Phantom pain and posttraumatic pain conditions

After limb or body part amputation, three different types of perceptual sensitive phenomena can be recognized. They can be all named posttraumatic neuropathies: painless sensations in phantom limb, painful phantom limb and painful posttraumatic stump. Painless sensations in phantom limb can be seen in 90% of cases in resected body parts as soon as first postoperative day, less often during the first week, and its clinical characteristics are usually stabilized during the first year. Painful posttraumatic stump appears because of pain neuroma existing, that forms at the proximal end of amputational stump as a consequence of physiological nerve regeneration attempt. Frequency of pain significantly varies considering authors from 5-90%, depending on definition of this phenomena and criteria used. It is considered that 5-10% mast be under permanent medicament treatment. Phantom pain appears more often in elderly and people with specific affective personality construction. It can be permanent, burning, nettling, tearing (25%), or intermittent, lancerating, in the shape of electrical discharging (32%), but it can also have bizarre attributes. Phantom pain appearance usually announces its duration in the longer period. After two years it is present at 59% of patients, with decreasing intensity, and only 5-10% suffer severe pain. In our Institute in the period from 1980-2003, 48 patients have been treated, 36 patients with medicamentous treatment, local blockades and chronic stimulations, and 12 patients, who did not react at conservative treatment were operated. In operated group in 10 patients pain disappeared, one patient it was with decreasing intensity, and one patient was without change.     

Discogenic pain in acute nonspecific low-back pain

Acute nonspecific low-back pain is characterized by the sudden onset and severe unendurable low-back pain without radicular pain or neurological deficit in the lower extremities. The study was carried out using 55 patients who visited our hospital for acute nonspecific low-back pain, who exhibited degeneration on T2-weighted MR images, and underwent intradiscal injection of local anesthetics,steroid and contrast medium. Intervertebral disc sites with an obvious enhanced region in the posterior annulus of the disc on enhanced T1-weghted MR images was selected for intradiscal injection. When no enhaced region was detected, the most severely degenerated disc on T2-weighted MR images was selected. Acute nonspecific low-back pain with an improvement rate of 70% or higher 5min after injection was judged to be discogenic. The clinical characteristics and pathogenesis of discogenic acute nonspecific low-back pain were investigated. Forty of the 55 patients (73%) had discogenic acute nonspecific low-back pain. As for the characteristics of patients, the mean age was 37 years, and onset occurred upon casual daily movements in 18 patients (45%). Nineteen patients (48%) had bilateral low-back pain, and 29 patients (73%) had no tenderness in the paravertebral muscles. On plain X-ray radiograms, degeneration of the disc was normal or mild in 36 patients(91%). On the discograms, a radial tear extending to the posterior annulus was noted in all patients, but epidural leakage was seen only in six patients (15%). The degree of disc degeneration on T2-weighted MR images (Gibsons classification) was grade 3 in 30 patients (75%). Gadolinium-DTPA enhanced T1-weighted MR images showed an obvious enhanced region in the posterior annulus of the intervertebral disc in 19 patients (48%). As for the clinical characteristics of discogenic acute nonspecific low-back pain, the relatively young adult patients had no tenderness in the paravertebral muscles, and showed moderately degererated intervertebral discs. The pathogenesis of discogenic acute nonspecific low-back pain is mostly considered to be a re-rupture in an asymptomatic ruputured region in the posterior annulus, repaired by granulation tissue, in a moderately degenerated intervertebral disc with a radial tear.     

Improvement of burn pain management through routine pain monitoring and pain management protocol

Introduction

Pain management is an important aspect of burn management. We developed a routine pain monitoring system and pain management protocol for burn patients. The purpose of this study is to evaluate the effectiveness of our new pain management system.

Methods

From May 2011 to November 2011, the prospective study was performed with 107 burn patients. We performed control group (n = 58) data analysis and then developed the pain management protocol and monitoring system. Next, we applied our protocol to patients and performed protocol group (n = 49) data analysis, and compared this to control group data. Data analysis was performed using the Numeric Rating Scale (NRS) of background pain and procedural pain, Clinician-Administered PTSD Scale (CAPS), Hamilton Depression Rating Scale (HDRS), State-Trait Anxiety Inventory Scale (STAIS), and Holmes and Rahe Stress Scale (HRSS).

Results

The NRS of background pain for the protocol group was significantly decreased compared to the control group (2.8 ± 2.0 versus 3.9 ± 1.9), and the NRS of procedural pain of the protocol group was significantly decreased compared to the control group (4.8 ± 2.8 versus 3.7 ± 2.5). CAPS and HDRS were decreased in the protocol group, but did not have statistical significance. STAIS and HRSS were decreased in the protocol group, but only the STAIS had statistical significance.

Conclusion

Our new pain management system was effective in burn pain management. However, adequate pain management can only be accomplished by a continuous and thorough effort. Therefore, pain control protocol and pain monitoring systems need to be under constant revision and improvement using creative ideas and approaches.     

