Seizures are temporary disruptions of brain function due to abnormal and excessive neuronal discharge. Epilepsy is the chronic condition of repeated seizures. Seizures “hijack” the normal function of the brain and the way the seizure presents itself depends on the area of the brain affected.
Positive manifestations of a seizure include various motor manifestations, such as muscle contractions and spasms, hearing of abnormal sounds and seeing abnormal visions. A negative manifestation of a seizure is the complete loss of awareness.
Classification of Seizures:
Focal Onset: The person having a seizure is completely aware of what is going on around them during the seizure, or they may have impaired awareness. It can be a motor type seizure (muscle contractions) or a non-motor seizure (hearing sounds, seeing visions) or a combination of both.
Generalized Onset. There is always a complete loss of consciousness. It can be a motor type seizure or a non-motor type seizure (mental absence).
Epileptogenesis is the process by which the normal brain is functionally altered and biased towards the generation of abnormal electrical activity that subserves chronic seizures. Traditional anti-epileptics can terminate a seizure and control future seizures but cannot prevent the process of epileptogenesis.
Why is epilepsy seizure classification needed?
• To identify the type of epilepsy and treatment needed.
• The classification system is also used to identify which patients are most likely to benefit from surgery to treat their epilepsy, as well as the type of surgery that is needed.
• If the doctor fails to recognize the syndrome, another medicine may be prescribed that may make the seizures worse instead of better.
Different types of epileptic seizures have their own signature EEG waveform pattern and a neurophysiologist can determine the type of epilepsy by observing these waveforms.