When it thinks about the pathophysiology and the treatment of tension-type headache, the classification and a diagnostic criteria of it are important. Tension-type headache is classified in one of the functional headaches by the headache classification committee of the international headache society in 1988, and contains a disease group such as tension headache when mental and physical stress becomes a cause. The ischemic contraction of the posterior neck muscle is one of the causative factors of tension-type headache associated with disordered of pericranial muscles, and then the participation of the central pathophysiology are pointed out. The imbalance condition of the immunity is suggested, too. Though what is done based on the pathophysiology is of course, a cause is multiple, and symptomatic therapy becomes important as for the treatment for tensiontype headache, too. There are various cures in the nerve block therapy, the medication, psychotherapy, physiotherapy, the laser treatment, and so on. A stellate ganglion block is often effective in the patient with tension-type headache. A stellate ganglion block returns imbalance condition of the function of the sympathetic nervous system and controls an edema and inflammation of the blood vessel wall. Yokota states that a stellate ganglion block influences a pineal and suggests the possibility that it is involved in the adjustment of the immunity. But, if it becomes the thing of evidence of the treatment, there is no report of proving a stellate ganglion block effect against the tension-type headache objectively. We must advance that evidence of the treatment is cleared by all means.

View full abstract

The authors investigated the factors, which could decide the prognosis of sudden hearing loss (SHL), in the 124 patients treated by stellate ganglion block (SGB) concomitant with conventional medical therapy since January 1999 through December 2000. SGB was performed for all the patients six times a week (totally 13±6 times) using 7ml of 1.0% lidocaine. The effectiveness of SGB was evaluated according to the recovery criteria by the official committee of SHL, Japan, i.e.; a) cure or complete return to <20dB in all tested frequencies; b) remarkable return to average pure tone score of >30dB; c) effective return to average pure tone score of >10dB; and d) ineffective. The complete and remarkable recovery rate (a+b) was 40.3% in the patients treated by SGB, whereas it was 33.3% in the patients without SGB (n=9). As the results of the analysis, four factors were suspected to be concerned in the improvement of the prognosis of SHL. Well-recovered patients are those; 1) who were male and younger than 50 years old; 2) who had some complications relating to microcirculatory disturbances as hypertension, diabetes or hyperlipidemia, and; 3) who received the first SGB earlier after the onset of SHL. Furthermore, the patients with vertigo were also successfully treated by SGB better than in former reports. On the other hand, female patients younger than 40 years old showed poorer prognosis. The results in this study indicate that SGB would be a useful therapy for a type of SHL simply brought on by some microcirculatory disturbances, as SGB could increase the blood supply to the cochlear.

View full abstract

About 40% of herpes zoster involves head and neck. Stellate ganglion block at the 6th or 7th cervical transverse process using 5 to 10ml of local anesthetics is adopted in Japan. Stellate ganglion block with this small dose of local anesthetics can relieve acute herpetic pain involving trigeminal region; however, it is hard to lessen acute herpetic pain involving the 6th cervical dermatome or lower. Preganglionic sympathetic fibers to the head and neck originate in the first to fourth thoracic segments. High thoracic epidural block covering these segments gives the same effects obtained by stellate ganglion block. Even severe acute herpetic pain involving head and neck can be relieved by continuous high thoracic epidural block. Stellate ganglion block has no effects on established postherpetic neuralgia itself. Relief of postherpetic neuralgia after stellate ganglion blocks may be caused by systemic effect of absorbed local anesthetics. Tricyclic antidepressant is the treatment of first choice for the treatment of established postherpetic neuralgia.

