Researchers reviewed all of the published studies on the prolactin blood test and found it may be useful in certain situations in determining whether an epileptic seizure occurred in adults and older children with unexplained seizures.
The test, which must be used within 10 to 20 minutes after a seizure, measures levels of the hormone prolactin in the blood. Prolactin is produced by the pituitary gland, but an area of the brain called the hypothalamus controls its release.
Researchers say epileptic seizures are thought to affect the hypothalamus and may alter the release of prolactin, causing levels of the hormone to rise.
New Test for Epileptic Seizures
In the study, which appears in the journal Neurology, researchers evaluated eight studies on the prolactin blood test.
The results showed that the test could accurately identify seizures in adults and older children and distinguish them from nonseizure type episodes. Levels of prolactin in the blood increase after seizures but not during nonseizure activity.
Researchers found the test was useful at differentiating epileptic seizures from those caused by mental problems. But they say the test cannot distinguish epileptic seizures from those caused by a fainting episode because prolactin levels also rise after these types of seizures.
Therefore, the guidelines say the test may be appropriate as a secondary test, especially in cases when EEG (electroencephalography, a technology used to analyze seizures) is not available.
More research is also needed to determine whether the prolactin blood test is suitable for young children.