Chronic regional pain and chronic pain syndromes

This paper seeks to consider the validity and utility of two related terms in spinal and other injuries: complex regional pain syndrome (CRPS) and chronic pain syndrome (CPS). It is argued that the words chronic regional pain syndrome convey neither understanding of the condition nor of its mechanism. They simply redefine the clinical problem, but fail to establish specific diagnostic features or consistent primary pathogenesis. CRPS is best construed as a reaction to injury, or to excessive, often iatrogenic, immobilization after injury; but it is not an independent disease. The diagnosis of CPS groups together ill-defined symptoms under a convenient, but medically untestable and therefore inept label. Patients, lawyers, and support groups commonly deny psychogenesis, with the sadly mistaken notion that this implies a bogus or spurious cause.     

Chronic musculoskeletal pain: Ultrasound guided pain control

The review demonstrates the unique advantages of ultrasonography in pain control. Several imaging modalities can be used to guide pain control, such as computed tomography, magnetic resonance imaging, and radiography. Ultrasonography has unique advantages over these other modalities in terms of its non-ionizing radiation, real-time imaging, portability, and cost-effectiveness. Ultrasonography with color Doppler and elastography can provide safer guidance to avoid blood vessels and the nerve trunk when using steroid or xylocaine infusions to encase the nerve trunk. This review focuses on the control of chronic pain in the upper limbs, lower limbs, and trunk.     

Visceral pain

Pain is one of the most common symptoms that patient presents with. Visceral organs were thought to be insensitive to pain in the past, but we now know this is not true. It is more common than somatic pain and originates from the internal organs in the thorax, abdomen or pelvis. These organs are innervated by the parasympathetic (vagus and sacral parasympathetic fibres) and sympathetic (thoracolumbar sympathetic chain: T1–L2) nervous systems. The afferent and efferent fibres to the organs accompany the sympathetic nervous system. The sensory system to the gut is specialized and divided into an enteric and extrinsic nervous system. The physiology of visceral pain is poorly understood compared to somatic pain, but it is well established that peripheral and central sensitization along with dysregulation of the descending pathways plays a significant role. Pain originating from visceral organs is usually diffuse, dull aching, poorly localized and can be associated with phenomenon such as referred somatic pain, referred hyperalgesia, visceral hyperalgesia and viscero-visceral hyperalgesia. Treatment of visceral pain involves identifying and treating the cause, if identified, and the management of pain. Patient education and information plays an important part in management along with pharmacological and non-pharmacological treatments.     

Visceral pain

Visceral pain originates from the internal organs in the thorax, abdomen or pelvis. It represents a major clinical problem and is more common than somatic pain. The internal viscera are innervated by the parasympathetic (craniosacral) and sympathetic (thoracolumbar) nervous systems. The physiology of visceral pain is poorly understood compared to somatic pain; however, it is well established that peripheral and central sensitization and dysregulation of the descending pathways contribute significantly. Pain originating from visceral organs is usually diffuse, dull, poorly localized and can be associated with phenomena such as referred pain, referred hyperalgesia, visceral hyperalgesia and viscero-visceral hyperalgesia. Treatment of visceral pain involves identifying and treating the underlying cause, if identifiable, and symptomatic pain management. Patient education and information play an important role in management in combination with pharmacological and non-pharmacological therapies.     

From pain research to pain treatment: the role of human experimental pain models

There is no objective measure of a complete pain perception; we can, however, measure different aspects of nociceptive processing and pain perception. Earlier, experimental pain models often only involved induction of cutaneous pain using a single stimulus modality. Recently new experimental models have been developed eliciting various modalities of deep and visceral pain which more closely resemble clinical pain conditions. It is imperative to use multi-modal and multi-structure pain induction and assessment techniques, because a simple model cannot describe the very complex and multi-factorial aspects of clinical pain. Furthermore, it is important to assess pain under normal and pathophysiological conditions.The importance of peripheral and central hyperexcitability for acute and chronic pain has been demonstrated in animals and, to some extent, in humans. However, in spite of our immense knowledge, we still do not know how to prevent and treat this hyperexcitability efficiently. Our understanding of nociceptive mechanisms involved in acute and chronic pain and the effects of anaesthetic drugs or combinations of drugs on these mechanisms in humans may also be expanded using human experimental models. This mechanism-based approach may help us to develop and test therapeutic regimes in patients with acute and chronic pain.     

Perineal pain

The investigation of patients suffering from perineal pain when sitting led us to perform an anatomical study of the pudendal nerve. We dissected 50 cadavers and found areas of conflict for the nerve fibers. The nerve trunk can become entrapped at the level of the ischiatic spine, in the Alcock's canal and when it crosses the falciform process. Considering the clinical and neurophysiological data, this type of chronic pain may arise from compression of the nerve between the sacro-tuberal and the sacro-spinal ligaments, and/or in the fascia of the internal obturator muscle. Much like treatment of entrapment of the median nerve in the wrist, we decided to treat chronic perineal pain by nerve blocks, and later by surgery. We describe here the clinical symptoms, the neurophysiological data, and the technique of the nerve blocks. For patients with persistent pain, we propose a posterior surgical approach which has provided successful pain relief in two third of patients.     

