Specialist expertise: Sleep Disorders, Epilepsy, Neurology, Headache.
Blackouts, seizures and epilepsy often display the same symptoms, so it can be difficult to distinguish them from one another. These are however three different medical occurrences, and it is important that diagnostic testing is done to identify which one you may be suffering with. The main differentiators between blackouts, seizures and epilepsy are what causes them, and how frequently they occur.
The term “blackout” refers to any temporary alteration of awareness or consciousness, and blackouts may have a wide range of causes.
Blackouts may be as a result of sudden drops in blood pressure (similar to fainting), may have a cardiac cause, can be seen in sleep disorders, can have a psychological cause or maybe as a result of neurological dysfunction, such as a seizure or a condition such as epilepsy.
Seizures represent the sudden development of unregulated, abnormal electrical activity within the brain, resulting in a temporary disruption of neurological function. Depending on where in the brain and how widespread this electrical activity is, seizures may result in minor symptoms such as brief speech disturbance, tremor, or confusion, but if the electrical activity spreads throughout the brain, this can cause a generalised convulsion. In most cases, a person will experience a seizure and never have one again.
One-off seizures are most often caused by an acute factor such as a certain medication, high fever, alcohol or drug withdrawal, low blood sugar or sodium levels, lack of sleep, a head injury, stroke or brain infection.
Recurring seizures are due to a brain condition called epilepsy. Epilepsy describes the tendency to have recurrent seizures in the absence of a clear physical trigger, and is usually diagnosed in this setting after two or more seizures. Occasionally, epilepsy may be diagnosed after a single seizure, if investigations point to a high likelihood of another seizure.
Common causes of epilepsy include inheriting certain genes, or an abnormality in the structure of the brain (commonly as a result of scarring due to previous brain injury, stroke or infection, or abnormal development of the brain before birth).