Electroencephalogram (EEG)
The pattern of electrical activity of the brain is recorded by means of electrodes stuck to the scalp. This is a painless and safe technique (although it may make a mess of your hair!). Sometimes more information is obtained if children also go to sleep during the recording.
Other special EEG techniques which are necessary in certain cases include an electroretinogram (ERG) and visual evoked responses (VER)which help in the assessment of vision.
Brain Scans
There are three methods in routine use:
Cranial ultrasound
This technique uses ultrasound in the same way as it is used during pregnancy. The fontanelle ("soft spot" on the skull) is a "window" on the brain. Ultrasound scans are very good at showing the size of the ventricles (fluid filled areas within the brain) and in telling whether bleeding has occurred.
Computerised Tomography (CT)
This technique uses X-rays and a computer to create a series of images of the brain in 2-dimensions. The dose of x-rays in small and unlikely to cause any harmful effects, especially if the scan only needs to be carried out once or twice. CT scans are very good at showing the general pattern of brain development and are the best method of showing up calcium in the brain (which can be important in some causes of infantile spasms).
Magnetic Resonance (MR)
This technique uses a powerful magnetic field and advanced electronic techniques to create a range of different images in various planes. A disadvantage for small children is the noise of the machine and the time they have to lie still in order to obtain good quality images. MR provides the most detailed assessment of brain structure and development of the techniques currently in routine use.
Blood tests
Blood tests are done for a variety of medical conditions which can cause infantile spasms. Some of the blood tests which are done include: chromosome analysis; tests for recent infection, or infection before birth; tests of body chemistry, both routine (glucose and calcium) and special (for instance amino acids).
Urine tests
Urine tests are usually carried out to detect previous infection (recent or before birth) and anomalies of body chemistry.
Lumbar Puncture
A lumbar puncture involves placing a tiny needle at the base of the spine below the spinal cord. Spinal fluid can be analysed for evidence of infection and in some cases chemical abnormalities.
Wood's Light
A near ultra-violet light is used in a darkened room to show up any unusual birth marks which may sometimes occur together with abnormal brain development as a cause of infantile spasms.
Not every child will require all of these tests. A few children may require tests other than these outlined here. Because infantile spasms (West Syndrome) is a condition of many different causes, the choice of test is determined by particular features in any one child
