JM
Puritan Board Doctor
Brain Worms and Brain Amoebas: They Do Exist
Tapeworm: From Pork Chops to the Brain
The pork tapeworm is one of the most common disease-causing brain parasites. This parasite infects over 50 million people worldwide, and is the leading cause of brain seizures. It is usually contracted from eating undercooked pork, and once in the gut, it attaches to the intestine, and then grows to be several feet long. Under certain circumstances, these worms can also invade the brain, where thankfully they don’t grow to be quite so large.
Why does the worm sometimes attach to the intestine but at other times travel to the brain? It all depends on what stage of its life cycle the worm is in when it is swallowed. In its larval stage, the worm will hook onto the intestine; however, if eggs are swallowed, they hatch in the stomach. From there the larvae can enter the bloodstream and eventually travel to the brain. But in order to reach the brain from the bloodstream, the larvae must traverse the blood-brain barrier. Unfortunately, researchers still don’t know exactly how this happens. Many scientists think that the larvae can release enzymes that are able to dissolve a small portion of the blood-brain barrier to allow the parasite to get through into the brain.
Once the larvae reach the brain, they cause a disease called neurocysticercosis, by attaching to either the brain tissue itself, or to cavities through which brain fluid flows. (Brain fluid carries nutrients and waste to and from the brain, and acts as a cushion to protect the brain against physical impact.) Once attached, the larvae develop into cyst-like structures. The location of the cysts determines the symptoms exhibited by the host. If the larvae attach to the brain tissue, then the host often experiences seizures. This occurs partly because the presence of the larvae causes the activity of the brain to become wild and uncontrolled, thereby causing a seizure. On the other hand, if the larvae attach to the brain-fluid cavities, the host experiences headaches, nausea, dizziness, and altered mental states in addition to seizures. These additional symptoms occur because the flow of the brain fluid is blocked by the larvae. Often, the presence of the larvae also causes the lining of the brain-fluid cavities to become inflamed, further constricting the flow of the brain fluid. Since the cavities are a closed system, blockage of the cavities exerts pressure on the brain. This increased cranial pressure forces the heart to pump harder in order to deliver blood to the brain area, increasing the pressure on the brain even more. If the condition is not treated, the heart eventually cannot pump enough blood to the brain, neurons begin to die off, and major brain damage occurs.
Tapeworm: From Pork Chops to the Brain
The pork tapeworm is one of the most common disease-causing brain parasites. This parasite infects over 50 million people worldwide, and is the leading cause of brain seizures. It is usually contracted from eating undercooked pork, and once in the gut, it attaches to the intestine, and then grows to be several feet long. Under certain circumstances, these worms can also invade the brain, where thankfully they don’t grow to be quite so large.
Why does the worm sometimes attach to the intestine but at other times travel to the brain? It all depends on what stage of its life cycle the worm is in when it is swallowed. In its larval stage, the worm will hook onto the intestine; however, if eggs are swallowed, they hatch in the stomach. From there the larvae can enter the bloodstream and eventually travel to the brain. But in order to reach the brain from the bloodstream, the larvae must traverse the blood-brain barrier. Unfortunately, researchers still don’t know exactly how this happens. Many scientists think that the larvae can release enzymes that are able to dissolve a small portion of the blood-brain barrier to allow the parasite to get through into the brain.
Once the larvae reach the brain, they cause a disease called neurocysticercosis, by attaching to either the brain tissue itself, or to cavities through which brain fluid flows. (Brain fluid carries nutrients and waste to and from the brain, and acts as a cushion to protect the brain against physical impact.) Once attached, the larvae develop into cyst-like structures. The location of the cysts determines the symptoms exhibited by the host. If the larvae attach to the brain tissue, then the host often experiences seizures. This occurs partly because the presence of the larvae causes the activity of the brain to become wild and uncontrolled, thereby causing a seizure. On the other hand, if the larvae attach to the brain-fluid cavities, the host experiences headaches, nausea, dizziness, and altered mental states in addition to seizures. These additional symptoms occur because the flow of the brain fluid is blocked by the larvae. Often, the presence of the larvae also causes the lining of the brain-fluid cavities to become inflamed, further constricting the flow of the brain fluid. Since the cavities are a closed system, blockage of the cavities exerts pressure on the brain. This increased cranial pressure forces the heart to pump harder in order to deliver blood to the brain area, increasing the pressure on the brain even more. If the condition is not treated, the heart eventually cannot pump enough blood to the brain, neurons begin to die off, and major brain damage occurs.