eMedicine Specialties > Neurology > Seizures and Epilepsy

Simple Partial Seizures

Jane G Boggs, MD, Associate Professor of Neurology, Wake Forest University; Clinical Associate Professor, Virginia Commonwealth University School of Medicine (Medical College of Virginia)

Updated: Sep 3, 2009

Introduction

Background

All partial seizures are characterized by onset in a limited area, or focus, of one cerebral hemisphere. The International Classification of Epileptic Seizures (ICES) classifies simple partial seizures (SPS) as those that are not associated with any impairment of consciousness.¹ Although the ability to respond may be preserved, motor manifestations or anxiety relating to the seizure symptoms may prevent a patient from responding appropriately. The level of consciousness may be difficult to determine during a partial seizure, especially in infants, cognitively impaired individuals, and aphasic patients. The lack of availability of trained persons to interact directly with the patient during and after the seizure can make distinctions between simple and complex partial seizures difficult, even with high-resolution video-EEG.

ICES defines an aura as "that portion of the seizure which occurs before consciousness is lost, and for which memory is retained afterwards." Auras without subsequent seizures should be considered a type of SPS.

Simple partial status epilepticus (SPSE) includes epilepsia partialis continua (ie, Kojewnikoff syndrome). Some researchers also have included periodic lateralized epileptiform discharges (PLEDs) and the spectrum of Landau-Kleffner syndromes as types of SPSE.

Pathophysiology

Any structural lesion of the brain that causes an electrical variation in the surrounding tissue can provide an adequate substrate for epileptogenesis. The epileptogenic zone is the area that generates seizures, but it may in fact be clinically silent. The clinical and EEG manifestations may be due to secondary activation of another cortical area.²

• The anatomical pathways involved in SPS determine the clinical symptoms. SPS may be characterized by motor, sensory, psychic, or autonomic symptoms. Motor or sensory SPS are caused by ictal discharges in the somatotopically representative gyri of the contralateral hemisphere.³
• Sensory or motor symptoms also can be caused by ictal discharges that spread to the sensorimotor cortex from the parietal, occipital, or temporal lobes.

Interestingly, the areas of the cortex with the lowest threshold for electrical stimulation are those that correspond to the body segments most commonly observed to be the regions responsible for motor or sensory SPS. Penfield and Jasper identified the perioral area, thumb, index finger, and great toe as the areas that usually are affected first in partial seizures. These are all anatomical parts having a disproportionately large area of representation in the cortical homunculus.⁴

Psychic SPS are characterized by complex cognitive or affective symptoms, such as déjà vu. They more commonly arise in temporal rather than extratemporal regions. Electrical stimulation experiments have demonstrated that similar psychic manifestations can be elicited from noncontiguous locations.⁵ This suggests that this type of SPS may have a more diffuse rather than a discrete localization. The origin of autonomic SPS is hypothesized to be hypothalamus, and its clinical manifestations are determined by the pattern of activation of the central autonomic network and the higher order autonomic control areas of the insula and prefrontal cortices.⁶

Frequency

United States

Among all seizures, partial seizures have the highest incidence after the first year of life. The incidence of all partial seizures for subjects aged 1-65 years is approximately 20 cases per 100,000 population. Although observational classification studies are imprecise, an estimated 6-12% of patients with epilepsy have SPS exclusively.⁷ The proportions of sensory, motor, special sensory, psychic, and autonomic SPS differ among various population studies, but most agree that SPS are found most frequently in association with other types of seizures.

International

Not enough studies are available to indicate the incidence of SPS as compared with that in the United States. In general, the incidence of epilepsy and the proportion of partial epilepsy are expected to be higher in developing countries because of the higher rates of infection and overall lower standard of health.

Mortality/Morbidity

• The risk for seizure recurrence after a single seizure has been reported to be higher in patients with partial seizures than in those with generalized seizures.
• However, the recurrence rates of simple and complex partial seizures appear to differ little, if at all.
• As accidents and aspiration leading to pneumonia are less common with SPS, morbidity and mortality rates are expected to be lower than in seizures that affect consciousness.
• SPS are frequently the result of symptomatic lesions; the underlying etiology may impart additional risk for morbidity or mortality.
• Individuals with idiopathic, complex partial epilepsy may have a higher survival rate than those with symptomatic epilepsy and SPS.

Race

SPS have no reported predilection for any race or ethnic group.

Sex

Males and females are affected equally.

Age

• The incidence of SPS is lowest in children younger than 1 year and increases gradually up to approximately age 65 years, after which it rises exponentially.
• The increase in SPS corresponds to the increase in all partial seizures with age, particularly those due to cerebrovascular disease.

Clinical

History

The ICES lists 18 categories of SPS. All types of SPS can be seen with subsequent complex partial secondarily generalized seizures. The suspicion of SPS is based on the history of typical, reproducible patterns as outlined here.

