuropathic pain model. They also advocate further clinical studies on topical gabapentin with regard to certain neuropathic pain syndromes

Autophagy impairment in a mouse model of neuropathic pain

Autophagy is an intracellular membrane trafficking pathway controlling the delivery of cytoplasmic material to the lysosomes for degradation. It plays an important role in cell homeostasis in both normal settings and abnormal, stressful conditions. It is now recognised that an imbalance in the autophagic process can impact basal cell functions and this has recently been implicated in several human diseases, including neurodegeneration and cancer

Influence of Psychological Factors on Pain and Disability in Anterior Knee Pain Patients

AKP patients express chronic pain but also disability. However, the correlation between pain and disability is not complete and linear. Some patients with a lot of pain show mild disability while others with much less pain also show great disability. The disability is profoundly influenced by other emotional and cognitive factors that are associated with the perception of pain. Therefore, the clinical efforts do not have to be focused only on treating the pain as a feeling but on identifying and modifying these factor

Exploration of nociceptive cortical processing with steady-state evoked potentials

The periodic presentation of a sensory stimulus induces, at certain frequencies of stimulation, a sustained electroencephalographic response known as steady-state evoked potentials (SS-EP). SS-EPs are considered to reflect entrainment of cortical sensory networks resonating at the frequency of stimulation. In the present study we characterize and compare SS-EPs elicited by the selective electrical activation of nociceptive Aδ-fibers and non-nociceptive Aβ-fibers. Nine subjects took part in the experiment. Ten second trains of nociceptive (intra-epidermal electrical stimulation) and non-nociceptive (transcutaneous electrical stimulation) stimuli were applied to the left and right hand in separate blocks. Trains consisted of 0.5 ms constant-current pulses modulated at 3, 7, 13, 23 and 43 Hz. Consistent nociceptive and non-nociceptive SS-EPs were recorded at all stimulation frequencies. Whereas non-nociceptive SS-EPs were maximal over the parietal region contralateral to the stimulated side, nociceptive SS-EPs were maximal at the vertex and symmetrically distributed over both hemispheres, thus indicating that the two responses reflect the entrainment of distinct neuronal populations. The recording of nociceptive and non-nociceptive somatosensory SS-EPs offers a unique opportunity to study the cortical representation of nociception and touch in humans

Clinical Efficacy of Radiofrequency Cervical Zygapophyseal Neurotomy in Patients with Chronic Cervicogenic Headache

The purpose of the present study was to assess the clinical efficacy of radiofrequency (RF) cervical zygapophyseal joint neurotomy in patients with cervicogenic headache. A total of thirty consecutive patients suffering from chronic cervicogenic headaches for longer than 6 months and showing a pain relief by greater than 50% from diagnostic/prognostic blocks were included in the study. These patients were treated with RF neurotomy of the cervical zygapophyseal joints and were subsequently assessed at 1 week, 1 month, 6 months, and at 12 months following the treatment. The results of this study showed that RF neurotomy of the cervical zygapophyseal joints significantly reduced the headache severity in 22 patients (73.3%) at 12 months after the treatment. In conclusion, RF cervical zygapophyseal joint neurotomy has shown to provide substantial pain relief in patients with chronic cervicogenic headache when carefully selected

Chronic pain among homeless persons: characteristics, treatment, and barriers to management

