Environmental neurology: Concepts and short history of an interdisciplinary approach to etiology, treatment and prevention.

Environmental Neurology (EN), a sub-discipline of Neurology and Neurological Sciences, favors an interdisciplinary collaboration allowing a holistic approach to understanding the impact of environmental factors on the nervous system and their relationship with neurological diseases. Several examples of diseases and conditions show the large scope of subjects addressed by EN. The EN sub-discipline focuses on both individual and population issues thus joining patient care and public health, respectively. Neuropathogenesis is addressed by several major questions: How do the environment and nervous system interact? Which exogenous factors can trigger neurological disease? When, where and how do they act? What are the therapeutic implications, and how can these disorders be controlled or prevented. To answer such questions, we address the incentive for, philosophy of and methods developed by EN, which seeks to safeguard Brain Health and, thus, the quality of life.

Direct and Indirect Neurotoxic Potential of Metal/Metalloids in Plants and Fungi Used for Food, Dietary Supplements, and Herbal Medicine.

Plants and mushrooms bioconcentrate metals/metalloids from soil and water such that high levels of potentially neurotoxic elements can occur in cultivated and wild species used for food. While the health effects of excessive exposure to metals/metalloids with neurotoxic potential are well established, overt neurological disease from prolonged ingestion of contaminated botanicals has not been recognized. However, the presence of metal elements may affect levels of botanical neurotoxins in certain plants and mushrooms that are established causes of acute and chronic neurological disease.

Kampo medicine and Muro disease (Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex): Postscript and Historical Footnote.

Western Pacific Amyotrophic Lateral Sclerosis and Parkinsonism-dementia Complex (ALS/PDC) is a disappearing neurodegenerative disease in three former high-incidence foci of the U.S. territory of Guam, Papua-Indonesia (New Guinea) and Kii Peninsula, Honshu Island, Japan (Muro disease). We report additional data that associate medicinal use of cycad seed to Muro disease in the southern Kozagawa focus of ALS/PDC. In the other two ALS/PDC-affected populations, cycad seed was used as a traditional topical medicine in New Guinea and Guam and, additionally, for food on Guam.

Kampo medicine and Muro disease (Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex).

Western Pacific Amyotrophic Lateral Sclerosis and Parkinsonism-dementia Complex (ALS/PDC) is a disappearing neurodegenerative disease in three former high-incidence foci of Guam-USA, Papua-Indonesia and Kii Peninsula, Honshu Island, Japan. The latter includes two distinct ALS/PDC-affected regions (Hohara and Kozagawa), where the disorder is known as Muro disease. In Hohara, oral exposure to plant (cycad) neurotoxins used in traditional medical practice has been linked previously to Muro disease. We report new observations that link Kampo medicine to Muro disease in the southern Kozagawa focus. Oral exposure to cycad seed toxins is associated with all three foci of Western Pacific ALS/PDC.

On the decline and etiology of high-incidence motor system disease in West Papua (southwest New Guinea).

The etiology of a high-incidence focus of amyotrophic lateral sclerosis and parkinsonism-dementia (ALS/P-D) in south West Papua (Irian Jaya, Indonesia), first described in the 1960s and 1970s, has been attributed to mineral deficiencies, hyperparathyroidism, and metal neurotoxicity arising from reliance on drinking water obtained from springs and shallow wells. More recent visits (1987 and 1990) to the south West Papua focus of neurodegenerative disease cast doubt on this explanation by revealing changes in disease prevalence in communities with an unchanged water supply. These communities have experienced a dramatic decline in ALS and a reversal in the relative prevalence of ALS and parkinsonism. The extrapyramidal disorder can be distinguished from Parkinson disease by pyramidal features (and dementia) reminiscent of Guam P-D. Topical use of cycad seed (termed kurru) gametophyte to treat large skin lesions is advanced as a plausible but unproven etiologic factor. Medicinal use of untreated cycad seed (Cycas sp.) has also been linked with ALS foci in Japan (oral use) and Guam (topical use), with the additional consumption on Guam of food items prepared from Cycas sp. seed or animals that consume cycad seed components.