• Motor simple partial seizures⁸
  • Clonic discharges in the sensorimotor cortex cause jerky, rhythmic movements that may remain restricted to one body segment or spread by "jacksonian march."
  • Benign focal epilepsy of childhood accounts for 15-25% of childhood epilepsy and eventually remits by age 16 years.
    • Typical seizures are simple and motor, affect the face or arm, and occur soon after falling asleep or awakening.
    • As it usually remits by age 16 years, this syndrome does not always require treatment.
  • Another subtype, epilepsia partialis continua (ie, Kojewnikoff syndrome), includes stereotypical periodic to semiperiodic clonic activity that may persist for years and is often refractory to treatment.⁹
    • Clonic jerking usually involves the thumb or great toe, and may or may not spread to other body parts.
    • This activity has been associated with stroke, tumor, trauma, hypoxia, Rasmussen encephalitis, syndrome of mitochondrial encephalomyopathy, lactic acidosis, and stroke (MELAS), subacute sclerosing panencephalitis (SSPE), and adult nonketotic hyperglycinemia.
  • Tonic-supplementary motor area (SMA) and premotor region discharges produce sustained contractions and unusual postures of a limb.¹⁰
    • In 72% of cases, SMA seizures are not associated with impaired consciousness.
    • Versive-smooth or jerky, tonic contractions of head and eye muscles, usually on the side contralateral to the discharge, often are followed by a secondarily generalized tonic-clonic seizure.
    • Phonatory activation of the primary or supplementary motor cortex produces vocalizations, speech arrest, or aphasia.
• Sensory simple partial seizures³
  • Somatosensory-primary sensory cortex seizures usually elicit positive or negative sensations contralateral to the discharge.
  • Symptoms associated with seizures from the postcentral gyrus include tingling, numbness, pain, heat, cold, agnosia, phantom sensations, or sensations of movement.
  • Abdominal pain usually originates from the temporal lobe, and genital pain from the mesial parietal sensory cortex.
  • The posterior parietal cortex is the likely origin of limb agnosia.
  • Supplemental sensory-secondary sensory cortex seizures may have ipsilateral or bilateral positive or negative sensations or vague axial or diffuse sensations.
  • Visual-calcarine cortex discharges produce elemental hallucinations including scintillations, scotomata, colored lights, visual field deficits, or field inversion.
  • The visual association cortex is the probable location of origin of complex visual hallucinations and photopsias.
  • Auditory SPS from the auditory cortex typically are perceived as simple sounds, rather than words or music.
  • Olfactory-uncinate seizures originate from the orbitofrontal cortex and the mesial temporal area. Perceived odors are usually unpleasant, often with a burning quality.
  • Gustatory seizures usually are associated with temporal lobe origin, although the insula and parietal operculum also have been implicated. Perceived tastes are typically unpleasant, often with a metallic component.
  • Vestibular seizures originate from various areas, including frontal and temporal-parietal-occipital junction. Symptoms include vertigo, a tilting sensation, and vague dizziness.
  • Psychic SPS arise predominantly from the temporal and limbic region, including the amygdala, hippocampus, and parahippocampal gyrus. Perceptual hallucinations or illusions are usually complex, visual or auditory, and are rarely bimodal.
    • Includes the déjà vu and jamais vu phenomena
    • Emotional: Fear is usual, but SPS can elicit happiness, sexual arousal, anger, and similar responses.
    • Cognitive: These responses include feelings of depersonalization, unreality, forced thinking, or feelings that may defy description.
• Autonomic simple partial seizures¹¹
  • Abdominal sensation phenomena
    • These are common in mesial temporal epilepsy but can arise from the operculum and occipital region.
    • Symptoms include nausea, pain, hunger, warmth, and "epigastric rising" sensations, and may be associated with piloerection (ie, gooseflesh).
  • Cardiovascular sensations¹²
    • The most common cardiac manifestation of any seizure is sinus tachycardia with arrhythmias, with bradycardia occurring infrequently.
    • Some patients have chest pain or a sensation of palpitation that mimics cardiac disease.
    • Respiratory inhibition has been reported with electrical stimulation of the temporal regions.¹³
  • Pupillary symptoms - Miosis, mydriasis, hippus, and unilateral pupillary dilatation
  • Urogenital symptoms
    • Seizures from the superior portion of the posterior central gyrus can result in genital sensations, while sexual auras arise more from the limbic or temporal regions.
    • Ictal orgasms have been reported, although rarely, in association with seizures arising from various cerebral locations.¹⁴
  • Other autonomic symptoms - Rarely perspiration, lacrimation, ictal enuresis, or flushing
• Postictal neurological deficits can occur after an SPS as a negative manifestation of the function affected by the seizure (eg, Todd paralysis).

Physical

The physical examination may show subtle or obvious neurological focality.

• Immediately following a SPS, the focality may become more pronounced owing to postictal inhibition (eg, Todd paralysis).
• If an examination is performed during a SPS, no impairment of awareness or responsiveness is observed.
  • Preservation of awareness implies that a person is able to recount simple events that happen during the ictus. This is best established by giving a specific, uncommon 2-syllable word to the patient during the SPS and asking for its recall soon after the seizure has resolved.
  • Preservation of responsiveness implies that a person is able to carry out simple commands or directed volitional actions.
  • Responsiveness may appear to be impaired because of interference by the motor manifestations of the SPS.
  • This is best established by asking the patient to perform simple, unilateral and bilateral neurological functions during the SPS.
  • If the patient is unable to perform a task because of the manifestations of the SPS, recollection of the instructions implies responsiveness was preserved.
• Motor, sensory, special sensory, psychic, and autonomic manifestations may begin in a small anatomical area and spread to a larger area of the body. This has been termed as "jacksonian march," and it typically progresses along contiguous parts of the body in a reproducible pattern.

