Dementia, epilepsy and polyneuropathy in a mercury-exposed patient: investigation, identification of an obscure source and treatment

Abstract

We present a patient aged 54 years with early onset of dementia, epilepsy and peripheral polyneuropathy. A mercury intoxication was diagnosed in 2010, chelation therapy with 2,3-dimercaptopropane-1-sulfonate had failed. A source of exposure could not be identified. MRI showed unspecific hyperintense brain lesions in 2015. She was referred for diagnosis and treatment. Neuropsychological testing indicated severe memory loss and nerve conduction speed measurements showed chronic neurogenically changed potentials. Mercury levels in blood and urine and neuron-specific enolase (NSE) were elevated. A detailed patient history revealed a daily application of mercury-containing skin lightening creams for 6 years. Treatment with 2,3-dimercaptosuccinic acid (DMSA) was started, blood mercury levels were falling during treatment. She was discharged with DMSA prescriptions. A renewed MRI revealed unchanged brain lesions. Blood and urine mercury levels and NSE were falling. Memory function had improved qualitatively and quantitatively.

Clinical management of chronic mercury intoxication secondary to skin lightening products: A proposed algorithm

“…Measurement of other forms, such as organic mercury levels, is essential in the case of disproportionate clinical manifestation. Most of the studies on chronic symptomatic cases reported the use of skin lightening products with mercury levels exceeding 1000 ppm [3,4,[6][7][8][9][10]12,14,[16][17][18][19]37,38]. However, mercury levels as low as 6.8 ppm have been reported to produce symptoms with longer duration [32].…”

“…Moreover, inorganic mercury has been shown to induce neuronal degeneration, which may manifest as early-onset dementia [ 9 ]. The mechanism of inorganic mercury effect on dementia is associated with its high affinity to selenium and selenoproteins.…”

“…Patients with chronic mercury intoxication may have no symptoms despite high levels of mercury in the body [ 5 , 14 ]. For those who develop symptoms, there is a wide range of symptoms that are usually non-specific and may resemble disorders or diseases such as nephrotic syndrome [ 3 , 37 ], systemic lupus erythematosus [ 3 ], pheochromocytoma [ 14 , 19 ], polyneuropathy, and dementia [ 9 ] ( Table 1 ).…”

“…According to the study conducted in the US, nearly half of the mercury-containing products had a very high mercury level, exceeding 10,000 ppm [2]. Skin-lightening products are manufactured in many countries, such as the UK [3], Mexico [4][5][6][7][8], Lebanon [9], Taiwan [9], Indonesia [10], China [2,11,12], Japan, Thailand, the Philippines, and Jamaica [2]. Both online and physical stores, such as beauty shops, stores [13] and flea markets, as well as relatives and friends [14] contribute to the availability and widespread use of skin lightening products.…”

Mercury Poisoning of a 4-Year-old Child by Indirect Contact to a Mercury Containing Facial Cream: Case Report

“…This is mainly caused by the reduced mercury use in industry and household applications. However, multiple cases of mercury poisoning due to the use of skin-whitening creams have been reported [1][2][3][4][5][6][7]. These creams are used to achieve a lighter skin-tone, a desired ideal of beauty in many countries.…”