Manganese Toxicity Linked to Parkinson’s Disease 

From the Journal Neurology  a  population-based case-control study  conducted among 250 newly diagnosed cases of Parkinson’s Disease  and matched controls between 1992 and 2002.  There was an apparent joint effect of iron and manganese; where dietary intake above median levels of both together conferred a nearly doubled risk of Parkinson’s Disease compared with lower intakes of each nutrient. Another study in Neurology several years earlier evaluated toxic effects of manganese in Rhesus monkeys. The monkeys were injected with weekly doses of  manganese and all developed Parkinson’s Disease-like syndromes.  In 1976 a patient with Parkinson’s Disease-like features and dementia had elevated manganese levels, and brain biopsy showed numerous neuritic plaques and neurofibrillary tangles typical of Alzheimer's disease. Manganese was elevated beyond toxic levels in serum, hair, urine, feces, and brain. It appears  there is a possible relationship between elevated manganese levels, dementia, and Parkinson’s Disease.

A report by Huang, Lu and Chu of a longitudinal follow-up study on six patients with chronic manganese-induced parkinsonism following after  manganese symptoms showed a slow progression after Manganese exposure had  stopped, particularly in gait disturbances such as freezing during turning and walking backward with retropulsion. exposure had been discontinued. Compared with a previous study in 1987 , their parkinsonian

Another study demonstrated an association between high seizure activity in treated epileptics and low tissue manganese levelst the concentrations of manganese and hair in 52 epileptics, 6 blood relatives, and 24 normal controls. Blood, and possibly hair manganese content, was significantly lower in treated epileptics than in controls (p <0.002). Although not all patients showed reduced tissue manganese levels, most those with frequent seizures had manganese below the lowest control level, suggesting a relationship between manganese tissue levels and high seizure activity. in whole blood levels falling

Ref . Powers et al Parkinson’s disease risks associated with dietary iron, manganese, and other nutrient intakes Neurology 2003

  Olanow, Good and Perl: Mangenese Intoxication in the Rhesus Monkey

                Neurology 1996;46:492-498

Bant and Marksbery Elevated manganese levels associated with dementia and extrapyramidal signs . Neurology 1977;27:213

Huang,Lu and Chu Progression After Chronic Manganese Exposure NEUROLOGY 1993;43