Causes

Any localized structural lesion of the brain can result in SPS, including the following:

• Developmental abnormalities
• Vascular lesions
• Meningitis/focal encephalitis
• Trauma
• Tumors
• Hypoxic insults
• Postsurgical changes
• Metabolic and electrolyte shifts
• Endocrine disorders
• Medications and toxins

Differential Diagnoses

Other Problems to Be Considered

Atypical facial pain
Benign epilepsy syndromes
Brainstem syndromes
Carcinoid syndrome
Cardiac disorders
Cervical disk syndromes
Gastrointestinal disorders
Hypoglycemic episodes
Transient ischemic attacks (TIAs)
Migraines
Myoclonus
Panic attacks
Psychosis

Workup

Laboratory Studies

• Electrolytes including serum glucose
• Thyroid-stimulating hormone and/or thyroid profile
• Toxin and drug screen

Imaging Studies

CT scan of the brain, with and without contrast, is primarily useful and appropriate in an emergency setting or for patients unable to have MRI studies. Coronal T2-weighted MRI with fluid-attenuated inversion recovery (FLAIR) and careful attention to the mesial temporal structures is more likely to demonstrate abnormalities if a diagnosis of SPS already has been established. Low resolution MRI, under 1.5 T, should be discouraged in any evaluation of epilepsy. This typically makes the use of "open MRI" inadequate.

Other Tests

• Electroencephalography
  • EEGs fortuitously obtained during the patient's symptoms can provide clear support for a diagnosis.
  • EEGs obtained soon after a suspected seizure often record nonspecific patterns or may be normal.
  • Activation by sleep deprivation, photic stimulation, and/or hyperventilation increases the ability to detect abnormalities on a single recording. Repeat or prolonged recording may increase the chance of recording interictal or ictal patterns of diagnostic significance.
  • Although interictal spikes in an appropriate anatomical location for the symptoms of the suspected seizure are highly suggestive of epilepsy, they may be distant in location from the actual area of seizure onset, giving poor localizing information for possible epilepsy surgery.
  • Single or rare interictal sharp waves may be normal variants, and further diagnostic confirmation should be pursued.
  • Normal EEG findings do not exclude the possibility of epilepsy.
• Video-EEG
  • Video-EEG is often necessary to record typical clinical events and to correlate them with any electrographic changes.
  • Many SPS are characterized by EEG patterns that are difficult to record, and the diagnosis may depend entirely on video analysis of reproducible ictal semiology of multiple events, or on observation by trained personnel.
• EEG performed with extra scalp electrodes or intracranial electrodes is necessary if involvement of mesial structures is suspected.
• Routine 12-lead ECG and a rhythm strip should be obtained in all subjects with cardiac, thoracic, gastrointestinal, or focal positive and negative sensations.
• Twenty-four–hour Holter monitoring and inpatient telemetry are appropriate if daily episodes are expected (based on history).
• A telephone transmittal cardiac recorder can be useful for episodes occurring infrequently.

Procedures

• Lumbar puncture should be performed in all cases of suspected meningitis, unless neuroimaging or funduscopic examination suggests increased intracranial pressure.
• Brain biopsy is strongly suggested to confirm the diagnosis in suspected cases of Rasmussen encephalitis, or in focal progressive lesions of unknown etiology.

Histologic Findings

• Various microscopic abnormalities, including the following, can be found in the epileptogenic zone:
  • Focal cortical dysplasia
  • Hippocampal sclerosis
  • Neoplasia
  • Cortical inflammation
  • Encephalomalacia
  • Vascular malformation

Treatment

Medical Care

• Numerous antiepilepsy drugs (AEDs) currently are approved worldwide with indications for SPS, and others are in development.
• No one drug of choice is recommended for SPS, since in clinical trials all the drugs have demonstrated similar levels of efficacy.
• Selection of the most appropriate medication is based on potential side effects, dosing schedules, available formulations, and individual factors.^{15,16,17,18,19}
• Benign focal epilepsy of childhood is usually a self-limited condition; if no seizures with secondarily generalization occur, patient care need not include AEDs.

Surgical Care

• Patients with medically refractory seizures may be candidates for epilepsy surgery, especially if they have a well-localized seizure onset documented by video-EEG and a corresponding lesion on neuroimaging. Such cases should be carefully evaluated preoperatively with the resection properly planned by the epilepsy surgical team to minimize the risk of postoperative deficit.
• Focal cortical resection, amygdalo-hippocampectomy, lesionectomy, or gamma knife surgery may be the most appropriate procedure. The specific procedure should be tailored individually to the features of each case.
• Rasmussen encephalitis responds poorly to medical treatment and usually is treated by hemispherectomy to prevent involvement of the contralateral hemisphere.
• Patients whose seizures are medically refractory but are not good candidates for epilepsy surgery may be candidates for implantation of a vagal nerve stimulator (VNS).

Consultations

• Cardiac, gastrointestinal, psychiatric, or endocrine consultation, depending on individual cases, may be necessary in diagnostically difficult cases.
• Psychiatric consultation may be necessary for management of concurrent depression, anxiety, and/or non-epileptic events.

Diet

• Although a ketogenic diet has been used successfully in refractory seizures, it is not used commonly for patients exhibiting SPS exclusively (except children) who are not responding to medication.²⁰
• The medium-chain triglyceride diet is more convenient and palatable, and does not result in hypercholesterolemia, although it appears to be less successful in the treatment of refractory seizures.²¹ The Atkins diet has also been reported to have some adjunctive benefit to some patients with refractory seizures.²²

Activity

• As SPS do not impair consciousness, activity may not need to be restricted severely as with other types of seizures.
• Compliant patients with a consistent, exclusively SPS pattern, which does not interfere with the ability to manipulate the controls of a motor vehicle, are allowed legally to drive in states in which the motor vehicle authority approves exceptions to complete seizure control. Compliance with state guidelines may require self-reporting by patients or specific documentation of patient symptoms, compliance, and medications by the treating physician.
• The safety of swimming and other potentially hazardous recreational or employment activities should be evaluated on an individual basis.
• The ability to care for infants in an unsupervised setting should be evaluated on an individual basis.

