Biomedical subjects

Tien-Yow Chuang

Publications and source records attributed to Tien-Yow Chuang.

7 recordsLinked to original sources

PubMed2003

Cervical root repair in adult rats after transection: recovery of forelimb motor function.

Functional recovery was achieved in rats after repairing the transected left sixth and seventh cervical roots. Intercostal nerves were used for reanastomosis between the transected roots and the spinal cord, and acidic fibroblast growth factor with fibrin glue was applied. Experimental rats showed relevant functional recovery of gait and grooming reflexes. Electromyography demonstrated less denervation and more regeneration. Horseradish peroxidase retrograde axonal tracing disclosed a statistically significant increase of motor neuron survival, suggesting that motor neuron survival was significantly correlated with functional recovery. It is our belief that this novel treatment strategy may help patients with similar injuries in the future.

Animals↗

PubMed2003

Neurourological changes before and after radical hysterectomy in patients with cervical cancer.

BACKGROUND: The severity of bladder dysfunction in patients receiving radical hysterectomy for cervical cancer has been related to the delicacy and the degree of radicality of the hysterectomy. Our goal was to evaluate the effect of modified radical hysterectomy on the storage and evacuation of the lower urinary tract. METHODS: In this prospective study, 18 patients underwent radical hysterectomy for cervical cancer with FIGO stages Ia, Ib and IIa. These patients participated in a pudendal motor nerve conduction study and a urodynamic study, including urethral pressure profile (UPP), cystometry (CMG) and uroflowmetry (UFR). These were carried out at preoperative baseline and at 2 weeks, 6 weeks, 3 months and 6 months following surgery. We used generalized linear models to evaluate, over time, the relationship between the different parameters marked in these profiles. RESULTS: The average pudendal nerve motor latency was prolonged at 2 and 6 weeks after surgery but recovered to baseline at 3 months postsurgery. Maximal urethral closing pressure revealed a tendency to decrease, and the CMG showed a significant increase in maximum intravesical filling pressure and a marked decrease in compliance throughout the investigative course. Increased residual urine volume and decreased uroflow rates were detected in a series of UFR. However, these values headed for baseline at 6 months after surgery. CONCLUSION: Transient neurological changes in the majority of our patients suggested that both somatic and autonomic demyelination with or without denervation might be responsible for the temporal changes in vesicourethral function after radical hysterectomy and recovery to baseline condition within 6 months.

Adult↗

PubMed2003

Acute urinary retention after use of assisted reproductive technology. A report of 2 cases.

BACKGROUND: Urinary retention in women is an unusual occurrence. Various conditions can cause it, including surgery, childbirth, pelvic masses, procidentia, vulva hematoma, incarceration of a gravid uterus, urologic disease, neurogenic disease and psychiatric disorders. CASES: Two infertile women underwent assisted reproductive technology (ART) and luteal-phase support during which acute urinary retention occurred. The patients were evaluated by means of physical examination, urodynamic study and determination of serum progesterone levels. Bladder distention was found during luteal-phase support. Urodynamic studies revealed detrusor areflexia. Serial serum progesterone levels were > 100 ng/mL. CONCLUSION: Cases of acute urine retention during luteal-phase support are rarely reported. Urine retention should be considered in the differential diagnosis when abdominal pain occurs after patients undergo ART. Transient elevation of the progesterone level may be the cause of the acute urine retention.

Acute Disease↗

PubMed2002

Forelimb muscle activity following nerve graft repair of ventral roots in the rat cervical spinal cord.

Current research on the cellular mechanisms of nerve regeneration suggests the application of nerve growth factors at the repair sites to be beneficial. To test the effectiveness of this approach, we performed transections of the C6 and C7 ventral rootlets from their original sites in the spinal cord of 18 rats. We investigated the electrophysiological changes in three groups of rats operated on by different repair strategies. Six rats comprised the control group (G1). In the other 12 rats, 24 rootlets were implanted into the spinal cord by means of an intercostal nerve graft through the pia mater immediately after transection. Six rats (G2) had fibrin glue applied at the incision. The last 6 rats (G3) had grafts with acidic fibroblast growth factor (aFGF) added to the fibrin glue. The rats' functional recovery was evaluated electrophysiologically at 6 weeks and 6 months after the operation. Needle electromyography showed profound fibrillation potentials (Daube's scoring system) in the deltoid, biceps, and triceps of the operated forelimbs in all groups 6 weeks after the operation. After 6 months, there was a significant decrease in the amount of fibrillation potentials in all groups (G1, G2 and G3, p < 0.0001, 0.0001, 0.0009, respectively, generalized estimating equation, repeated measures) and a significantly high probability for motor units present in sampled muscles of G2 and G3 as compared to G1 (log odds ratio in G2 = 51.8316, G3 = 57.4262, generalized estimating equation). We conclude that several cervical roots can regenerate through intercostal nerve grafts applied using fibrin glue. Adding aFGF may increase the efficacy of sprouting.

