Different sizes of valves are available. In addition, valves are available with several operating pressures and in different pressure ranges. Thus, shunts can be used to treat hydrocephalus for adults as well as children.
In the presence of specific symptoms detailed in the chapter What is the origin of hydrocephalus? The physician may suspect hydrocephalus. Several tools are available to confirm his/her hydrocephalus diagnosis and to perform a complete neurological examination. These tools will also help the physician to find out if a shunt is an appropriate therapy for his/her patient. Indeed, the shunt therapy will meet most patients' needs. However, in presence of other pathologies, the physician will need to take them into account to define the appropriate therapy. These tests could also be useful to check and evaluate the shunt in case of malfunctions and infections.
The physical examinations are similar from one patient to another but the physician will look for different reactions depending on patient's age. They aim to determine if hydrocephalus reduces functional brain capacity.
For premature infant and small children (under the age of 18 months), the physician will look mainly at abnormal head swelling or downward displacement of the eyes. For older children, depending on age, the physician will look for development signs such as smiling, walking, speaking, memorizing and coordination.
For adults, there is a need to check the usual skills of the patient: speaking, walking, understanding and memorizing, amongst others.
The medical tests that can be used by the medical staff are numerous and will be chosen depending on patient's condition, his/her age and other factors such as other pathologies. Some of them are described below:
- MRI (Magnetic Resonance Imaging) is a medical imaging technique using strong magnetic fields and radiowaves to draw digital pictures of the brain and the ventricles. It creates a “map" of the brain, detailing any CSF blockage. It is a non-invasive technique.
- Ultrasound is an imaging technique used to diagnose congenital hydrocephalus in utero.
- Echography is a medical examination of the internal structures of the brain by ultrasound. It is mainly dedicated to small children as their fontanelles are still visible.
- CT scan (Computed Tomography) or scanography is a medical imaging technique estimating x-rays absorption by the brain on different levels which will be, thanks a computer assistance, put together to create 2D or 3D brain pictures.
- Cisternography is an examination that allows creating a subarachnoid spaces map, where the CSF is circulating, thanks to the injection of a radioactive substance in the CSF. This technique allows the physician to distinguish the communicating hydrocephalus from the non-communicating and helps to know the CSF circulation pathways.
For normal pressure hydrocephalus, two other medical tests are available:
- Controlled lumbar puncture which will indicate, by evacuating CSF in excess, if the patient would benefits from a shunt implantation.
- Lumbar infusion test is a medical test where the medical staff will inject a liquid in the lumbar region to evaluate the CSF absorption capacity of the patient.