Medication

Many anticonvulsants currently are approved by the US Food and Drug Administration (FDA) for partial seizures with and without secondary generalization. These drugs have approval for treatment of SPS as well. No single agent is the drug of choice for SPS.

Anticonvulsants

These agents prevent seizure recurrence and terminate clinical and electrical seizure activity.

Carbamazepine (Tegretol, Tegretol-XR, Carbatrol, Epitol)

Tricyclic compound extensively metabolized to active metabolite, CBZ-epoxide. Markedly induces its own metabolism and highly bound to plasma proteins. Available as 100 mg/mL susp; 100 mg chewable tab; 200 mg tab; 100, 200, and 400 mg delayed-release tab (Tegretol-XR); 200, 300 mg extended-release capsules (Carbatrol).

Dosing

Adult

8-20 mg/kg/d PO bid/qid (all formulations—susp, chewable, or tab)

Pediatric

10-35 mg/kg/d PO bid/qid (all formulations—susp, chewable, or tab)

Interactions

Decreases estrogen and progestin plasma concentrations with concurrent use of oral contraceptives; also decreases levels of cyclosporin, corticosteroids, protease inhibitors, theophylline, tricyclic antidepressants, antipsychotics, and warfarin
May increase danazol levels significantly within 30 days of coadministration (avoid whenever possible); do not coadminister with MAOIs; cimetidine may increase toxicity, especially if taken in first 4 wk of therapy; may decrease primidone and phenobarbital levels—either may increase carbamazepine level; propoxyphene, macrolides may increase carbamazepine levels

Contraindications

Documented hypersensitivity; concurrent MAOIs

Precautions

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Common adverse effects include drowsiness, dizziness, diplopia, ataxia, blurry vision, osteopenia, peripheral neuropathy, hyponatremia, and alopecia
Idiosyncratic adverse effects include skin rash, hepatotoxicity, and rarely blood dyscrasias; caution with increased intraocular pressure; obtain CBCs and serum iron baseline prior to treatment, during first 2 months, and yearly or every other year thereafter; caution while driving or performing other tasks requiring alertness

Divalproex sodium (Depacon, Depakene, Depakote, Depakote-ER)

Branched chain fatty acid that undergoes oxidative metabolism and is highly protein bound. Amount of protein binding increases with dose. Available as 250 mg/5 mL syr; 250 mg capsules; 125 mg sprinkle capsules; 125, 250, 500 mg delayed-release tab; 250 and 500 mg extended-release tab, 100 mg/mL injectable solution.

Dosing

Adult

Initial dose: 5-15 mg/kg/d PO
Maintenance dose: 15-60 mg/kg/d PO bid/qid

Pediatric

15-60 mg/kg/d PO bid/qid

Interactions

Cimetidine, salicylates, felbamate, and erythromycin may increase toxicity; rifampin may significantly reduce levels; in children, salicylates decrease protein binding and metabolism; may result in variable changes of carbamazepine concentrations with possible loss of seizure control; may increase diazepam and ethosuximide toxicity (monitor closely); may increase phenobarbital and phenytoin levels while either may decrease valproate levels; may displace warfarin from protein-binding sites (monitor coagulation tests); salicylates displace valproate from plasma protein-binding sites; methylphenidate may increase toxicity; may increase zidovudine levels

Contraindications

Documented hypersensitivity; preexisting hepatotoxicity; age <2 y

Precautions

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Common adverse effects include nausea, vomiting, drowsiness, tremor, dizziness, alopecia, weight gain, and thrombocytopenia at high serum concentrations
Idiosyncratic adverse effects include hepatotoxicity (especially children aged <2 y), pancreatitis, and blood dyscrasias
Thrombocytopenia and abnormal coagulation parameters have occurred—risk of thrombocytopenia increases significantly at total trough plasma concentrations >110 mcg/mL in females and 135 mcg/mL in males; at periodic intervals and prior to surgery, determine platelet counts and bleeding time before initiating therapy; reduce dose or discontinue therapy if hemorrhage, bruising, or hemostasis/coagulation disorder occur; hyperammonemia may occur, resulting in hepatotoxicity; monitor patients closely for appearance of malaise, weakness, facial edema, anorexia, jaundice, and vomiting

Gabapentin (Neurontin)

Saturable gastric absorption with virtually no protein binding and no metabolism, primarily renal excretion. Available as 100, 300, 400 mg capsules, and 600 mg and 800 mg tab, and 50 mg/mL solution.

Dosing

Adult

300-1200 mg PO tid

Pediatric

30-60 mg/kg/d PO tid

Interactions

Antacids may reduce bioavailability significantly (administer at least 2 h following antacids)

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Common adverse effects include fatigue, somnolence, dizziness, ataxia, ankle swelling, and mild weight gain; caution in severe renal disease

Lamotrigine (Lamictal)

Hepatically metabolized, moderate protein binding, with shorter half-life in presence of enzyme-inducing compounds. Available as 2, 5, and 25 mg dispersible tab; 25, 100, 150, and 200 mg tab.