Animals↗

PubMed2002

Electrophysiologic findings and muscle strength grading in brachioplexopathies.

The electrophysiological evaluations and the British Medical Research Council (MRC) scale (0-5) findings of target muscles in brachioplexopathies before surgery and 1 year postsurgery were conducted. Each component of the brachial plexus was analyzed in 15 patients with injuries, among them, to 5 roots, 19 trunks, 7 cords, and 13 terminal nerves. In each of these cases, neurolysis and/or nerve transfer and/or neurotization were performed, within 3 weeks to 6 months after the injury was incurred, to ameliorate the resulting severe disabilities. The degrees of impairment were graded using a modified version of Dumitru's and Wilbourn's scale (mild: normal to slight decrease of SNAP amplitude and CMAP amplitude, and occasional denervation; moderate: profound decrease of SNAP amplitude and CMAP amplitude, constant denervation, and normal to slight decrease in motor unit recruitment; severe: absent SNAP amplitude, absent CMAP amplitude, marked denervation, and profound decrease or no volitional motor unit recruitment. mild = 1; moderate = 2; severe = 3). The motor power of the target muscles was graded through MRC scores. The presurgical versus postsurgical differences in the severity of the injury to each brachial plexus component, and differences in the grading of target muscle power, were calculated through the Wilcoxon signed-rank test. The presurgical degrees of the severity of injury, as measured by the electromyography (EMG) were 3.00 +/- 0.00 (mean +/- SD) in root, 2.84 +/- 0.50 in trunk, 3.00 +/- 0.00 in cord, and 2.85 +/- 0.38 in terminal nerves. The postsurgical results were 2.60 +/- 0.55 in root, 2.53 +/- 0.70 in trunk, 2.43 +/- 0.53 in cord, and 1.77 +/- 0.73 in terminal nerves. There was significant improvement at the trunk, cord, and terminal nerve levels after repair, but not at the root levels. Moreover, although the MRC grading showed significant motor recovery in the infraspinatus, deltoid, biceps, and triceps muscles, there was little apparent improvement in the pectoralis major, EDC, APB, and ADM muscles. Nerve repair was notably successful in all plexuses except at the root level. However, our cases demonstrated only poor motor power gains in the forearm and the hand muscles. Consequently, future surgical techniques for brachioplexopathy repairs need further improvement.

Adolescent↗

PubMed2002

The comparison of electrophysiologic findings of traumatic brachial plexopathies in a tertiary care center.

This study was undertaken to demonstrate the distribution of causative factors of brachial plexopathy (BP), to assess the association between the mechanism of injuries and the predominant level of the brachial plexus involved in the injuries, and to characterize the extent and degree of severity of injury in patients with BPI. It consisted of a cross-sectional, retrospective review of electrophysiological data of 5547 patients with 117 patients being identified as having BPI, of whom 86 patients were recruited into the study. The patients were divided into six subgroups according to the mechanism of the damage. The injury was subdivided according to the brachial plexus levels predominantly affected, and each component of the four major anatomical plexus levels-root, trunk, cord and nerve levels was analyzed. The affiliation between the type of injuries and the specified brachial plexus levels was calculated via a two-tailed Fisher's exact test. These findings demonstrated that the type of brachial plexus injury (BPI) is significantly related to the brachial plexus level involved. The motorcycle and birth injury groups were affected at the trunk level, the fall group at the nerve level, the automobile group at the cord level, and the blunt injury group at the cord or nerve level. Moreover, the majority of patients in the motorcycle, fall, and pedestrian groups suffered from severe, incomplete lesions, while the neurophysiological results of the other groups varied.

Accidents, Traffic↗

PubMed2002

A virtual reality-based system for hand function analysis.

The goal of this study was to demonstrate the usability and usefulness of virtual reality technology in assessing hand functions. Ten healthy, non-disabled right-handed adult volunteers were recruited. Each volunteer used a dataglove to insert three-dimensional virtual representations of a cylinder and a prism into the target holes. To verify the reliability of the tests, each subject was retested twice. The performance testing assessed the visual-motor coordination a person needs to achieve a task accurately and within a set time. For each trial, the root mean square (RMS) value of the hand movement trajectory was projected onto the X, Y, and Z axes. This projection enabled us to measure the extent of the genuine, summative displacement of the manipulating hand. The reproducibility of the virtual reality assessment was analyzed using the intraclass correlation (ICC) approach. The total ICC values of 10 subjects demonstrated a high task completion time and RMS on the X and Z axes for the transferring of the prism. However, the values were low for the transferring of the cylinder. Because the individual coefficients of variations (CVs) varied widely in the moving of both the cylinder and the prism, the total (CVs) showed a high reading for the task completion time. Although rehabilitation clinics routinely carry out peg-moving exercises for disabled patients, our model provides a valuable quantitative real time and off-line measure of whole hand functions.

Adult↗