germanium and Nerve-Degeneration

Sensory ataxia in inorganic germanium intoxication is rare. A 63-year-old housewife had taken inorganic germanium preparations at a dosage of 36 mg a day for about 6 years (total dose about 80 g). She subsequently developed difficulty in writing and gait disturbance with peripheral neuropathy and renal involvement. Germanium, which is not usually detected in the non-germanium user, was accumulated in her hair and nails, permitting a diagnosis of inorganic germanium intoxication. The peripheral neuropathy and renal injury were not reversible after discontinuing the preparation. Pneumonia and sepsis then supervened and the patient died. Autopsy findings showed degeneration and loss of the dorsal root ganglion cells and degeneration of the dorsal column of the spinal cord. Two previously reported cases presented with ataxia. These patients took germanium for long periods and/or large quantities like our case. It was supposed that sensory ataxia was induced by chronic and dose dependent toxicity of inorganic germanium.

Topics: Aged; Ataxia; Brain; Female; Ganglia; Germanium; Humans; Kidney Diseases; Magnetic Resonance Imaging; Motor Neurons; Nerve Degeneration; Neural Conduction; Spinal Cord

Toxic side effects of germanium dioxide contained in drugs that promote health, include nephropathy, anemia and peripheral neuropathy. Although the neuropathy, which we are interested in, is believed to occur in the patients taking excessive amounts of germanium dioxide, the pathogenesis of such neuropathy is not well understood. Therefore, we studied whether germanium dioxide causes the degeneration of the peripheral nerve in rats and monkeys. Our results showed that in rats, germanium dioxide administered orally and intraperitoneally, 100 mg/kg per day, 3 days a week for 8 weeks and 400 mg/kg per day, once a week for 8 weeks, respectively, did not produce a degeneration of myelinated fibers in teased fiber preparations and Epon-embedded sections of the peripheral nerve. In two monkeys also, germanium dioxide, administered orally, 30 to 40 mg/kg per day, 5 days a week for 8 months, did not produce a degeneration of myelinated fibers of the sural nerve on biopsy, although our results revealed proteinuria and elevated blood urea nitrogen. Further studies are warranted to elucidate the pathogenesis of germanium dioxide induced neuropathy.

Topics: Animals; Germanium; Haplorhini; Nerve Degeneration; Nerve Fibers, Myelinated; Peripheral Nerves; Rats