The effectiveness of microvascular decompression in various types of vascular compression in patients with trigeminal neuralgia

The aim of the work was to evaluate the efficacy of microvascular decompression (MVD) in different types of vascular compression (VC) in 20 patients with the idiopathic form of trigeminal neuralgia (TN). The typical VC was found in 17 cases. An arterial vessel was the cause of VC in 6 cases, a venous vessel in 5. The mixed type of VC was present in 6 cases. In every case of the mixed VC one of the vessels compressing the 5th nerve predominated: arterial in 5 and venous in 1. In 3 cases of TN no VC was found. Observation time after MVD was from 6 to 61 months (median 26.7 months). In the TN patients with the arterial VC (including the mixed VC with the arterial predominance) pain relief was complete in 7 cases, satisfactory in 2 and none in 1 case. In patients with venous VC (including mixed VC with venous predominance) pain relief was complete in 4 cases and satisfactory in 2. In the TN patients without VC pain relief was satisfactory in 1, unsatisfactory in 1 and none in 1 case. Long term results of MVD in the analyzed series of the TN patients confirm the efficacy of MVD when vascular compression of the 5th nerve--either arterial or venous--is found intraoperatively.

Postoperative pain relief by demand analgesia.

Postoperative pain relief is only apparently an easy task. A brief survey of literature investigating the discomfort experienced in the postoperative phase is all but encouraging. One can identify four basic problems in obtaining adequate results by delivery of analgesic drugs: a) the biological variability among individual patients, b) the unpredictable uptake of the drug administered intramuscularly, c) the time lag involved between request by the patient and the subsequent administration of a single dose and d) the lack of knowledge about the nature of the discomfort and its remedies. An alternative strategy introducing "On-Demand" analgesia administering prescribed doses at the right moment is presented and analysed a) as an operant conditioning process implementing a particular reinforcement schedule (behavioural sciences), as well as b) a negative feedback control loop that entrust the central judgement to the patient (system theory). Both approaches give insight into the results: the technique copes with biological variability; anticipating pain induced by fear disappears; the feedback strategy works well and patients adapt to a wide range in prescriptions; intermittent administration makes more efficient use of the analgesic; an optimal result is demonstrated in studies comparing on-demand analgesia with the normal IM-regime and epidural analgesia; continuity in pain relief can be obtained in routine clinical practice.

Percutaneous echography-guided alcohol block of the celiac plexus as treatment of painful syndromes of the upper abdomen: study of 21 cases

Celiac plexus block is usually performed under fluoroscopic or tomodensitometric guidance. We report on a new procedure using sonographic guidance. the patient lies in supine position. We use a real-time sonograph with a 3.5 MHz probe. On a transverse plane, the celiac axis is localized emerging from the aorta. Under local anesthesia, the tip of the spinal needle (177 mm, 22 g) is placed close to the aorta (about 5 mm) on both sides. 5 to 10 ml of 1% lidocaine, then 10 to 20 ml of absolute alcohol, are injected on each side. 21 patients (10 males, 11 females, mean age: 61.4) underwent the procedure. They presented with cancer of the pancreas in 14 cases, metastatic nodes from an extra-pancreatic tumor in 5 cases and chronic calcifying pancreatitis (CCP) in 2 cases. No pain relief was secured in 3 patients (14%). One of these presented with CCP, but endoscopic cystic diversion of a small cyst was successful in eradicating pain. Partial pain relief was secured in 5 cases (24%) and total pain relief in 13 cases (62%). No treatment-related complication was observed. We conclude that sonography is a simple and safe method of guidance in performing alcohol block of the celiac plexus. The anterior approach may prevent neurologic complications occurring with other methods of guidance using a posterior approach.

Prospective study of transcutaneous oxygen tension (TcPO2) measurement in the testing period of spinal cord stimulation in diabetic patients with critical lower limb ischaemia.