View full abstract

Myocardial ischemia/reperfusion injury has come to be a serious phenomenon in clinical practice as the progression of interventional recanalization to salvage ischemic myocardium. Brief coronary occlusion lasting<20 minutes produces depression of myocardial contractile function for several hours. This reversible injury is referred to as “myocardial stunning”. Coronary blood flow to stunned myocardium is restored to normal or near normal. Myocardial Stunning may occur in a number of clinical settings including cardiac surgery, cardiac transplantation, percutaneous transluminal coronary angioplasty, and angina pectoris. Thoracic epidural anesthesia (TEA) increases subendocardial blood flow before ischemia and enhances functional recovery of left ventricular contractility after reperfusion. The possible mechanisms of this cardioprotection are improvement of subendocardial blood flow due to suppression of excessive excitation of cardiac adrenergic system, or decrease in myocardial oxygen consumption. Though details have not been clarified, elevated concentration of cardiac interstitial norepinephrine (NE) release has been observed during myocardial ischemia. We investigated the effects of NE administration for TEA induced cardioprotection on stunned myocardium in dogs. NE administration during ischemia and early reperfusion period suppressed functional recovery after reperfusion under cardiac sympathetic nerve blockade by TEA. Cardioprotective effects of TEA would be produced through suppression of cardiac NE release during ischemia. The anti-ischemic effect of TEA might be influenced with co-existing general anesthetics. Halogenated anesthetics improve myocardial functional recovery in myocardial stunning. Sevoflurane protects stunned myocardium through activation of mitochondrial ATP-sensitive potassium channels. TEA has no additional protective effect on recovery of stunned myocardium during sevoflurane anesthesia. Propofol, an intravenous anesthetic, can not improve functional recovery of myocardial contractility. TEA does not improve functional recovery of stunned myocardium during propofol anesthesia. Although cardioprotective effects of TEA might be influenced by general anesthetics, TEA can exert beneficial effects to prevent lethal cardiac event for patients with coronary artery disease especially in perioperative period which increases risk of myocardial ischemia.

View full abstract

Neuropathic pain had been considered a difficult condition to treat with opioid analgesics. But our clinical results indicated that postherpetic neuralgia (PHN), a most familiar neuropathic pain to Pain-Clinicians, was relieved effectively by oral codeine medication. In several clinical investigations it was reported that oxycodone, morphine and other opioids had the equal or superior effect on PHN or neuropathic pain to other types of chronic pain. Although usefulness and safety of opioid analgesics is established in the treatment of acute pain and cancer pain, for practical control of neuropathic pain following considerations are required: 1) To administer the drug until sufficient pain relief attained, 2) To repeat patient compliance instruction until understanding of the drug reached, 3) To control acute pain of herpes zoster and nerve injury in the early stages.

View full abstract

The action of NSAIDs is characterized by a certain selectivity in their effects. They produce reversible cyclo-oxygenase (COX) inhibition by competing with the substrate arachidonic acid for the active site of the enzyme. NSAIDs thus prevent the pathological production of prostaglandins (PGs) by COX-2 and the physiological formation of prostanoids by COX-1. Their gastrointestinal toxicity arises from inhibition of PGE₂ and PGI₂ due to inducing COX-1 formation. The kidney is a rich source of COX-1 produced PGs which are necessary for keeping its normal function. Most of unwanted renal effects of NSAIDs, such as reduction of renal blood flow and glomerular filtration rate, sodium retention and hyperkalemia, have been attributed to inhibition of PG synthesis. Selective COX-2 inhibitors appear to be so largely devoid of unwanted renal and gastrointestinal effects that we can prescribe COX-2 selective NSAIDs quite safely recently.
The activity and metabolism of peripheral afferent sensory fibers is altered by chemical mediators generated by inflammation following tissue injury. PGs enhance local nociceptors and some of them sensitize sensory neurons to other stimuli and contribute to mechanism of peripheral hyperalgesia. The interrelationship between NMDA receptor-induced activation of the NO system and expression of COX is believed today an important part in the development of neuronal plasticity and central sensitization. These suggest that NSAIDs should have new and more active role in the treatment of neuropathicpain such as CRPS after tissue injury or nerve injury.
If it is definitely established that COX-2 and PGE₂ are expressed in the central nervous system and related with the central sensitization or inflammatory hyperalgesia, this may offer implications for therapy with NSAIDs in neuropathicpain. After C-fiber stimulation, there is evidence of prostanoid release in the spinal cord and COX inhibition blocks the hyperalgesia induced by both substance P and NMDA. Repetitive C-fiber stimulation evokes a state of spinal facilitation referred to as wind up and an increase in the size of their respective fields. In spite of appropriate preclinical toxicity testing has not been performed for any commercially available NSAIDs and intraspinal application is premature, one report has showed the excellent efficacy of administration of infra epidural NSAIDs for cancer pain. Intraspinal NSAIDs applications should be advanced therapy for neuropathicpain and other pain such as cancer pain in the near future.

