Periodic paralysis is a group of rare genetic diseases that lead to weakness or paralysis from common triggers such as cold, heat, high carbohydrate meals, not eating, stress or excitement and physical activity of any kind. The underlying mechanism of these diseases are malfunctions in the ion channels in skeletal muscle cell membranes that allow electrically charged ions to leak in or out of the muscle cell, causing the cell to depolarize and become unable to move.The symptoms of periodic paralysis can also be caused by hyperthyroidism, and are then labeled thyrotoxic periodic paralysis; however, if this is the underlying condition there are likely to be other characteristic manifestations, enabling a correct diagnosis. Types
Periodic paralysis is an autosomal dominant myopathy with considerable variation in penetrance, leading to a spectrum of familial phenotypes (only one parent needs to carry the gene mutation to affect the children, but not all family members who share the gene are affected to the same degree). Specific diseases include:
Hypokalemic periodic paralysis (Online Mendelian Inheritance in Man (OMIM): 170400), where potassium leaks into the muscle cells from the bloodstream. Hyperkalemic periodic paralysis (Online Mendelian Inheritance in Man (OMIM): 170500), where potassium leaks out of the cells into the bloodstream. Paramyotonia congenita (Online Mendelian Inheritance in Man (OMIM): 168300), a form which often accompanies hyperkalemic periodic paralysis, but may present alone. The primary symptom of paramyotonia congenita is muscle contracture which develops during exercise or activity. Paramyotonia congenita attacks may also be triggered by a low level of potassium in the bloodstream.
Pathogenicity
Liver fluke infections cause serious medical and veterinary diseases. Fasciolosis of sheep, goats and cattle, is the major cause of economic losses in dairy and meat industry. Fasciolosis of humans produces clinical symptoms such as fever, nausea, swollen liver, extreme abdominal pain, jaundice and anemia.Clonorchiasis and opisthorchiasis (due to Opisthorchis viverrini) are particularly dangerous. They can survive for several decades in humans causing chronic inflammation of the bile ducts, epithelial hyperplasia, periductal fibrosis and bile duct dilatation. In many infections these symptoms cause further complications such as stone formation, recurrent pyogenic cholangitis and cancer (cholangiocarcinoma). Opisthorchiasis is particularly the leading cause of cholangiocarcinoma in Thailand and Laos. Both clonorchiasis and opisthorchiasis are classified as Group 1 human biological agents (carcinogens) by International Agency of Research on Cancer (IARC). Species
Species of liver fluke include:
Clonorchis sinensis (the Chinese liver fluke, or the Oriental liver fluke)
Dicrocoelium dendriticum (the lancet liver fluke)
Dicrocoelium hospes
Fasciola hepatica (the sheep liver fluke)
Fascioloides magna (the giant liver fluke)
Fasciola gigantica
Fasciola jacksoni
Metorchis conjunctus
Metorchis albidus
Protofasciola robusta
Parafasciolopsis fasciomorphae
Opisthorchis viverrini (Southeast Asian liver fluke)
Opisthorchis felineus (Cat liver fluke)
Opisthorchis guayaquilensis

See also
The Integrated Opisthorchiasis Control Program


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