Do Not Pen Down Epilepsy Diagnosis Until You Are Very Sure
Diagnosing epilepsy is not always easy. A detailed clinical history followed by physical examination with some investigations, to assess the type of seizures and make a diagnosis is required.
The primary diagnosis of epilepsy is made by a doctor with a proper detailed patient and witness account and start treatment as suitable. The accuracy of the diagnosis is based on the pursuit of the doctor to obtain maximum information about the seizure from the patient and importantly from the witness. A home video of the episode adds much information and is advised. In addition, medical details of the person since birth and about the mother’s pregnancy are important as is the family history. The doctor may also order some diagnostics.
The doctor, if for any reason is unsure about the diagnosis, must defer from labeling the person to be having epilepsy until definitely proven. For this, investigations and clinical reassessment and detailed interview of the person who has seen more than one seizure should be done. Home video recordings can be very helpful. Diagnosis of epilepsy can have a social and emotional impact on the person as well as family members, and counseling is extremely important.
Requisites for proper diagnosis of epilepsy
Detailed patient and witness account.
Physical examination.
Electroencephalogram (EEG): An EEG examines electrical activity in the brain. Electrical changes are often only seen during a seizure and hence the EEG can be normal. This does not mean that the person does not have epilepsy. It simply means that the abnormal electrical activity was not occurring when the test was taken. An abnormal EEG can suggest that a person is more likely to have seizures and helps the doctor suggest the appropriate type and dose of ASMs. However, an EEG can be abnormal for a variety of reasons unrelated to seizures. Hence clinical correlation is extremely important.
Types of EEG recordings
Routine EEG with or without video recording called interictal EEG is a routine diagnostic test.
Prolonged Video EEG or Telemetry is a continuous EEG with video monitoring performed in hospital over several days to capture a seizure on video and correlate it with simultaneously ongoing EEG. This is done to rule out suspicious seizure-like events and is an important pre- surgical evaluation test for epilepsy surgery.
Ambulatory EEG (AEEG) is not commonly done and may take place in the person’s home or a medical setting, not being confined to the recording chair or bed.
Neuroimaging: Computed tomography (CT) and Magnetic resonance imaging (MRI) help detect a cause for seizure activity like tumour which can be surgically removed or an infective brain lesion like a tuberculoma that can be treated with adequate drugs.
Laboratory tests like blood sugar levels, electrolytes etc. to rule out other causes of seizures.
Additional tests: SPECT (single-photon emission computed tomography) and PET (positron emission tomography) scans may be recommended. However, not everyone needs to undergo these tests. Usually, they are used as part of pre-surgical evaluation for epilepsy surgery. A PET scan provides information about how an organ or system in the body is working, and a SPECT scan shows how blood flows to tissues and organs – both scans can assist in identifying seizure onset zones in the brain.