All parts of the jimsonweed plant are poisonous to horses and humans; toxicity is caused by tropane alkaloids. Symptoms of poisoning in horses include a weak, rapid pulse, dilated pupils, dry mouth, incoordination, diarrhea, convulsions, coma, and sometimes death.
Meningioma Causes. The causes of meningioma are not yet fully understood. In fact, several research studies suggest that many meningiomas develop spontaneously, or without a known cause. Sometimes, these tumors can disappear spontaneously as well. Meningiomas, like other solid tumors, develop when healthy cells undergo genetic mutations that cause them to replicate uncontrollably.
The tumors may be nodular, plaquelike, or diffuse lesions that invade the skull, causing bone erosion and compression of brain tissue. Meningiomas usually occur in adults. A tumour of meninges and meningeal cells, which is most common in middle-aged women and may occur in a background of neurofibromatosis type 2.