Holly
09-21-2007, 07:08 PM
Hydrocephalus occurs most often in infants and children and can result from congenital defects, injury, infection or tumors. Normally, cerebrospinal fluid (CSF) is produced in cavities, called ventricles, inside the brain, circulates among the ventricles and over the surface of the brain and spinal cord, and then gets re-absorbed into the blood stream. In congenital hydrocephalus that circulation pattern may become blocked or the balance between production and absorption is lopsided. In acquired hydrocephalus, trauma or infection can cause swelling or bleeding into the brain cavity.
In either case, pressure inside the skull (intracranial pressure or ICP) rises, compressing sensitive tissues and restricting blood flow and leading to headaches, irritability, vomiting, and loss of motor function and seizures. In young children, the joints (called sutures) between skull plates have not yet fused, so the increased pressure can cause a rapid increase in head size or bulge at the "soft spot" (fontanelle). Approximately one in 500 infants is born with hydrocephalus or develops it shortly after birth.
Hydrocephalus is commonly known as 'water on the brain', although this is not accurate. A watery fluid, known as cerebro-spinal fluid (or CSF, for short), is produced constantly inside each of the four spaces or ventricles inside the brain. The CSF normally flows through narrow pathways from one ventricle to the next, then out over the outside of the brain and down the spinal cord. The CSF is absorbed into the bloodstream and the amount and pressure are normally kept within a fairly narrow range. If the drainage pathways are obstructed at any point, the fluid accumulates in the ventricles inside the brain, causing them to swell - resulting in compression of surrounding tissue. In babies and infants, the head will enlarge. In older children and adults, the head size cannot increase as the bones which form the skull are completely joined together. The majority of babies born with spina bifida have hydrocephalus. In addition to the lesion in the spinal cord, there are abnormalities in the physical structure of certain parts of the brain which develop before birth. This prevents proper drainage of the CSF. The increase in pressure due to this can also compress the abnormal parts of the brain even further.
http://www.fortunecity.com/millenium/plumpton/268/sb.htm
In either case, pressure inside the skull (intracranial pressure or ICP) rises, compressing sensitive tissues and restricting blood flow and leading to headaches, irritability, vomiting, and loss of motor function and seizures. In young children, the joints (called sutures) between skull plates have not yet fused, so the increased pressure can cause a rapid increase in head size or bulge at the "soft spot" (fontanelle). Approximately one in 500 infants is born with hydrocephalus or develops it shortly after birth.
Hydrocephalus is commonly known as 'water on the brain', although this is not accurate. A watery fluid, known as cerebro-spinal fluid (or CSF, for short), is produced constantly inside each of the four spaces or ventricles inside the brain. The CSF normally flows through narrow pathways from one ventricle to the next, then out over the outside of the brain and down the spinal cord. The CSF is absorbed into the bloodstream and the amount and pressure are normally kept within a fairly narrow range. If the drainage pathways are obstructed at any point, the fluid accumulates in the ventricles inside the brain, causing them to swell - resulting in compression of surrounding tissue. In babies and infants, the head will enlarge. In older children and adults, the head size cannot increase as the bones which form the skull are completely joined together. The majority of babies born with spina bifida have hydrocephalus. In addition to the lesion in the spinal cord, there are abnormalities in the physical structure of certain parts of the brain which develop before birth. This prevents proper drainage of the CSF. The increase in pressure due to this can also compress the abnormal parts of the brain even further.
http://www.fortunecity.com/millenium/plumpton/268/sb.htm