Partial seizures
This describes a localised or focal seizure, which starts in and normally stays in one part of the brain.
There are 3 types of partial seizures:
- Simple partial with no loss of consciousness (previously called Jacksonian seizures).
In this type of seizure the abnormal electrical impulse originates in the motor cortex of the brain, which controls muscular movements.
Typically, jerking movements begin at the angle of the mouth, or in the thumb and index finger. The jerking may spread gradually to involve the whole limb on the affected side. This spread is called the march of the seizure. Attacks may last from a few seconds to several hours.
If the seizure is prolonged and affects the entire limb then weakness or paralysis of the affected limb (s) (Todd’s Paralysis) may be present for several hours after the seizure ceases.
There is no loss or impairment of consciousness with simple partial seizures, and the person is generally aware throughout the entire event.
- Complex partial with variable impairment or loss of consciousness. Previously often called Temporal lobe Epilepsy)
In Complex partial seizures, the abnormal electrical impulse commonly originates in the temporal lobe of the brain, but may start in any part.
Depending on the part of the brain affected the person may behave in a strange manner for a few seconds or minutes. They may fiddle with an object or pluck at their clothing, mumble incoherently, or exhibit automatisms such as blinking, twitching, mouth movements or walking in a circle. (These are non- convulsive attacks, and sometimes it may not be obvious to the medical staff or observer, that this person is fitting).
Individuals may also continue activities started before the seizure began, such as washing dishes, but these activities are continued in a repetitive unproductive manner.
Such seizures may last from a few seconds to several minutes. Consciousness is normally impaired or lost, and there may be no recollection of the event.
The person may feel dazed and muddled for a short while following the attack. The person does not normally fall or collapse to the ground.
Some people with complex partial seizures experience an aura – unusual sensations that warn of an impending attack. Such sensations may on occasion mimic psychiatric conditions. Deja-vu, which is a subjective feeling that an experience which is occurring for the first time has been experienced before, may occur.
- Complex partial evolving to generalised tonic-clonic seizures.
In a small proportion of people the partial seizure spreads out of its localised area to involve the rest of the brain. A generalised convulsion (tonic-clonic) then occurs with complete loss of consciousness. This is termed Secondary Generalised Seizure (figure C of the seizure diagram refers).
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Amended November 2008
