Mercury toxicity mimickin...

Acquired neuromyotonia is a rare disorder of peripheral nerve hyperexcitability (PNH). It shows neuromuscular manifestations of muscle stiffness, muscle twitching, and autonomic disturbances. VGKC-complex antibodies are usually positive. Indian traditional medicinal systems use heavy metals in preparation of medicines after purification and detoxification. Among the heavy metals, mercury is extensively used in siddha medicine after detoxification. Our case is a 29 year old male, presented with pain and rippling of muscles of both upper and lower limbs of 02 month duration; associated with insomnia, constipation, tremors of hands, urinary hesitancy and skin peeling in palms and soles. There was history of alternative medications use for bronchial asthma from an unlicensed siddha medicine practitioner. Evaluation revealed continuous doublet, triplet and multiple motor unit discharges firing at high intraburst frequency on electromyography (EMG), high urine mercury levels of 40.50 mcg/L (<10 mcg/L is normal) and positive voltage-gated potassium channels (VGKC) antibodies. He was successfully managed with Inj Methyl Prednisolone 1gm IV was given for 05 days followed by oral Prednisolone 10mg/day for next 06 weeks. Link for video (to see video of the rippling muscles) https://drive.google.com/file/d/1_-X0asrysgGGz_KlSP-XvtLGk1UdEQzJ/view?usp=sharing LEARNING: Blood and urine mercury levels should be ordered all patients with above presentation. An early diagnosis can reduce the period of suffering of the patient and complete recovery with the available treatment modalities. There should be strict vigilance system for identifying unlicenced practitioners of traditional Indian medicinal systems to avoid heavy metal toxicity in consumers.