A Case of Mercury Toxicity Complicated by Acute Inflammatory Demyelinating Polyneuropathy

Abstract

A 13-year-old African American male presented with 2 months of subacute altered mental status, ptosis, areflexia, disordered gait, constipation, weight loss, abdominal and testicular pain, and hyperhidrosis. Initial workup at our facility was unrevealing until elevated serum mercury level was detected. Diagnosis of mercury toxicity was confirmed, and chelation therapy with succimer was started. After beginning succimer, the patient developed acute-onset weakness and was diagnosed with acute inflammatory demyelinating polyneuropathy. Supportive studies included elevated cerebrospinal fluid protein and acquired demyelinating polyneuropathy on nerve conduction study. He responded well to treatment with intravenous immunoglobulin and returned to his baseline state of health. Although there is a known association between mercury toxicity and axonal neuropathy, there is only 1 other case report of acute inflammatory demyelinating polyneuropathy in the setting of mercury toxicity. The nature of the correlation between these 2 entities in our case remains unclear.

Guillain-Barré Syndrome After Exposure to Mercury

“…Stacey Evans and coworkers 1 are to be complimented on their original article on the association between acute inflammatory demyelinating polyneuropathy (AIDP) and mercury (Hg 0 ) overexposure. 1 The authors describe a 13-year-old African-American boy with a history of a long-term exposure to indoor mercury vapors in his home. 1 The source of chronic Hg 0 intoxication of domestic origin was the liquid form of metallic mercury (Hg 0 ) spilled from a broken thermometer.…”

“…1 The authors describe a 13-year-old African-American boy with a history of a long-term exposure to indoor mercury vapors in his home. 1 The source of chronic Hg 0 intoxication of domestic origin was the liquid form of metallic mercury (Hg 0 ) spilled from a broken thermometer. 1 He had inhaled elemental mercury vapors daily for several months.…”

“…1 The source of chronic Hg 0 intoxication of domestic origin was the liquid form of metallic mercury (Hg 0 ) spilled from a broken thermometer. 1 He had inhaled elemental mercury vapors daily for several months. 1 The level of serum mercury of 23 µg Hg/L was certainly in the toxic range and it would have been higher if it had been determined in whole-blood specimen, 2 as mercury accumulates in red blood cells more than in serum, because of its high affinity for red blood cells.…”

“…1 He had inhaled elemental mercury vapors daily for several months. 1 The level of serum mercury of 23 µg Hg/L was certainly in the toxic range and it would have been higher if it had been determined in whole-blood specimen, 2 as mercury accumulates in red blood cells more than in serum, because of its high affinity for red blood cells. 2 And the rapid onset (acute) of Guillain-Barré syndrome—an axonal inflammatory demyelinating polyneuropathy—developed 2 weeks after the institution of oral chelation therapy with succimer (meso-2,3-dimercaptosuccinic acid isomer [DMSA]).…”

“…2 And the rapid onset (acute) of Guillain-Barré syndrome—an axonal inflammatory demyelinating polyneuropathy—developed 2 weeks after the institution of oral chelation therapy with succimer (meso-2,3-dimercaptosuccinic acid isomer [DMSA]). 1 Their interesting case report 1 clearly and eloquently illustrates the association between metallic mercury (Hg 0 ) overexposure and autoimmune axonal neuropathy. Mercury is a well-known neurotoxicant and is able to damage the peripheral nerve myelin.…”