Many cases of cysticercosis are asymptomatic, but depending upon the size, location, and number of cysticerci, T. solium infection can cause very serious symptoms, even death. There are three main types of cysticercosis:
Muscular/ Subcutaneous Cysticercosis
In general muscular/subcutaneous cysticercosis does not cause symptoms, however in severe infections with a large number of cysticerci, one may be able to feel or see bumps under the skin. Muscle cysticercosis may casue pain and hypertrophy and dead and calcified cysts will show up quite clearly on x-rays and often cause inflammations due to the immune system's response. Muscular/subcutaneous cysticercosis is the least prevalent type, but there are areas of India with prevalence as highs as 10%.
Ocular cysticercosis is also extremely rare with a prevalence of 2.5% in some countries. Ocular cysticercosis is caused by cysticerci floating in the retina, causing blurry/disturbed vision, retinal swelling, and in extreme cases, retinal detachment.
Neurocyticercosis is by far the most prevalent and dangerous form of cysticercosis. At any time during infection neurocysticercosis caused by living or dead cysticerci can cause a host of different symptoms (pleomorphic) including headaches, nausea, vomiting, blurred vision, neurologic changes, acute confusion, increased intracranial pressure, focal neurologic deficit, intellectual deficit, and perhaps most importantly epilepsy. Epilepsy occurs in nearly 70% of neurocysticercosis cases and studies have shown that areas endemic to T. solium have epilepsy rates that are twice as high as similar non-endemic countries (prompting the WHO to deem neurocysticercosis an "important" cause of epilepsy globally). Neurocysticercosis is the #1 cause of adult onset epilepsy and in addition, epilepsy is often the single manifestation of neurocysticercosis.