Biomedical subjects

Jennifer Chu

Publications and source records attributed to Jennifer Chu.

4 recordsLinked to original sources

PubMed2004

Pharynx and oesophagus evaluation during the swallow using helical computerized tomography.

PURPOSE: Videofluorography (VF) and endoscopy are commonly used for dynamic imaging (DI) of pharyngeal swallowing but do not offer transverse plane (TP) information. The aim of the present study was to evaluate helical computerized tomography (HCT) to measure the DI capability pharyngeal swallowing in the TP. METHODS: The HCT scan technique used was a single-slice cine mode with scan times of 100 ms. All 15 subjects were studied supine during dry swallow, swallowing of barium sulphate jelly and 3, 10, 15 or 20 ml of a 40% barium sulphate solution. Nine subjects repeated the test twice at more than 1 week's interval to determine the test-retest reliability. RESULTS: Swallowing leads to closure of the vocal folds, pharyngeal constriction and narrowing of the piriform sinuses allowing jelly passage between the sinuses. Laryngeal elevation then occurs with the opening of the pharyngoesophageal segment (PES). Swallowing a bolus of 20 ml produced the maximum anteroposterior and transverse diameters as well as the maximum opening area of the PES. The test-retest intraclass correlation coefficients with liquid deglutition ranged from 0.86 to 0.98. CONCLUSIONS: This study shows that HCT enables visualization of TP of PES complementing VF or endoscopic swallowing studies.

Adult↗

PubMed2004

Reliability of quantitative motor unit action potential parameters.

We evaluated the test-retest reliability (reproducibility) of motor unit action potential (MUAP) parameters in multi-MUAP analysis over time. Reproducibility studies are not available for needle quantitative electromyography (QEMG) performed by the same examiner. Fourteen consecutive individuals (10 men and 4 women) had repeat QEMG at 3 hours after the first examination, and seven (5 men and 2 women) had a repeat QEMG after 4-10 days. The intraclass correlation coefficient (ICC) was 87-97% with same-day testing and 52-81% with different-day testing. Size index and firing rate were the most reproducible, suggesting use in follow-up multi-MUAP studies.

Action Potentials↗

PubMed2004

Electrical twitch-obtaining intramuscular stimulation in lower back pain: a pilot study.

OBJECTIVES: To determine if electrical twitch-obtaining intramuscular stimulation (ETOIMS) provides greater myofascial lower back pain relief than muscle stimulation or skin stimulation. DESIGN: In this single-blinded, crossover, pilot trial performed at a university-affiliated outpatient rehabilitation medicine department in Taiwan, 12 acupuncture-naive patients with lower back pain of 3-60 mos duration received one crossover treatment every 2 wks by monopolar needle electrode insertion at bilateral T10-S1 levels to: (1) paraspinal muscles, (2) overlying skin, and (3) paraspinal muscles with ETOIMS applied via the needle electrode at individual treatment sites. A total of 30 manual insertions per side per treatment were performed, with withdrawal after 2 secs. Beginning 1 wk before each trial and continuing until 2 wks after, patients completed a visual analog scale twice daily. In addition, on the day of treatment, patients received a physical examination and completed a visual analog scale both before and after treatment. RESULTS: Significant and immediate reduction in the visual analog scale levels was noted only with ETOIMS. Immediate improvement occurred in one of nine physical tests with muscle stimulation and ETOIMS only. In the 2 wks after treatment, absolute visual analog scale levels for ETOIMS were significantly lower than muscle stimulation and skin stimulation. ETOIMS resulted in a greater percentage of pain relief in the first week after treatment, although it was not statistically significant from muscle stimulation and skin stimulation. CONCLUSIONS: ETOIMS provided significantly greater immediate and sustained myofascial lower back pain relief than muscle stimulation and skin stimulation. Although a greater percentage of pain reduction occurred with ETOIMS, it was not statistically significant.

Acupuncture Therapy↗

PubMed2002

The local mechanism of acupuncture.

Scientific development of acupuncture is described to increase its therapeutic efficacy and ultimate utilization. Acupuncture may have central, local and placebo effects. Little is known about the local effects of acupuncture specific to needle penetration and/or movement. Acupuncture points, muscle trigger points and motor end-plate zones are identical. Therefore, the benefit of acupuncture in musculoskeletal pain relief for which it is most commonly used, would not be limited to classical acupuncture points on the meridians. Intramuscular movements of the needle causes insertional activity which can be recorded on electromyography (EMG). The insertional activity occurs from depolarization of innervated single or grouped muscle fiber discharges which are micro-twitches and this is the basis of pain relief with EMG and intramuscular stimulation methods. Occasionally, needle penetration or manipulation in classical or electrical acupuncture may also evoke small local twitches. These observations suggest that needle induced local muscle twitches mediate musculoskeletal pain relief in acupuncture. These micro-twitches are capable of producing micro stretch effects on the adjacent shortened muscle fibers undergoing varying stages of denervation. This reduces the mechanical traction effect produced by these shortened muscle fibers on pain sensitive structures including intramuscular nerves and blood vessels. This theory of stretching shortened muscle fibers to produce pain relief would be justified when even more significant musculoskeletal pain relief can be obtained through inducing larger force twitches. Therefore, automated and electrical twitch-obtaining intramuscular stimulation methods were invented to elicit larger twitches. These methods allow the objective localization of the motor end-plate zones and allow recording of the number, frequency and force of the twitches. Therefore, by mechanism of action and associated therapeutic relief, the twitch may be the local key to pain relief, notjust a diagnostic sign for the localization of myofascial trigger points.

Acupuncture↗