Mercury Intoxication Simulating Amyotrophic Lateral Sclerosis

Subacute Motor Neuron Hyperexcitability with Mercury Poisoning: A Case Series and Literature Review

“…A case of LEMS with mercury poisoning has not been reported. Case 3 in the present series had the same features as the three cases of ALS-like syndrome with mercury poisoning in the literature [19,20]: middle-aged male, inorganic or elemental mercury poisoning, muscle fatigue and waste with fasciculation and normal strength, abnormal spontaneous activity or unstable fasciculation potential on EMG, normal upper motor neuron, anorexia, insomnia, weight loss, and autonomic dysfunction (constipation, micturition difficulty, and impotence). All cases recovered within 3 months after the exposure to mercury was stopped, with or without the chelation therapy.…”

“…In addition, the fatigue and autonomic dysfunctions with classic RNS abnormalities suggested the diagnosis of LEMS. We searched the literature for reports of ALS or ALS-like syndrome and LEMS associated with mercury poisoning and found six English-language reports of ALS or ALS-like syndrome associated with mercury poisoning [16,17,18,19,20,21]. Three ALS patients in three studies died or were disabled after long-term follow-up [16,17,18].…”

“…Three ALS patients in three studies died or were disabled after long-term follow-up [16,17,18]. However, 22 cases of ALS-like syndrome in two studies recovered well in a short time [19,20]. One study reported 11 cases of organic mercury poisoning with ALS, but four had a 6-month follow-up with an indefinite diagnosis [21].…”

Case Files of the Emory University Medical Toxicology Fellowship: Inhalational Mercury Toxicity from a Traditional Vietnamese Product

“…Neurological damage can occur after shortand long-term low-level exposure and can lead to findings including intention tremor, emotional lability, insomnia, and memory loss. Headaches, neuromuscular changes, and polyneuropathies including muscle atrophy and twitching have also been reported [45]. Tremors associated with elemental mercury toxicity characteristically affect the hands, are abolished during sleep, and are usually not debilitating.…”

The experimental toxicology of metallic mercury on the murine peripheral motor system: A novel method of assessing axon calibre spectra using the phrenic nerve

“…Acute, high level exposure to mercury vapour (Hg 0 ) is known to cause transient reversible symptoms resembling MND (Yanagihara, 1982;Adams et al, 1983;Schwarz et al, 1996). In the wider population, the human peripheral motor system is vulnerable to persistent exposure by Hg 0 arising from stressed surfaces of dental amalgam during mastication (Svare et al, 1981;Abraham et al, 1984;Vimy and Lorscheider, 1985;Patterson et al, 1985).…”