View full abstract

Repeated applications of Stellate Ganglion Block (SGB) are known to improve symptoms of allergic rhinitis but the mechanism of the effects is not clear. Correlation between sympathetic nervous system and pain, and or immune system has been reported. To examine if the blockade of the part of sympathetic nervous system like SGB could affect pain threshold and immune system activity of whole body. Four weeks after the operation Tail Flick test was examined. YAC1 cell lytic activities of the splenic natural killer cell (NK activity) between sham operation group and cervical sympathetic denervation group also were compared. Pain threshold was no change between two groups. But, NK activity of denervation group was significantly lower than that of sham group. The result suggests the possibility of manipulation of immune activity of individuals by partial blockade of sympathetic nervous system.

View full abstract

We have studied whether epidural nitroglycerin, an NO donor, induces hyperalgesia. Epidural, but not systemic, nitroglycerin induced hyperalgesia which was completely blocked by methylene blue but not by L-NAME. Epidural L-arginine, but not D-arginine, also induced hyperalgesia which was completely blocked by L-NAME. Nitrite was detected in vitro in a reaction mixture of nitroglycerin and the spinal cell suspension. Epidural nitroglycerin induces hyperalgesia via synthesis of nitric oxide at the spinal cord.

View full abstract

Pain is perceived when the noxious stimuli are taransduced to neural electrical signals (action potentials), and are transmitted in the peripheral axon of nociceptors to the spinal cord and then further transmitted through the thalamus to the cerebral cortex. The first event that occurs after noxious stimulus arriving at the nociceptor terminals is energy transduction to electrical signals (receptor potentials). Nociceptors like polymodal receptors that respond to multiple modes of stimuli are considered to have multiple transducers and/or ion channels on the nociceptor terminals. This review will provide a short introduction on the present status of research on transducers (heat transducers, e. g. VR1 and VRL-1), ion channels (e. g. P2X3 receptors) and receptor molecules (e. g. bradykinin receptors and prostaglandin receptors) that are involved in transduction in nerve terminals. Hyperalgesia is common in injured or inflamed tissues, and one of the mechanism for hyperalgesia is sensitization of nociceptors by inflammatory mediators. Samples of nocieptor sensitization by inflammatory mediators (bradykinin, histamine, prostaglandins, ATP and NGF) are introduced, and possible molecular mechanism is also touched.

View full abstract

Radio frequency thermal coagulation has been applied to treat various types of neuralgia. The procedure is applied to the type of pain for which nerve block is only temporarily effective and there are no other analgesic modalities available. The basic approach taken is same as that for trigger point and nerve root blocks: specifically, the electrode needle is inserted after administering a light local anesthesia. It may be conducted under fluoroscopy or guided by CT. The tip of the needle may be located by using reproducible referred pain or radiographic findings as a reference. It is made certain that the electrode needle does not affect the motor nerves and is located near the sensory nerve. The coagulation temperature is set between 60 and 90°C and the coagulation time, between 90 and 120 seconds. The effect of the procedure is judged based on analgesia 2 to 3 days after the treatment. A satisfactory analgesic effect is often noted immediately after coagulation. If it is applied to suitable pain conditions, the procedure may be an effective analgesic method that can be conducted at a pain clinic. It is indicated for refractory RSD, trigeminal neuralgia, spondylosis deformans with marked radicular symptoms, compression fractures, and postherpetic neuralgia. Adverse effects include numbness, pain at the site of coagulation, and slight motor dysfunction. Clinical cases are presented together with some explanation.