Dosing

Adult

With valproic acid: 200 mg PO qd
Without valproic acid: 300-500 mg/d PO bid

Pediatric

With valproic acid: 1-5 mg/kg/d PO qd or divided bid
Without valproic acid: 5-15 mg/kg/d PO qd or divided bid

Interactions

Oral contraceptives may decrease lamotrigine levels; acetaminophen increases renal clearance, decreasing effects; similarly, phenobarbital and phenytoin increase metabolism, causing decrease in levels; valproic acid increases half-life

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Common adverse effects include dizziness, ataxia, sedation, diplopia, and nausea
Idiosyncratic adverse effects include skin rash (risk of Stevens-Johnson especially increased in children, polytherapy with valproic acid, and with rapid dose titration), hepatotoxicity, and blood dyscrasias
Caution in impaired renal or hepatic function

Phenobarbital (Barbital, Luminal, Solfoton)

Highly metabolized, moderately protein bound with very long half-life and linear kinetics. Available as 16 mg capsule; 15, 20 mg/5 mL elixir; 15, 30, 60, 100 mg tab; 30 mg/mL, 60 mg/mL, 130 mg/mL injectable solution (all contain 69% propylene glycol).

Dosing

Adult

Loading dose: 10-20 mg/kg PO qd
Maintenance dose: 1-3 mg/kg/d PO qd

Pediatric

Neonates: 3-4 mg/kg/d PO qd
<12 years: 3-7 mg/kg/d PO qd/bid

Interactions

May decrease effects of chloramphenicol, digoxin, corticosteroids, carbamazepine, theophylline, verapamil, metronidazole, and anticoagulants (patients whose coagulation tests are stabilized on anticoagulants may require dosage adjustments if added to or withdrawn from their regimen); alcohol may produce additive CNS effects and death; chloramphenicol, valproic acid, and MAOIs may increase toxicity; rifampin may decrease effects; induction of microsomal enzymes may result in decreased effects of oral contraceptives in women (must use additional contraceptive methods to prevent unwanted pregnancy; menstrual irregularities may also occur)

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Adverse effects include sedation, dizziness, mood change, insomnia, hyperkinesias, cognitive dysfunction, osteomalacia, Dupuytren contracture, frozen shoulder, and decreased libido
Idiosyncratic adverse effects include skin rash, hepatotoxicity, and blood dyscrasias
In prolonged therapy, evaluate hematopoietic, renal, hepatic, and other organ systems; caution in fever, hyperthyroidism, diabetes mellitus, and severe anemia, since adverse reactions can occur; caution in myasthenia gravis and myxedema

Phenytoin (Dilantin, Phenytek)/ Fosphenytoin (Cerebyx)

Poorly soluble compound, highly protein bound, metabolized by cytochrome P-450 system, and has nonlinear pharmacokinetics.
Available as 125 mg/5 mL susp; 50 mg chewable tab; 30 mg capsules; 100 mg capsules; 50 mg/mL injectable phenytoin solution (contains propylene glycol).
Fosphenytoin is phosphorylated phenytoin, a prodrug that is highly soluble and converted rapidly to phenytoin; 50 mg phenytoin equivalent per mL solution (fosphenytoin).

Dosing

Adult

Loading dose: 15-20 mg/kg PO; 10-20 mg/kg IV PE
Maintenance dose: 4-5 mg/kg/d PO qd/tid

Pediatric

4-7 mg/kg/d PO

Interactions

Amiodarone, benzodiazepines, chloramphenicol, cimetidine, disulfiram, ethanol (acute ingestion), omeprazole, phenacemide, phenylbutazone, succinimides, fluconazole, isoniazid, metronidazole, miconazole, sulfonamides, trimethoprim, and valproic acid may increase toxicity; phenytoin decreases efficacy of oral contraceptives

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Death from cardiac arrest has occurred after too-rapid IV administration of phenytoin, preceded sometimes by marked QRS widening (not reported with fosphenytoin)
Blood dyscrasias have occurred and thus blood counts and urinalysis should be done when therapy is begun and at monthly intervals for several months thereafter; discontinue use if skin rash appears—do not resume use if rash is exfoliative, bullous, or purpuric; administer cautiously to patients with acute intermittent porphyria; exercise caution when administering to patients with diabetes, may raise blood glucose levels; discontinue drug if hepatic dysfunction occurs

Primidone (Mysoline)

Metabolized to phenobarbital and phenylethylmalonamide (PEMA), which also possesses some weak anticonvulsant activity. Available as 250 mg/5 mL susp; 50, 250 mg tab.

Dosing

Adult

250-2000 mg PO tid

Pediatric

10-25 mg/kg/d PO tid

Interactions

Valproic acid increases toxicity; may decrease serum concentrations of ethosuximide, griseofulvin, valproic acid; phenytoin may decrease serum levels

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Common adverse effects include sedation, dizziness, mood change, insomnia, hyperkinesias, cognitive dysfunction, osteomalacia, Dupuytren contracture, frozen shoulder, and decreased libido
Idiosyncratic adverse effects include skin rash, hepatotoxicity, and blood dyscrasias

Tiagabine (Gabitril)

GABA reuptake inhibitor, with its metabolism enhanced by cytochrome P-450 inducers. Highly protein bound. Available as 2, 4, 12, and 16 mg tab.

Dosing

Adult

32-56 mg/d PO bid/qid

Pediatric

4-32 mg/kg/d PO bid/qid

Interactions

Cleared more rapidly in patients treated with carbamazepine, phenytoin, primidone, or phenobarbital than in patients who have not received these drugs

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Common adverse effects include dizziness, asthenia, sedation, nervousness, irritability, and tremor, "knee-buckling"
Patients receiving valproate monotherapy may require lower doses or slower dose titration of tiagabine for clinical response; moderately severe to incapacitating generalized weakness has been reported following administration of tiagabine in as many as 1% of patients with epilepsy—weakness may resolve after reduction in dose or discontinuation; should be withdrawn slowly to reduce potential for increased seizure frequency; possible nonconvulsive status epilepticus in patients noted to have new altered mental status; can trigger seizures in nonepileptic patients

Topiramate (Topamax)

Undergoes moderate hepatic metabolism, and excreted largely by kidneys. Has low protein binding. Available as 15, 25 mg sprinkle capsules; 25, 100, and 200 mg tab.

