Biomedical subjects

C P Leong

Publications and source records attributed to C P Leong.

5 recordsLinked to original sources

PubMed2001

Static wrist position associated with least median nerve compression: sonographic evaluation.

OBJECTIVE: To determine the wrist angle that produces the least compression to the median nerve and to evaluate the usefulness of sonography in determining the optimal position. DESIGN: Seventeen wrists of 17 healthy volunteers received dynamic, high-frequency (8 MHz), high-resolution sonography with the wrist splinted at various positions: 15 degrees of flexion, neutral position, and 15 degrees and 30 degrees of extension. The morphologic changes of the median nerve were evaluated with the wrist positioned at various angles. RESULTS: The neutral position caused significantly lower compression of the median nerve than it did in the other positions. However, in some cases, the lowest pressure was found when the wrist was fixed in 15 degrees of flexion or 15 degrees of extension. Because median nerve compression may decrease the anteroposterior diameter, increase the transverse diameter, and decrease the cross-sectional area, greater anteroposterior diameter, lower flattening ratio (transverse diameter/anteroposterior diameter), and greater cross-sectional area were considered to indicate lower median nerve compression. CONCLUSIONS: Neutral position of the wrist is the best position with the least median nerve compression in most individuals. However, the optimal position may vary from person to person. Sonographic examination can help to determine the splint position that results in the lowest median nerve compression.

Adult↗

PubMed1999

Alien hand syndrome: report of two cases.

Alien hand syndrome (AHS) refers to the occurrence of apparently purposeful movements in the hand which are independent of volitional control. Two subtypes of AHS have been proposed: frontal AHS, with grasp reflex and compulsive manipulation of tools by the dominant hand, and callosal AHS, which occurs in the nondominant hand and is characterized mainly by intermanual conflict. Here, we report two cases of frontal-type alien hand syndrome with symptoms of reflexive grasping, impulsive groping, and apraxia (in case 1), and compulsive manipulation of tools (in case 2). Brain computed tomography revealed a left anterior cerebral artery (ACA) territory infarct and multiple small infarcts of both hemispheres in patient 1 and a left ACA infarct in patient 2. The involuntary movements were bothersome to these patients in their daily activities. Both patients attended conventional physical and occupational therapies, and patient 2 received additional biofeedback training. Follow-up studies showed the spontaneous grasping behavior was still present in patient 1 and AHS had subsided in patient 2. We also describe a potentially effective technique involving biofeedback for patients with alien hand syndrome.

Aged↗

PubMed1995

Neuromuscular recovery after parathyroidectomy in primary hyperparathyroidism.

BACKGROUND: Primary hyperparathyroidism today is diagnosed in the asymptomatic phase because of the inclusion of serum calcium in sequential multichannel analysis. The purpose of present study was to test for neuromuscular abnormalities in asymptomatic patients and to test the improvement of neuromuscular performance after parathyroidectomy. METHODS: Nine patients with primary hyperparathyroidism and nine patients with nodular goiter were enrolled in this study. Neuromuscular recovery including muscle power, sensation, and fine motor movement was studied before operation and 1 week and 4 weeks after operation. The muscle power was measured as grip power, palm pinch, lateral pinch, and three-chuck pinch. The sensation was measured as touch sensation and two-point discrimination. The fine motor movement was measured with the Purdue Pegboard Test and the Minnesota Manual Dexterity Test. RESULTS: Four weeks after the operation the patients with hyperparathyroidism had increased their muscle strength and had improved fine motor movement but no change was noted in two-point and touch sensation. When the postoperative muscle recovery was compared, there was a reversible correlation (r = -0.62; p < 0.05) with the preoperative muscle strength and no correlation with the preoperative serum calcium, phosphate, alkaline phosphatase, and intact parathyroid hormone levels. No such improvement was detectable among the control subjects. CONCLUSIONS: Surgery can improve muscle strength and fine motor movement but does not affect sensation in asymptomatic patients.

Adult↗

PubMed1994

Study of low-temperature thermoplastic modified custom-molded cervical orthosis for cervical spine fixation.

The purpose of this experiment is to use a low-temperature thermoplastic material (Aquaplast) to make a modified custom-molded cervical orthosis. Sixteen normal young subjects who do not have previous cervical problems are tested in this study. This modified orthosis is applied on these volunteers so that external fixation of the cervical spine can be tested. Various roentgenograms for cervical flexion and extension, as well as neutral position and lateral bending, are taken to determine the fixation property of the cervical spine. A study of rotation of the cervical spine is also carried out through goniometer measurements. This clinical study proves that this low-temperature thermoplastic cervical orthosis provides good fixation for the cervical spine, especially in flexion and rotation, but is not suitable for C1- and C2-injured patients.

Adult↗

PubMed1992

The traction angle and cervical intervertebral separation.

Seventeen normal young adults were evaluated for cervical intervertebral separation under different traction angles through motorized intermittent traction in the supine position. In all cases, the anterior and posterior intervertebral spaces were increased by traction at neutral position and in 30 degrees flexion, but not in 15 degrees extension. The effects of separation were 1) neutral position: anterior intervertebral separation C4-5 (12%) greater than C3-4 (8%), posterior intervertebral separation C6-7 (37%) greater than C3-4 (22%) greater than C4-5 (19%); and 2) 30 degrees flexion: anterior intervertebral separation C2-3 (21%) greater than C4-5 (16%) greater than C5-6 (15%) greater than C3-4 (10%), posterior intervertebral separation C6-7 (20%) greater than C5-6 (19%) greater than C4-5 (17%). There was a significant decrease in intervertebral separation posteriorly in extension traction, especially at C6-7 (-50%), C5-6 (-37%), C4-5 (-26%), and C3-4 (-14%). The separation of facet joint surfaces was found after traction at 15 degrees extension, but not in the neutral or flexion positions.

Adult↗