View full abstract

The method for cancer pain relief proposed by the World Health Organization consists of guidelines for a three-step treatment, from non-opioids to weak and then strong opioids. The immunomodulatory effects of opioids have been documented by numerous reports. However, little is known about how morphine may alter immune functions in terminally ill cancer patients. This study was designed to evaluate the effect of morphine on immune status as designated by the lymphocyte cluster in peripheral blood of terminally ill cancer patients.
Consecutive terminally ill cancer patients admitted to Palliative Care Center in Tohoku University Hospital from January to May 2001 were enrolled in this study. Of 61 patients who gave a written informed consent, 37 had been treated for their pain with morphine. Common serum enzyme markers were determined using standard hospital laboratory methods. Cellular immunity status was evaluated by lymphocyte-subset analysis in peripheral blood by flow cytometry.
No difference was seen in pain control between the morphine group and the control group (numerical rating score: 1.4±2.2vs. 1.2±1.9). We found significant difference in C^- reactive protein (morphine group: 9.08±1.96vs. control group: 3.24±4.16, p=0.023), CD3^- CD56⁺ cell- counts (117.5±156.1vs. 277.3±339.5, p=0.017) and CD8⁺ cell- counts (122.7±104.8vs. 247.0±231.0, p=0.006). Single regression analysis, however, revealed that the immune alteration of terminally ill patients was not associated with the serum concentration of morphine.

View full abstract

Purpose: To assess the long term outcome of multidisciplinary treatment for complex regional pain syndrome (CRPS).
Methods: A questionnaire was sent by mail to 80 patients who had recently received inpatient care at Osaka University Hospital. The questionnaire contained questions concerning current pain, daily sleeping pattern, health care service, current occupation, quality of life and patient satisfaction.
Results: The questionnaire was answered by 55 patients (69%). Approximately 70% of patients considered inpatient treatment effective for reducing pain and recovering motor function. The current numerical pain rating scale showed 4.2±3.5, 51% of the patients had good sleeping status, 15% of the patients required assistance for daily life, and 53% continuously received health care. Occupational difficulty was reported in most cases; only 18% of the patients were able to return to former jobs.
Conclusion; Our results showed that CRPS patients were able to receive effective treatment in an inpatient setting. Most CRPS patients not only suffer from pain after hospital discharge but are also faced with long term therapy, occupational difficulties, together with physical and social disability problems.

View full abstract

The effectiveness of Static Magnetic Fields (SMF) for pain was studied in rats with adjuvant-induced arthritis (AA). AA rats were raised for 6 months as the chronic pain model. These model animals were exposed to SMF and the rats tail skin temperature, locomotor activity and bone mineral density (BMD) were measured using thermography, blood analysis and dual-energy X-ray absorptiometry (DEXA).
In AA rats, the tail temperature and locomotor activity were obviously lower than in control rats. After exposure to SMF, the tail temperature and locomotor activity in AA rats were significantly higher when compared with those before exposure to SMF. Moreover, the decrease of BMD was significantly inhibited.
These findings suggest that the pain relief effects of SMF might be primarily due to improvement in the blood circulation, and the increase of BMD was considered partly ascribable to the increase of locomotor activity.

View full abstract

Complex regional pain syndrome (CRPS) has been considered to be contraindicative to surgical treatment because of its poor outcome. In the last 7 years, we have had 8 patients with CRPS who received surgical treatment including tendon detachment, peripheral nerve decompression, tendon extension, replacement of humeral head and surgical correction. Range of motion and activity in daily life improved after surgery in 6 cases. According to our experience, for improving motor function in patients with CRPS, surgical treatment is not contraindicative. Careful selection of surgical candidates perioperative pain management and early physical treatment are important for a favorable outcome.

