Electrical stimulation of denervated rat skeletal muscle retards trabecular bone loss in early stages of disuse musculoskeletal atrophy.

OBJECTIVES: We aimed to determine the intensity of muscle stimulation required to prevent structural failure as well as bone and skeletal muscle loss after denervation-induced disuse. METHODS: Seven-week-old rats (weight, 198-225 g) were randomly assigned to age-matched groups comprising control (CON), sciatic nerve denervation (DN) or direct electrical stimulation (ES) one day later [after denervation] with 4, 8 and 16 mA at 10 Hz for 30 min/day, six days/week, for one or three weeks. Bone architecture and mean osteoid thickness in histologically stained tibial sections and tension in tibialis anterior muscles were assessed at one and three weeks after denervation. RESULTS: Direct ES with 16 mA generated 23-30% maximal contraction force. Denervation significantly decreased trabecular bone volume fraction, thickness and number, connectivity density and increased trabecular separation in the DN group at weeks one and three. Osteoid thickness was significantly greater in the ES16 group at week one than in the DN and other ES groups. Trabecular bone volume significantly correlated with muscle weight. CONCLUSIONS: Relatively low-level muscle contraction induced by low-frequency, high-intensity electrical muscle stimulation delayed trabecular bone loss during the early stages (one week after DN) of musculoskeletal atrophy due to disuse.

Reduction in subluxation and improved muscle function of the hemiplegic shoulder joint after therapeutic electrical stimulation.

Seventeen hemiplegic patients with chronic shoulder subluxation secondary to a cerebrovascular accident (CVA) were divided into three groups, two of which were subjected to 6 weeks of therapeutic electrical stimulation (TES) for 15 minutes twice a day, in order to assess the effectiveness of the treatment in reducing subluxation, and in improving shoulder abduction function. The third group was used as a control (C group). After 6 weeks of electrical stimulation of the supraspinatus (S group) and deltoid (D group), a significant (p<0.05) reduction in subluxation was observed in both groups when compared to the C group. The maximal force of shoulder abduction showed a tendency to increase in the S group (p<0.10). A significant increase in maximal force was also observed in the D group. In most of the TES-treated muscles, the interference pattern of EMG at maximum voluntary contraction increased. The amplitude of the EMG activity of the stimulated muscle also increased. Thus, we concluded that electrical stimulation therapy of the supraspinatus and the deltoid muscle is an effective treatment modality for shoulder subluxation and shoulder abduction function in hemiplegic patients.

Newly developed transurethral radiofrequency thermotherapy device for benign prostatic hyperplasia: a pilot study in canine prostate.

The safety and efficacy of transurethral microwave thermo-therapy (TUMT) for the treatment of symptomatic benign prostatic hyperplasia (BPH) have been demonstrated in the urological literature. Since a radiofrequency electromagnetic wave has deeper and more even transmission of heat to tissues than a microwave, we have developed a new prototype device for transurethral thermotherapy using a radiofrequency electromagnetic wave. The device consists of a microcomputer-controlled heat generator operating at 8 Mhz, a temperature monitoring system, a urethral cooling system and a urethral applicator and a rectal thermosensor probe. A balloon electrode encased in a specialized Foley catheter is connected parallel to twin plate electrodes on both sides of the pelvic region. An 8-MHz electromagnetic wave is directed to the prostate by means of capacitive coupling. The water coolant continuously perfused through the catheter allows high temperatures within the prostate while preserving the urethral mucosa. Heating experiment using agar phantom showed the hot spots to be distributed at 0.5-3 cm from the catheter surface. Heating experiment using canine prostates demonstrated that an intraprostatic temperature of > 48 degrees C could be achieved while the urethral and rectal temperatures had not exceeded 36 and 40 degrees C respectively. Histological examination immediately after the experiment showed the urethral mucosa to be preserved while coagulation necrosis of the periurethral prostate accompanied with congestion and hemorrhage of small blood vessels were observed at 5-8 mm from the urethra. The bladder and the rectum showed no gross alterations. Histopathological examination 10 days after the experiment revealed the intact urethral mucosa and mild mononuclear infiltration around the destroyed periurethral glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Increasing the thermal dose in transurethral microwave thermotherapy produces no improvement in therapeutic efficacy.

BACKGROUND: Transurethral microwave thermotherapy (TUMT) is a minimally invasive treatment for benign prostatic hyperplasia (BPH). It has been reported that increased thermal dose and higher intraprostatic temperatures resulted in improved clinical response. Recently we treated BPH patients with the prostatron device using a new version of software (Prostasoft 2.5), which was intended to increase thermal delivery by allowing maximum power up to 70W. The safety and clinical results were compared between the patients treated with Prostasoft 2.5 and those treated with the currently available software (Prostasoft 2; maximum power up to 50W). METHODS: A total of 105 patients were treated successively with two treatment protocols. Sixty-three patients were treated with Prostasoft 2 between September 1992 and July 1993, while 42 were treated with Prostasoft 2.5 between August 1993 and April 1994. Therefore, this investigation was a retrospective nonrandomized study. There was no significant difference in the baseline patient characteristics between the two groups. RESULTS: Total thermal dose delivered to the prostate was significantly higher in the Prostasoft 2.5 group than that in the Prostasoft 2 group (137 kJ versus 116 kJ, P < 0.05). No serious complications were encountered in either group. Six months after TUMT, in both the Prostasoft 2.5 and Prostasoft 2 groups there was an improvement in patient condition as measured by the mean I-PSS, QOL, and peak flow rate values, as well as the overall therapeutic efficacy. The two groups differed in the amount of posttreatment improvement from between 8% and 22%, but this difference was not statistically significant. CONCLUSIONS: Our study suggests that higher thermal dose attained by Prostasoft 2.5 does not necessarily result in more pronounced clinical improvement, although clinical response to TUMT has often been reported to be dependent upon thermal dose.