BACKGROUND: Spinal cord stimulation improves microcirculatory blood flow, relieves diabetic neuropathic and ischaemic pain and reduces the amputation rate in patients with severe peripheral arterial occlusive disease. Aim: To evaluate whether transcutaneous oxygen tension (TcPO2) measurements can be used as a specific prognostic parameter in the assessment of suitability for permanent device implantation in a prospective controlled study on diabetic patients with peripheral arterial occlusive disease. METHODS: Sixty patients (39 men, 21 women; mean age: 60 years; range: 46-75) were submitted to implantation of a spinal cord electrical generator for severe peripheral vascular disease, after failed conservative or surgical treatment. The clinical status was classified as Fontaine's stage III and IV and the main pathology was diabetic vascular disease. Pedal TcPO2 was assessed on the dorsum of the foot and ankle and toe pressure Doppler measurements were performed before, two weeks and four weeks after implantation. RESULTS: pain relief of over 75% and limb salvage were achieved in 35 diabetic patients, while in 12 a partial success with pain relief over 50% and limb salvage for at least 6 months was obtained. In 13 patients the method failed and the affected limbs were amputated. Clinical improvement and spinal cord stimulation success were associated with increases of TcPO2, within the first two weeks after implantation (temporary period). Limb salvage was achieved with significant increase of TcPO2 within the first two weeks of the testing period (from 21.4 to 31.5 mmHg in rest pain patients, p=0.030, from 15.1 to 22.0 mmHg, p=0.030 in patients with trophic lesions under 3 cm2 in size and in those with trophic lesions over 3 cm2, from 12.1 to 17.9 mmHg, p=0.025) unrelated to the stage of the disease and the initial TcPO2 value. TcPO2 changes were related to the presence of adequate paraesthesias and warmth in the painful area during the trial period. The systolic ankle/brachial blood pressure index and toe pressure did not change under stimulation. CONCLUSIONS: A two-week testing period should be performed in all diabetic patients treated with spinal cord stimulation for peripheral arterial occlusive disease to identify the candidates for permanent implantation. Only diabetic patients with significant increases of TcPO2 and clinical improvement, during the test period, should be considered for permanent implantation and not merely all patients with pain relief. TcPO2 changes could be used as a predictive index of the therapy success and should be considered in terms of cost effectiveness before the final decision to permanent implantation.

The relationship between the visual analog pain intensity and pain relief scale changes during analgesic drug studies in chronic pain patients.

BACKGROUND: Most analgesic drug studies in humans quantify drug action based on verbal reports of pain intensity and pain relief. Although measures of pain intensity and pain relief show a good overall correlation, it is not known if they relate to each other consistently over time Such consistency is necessary if both measures are used to depict analgesic drug action versus time. This study examined in chronic pain patients if the relationship between visual analog pain intensity and pain relief scores was consistent during two analgesic drug studies. METHODS: Data from two independently performed analgesic drug studies were analyzed using linear regression. Data were split into pain intensity and pain relief scores recorded before and after patients' experience of maximum analgesia (>90% of maximum pain relief). The slopes of the linear regression line depicting pain intensity versus pain relief scores before and after maximum analgesia were statistically compared. RESULTS: The slope of the linear regression line before and after maximum analgesia was significantly different in both drug studies (nonoverlapping 95% confidence intervals), -2.16+/-0.57 versus -1.05+/-0.10 and -1.47+/-0.26 versus -1.09+/-0.07, respectively. These results are compatible with the observation that patients indicating the same pain intensity before and after maximum analgesia reported a different magnitude of pain relief. CONCLUSIONS: The relationship between visual analog pain intensity and pain relief scores changed systematically during both analgesic drug studies. The authors hypothesize that patients' interpretation of the pain relief scale had changed during the studies and therefore suggest using the pain intensity scale to quantify analgesic drug action over time.

Triple arthrodesis in rheumatoid arthritis.

Fifty-five patients with rheumatoid arthritis were treated with 65 triple arthrodeses of the hindfoot from March 1975 through July 1985. Twelve patients (12 procedures) have died, and follow-up evaluation could not be completed on three patients (four procedures), leaving 40 patients (49 procedures) available for clinical and roentgenographic evaluation. There were 32 women and eight men, with an average age at the time of surgery of 50 years. The follow-up period averaged five years. Standard operative technique involved medial and lateral incisions with staple fixation and local bone grafting. Correction of deformity was performed with closing wedge osteotomies. All patients had moderate to severe pain preoperatively and difficulty with ambulation. Postoperatively, 94% of the patients had significant pain relief and 83% had complete pain relief. Ambulatory status was improved in 80% of the patients. Ninety percent were at least community ambulators at the time of review, whereas more than half the patients were limited to household ambulation preoperatively. Complications included four superficial wound infections, all of which responded to local care. One patient required revision surgery for pseudarthrosis, and three patients had progression of ankle disease and required pantalar arthrodeses. There was no significant progression of fore-foot or knee symptoms, however, and there was no progression of ankle symptoms in patients whose hindfeet were corrected to 0 degrees-10 degrees valgus. Triple arthrodesis in the rheumatoid population has a high union rate. pain relief and ambulation improvement can be expected.

Treatment of pain of diffuse metastatic cancer by stereotactic chemical hypophysectomy: long term results and observations on mechanism of action.

Stereotactic instillation of absolute alcohol into the sella turcica for pituitary destruction was carried out in 29 patients divided into two groups. Seventeen with prostatic carcinoma underwent a total of 19 injections with 94% good to excellent results that persisted throughout the remainder of the patient's life-span. The longest survival was 9 months. Brief relapses did occur, but spontaneous remissions were the rule. A second group of mixed cancers contained 12 patients who received a total of 13 injections. Eleven patients had good to excellent results that persisted in all but 1 patient. The longest survival was 7 months. Hormonal levels and prolactin stimulation tests failed to show any correlation between hormonal changes and pain relief. Naloxone reversal of analgesia did not occur. There was no loss of cognitive function shown on psychological testing. Pathological studies showed destruction of the pituitary gland, which was subtotal in some patients despite good pain relief. All examinations showed that the pituitary stalk was destroyed. Patients who survived longer also showed degeneration of the supraoptic and paraventricular nuclei of the hypothalamus and the median eminence. All but 1 patient with pain relief exhibited a lack of antidiuretic hormone (ADH) production. Interpretation of the data indicates that ADH or its associated neurophysins act as central pain transmitters. The production of these transmitters is decreased or abolished by chemical hypophysectomy through the destruction of hypothalamic nuclei.