Dosing

Adult

200-600 mg/d PO bid

Pediatric

1-9 mg/kg/d PO bid

Interactions

Phenytoin, carbamazepine, and valproic acid can decrease levels significantly; reduces digoxin and norethindrone levels; CNS depressants may have additive effect as well as other adverse cognitive or neuropsychiatric events, use with caution

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Common adverse effects include sedation, fatigue, psychomotor slowing, difficulty in concentrating, confusion, paresthesias, weight loss
Risk of developing kidney stone increased 2-4 times that of untreated population; risk may be reduced by increasing fluid intake; caution in renal or hepatic impairment; carbonic anhydrase inhibitor chemistry also increases risk of angle-closure glaucoma, mild metabolic acidosis, and oligohidrosis

Oxcarbazepine (Trileptal)

The pharmacological activity of oxcarbazepine is primarily performed by the 10-monohydroxy metabolite (MHD) of oxcarbazepine. May block voltage-sensitive sodium channels, inhibit repetitive neuronal firing, and impair synaptic impulse propagation. Anticonvulsant effect may also occur by affecting potassium conductance and high-voltage activated calcium channels.
Drug pharmacokinetics are similar in older children (>8 y) and adults. Young children ( <8 y) have a 30-40% increased clearance compared with older children and adults. Available as 150-, 300-, and 600-mg tab and 300 mg/5 mL solution.

Dosing

Adult

600-2400 mg/d PO bid

Pediatric

6-50 mg/kg/d PO bid

Interactions

May decrease levels of dihydropyridine calcium antagonists and oral contraceptives; can reduce serum concentrations of carbamazepine, phenobarbital, phenytoin, and valproic acid; when oxcarbazepine is given in doses above 1200 mg/d, may increase phenytoin and phenobarbital serum concentrations significantly; oxcarbazepine may reduce serum concentrations of oral contraceptives; can increase clearance of felodipine

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Can cause cognitive side effects; in persons with impaired renal function (creatinine clearance <30 mL/min), oxcarbazepine dose should begin at one-half usual starting dose; dose increments should be made more slowly; oxcarbazepine can cause hyponatremia (sodium <125 mmol/L); among persons with hypersensitivity to carbamazepine, 25-30% will have hypersensitivity to oxcarbazepine; rapid withdrawal of oxcarbazepine can cause exacerbation of seizures; observe for side effects and monitor plasma levels of concomitant anticonvulsants during dose titration; idiosyncratic reactions reported (serious skin rash and hypersensitivity syndrome)

Levetiracetam (Keppra)

Mechanism of action is unknown. Approved for adjunctive use in partial epilepsy. Available as 250-, 500-, 750-, and 1000-mg tab and 100 mg/mL solution.

Dosing

Adult

1-3 g/d PO bid

Pediatric

10-30 mg/kg/d PO bid

Interactions

None reported

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in renal impairment; major side effects include somnolence, asthenia, incoordination, mild leukopenia (3%), and behavioral changes such as anxiety, hostility, emotional lability, depression and psychosis (1-2%), and depersonalization

Zonisamide (Zonegran)

Indicated for adjunctive treatment of partial seizures with or without secondary generalization. Available as 25-, 50-, and 100-mg sprinkle cap. There is evidence that it is effective in myoclonic and other generalized seizure types as well.

Dosing

Adult

200-600 mg/d PO qd

Pediatric

2-12 mg/kg/d PO bid

Interactions

May increase serum carbamazepine levels; carbamazepine may increase zonisamide concentrations; phenobarbital may decrease zonisamide levels

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

May cause drowsiness, weight loss, ataxia, nausea, and slowing of mental activity
As carbonic anhydrase inhibitor can increase risk of renal stones and oligohidrosis

Pregabalin (Lyrica)

Structural derivative of GABA. Mechanism of action unknown. Binds with high affinity to alpha₂ -delta site (a calcium channel subunit). In vitro, reduces calcium-dependent release of several neurotransmitters, possibly by modulating calcium channel function. FDA approved for neuropathic pain associated with diabetic peripheral neuropathy or postherpetic neuralgia and as adjunctive therapy in partial-onset seizures.
Available as 25, 50, 75, 100, 150, 200, 225, 300 mg capsules

Dosing

Adult

150-600 mg/d PO divided bid/tid; initially 50 mg PO tid or 75 mg PO bid, if needed, may increase dose to maximum of 600 mg/d

Pediatric

Not established

Interactions

May cause additive effects on cognitive and gross motor functioning when coadministered with drugs that cause dizziness or somnolence

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Discontinue gradually (over a minimum of 1 wk) to minimize increased seizure frequency in patients with seizure disorders; may cause insomnia, nausea, headache, or diarrhea with abrupt withdrawal; common adverse effects include dizziness, somnolence, blurred vision, weight gain, and peripheral edema; may elevate creatinine kinase level, decrease platelet count, and increase PR interval; doses >300 mg/d associated with higher rate of adverse effects and treatment discontinuation; decrease dose with renal impairment (ie, CrCl <60 mL/min)

Lacosamide (Vimpat)

Selectively enhances slow inactivation of voltage-gated sodium channels, resulting in stabilization of hyperexcitable neuronal membranes and inhibition of repetitive neuronal firing. Indicated for adjunctive therapy for partial onset seizures.

