Final answer:
Generalized onset seizures affect the entire brain and involve loss of consciousness. Tonic-clonic seizures feature a tonic phase with muscle stiffening and a clonic phase with mayoclonic movements, atonic seizures cause sudden muscle relaxation leading to falls, and tonic seizures involve prolonged muscle stiffening without the involuntary movements.
Step-by-step explanation:
Generalized Onset Seizures
Generalized onset seizures are a type of seizure that affect both sides of the brain simultaneously from the outset. These seizures typically involve a loss of consciousness and are not limited to one area of the brain. The different kinds of generalized seizures include tonic-clonic, atonic, and tonic seizures, each with its own characteristics.
Tonic-Clonic Seizures
The term tonic-clonic refers to seizures that involve two phases: the tonic phase, where the muscles stiffen, and the clonic phase, which features rhythmic muscle contractions. During a tonic-clonic seizure, the patient typically loses consciousness, may bite their tongue.
Atonic Seizures
Atonic seizures are also known as 'drop' seizures because they are characterized by a sudden loss of muscle tone, which can lead to falls or head drops. During an atonic seizure, the patient may collapse to the ground, and these seizures are brief, typically lasting less than 15 seconds.
Tonic Seizures
Tonic seizures are defined by muscle stiffness that is generally more prolonged than the tonic phase of a tonic-clonic seizure. Unlike tonic-clonic seizures, there is no clonic phase following the tonic activity. In tonic seizures, patients often remain conscious but cannot move due to the muscle stiffness, and these seizures typically last less than 20 seconds.
The difference between these seizures lies mainly in the patient's experience and physical symptoms during the event. Tonic-clonic seizures involve both stiffness and involuntary movements, atonic seizures lead to an abrupt loss of muscle tone, and tonic seizures involve sustained muscle stiffness.