Test instrument for predicting the effect of rigid braces in cases with low back pain.

The difficulty of predicting the acceptance and the result of wearing rigid braces has been identified before and is reported in the literature. Therefore a test instrument has been developed and tested. The intention is that the test instrument can imitate a rigid brace. Furthermore, different attributes of the rigid brace can be altered. Thus the range of the lordosis, the level of maximal dorsal support and the amount of abdominal support can be altered. By changing these parameters the maximal pain relief is sought. A good correlation between the result in the test instrument and the rigid brace manufactured according to the information from the former was seen (93%). No false negative results were seen. Thus, if no acceptance or pain relief was seen in the test instrument no pain relief could be expected in a rigid brace. Another purpose of this test instrument is to simplify the manufacture of the brace and to transfer easily the information gained from the test instrument to the brace with the aid of a so called measuring device.

Percutaneous controlled radiofrequency trigeminal rhizotomy for the treatment of idiopathic trigeminal neuralgia: 25-year experience with 1,600 patients.

OBJECTIVE: The objective of this study was to evaluate the effectiveness of percutaneous, controlled radiofrequency trigeminal rhizotomy (RF-TR). The outcome of 1,600 patients with idiopathic trigeminal neuralgia after RF-TR was analyzed after a follow-up period of 1 to 25 years. METHODS: A total of 1,600 patients with idiopathic trigeminal neuralgia underwent 2,138 percutaneous radiofrequency rhizotomy procedures between 1974 and 1999. Sixty-seven patients had bilateral idiopathic trigeminal neuralgia, and 36 of them were treated with bilateral RF-TR; 1,216 patients (76%) were successfully managed with a single procedure, and the remainder were treated with multiple procedures. Benzodiazepines and narcotic analgesics were used for anesthesia because patient cooperation during the procedures was essential so that the physician could create selective, controlled lesions. RESULTS: The average follow-up time was 68.1 +/- 66.4 months (range, 12-300 mo). Acute pain relief was accomplished in 97.6% of patients. Complete pain relief was achieved at 5 years in 57.7% of the patients who underwent a single procedure. pain relief was reported in 92% of patients with a single procedure or with multiple procedures 5 years after the first rhizotomy was performed. At 10-year follow-up, 52.3% of the patients who underwent a single procedure and 94.2% of the patients who underwent multiple procedures had experienced pain relief; at 20-year follow-up, 41 and 100% of these patients, respectively, had experienced pain relief. No mortalities occurred. After the first procedure was performed, early pain recurrence (<6 mo) was observed in 123 patients (7.7%) and late pain recurrence was observed in 278 patients (17.4%). Complications included diminished corneal reflex in 91 patients (5.7%), masseter weakness and paralysis in 66 (4.1%), dysesthesia in 16 (1 %), anesthesia dolorosa in 12 (0.8%), keratitis in 10 (0.6%), and transient paralysis of Cranial Nerves III and VI in 12 (0.8%). Permanent Cranial Nerve VI palsy was observed in two patients, cerebrospinal fluid leakage in two, carotid-cavernous fistula in one, and aseptic meningitis in one. CONCLUSION: Percutaneous, controlled RF-TR represents a minimally invasive, low-risk technique with a high rate of efficacy. The procedure may safely be repeated if pain recurs.

Analgesic efficacy and pharmacokinetic evaluation of meperidine and hydroxyzine, alone and in combination.

As part of a study to evaluate the analgesic efficacy of meperidine and hydroxyzine, alone and in combination, a double-blind complete crossover study of meperidine (50 mg IM), hydroxyzine (100 mg IM), meperidine (50 mg IM) plus hydroxyzine (100 mg IM), and saline placebo was conducted. Thirty patients with chronic moderate to severe pain due to metastatic cancer were evaluated as to pain relief following administration of all four study medications. All of the treatment groups showed statistically significant analgesic activity as compared to placebo. Hydroxyzine provided sustained pain relief to six hours, whereas meperidine produced analgesia up to two hours. The combination produced additive analgesia only during the first 2 hr. The pharmacokinetics of meperidine and hydroxyzine were compared to observed analgesia. Significant correlation between serum drug levels of meperidine and hydroxyzine and pain relief resulted and the serum levels of meperidine and hydroxyzine necessary for analgesia were calculated to be 0.10-0.15 mg/ml and 60-70 ng/ml; respectively. The observed analgesia of the meperidine/hydroxyzine combination was correlated with the analgesia of the individual agents and the limited additive analgesia observed with the addition of meperidine to hydroxyzine does not justify the added toxicity of the narcotic.