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Tom Chau

Publications and source records attributed to Tom Chau.

22 records · Page 2Linked to original sources
PubMed2003

Electrocardiographic manifestations in patients with thyrotoxic periodic paralysis.

BACKGROUND: Thyrotoxic periodic paralysis (TPP) commonly precedes the overt symptoms and signs of hyperthyroidism and may be misdiagnosed as other causes of paralysis (non-TPP). Because the cardiovascular system is very sensitive to elevation of thyroid hormone, we hypothesize that electrocardiographic manifestations may aid in early diagnosis of TPP. METHODS: We retrospectively identified 54 patients who presented to the emergency department (ED) with hypokalemic paralysis during a 3.5-year period. Thirty-one patients had TPP and 23 patients had non-TPP, including sporadic periodic paralysis, distal renal tubular acidosis, diuretic use, licorice intoxication, primary hyperaldosteronism, and Bartter-like syndrome. Electrocardiograms during attacks were analyzed for rate, rhythm, conduction, PR interval, QRS voltage, ST segment, QT interval, U waves, and T waves. RESULTS: There were no significant differences in age, sex distribution, and plasma K+ concentration between the TPP and non-TPP groups. Plasma phosphate was significantly lower in TPP than non-TPP. Heart rate, PR interval, and QRS voltage were significantly higher in TPP than non-TPP. Forty-five percent of TPP patients had first-degree atrioventricular block compared with 13% in the non-TPP group. There were no significant differences in QT shortening, ST depression, U wave appearance, or T wave flattening between the 2 groups. CONCLUSION: Relatively rapid heart rate, high QRS voltage, and first-degree AV block are important clues suggesting TPP in patients who present with hypokalemia and paralysis.

Acidosis, Renal Tubular↗
PubMed2002

Automatic stride interval extraction from long, highly variable and noisy gait timing signals.

This paper presents a probabilistic algorithm for automatically extracting the stride interval time series from long, highly variable and noisy two-state timing signals. Long interstride temporal records are of particular interest in nonlinear dynamical analysis of gait. The proposed method consists of probabilistic estimation and extraction followed by post-extraction filtering. With noisy timing signals from 10 children with Spastic Diplegia, no statistical differences in the numbers of extracted strides (p=0.94), the mean stride intervals (p=0.55) and the scaling exponents (p=0.94) (a measure of temporal heterogeneity) were found between series extracted by hand and by the probabilistic algorithm. The method is robust to noise and violations of normality. Results support the use of probabilistic extraction as an alternative to laborious manual extraction.

Algorithms↗
PubMed2002

Osmotic demyelination syndrome after correction of chronic hyponatremia with normal saline.

Rapid correction of severe chronic hyponatremia with hypertonic saline has been known to cause osmotic demyelination syndrome (ODS). Less recognized are the dangers of rapid correction with normal saline. A 60-year-old woman on thiazide diuretics for hypertension presented with profound hyponatremia (94 mmol/L) and hypokalemia (1.9 mmol/L) associated with volume depletion. Normal saline (2 L/day) and (KCl 40 mmol/day) were given for 5 days. Serum Na+ concentration rose to 106 mmol/L within 18 hours. With improvement of her hyponatremia, she became more alert although the hypokalemia persisted. However, she developed progressive obtundation, quadriplegia, and respiratory failure 6 days later. Magnetic resonance imaging of the brain clearly showed typical features of pontine and extrapontine myelinolysis. We suggest that the aggressive KCl supplement would have been the first-line therapy for this patient presenting with chronic hyponatremia and hypokalemia associated with volume depletion.

Benzothiadiazines↗