View full abstract

Anesthesia dolorosa is a troublesome complication following the treatment of trigeminal neuralgia. The authors successfully treated a patient with anesthesia dolorosa by permanent placement of a Spinal Cord Stimulation (SCS) system at the upper cervical epidural space. A 52-year-old woman with a history of left-sided facial pain affecting the maxillary and mandibular divisions had undergone retrogasserian trigeminal nerve block with anhydrous glycerol. Soon after treatment, her left face became symptomatic consistent with anesthesia dolorosa. Various treatments, including analgesics and stellate ganglion block, had been attempted for the treatment of her pain with no relief. As an alternative treatment, high cervical epidural SCS was performed. The “PISCES Quad” electrode was placed at her C_2/3 level left of midline, under fluoroscopic control. After a few seconds of stimulation, she noticed alleviation of left facial pain and her left eyelid opened completely. She subsequently lowered her dose of carbamazepine (Tegretol) by using 30-minute Spinal Cord Stimulation 3 times a day. SCS-induced increases in norepinephrine and glycine in the cerebrospinal fluid suggests that activation of inhibitory system is the mechanism of pain relief.

View full abstract

Ossification of the anterior longitudinal ligament (OALL), one of the diffuse idiopathic skeletal hyperostoses, is a rheumatological abnomality in which severe ossification occurs along ligaments throughout the body. It is relatively rare, affeciting older male predominantly. The disease is usually asymptomatic but can produce nonspecific postural symptoms such as chronic back pain. We report a terminally ill pancreatic cancer patient with OALL who suffered from severe abdomined and back pain. Although the neurolytic celiac plexus block successfully reduced the upper abdominal pain and daily analgesic dose, the patient's overall activity of daily living did not improve because of persistent back pain in supine position. The postprocedural lateral spinal radiograph revealed diffuse calcification of the anterior longitudinal ligaments along the spine, that was probably responsible for his back pain. This case highlighted the importance of intense assessment of cancer-unrelated pain, including muscloskeletal components, especially in elderly cancer patients.

View full abstract

Percutaneous epiduroscopic adhenolysis is recently indicated in cases with low back pain resistant to drug therapy or various kinds of nerve blockades. Because a large quantity of physiologic saline is injected into the epidural space during the procedure, cerebrospinal pressure elevates. Therefore, some complications such as cervicodynia, headache, convulsion and retinal hemorrhage have been reported. We inserted the epidural catheter at the level of C_6/7, and monitored the epidural pressure intraoperatively in order to investigate the relation between headache and cervical epidural pressure. We examined the cervical epidural pressure curves in two cases of cervicodynia with headache during the procedure. These symptoms occurred when the epidural pressure elevated over 80mmHg due to the body movement caused by severe pain during adhenolysis, or due to the bolus injection of saline following adhenolysis. This transient elevation of epidural pressure returned to the baseline level within a couple of minutes after stopping the saline injection. These results suggest that monitoring cervical epidural pressure during epiduroscopy is useful to predict the complications of elevated cerebrospinal pressure and clarify the mechanisms involved.

View full abstract

Because of high lipid solubility fentanyl can be administered by the transdermal route to treat cancer pain. We studied the effects of fentanyl patch in 10 patients whose medication for cancer pain was converted from standard morphine medication to fentanyl patch. Supplemental rescue dose of morphine was given if necessary. Conversion ratio of morphine to transdermal fentanyl was 150 to 1. The severity of pain, nausea, vomiting, sleepiness and constipation were compared before and after the application of transdermal fentanyl.
Visual analogue scale of pain score was significantly decreased after the application of fentanyl patch. No significant changes were found in the frequencies of nausea, vomiting and sleepiness before and after administration of fentanyl. Nausea and vomiting were diminished in two patients after fentanyl. In two patients, the sleepiness caused by morphine was decreased. Severe constipationin was reselved in four patients lessened.
We have a new advantageous tool to treat cancer pain.

View full abstract