Transurethral microwave thermotherapy for benign prostatic hyperplasia: clinical results after a 1-year follow-up.

Since September 1992, 63 patients with symptomatic benign prostatic hyperplasia (BPH) have been treated with transurethral microwave thermotherapy (TUMT) using the Prostatron device. The International Prostate Symptom Score (I-PSS) and quality of life (QOL) score were used to evaluate subjective symptoms. The mean I-PSS (total, irritative and obstructive scores) and QOL scores had decreased by 40, 38, 45 and 40%, respectively, at 12 months (p < 0.0001). While the mean peak flow rate had increased by 72% (p < 0.001). The clinical efficacy at 12 months was 42%, using a modification of the response criteria proposed at the 2nd International Consultation on Benign Prostatic Hyperplasia. There were no significant differences in the baseline and treatment parameters between those who responded favorably to TUMT and those who did not. The total thermal dose delivered to the prostate did not predict clinical response. However, there was a positive correlation between I-PSS or QOL at baseline and % reduction at 3, 6 and 12 months, and a negative correlation between peak flow rate at baseline and % increase at 3 and 6 months. There were no major complications associated with TUMT during the follow-up period. In summary, our 1-year clinical results are compatible with previous reports, suggesting that TUMT is a safe, effective and lasting non-surgical treatment for BPH. However, evaluation of efficacy should be based on uniform criteria to facilitate comparisons of different clinical trials. The most suitable patient profiles for TUMT could not be identified by retrospective analysis.

Transurethral microwave thermotherapy for benign prostatic hyperplasia: patient characteristics in good and poor responders.

Transurethral microwave thermotherapy (TUMT) has been shown to produce a clinical benefit in patients with symptomatic benign prostatic hyperplasia. In order to identify the features of the ideal candidate, a retrospective analysis was conducted in 32 patients who were followed for 2 mo or more. Good responders (GR) were defined as having their Siroky peak flow rate (PFR) standard deviation (SD) increase by < 0.5 or a decrease in the International Prostatic Symptom Score (I-PSS) of > 10 (22 patients). Poor responders (PR) were defined as having their PFR SD increase by < or = 0.5 and their I-PSS decrease by < or = 10 (10 patients). The prostate volume, pre-TUMT I-PSS and intravesical opening pressure were significantly greater in the GR group, while there were no significant differences between the 2 groups for the other baseline patient characteristics: age, prostate length, PFR, PFR SD, post-voiding residual volume and quality of life. Concerning the operational parameters, significantly more total energy was delivered to the prostate in the GR group (mean 131 kJ) than in the PR group (mean 101 kJ). Moreover, the 7 patients with anti-androgen therapy pre-TUMT received less total energy and 5 of the 7 were poor responders. These results suggest that patients with apparent obstructive symptoms and with moderate enlargement of prostate could benefit more from this less invasive therapy. Clinical response seems to be dose-dependent and patients with a history of recent anti-androgen treatment may have a less favorable response.(ABSTRACT TRUNCATED AT 250 WORDS)

[Transurethral microwave thermotherapy for benign prostatic hyperplasia: clinical evaluation with International Prostate Symptom Score (I-PSS)].

Forty patients with symptomatic benign prostatic hyperplasia were treated with a single session of transurethral microwave thermotherapy (TUMT) using a Prostatron. The clinical effectiveness was evaluated by analyzing the subjective and objective responses following the treatment. The International Prostate Symptom Score (I-PSS) and quality of life (QOL) scale were used to evaluate the subjective symptoms. At three months after treatment, significant improvements in I-PSS (p < 0.0001). QOL (P < 0.0001), and peak flow rate (Qmax) (p < 0.05) were observed. Improvement of both I-PSS and Qmax was found in 90% (18/20) of the patients at 2 months. Although 15 patients noted transient urinary retention and 15 patients had mild to moderate macroscopic hematuria immediately after TUMT, no severe adverse effects occurred during the follow-up period. A significant correlation was found between I-PSS improvement and the total thermal dose delivered. However, the thermal dose could not be predicted in each case. The preliminary findings suggest that TUMT by Prostatron is safe and effective as a nonsurgical treatment for benign prostatic hyperplasia. The clinical response seems to be thermal dose dependent. I-PSS is clinically sensitive and is useful in practice.

[MR imaging of amyotrophic lateral sclerosis].

Magnetic resonance imaging (MR imaging) provides a sensitive method for mapping the normal and pathological distribution of iron in the brain. High field strength MR imaging (1.5 T) was used to evaluate eight patients with amyotrophic lateral sclerosis (ALS) and 49 neurological normal control patients. All eight ALS patients showed decreased signal intensity in the motor cortex on T2-weighted images, while only one of the normal control patients showed this finding. The results suggested that the decreased signal intensity in the motor cortex in ALS was caused by the deposition of iron in this area.