Dosing

Adult

50 mg PO bid initially; may increase at weekly intervals in 100-mg/d increments to a daily dose range of 200-400 mg/d
Switching from PO to IV: Initial total daily IV dose should be equivalent to total daily PO dose and infused IV over 30-60 min; also may divide total daily dose bid for up to 5 d
Switching from IV to PO: Switch to PO administration at equivalent daily dosage and frequency of IV administration
CrCl <30 mL/min: Not to exceed 300 mg/d
Mild-to-moderate hepatic impairment: Not to exceed 300 mg/d
Hemodialysis: Supplement with 50% of dose following 4-h hemodialysis

Pediatric

<17 years: Not established
>17 years: Administer as in adults

Interactions

Data limited; CYP2C19 substrate; caution if coadministered with other drugs that affect heart conduction (eg, antiarrhythmic agents, drugs that increase PR interval)

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in patients with suicidal ideation and monitor for emergence or worsening of depression, suicidal thoughts or behavior, or unusual changes in mood or behavior; common adverse effects (>10%) include diplopia, headache, dizziness, and nausea; dose-dependent prolongation of PR interval may occur; patients with diabetic neuropathy may experience atrial fibrillation, atrial flutter, or syncope; warn patients that dizziness or ataxia may occur and to not abruptly discontinue drug; as with all antiepileptic drugs, withdraw gradually (over minimum of 1 wk) to decrease risk of increased seizure activity; 1 case of multiorgan hypersensitivity reaction observed (n=4011); shown in rats during neonatal and juvenile rats to interfere with CRMP-2 activity (protein involved in neuronal differentiation and axonal outgrowth) activity

Follow-up

Further Inpatient Care

• Patients diagnosed with SPS may require follow-up inpatient care if new patterns of seizures develop.
• EEG or video-EEG studies are often necessary to clarify the nature of the new seizure type.
• Neuroimaging and laboratory studies may help in identifying reasons for seizure exacerbations.
• Medications usually can be adjusted more quickly in inpatients, and hospitalization in a video-EEG-monitoring unit optimizes the safety of rapid adjustment in the doses of medication.

Further Outpatient Care

• At least monthly outpatient follow-up is recommended when seizures are not well controlled.
• As seizure control improves, the interval between evaluations can be increased.
• Seizure-free patients may be monitored by a neurologist once or twice annually.
• Outpatient laboratory studies should be performed to monitor metabolic effects of the medications used to treat SPS, and to monitor underlying medical conditions.
• AED levels should be performed when toxicity is suspected, or to confirm adequate compliance or absorption of medications. In the absence of side effects of medication, metabolic changes, or breakthrough seizures, routine monitoring of AED levels usually is not justified.

Prognosis

• The prognosis of patients with SPS is similar to that of patients with complex partial seizures.
• Poorly controlled seizures can result in chronic neurological and cognitive complications, the severity of which is largely dependent on the underlying etiology of the seizures.
• As consciousness is preserved throughout the ictal event, patients with SPS are less likely to suffer from epilepsy-related injuries.
• However, focal motor SPS still can result in falls and risk of trauma.

Patient Education

• Patients with SPS have the same requirement for education concerning epilepsy as those individuals with other seizure types.
• SPS can be mimicked by many other disorders, and reassurance about the diagnosis may be necessary.
• Education should not be limited only to the patients, but should include family members, caretakers, and employers to limit unnecessary stigmatization and discrimination.

Miscellaneous

Medicolegal Pitfalls

• The greatest medical/legal pitfall for SPS is in the potential for a misdiagnosis.
• Video-EEG is extremely helpful to avoid treating the wrong condition.
• Disability applications, child-custody hearings, and driving restrictions are dependent on a correct diagnosis. Only some state laws allow patients with SPS to drive without a formal medical review by that state.

Special Concerns

• Although often perceived to be less severe than complex partial and generalized seizures, SPS in pregnancy can be associated with fetal distress.
• Every effort must be made to control seizures during pregnancy by using appropriate doses of the most successful agent for the individual. If possible, avoid AED drug changes.

References

1. Gastaut H, Gastaut JL, Goncalves e Silva GE, et al. Relative frequency of different types of epilepsy: a study employing the classification of the International League Against Epilepsy. Epilepsia. Sep 1975;16(3):457-61. [Medline].

2. Salanova V, Van Ness PC, Andermann F. Frontal, parietal and occipital epilepsies. In: Wyllie E, ed. The Treatment of Epilepsy: Principles and Practice. 2nd ed. Baltimore: Williams & Wilkins;. 1997:423-431.

3. Ajmone-Marsan C, Goldhammer L. Clinical ictal patterns and electrographic data in cases of partial seizures of fronto-central-parietal origin. In: Epilepsy, its Phenomenon in Man. San Diego, Calif: Academic Press; 1973:. 235-58.

4. Penfield W, Jasper H. In: Epilepsy and the Functional Anatomy of the Human Brain. Boston: Little Brown;. 1954:15-33.

5. Fish DR, Gloor P, Quesney FL, Olivier A. Clinical responses to electrical brain stimulation of the temporal and frontal lobes in patients with epilepsy. Pathophysiological implications. Brain. Apr 1993;116 ( Pt 2):397-414. [Medline].

6. Benarroch EE. The central autonomic network: functional organization, dysfunction, and perspective. Mayo Clin Proc. Oct 1993;68(10):988-1001. [Medline].

7. Hauser WA, Annegers JF, Kurland LT. Incidence of epilepsy and unprovoked seizures in Rochester, Minnesota: 1935-1984. Epilepsia. May-Jun 1993;34(3):453-68. [Medline].

