Normo-Calcemic Tetany in a Patient with Hypokalemic Periodic Paralysis of Sjogren’s Syndrome: Neuromuscular Excitability Secondary to the ‘Forgotten Cation’

: A young lady, a known case of Sjogren’s syndrome, presented to our hospital with hypokalemic flaccid paralysis requiring ventilatory support. She was investigated and found to have severe hypokalemia and metabolic acidosis. During her hospitalization, she had severe persistent carpopedal spasm with normal ionized calcium. Following further evaluation, there was evidence of hypomagnesemia. The spasms were improved after her hypomagnesemia was corrected. This case report illustrate the role of hypomagnesemia in neurological abnormalities in hospitalized patients.

The I/T curve coefficient for evaluating changes in neuromuscular excitability after polarized light irradiation - a placebo-controlled randomized trial

Introduction: PILER light affects the sensory and motor excitability of the tissue, and these changes may depend on the color of the filter used in the irradiations. Objective: To evaluate changes in neuromuscular excitability after PILER irradiation with different filters. To evaluate the usefulness of the I/T curve coefficient in neuromuscular excitability test. Material and methods: 60 healthy volunteers assigned to four groups: group v - without filter (n=15), group x - red filter (n=15), group y - blue filter (n=15), group z - placebo (n=15) had biceps brachii irradiated with PILER light. Outcome Measures: I/T curve coefficient for rectangular (■I/T coeff) and triangular (▲I/T coeff) pulses for sensory and motor excitability and the pressure pain threshold (PPT). Results: ■I/T coeff (p=0.0013) and ▲I/T coeff (p=0.0011) for sensory excitability increased significantly in the irradiated group. ■I/T coeff (p=0.0356) and ▲I/T coeff (p=0.0022) increased significantly after blue light irradiation. A significant increase in the▲I/T coeff (p=0.0439) in motor excitability was observed in the irradiated group. ■I/T coeff (p=0.0309) and ▲I/T coeff (p=0.0064) increased significantly after blue light irradiation. Conclusion: PILER light may reduce muscle excitability. Using a blue filter may increase the sensory threshold, and myorelaxation. Further experiments are necessary to confirm the usefulness of the I/T curve coefficient.

A case of functional hypoparathyoidism due to hypomagnesaemia leading to hypocalcaemic seizures

This case report describes an elderly lady who was maintained on a high dose of loop diuretics following resolution of her acute pulmonary oedema, which in turn led to wasting of calcium and magnesium at the nephron level. Her hypomagnesaemia further contributed to the hypocalcaemia by rendering ineffective the normal parathyroid negative feedback physiological response. This state of low calcium increased the neuromuscular excitability leading to myoclonic epilepsy which was resistant to benzodiazepines. Such hypocalcaemic tetany in this case would only be adequately addressed once the magnesium levels are repleted, as this would allow the parathyroid mechanism to function effectively and redress the calcium level as a result.

SIR-2.1 integrates metabolic homeostasis with the reproductive neuromuscular excitability in early aging male Caenorhabditis elegans

The decline of aging C. elegans male’s mating behavior is correlated with the increased excitability of the cholinergic circuitry that executes copulation. In this study, we show that the mating circuits’ functional durability depends on the metabolic regulator SIR-2.1, a NAD+-dependent histone deacetylase. Aging sir-2.1(0) males display accelerated mating behavior decline due to premature hyperexcitability of cholinergic circuits used for intromission and ejaculation. In sir-2.1(0) males, the hypercontraction of the spicule-associated muscles pinch the vas deferens opening, thus blocking sperm release. The hyperexcitability is aggravated by reactive oxygen species (ROS). Our genetic, pharmacological, and behavioral analyses suggest that in sir-2.1(0) and older wild-type males, enhanced catabolic enzymes expression, coupled with the reduced expression of ROS-scavengers contribute to the behavioral decline. However, as a compensatory response to reduce altered catabolism/ROS production, anabolic enzymes expression levels are also increased, resulting in higher gluconeogenesis and lipid synthesis.