<p>Abstract</p> <p>Background</p> <p>Little information is available on the problem of chronic pain among homeless individuals. This study aimed to describe the characteristics of and treatments for chronic pain, barriers to pain management, concurrent medical conditions, and substance use among a representative sample of homeless single adult shelter users who experience chronic pain in Toronto, Canada.</p> <p>Methods</p> <p>Participants were randomly selected at shelters for single homeless adults between September 2007 and February 2008 and screened for chronic pain, defined as having pain in the body for ≥ 3 months or receiving treatment for pain that started ≥ 3 months ago. Cross-sectional surveys obtained information on demographic characteristics, characteristics of and treatments for chronic pain, barriers to pain management, concurrent medical conditions, and substance use. Whenever possible, participants' physicians were also interviewed.</p> <p>Results</p> <p>Among 152 homeless participants who experienced chronic pain, 11 (8%) were classified as Chronic Pain Grade I (low disability-low intensity), 47 (32%) as Grade II (low disability-high intensity), 34 (23%) as Grade III (high disability-moderately limiting), and 54 (37%) as Grade IV (high disability-severely limiting). The most common self-reported barriers to pain management were stress of shelter life, inability to afford prescription medications, and poor sleeping conditions. Participants reported using over-the-counter medications (48%), street drugs (46%), prescribed medications (43%), and alcohol (29%) to treat their pain. Of the 61 interviewed physicians, only 51% reported treating the patient's pain. The most common physician-reported difficulties with pain management were reluctance to prescribe narcotics due to the patient's history of substance abuse, psychiatric comorbidities, frequently missed appointments, and difficulty getting the patient to take medications correctly.</p> <p>Conclusions</p> <p>Clinicians who provide healthcare for homeless people should screen for chronic pain and discuss barriers to effective pain management with their patients.</p

Validity of the ADHD module of the Mini International Neuropsychiatric Interview PLUS for screening of adult ADHD in treatment seeking substance use disorder patients: ADHD screening with MINI-Plus

Az ADHD szűrési lehetőségei a Mini-plus mérőeszköz segítségéve

Coping strategies, stress, physical activity and sleep in patients with unexplained chest pain

BACKGROUND: The number of patients suffering from unexplained chest pain (UCP) is increasing. Intervention programmes are needed to reduce the chest pain and suffering experienced by these patients and effective preventive strategies are also required to reduce the incidence of these symptoms. The aim of this study was to describe general coping strategies in patients with UCP and examine the relationships between coping strategies, negative life events, sleep problems, physical activity, stress and chest pain intensity. METHOD: The sample consisted of 179 patients younger than 70 years of age, who were evaluated for chest pain at the emergency department daytime Monday through Friday and judged by a physician to have no organic cause for their chest pain. The study had a cross-sectional design. RESULTS: Emotive coping was related to chest pain intensity (r = 0.17, p = 0.02). Women used emotive coping to a greater extent than did men (p = 0.05). In the multivariate analysis was shown that physical activity decreased emotive coping (OR 0.13, p < 0.0001) while sex, age, sleep, mental strain at work and negative life events increased emotive coping. Twenty-seven percent of the patients had sleep problems 8 to14 nights per month or more. Permanent stress at work during the last year was reported by 18% of the patients and stress at home by 7%. Thirty-five percent of the patients were worried often or almost all the time about being rushed at work and 23% were worried about being unable to keep up with their workload. Concerning total life events, 20% reported that a close relative had had a serious illness and 27% had reasons to be worried about a close relative. CONCLUSION: Our results indicated that patients with more intense UCP more often apply emotive coping in dealing with their pain. Given that emotive coping was also found to be related to disturbed sleep, negative life events, mental strain at work and physical activity, it may be of value to help these patients to both verbalise their emotions and to become cognizant of the influence of such factors on their pain experience

Evoked potentials in the Atlantic cod following putatively innocuous and putatively noxious electrical stimulation: a minimally invasive approach

Aspects of peripheral and central nociception have previously been studied through recording of somatosensory evoked potentials (SEPs) to putative noxious stimuli in specific brain regions in a few freshwater fish species. In the present study, we describe a novel, minimally invasive method for recording SEPs from the central nervous system of the Atlantic cod (Gadus morhua). Cutaneous electric stimulation of the tail in 15 fish elicited SEPs at all stimulus intensities (2, 5, 10 and 20 mA) with quantitative properties corresponding to stimulus intensity. In contrast to previous fish studies, the methodological approach used in Atlantic cod in the current study uncovered a number of additional responses that could originate from multiple brain regions. Several of these responses were specific to stimulation at the highest stimulus intensities, possibly representing qualitative differences in central processing between somatosensory and nociceptive stimuli