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Complex Partial Seizures

Practice Essentials

A complex partial seizure, now known as a focal impaired awareness seizure according to the updated classification system from the International League Against Epilepsy (ILAE),
 starts focally within the brain and causes impairment of consciousness. In most patients, focal impaired awareness seizures represent underlying temporal lobe epilepsy. See the image below.

Left temporal lobe seizure.

Left temporal lobe seizure.

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Signs and symptoms

Focal impaired awareness seizures typically last 30 seconds to 2 minutes. Longer seizures may occur when seizures become generalized with full-body convulsions or transform to a state of partial status epilepticus.

Aura

Typically of brief duration, rarely lasting longer than seconds

Eight different varieties are recognized: somatosensory, visual, auditory, gustatory, olfactory, autonomic, abdominal, and psychic

Auras precede temporal lobe seizures in approximately 80% of cases; the most common are abdominal (a rising epigastric sensation) and psychic (fear, déjà vu, jamais vu)

Parietal lobe seizures may begin with a contralateral sensation, usually of the positive type (electrical sensation, tingling)

Occipital lobe seizures may begin with contralateral visual changes, usually of the positive type (eg, colored lines, spots, or shapes) or a loss of vision

Temporal-parietal-occipital seizures may produce more formed auras

Impaired consciousness

Usually, during a focal impaired awareness seizure, the patient is unresponsive and does not remember events that occurred

Although patients typically do not respond to external stimuli, they may make simple verbal responses; follow simple commands; or continue to perform simple or, less commonly, complex motor behaviors (eg, operating a car)

Automatisms

Automatisms are nonpurposeful, stereotyped, and repetitive behaviors that commonly accompany complex partial seizures

The behavior is inappropriate for the situation

Patients are usually amnestic to their automatisms

Verbal automatisms range from simple vocalizations, such as moaning, to more complex, comprehensible, stereotyped speech

The most common automatisms, at least in temporal lobe epilepsy, are oral (eg, lip smacking, chewing, swallowing) and manual (eg, picking, fumbling, patting
)

Unilateral manual automatisms accompanied by contralateral arm dystonia usually indicates seizure onset from the cerebral hemisphere ipsilateral to the manual automatisms

Automatisms can also be more elaborate, coordinated movements involving bilateral extremities (eg, cycling movements of the legs, stereotyped swimming movements)

Bizarre automatisms (eg, alternating limb movements, right-to-left head rolling, sexual automatisms) may occur with frontal lobe seizures

Seizure features by site of origin

Temporal lobe seizures often begin with a motionless stare followed by oral or manual automatisms

Frontal lobe seizures often begin with vigorous motor automatisms or stereotyped clonic or tonic activity

Extratemporal lobe seizures may spread quickly to the frontal lobe and produce motor behaviors similar to those associated with complex partial seizures of the frontal lobe

In temporal lobe seizures, lateralizing signs with corresponding sensitivities include the following
:

Contralateral – Unilateral sensory aura (89%), hemifield visual/sensory aura (100%), motor version (100%), clonic activity (83%), tonic activity (100%); figure 4 sign (89%); unilateral dystonic posturing (100%); postictal palsy (93%)

Ipsilateral – Postictal nose wiping (92%)

Nondominant lobe – Ictal spitting (75%), ictal vomiting (81%), ictal speech (83%)

Dominant lobe – Ictal aphasia/dysphasia (100%)

See Clinical Presentation for more detail.

Diagnosis

Laboratory studies aim to rule out potential causes or, more often, triggers for seizures. Routine workup for all patients should include EEG and MRI of the brain; most of the time, the results will be normal. A patient with seizures that are difficult to control should be reassessed for a possible alternative diagnosis or temporal lobe epilepsy, using prolonged EEG-video monitoring to record patient events. Lumbar puncture may be indicated for a patient with new-onset seizure when an acute inflammatory or infectious process is being considered, but it is not indicated in patients with chronic epilepsy.

Laboratory studies

Electrolyte levels

Concentrations of antiepileptic drugs, if being used

Consider a urine drug screen

Brain MRI

Used to exclude an obvious structural lesion as the cause

Should include contrast with gadolinium to allow assessment of possible neoplastic and vascular etiologies

MRI with temporal cuts measures hippocampal volumes in assessment for temporal lobe epilepsy

Increased signal on fluid-attenuation inversion recovery (FLAIR) T2-weighted MRI can detect sclerosis of the mesial temporal lobe in 80-90% of cases

Electroencephalography

EEG within 24 hours is more sensitive for diagnosing epileptiform abnormalities than later EEG is (51% sensitivity vs 34%), but it is often impractical

Epileptiform discharges, when present, help localize the seizure focus

A negative interictal EEG does not exclude a diagnosis of epilepsy

If the waking EEG is negative, a sleep-deprived EEG may demonstrate epileptiform abnormalities

See Workup for more detail.

Management

Treatment of focal impaired awareness seizures may involve pharmacologic therapy and, in certain cases, epilepsy surgery.
Special considerations apply to women with childbearing potential.

Anticonvulsant therapy

Treatment with antiepileptic medication should always be initiated once a diagnosis of epilepsy is made

All current antiepileptic drugs (AEDs), with the exception of ethosuximide, can be used in the treatment of complex partial seizures

The best-tolerated AED should be selected for the patient on the basis of side effects and drug interactions

Monotherapy is always initially preferred over polytherapy for treating seizures

High dosages of a single agent may be required to achieve seizure control before adding a second agent

Women of childbearing age should be educated regarding the drug interactions between AEDs and contraceptive therapy

Women who become pregnant and have a history of seizures should be continued on current AED therapy that controls seizures and should not be switched to a secondary agent simply because of pregnancy

Surgical treatment

Epilepsy surgery is indicated for patients who have frequent, disabling seizures despite adequate trials of 2 or more anticonvulsants

Video EEG should be used before surgical referral to qualify events, assess severity, and aid in localization

Surgical procedures include temporal lobectomy, extratemporal resections, corpus callosotomy, placement of a vagus nerve stimulator, hemispherectomy, and multiple subpial transection

See Treatment and Medication for more detail.

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