8. Kotagal P, Luders H. Simple motor seizures. In: Engel J Jr, Pedley TA, eds. Epilepsy: A Comprehensive Textbook. Philadelphia: Lippincott-Raven;. 1998:525-532.

9. Blume WT. Focal motor seizures and epilepsia partialis continua. In: Wyllie E, ed. The Treatment of Epilepsy: Principles and Practice. 2nd ed. Baltimore: Williams & Wilkins;. 1997.

10. Bleasel AF, Morris III HF. Supplementary sensorimotor are seizures. In: Wyllie E, ed. The Treatment of Epilepsy: Principles and Practice. 2nd ed. Baltimore: Williams & Wilkins;. 1997:432-441.

11. Liporace JD, Sperling MR. Simple autonomic seizures. In: Engel J Jr, Pedley T, eds. Epilepsy: A Comprehensive Textbook. Philadelphia: Lippincott-Raven: 1998:. 549-56.

12. Keilson MJ, Hauser WA, Magrill JP. Electrocardiographic changes during electrographic seizures. Arch Neurol. Nov 1989;46(11):1169-70. [Medline].

13. Kaada BR, Jasper H. Respiratory responses to stimulation of the temporal pole, insula and hippocampal and limbic gyri in man. J Neurophysiol. 1949;12:385.

14. Calleja J, Carpizo R, Berciano J. Orgasmic epilepsy. Epilepsia. Sep-Oct 1988;29(5):635-9. [Medline].

15. French JA, Kanner AM, Bautista J, et al. Efficacy and tolerability of the new antiepileptic drugs I: treatment of new onset epilepsy: report of the Therapeutics and Technology Assessment Subcommittee and Quality Standards Subcommittee of the American Academy of Neurology and the American Epilep. Neurology. Apr 27 2004;62(8):1252-60. [Medline].

16. French JA, Kanner AM, Bautista J, et al. Efficacy and tolerability of the new antiepileptic drugs II: treatment of refractory epilepsy: report of the Therapeutics and Technology Assessment Subcommittee and Quality Standards Subcommittee of the American Academy of Neurology and the American Epil. Neurology. Apr 27 2004;62(8):1261-73. [Medline].

17. Glauser T, Ben-Menachem E, Bourgeois B, et al. ILAE treatment guidelines: evidence-based analysis of antiepileptic drug efficacy and effectiveness as initial monotherapy for epileptic seizures and syndromes. Epilepsia. Jul 2006;47(7):1094-120. [Medline].

18. Karceski S, Morrell M, Carpenter D. The Expert Consensus Guideline Series: Treatment of Epilepsy. Epilepsy Behav. 2001;2:A1-A50.

19. Karceski S, Morrell MJ, Carpenter D. Treatment of epilepsy in adults: expert opinion, 2005. Epilepsy Behav. Sep 2005;7 Suppl 1:S1-64; quiz S65-7. [Medline].

20. Witrow CD. The ketogenic diet: mechanisms of anticonvulsant action. In: Glaser GH, Penry JK, Woodbury DM, eds. Symposium on Mechanisms of Action of Antiepileptic Drugs, St. Louis, Missouri, 1977. New York: Raven Press,. 1980; 27;635-642.

21. Huttenlocher PR, Wilbourn AJ, Signore JM. Medium-chain triglycerides as a therapy for intractable childhood epilepsy. Neurology. Nov 1971;21(11):1097-103. [Medline].

22. Kossoff, Eric H and Dorward, Jennifer L. The Modified Atkins Diet. Epilepsia. Nov 2008;49 (suppl. 8):37-41.

Keywords

focal seizures, simple localization-related epilepsy, SPS, epilepsy, simple partial status epilepticus, SPSE, epilepsia partialis continua, Kojewnikoff syndrome, periodic lateralized epileptiform discharges, PLEDs, Landau-Kleffner syndromes, epileptogenic zone, partial seizures, simple partial seizures

Contributor Information and Disclosures

Author

Jane G Boggs, MD, Associate Professor of Neurology, Wake Forest University; Clinical Associate Professor, Virginia Commonwealth University School of Medicine (Medical College of Virginia)
Jane G Boggs, MD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, American Epilepsy Society, and Stroke Council of the American Heart Association
Disclosure: Abbott Grant/research funds Speaking and teaching; GSK Honoraria Speaking and teaching; Pfizer Honoraria Speaking and teaching

Medical Editor

Joseph F Hulihan, MD, Vice President, Medical Affairs, Ortho-McNeil Janssen Scientific Affairs, LLC
Joseph F Hulihan, MD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, American Epilepsy Society, American Headache Society, and American Medical Association
Disclosure: Johnson & Johnson Salary Employment; Johnson & Johnson Stock Employment

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Selim R Benbadis, MD, Professor, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida School of Medicine, Tampa General Hospital
Selim R Benbadis, MD is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Clinical Neurophysiology Society, American Epilepsy Society, and American Medical Association
Disclosure: Nothing to disclose.

CME Editor

Matthew J Baker, MD, Consulting Staff, Collier Neurologic Specialists, Naples Community Hospital
Matthew J Baker, MD is a member of the following medical societies: American Academy of Neurology
Disclosure: Nothing to disclose.

Chief Editor

Selim R Benbadis, MD, Professor, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida School of Medicine, Tampa General Hospital
Selim R Benbadis, MD is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Clinical Neurophysiology Society, American Epilepsy Society, and American Medical Association
Disclosure: Nothing to disclose.

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