Facial pain

Summary In a prospective material of 1052 patients the precipitating factors, associated symptoms, psychological and neurological deficits have been examined.Mastication and talking are the most frequently occurring precipitating factors, 76% as regards Neuralgia, with typical starting difficulties. As regards Non-neuralgiform Pain 24%, with precipitation late in the masticatory process. There were trigger zones in 50% of the cases of Typical Trigeminal Neuralgia and in 9% of the patients with Non-neuralgiform Pain. In a series of cases the jaw joint is perceived as a trigger zone. Cold precipitates pain in 48%–39%. Other precipitating factors are much more rare-psychological stress in 15% of the patients with Non-neuralgiform Pain, however.Vegetative associated symptoms were relatively frequent, lacrimation occurred in 31% of the cases of Typical Trigeminal Neuralgia and in 20% of the cases of Non-neuralgiform Pain. Rhinorrhea and salivation were less frequent. In terms of figures migrainoid associated symptoms had no connection with vegetative associated symptoms or with pain in the eye.In 11 % of the patients pain occurred most frequently during the night and in 20% the frequency of pain was the same day and night. About 1/3 of the patients with Neuralgia experienced seasonal variations.Tenderness of foramina is a symptom of no significance. Very few patients had primary sensory loss. No eye or ear symptoms have been found which may be referred to as the patho-anatomical basis of the pain.About 1/3 of the patients with Non-neuralgiform Pain had psychological symptoms whereas hardly any patients with Neuralgia had them. MMPI test performed on a small matched material showed no difference between Neuralgia and Non-neuralgiform Pain.In material B an examination has been made of the jaw joint arthrosis symptoms. A restriction of the diagnosis of arthrosis has had the effect that it must be recognized that patients with facial pain do not have the high frequency of jaw joint diseases previously assumed. As was also the case in a series of normal material previously published, between 1/5 and 1/3 of the patients with Neuralgia had jaw joint arthrosis which was due to old age.This study has not revealed any connection between previous diseases, the onset of pain, the character and course of the pain, the character of the attack, the localization of pain, precipitating factors, associated symptoms and symptoms of loss on the one hand and the patho-anatomical substratum on the other.The psychological examinations were performed by Mr. Peter Bruun, chief psychologist, for whose cooperation I am grateful.     

Myofascial pain in patients with postthoracotomy pain syndrome

OBJECTIVE: Postthoracotomy pain syndrome is generally considered to be neuropathic pain due to intercostal nerve injury. However, nonneuropathic pain can also occur following thoracic surgery. We present a series of cases with postthoracotomy pain syndrome in which myofascial pain was thought to be a causative component of postthoracotomy pain syndrome. CASE REPORT: Twenty-seven patients (17 men and 10 women) were treated with trigger point injections, intercostal nerve blocks, and/or epidural blocks. Clinical criteria were used to diagnose the myofascial pain. A visual analogue scale was used, and sensory disturbances were recorded before and after treatment. A trigger point in a taut muscular band within the scapular region, which we diagnosed as myofascial pain, was observed in 67% of the patients. The existence of this trigger point significantly increased the rate of success for the treatments. CONCLUSIONS: Postthoracotomy pain may result, at least in part, from a nonneuropathic origin (myofascial pain). It is recommended that each patient be examined in detail to determine whether there is a trigger point in a taut muscular band within the scapular region. If found, this point is suggested as a good area for anesthetic injection.     

Cancer pain (classification and pain syndromes)

Inspite the new informations about the physiology and biochemistry of pain, it remains true that pain is only partially understood. Cancer pain is often experienced as several different types of pain, with combined somatic and neuropathic types the most frequently. If the acute cancer pain does not subside with initial therapy, patients experience pain of more constant nature, the characteristics of wich vary with the cause and the involved sites. Chronic pain related to cancer can be considered as tumor-induced pain, chemotherapy-induced pain, and radiation therapy-induced pain. Certain pain mechanisms are present in cancer patients. These include inflammation due to infection, such as local sepsis or the pain of herpes zoster, and pain due to the obstruction or occlusion of a hollow organ, such as that caused by large bowel in cancer of colon. Pain also is commonly due to destruction of tissue, such as is often seen with bony metastases. Bony metastases also produce pain because of periostal irritation, medullary pressure, and fractures. Pain may be produced by the growth of tumor in a closed area richly supplied with pain receptors (nociceptors). Examples are tumors growing within the capsule of an organ such as the pancreas. Chest pain occurring after tumor of the lung or the mediastinum due to invasion of the pleura. Certain tumors produce characteristic types of pain. For example, back pain is seen with multiple myeloma, and severe shoulder pain and arm pain is seen with Pancoast tumors.