A brief, temporary change in movement, sensation, or autonomic function caused by abnormal electrical activity in a discrete area of the brain, without changes in alertness or awareness. This distinguishes it from a partial complex seizure in which consciousness is impaired.

Alternative Names

Simple seizure; Jacksonian seizure; Seizure - partial (focal)

Causes, incidence, and risk factors

A partial (focal) seizure affects approximately 8 out of 100,000 people. This type of seizure may occur at any age, as a single episode or as a repeated, chronic condition ( seizure disorder , epilepsy ). It is seen less frequently in children than in adults, but still accounts for about 45% of pediatric seizure disorders . Transmission of information from nerve cell to nerve cell occurs by an electrochemical process. This process can be detected as electrical activity by an electroencephalograph ( EEG ). Abnormal patterns of electrical activity are associated with seizures. Given sufficient circumstances, any person will have a seizure. Simple focal seizures are commonly the result of abnormal electrical activity in the motor (movement) and sensory (sensation) areas of the cerebral cortex. There are motor or sensory symptoms without loss of consciousness . Seizures are commonly associated with epilepsy (seizure disorders). Spontaneous seizures may occur because of unknown causes. In some people, they can be triggered by menstruation; trauma; hypoxia ; sensory stimuli such as lights, sounds, touch, reading; or other stimuli. Specific causes of partial (focal) seizures most commonly include localized areas where tissue has been damaged by lack of oxygen, or tissue damage caused by brain tumors or discrete brain lesions of any sort. The most common location for the lesion is in the temporal lobe of the brain (temporal lobe seizures), but the lesion may occur in any location. In children, focal seizures are less likely to be caused by a definable lesion when compared to adults. More commonly, partial seizures arise from static lesions acquired during intra-uterine life.

Signs and tests

The diagnosis is based primarily on the symptoms presented, especially movement or sensation abnormalities without a loss of consciousness . The diagnosis of the cause may include a complete physical examination , including a detailed neuromuscular examination. Psychometric assessment may be useful.

An

EEG can show characteristic changes confirming a partial (focal) seizures, and may show the focus (the location of the cause). A normal EEG does not rule out seizures.

A

Head CT or head MRI scan may show the location and extent of the lesion causing the symptom.

Treatment

Record details of the seizure to report to the health care provider. Include the date and time of the seizure, how long it lasted, which body parts were affected, the type of movements or other symptoms, possible causes, and other factors noted. Emergency treatment may not be required unless the seizure becomes generalized or consciousness is lost. First-aid measures should be performed as appropriate, including protection from injury, prevention of aspiration of vomit or mucus into the lungs, and protection of the airway, or assistance with breathing. Treatment of the causes may stop the occurrence of seizures. This may include medical treatment of disorders, surgical repair of tumors or brain lesions, or other treatments. An isolated seizure with an obvious avoidable trigger, such as fever or toxic reactions, is treated by removing or treating the precipitating (trigger) factor. An isolated seizure without an obvious cause (normal results of an examination, normal EEG and no abnormalities on other testing) may not require treatment. Oral anticonvulsants (anti-seizure medications) are used to prevent or reduce the number of seizures. The response varies, and medication and dosage may have to be adjusted repeatedly. An isolated seizure with abnormal findings on an EEG or other tests is treated with anticonvulsant medications such as phenytoin, carbamazepine, phenobarbital, or valproic acid. Multiple, repeated seizures are usually treated with phenytoin or carbamazepine for preventive, long-term use. Other medications include gabapentin, Gabitril, levetiracetam, lamotrigine, and oxcarbazepine. Follow-up includes review of the need for drugs at least yearly. Drugs may need to be continued indefinitely. Pregnancy , lack of sleep, skipping doses of medications, use of drugs and medications or alcohol, or illness may cause seizures in a person with a previously well-controlled seizure disorder. Wearing informational jewelry or cards (such as Medic-Alert) may be advised to aid in obtaining prompt medical treatment if a seizure occurs.

Expectations (prognosis)

Seizures can occur as a single isolated incident, at closely repeated (recurrent multiple seizures) intervals, or at various intervals (episodic, paroxysmal). Seizures that recur with little or no observable cause are most commonly associated with seizure disorders ( epilepsy ). This is a chronic , lifelong condition. Seizures that occur singly or in a closely associated group are commonly triggered by an acute condition such as brain injury . They may occur as an isolated incident, or they may develop into a chronic seizure disorder. Seizures within the first two weeks of a brain injury do not necessarily mean that a chronic seizure disorder will develop. A seizure-free period may indicate that reduction or elimination of medications may be possible. Medication should only be changed by the health care provider. Death or permanent brain damage from seizures is rare, but either can occur if the seizure is prolonged or many seizures occur in close proximity. Serious injury can occur if the seizure happens while the person is driving or operating dangerous equipment. These activities may be restricted for people with poorly controlled seizure disorders. Infrequent seizures may not severely restrict lifestyle. Work, school, and recreation do not necessarily need to be restricted.

Complications

progression to generalized

seizures

epilepsy

(recurrent seizures)

prolonged seizures, closely occurring seizures (status epilepticus)

injury from falls, bumps, biting self

injury caused by

seizure during driving/operating machinery

aspiration pneumonia

permanent brain damage (

stroke or other damage)

side effects of medications (with or without observable symptoms)

complications of surgery

women who choose to get pregnant should inform their doctor in advance for appropriate adjustments in medications (many of the anti-epileptic medications can cause birth defects)

Calling your health care provider

Call your health care provider if this is the first time the person has had seizures . Call your health care provider if this is a new type of seizure for the person. Go to the emergency room or call the local emergency number (such as 911) if the seizure lasts longer than 2 to 3 minutes, or if repeated seizures occur (over any amount of time). Repeated seizures over a few minutes, or repeated seizures where consciousness is not regained between them (status epilepticus) is an emergency situation. Call your health care provider if any new symptoms occur, including possible side effects of medications:

changes in mental status

(

drowsiness , restlessness , confusion , sedation, or others)

nausea/vomiting

rash

loss of hair

tremors

or abnormal movements

problems with coordination

Prevention

Treatment of the underlying disorders may reduce the risk of seizures. In most cases, the seizures may not be preventable.