The worms that invade your brain!

• The most common form of brain tapeworm is mainly the pork tapeworm.
• Once you consume them, they can move throughout your body, your eyes, your tissues and most commonly your brain.
• They leave doctors puzzled in their wake as they migrate and settle to feed on the body they're invading; a classic parasite, but this one can get into your head.
• "Very few things move in the brain," says Dr. Effrossyni Gkrania-Klotsas about a British man found to have a tapeworm moving inside his brain in 2013. This form of tapeworm had never been seen before in the United Kingdom.
• The patient, who was of Chinese descent, had recently visited China, which along with South Korea, Japan and Thailand, has more regular occurrences of the parasite known as Spirometra erinaceieuropaei. Four years earlier the man had first experienced symptoms, such as headaches, which the team of doctors at Addenbrookes Hospital, in Cambridge, had treated as tuberculosis. But then he returned.
• "When he reappeared, he had new symptoms," says Gkrania-Klotsas. The worm was now pushing on a new part of his brain, causing seizures and weakness in his legs. The condition associated with his infection was in fact Sparganosis. There is no known drug to effectively treat the infection meaning that upon diagnosis doctors had to be quick to remove the worm surgically.
• These worms are pretty mysterious!
• The adult form of the Spirometra tapeworm only occurs in the intestines of cats and dogs but as these animals shed the worms' eggs in their faeces the eggs can enter, and contaminate, water. The resulting juvenile form of tapeworm  known as larvae  can then stay in the water within certain small crustaceans or end up in frogs and snakes. As larvae they can invade humans through ingestion or direct contact with infected animals. 
• The pork species, known as Taenia Solium, can infect humans in two forms. The first is by eating undercooked pork from infected pigs, resulting in taeniasis -- an adult worm residing in the intestine. The second, in the larval form, through contact with the faeces of an infected pig or human, which can go on to infect many tissues. If the larval worm enters the nervous system, including the brain, it can result in a condition known as neurocysticercosis.