Epilepsy - Diagnosis

Computerized Tomography (CT) Scans. Usually, the first brain imaging test ordered for most adults and children with first-time seizures is a CT scan. This imaging technique is sensitive enough for most purposes. In children, even if the scan is normal, the doctor will follow up to be sure other problems are not present.

A CT or CAT scan (computed tomography) is a much more sensitive imaging technique than X-ray, allowing high definition not only of the bony structures, but of the soft tissues. Clear images of organs such as the brain, muscles, joint structures, veins and arteries, as well as anomalies like tumors and hemorrhages may be obtained with or without the injection of contrasting dye.

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Magnetic Resonance Imaging (MRI). Experts now strongly recommend MRIs for children with first seizures in certain cases, such as children under one year old and those with seizures that are associated with any unexplained significant mental or motor problems. These images may help to determine if the disorder can be treated with surgery, and may be used as a guide for surgeons.

Other Advanced Imaging Techniques. More advanced scanning techniques, particularly magnetic resonance spectroscopy (MRS), magnetoencephalography (MEG), positron emission tomography (PET), and single-photon emission computer tomography (SPECT), are emerging as important tools for epilepsy researchers. They are useful for detecting abnormalities, such as changes in brain activity, damaged or scarred locations in the brain where partial seizures are triggered, or tumors and other abnormalities that may be causing seizures. Some, such as MEG, may help determine which patients with severe epilepsy are good candidates for surgery.

Polysomnography

Some researchers recommend polysomnography for certain patients. This test is used to detect sleep disorders, such as obstructive sleep apnea, that are can be associated with epilepsy.

Investigative Diagnostic Procedures

Low brain levels of the neurotransmitter gamma aminobutyric acid (GABA) are associated with an increased risk of seizure recurrence. Some researchers suggest that measuring GABA levels, along with EEG recordings, could help beter assess the risk of recurring seizures, and may identify which patients might benefit from GABA-stimulating drugs.