Definition:
A seizure is a sudden and uncontrolled electrical disturbance in the brain, resulting in abnormal and excessive neuronal activity. This disturbance can manifest in various ways, from altered consciousness and sensory perceptions to convulsions and involuntary movements. Seizures can be caused by various factors, including epilepsy, head injuries, infections, and certain medical conditions.
Examples:
1. Absence Seizures: These seizures, often associated with epilepsy, involve a brief loss of consciousness and awareness. During an absence seizure, a person may stare blankly into space for a few seconds, appearing momentarily disconnected from their surroundings.
2. Tonic-Clonic Seizures: Formerly known as grand mal seizures, these are characterized by a sudden loss of consciousness, followed by stiffening of the body (tonic phase) and then convulsive movements (clonic phase). Tonic-clonic seizures can be intense and may last for a few minutes.
3. Simple Partial Seizures: In these seizures, only a specific part of the brain is affected. The person may experience altered sensations, emotions, or movements without losing consciousness. For instance, a simple partial seizure might cause repetitive hand movements or sensory distortions.
4. Complex Partial Seizures: These seizures impact a larger portion of the brain and often involve altered consciousness or awareness. Individuals experiencing complex partial seizures may exhibit unusual behaviors, such as repetitive movements or confused actions, and may not remember the episode afterward.
5. Febrile Seizures: Common in children, febrile seizures are typically triggered by a sudden spike in body temperature, often due to an infection. These seizures are usually brief and may involve convulsions.
6. Atonic Seizures: Also known as drop attacks, atonic seizures cause a sudden loss of muscle tone, leading to a person collapsing or falling to the ground. These seizures are characterized by a temporary loss of muscle strength and may be associated with injuries from falls.