Frontal lobe epilepsy is characterized by recurrent seizures arising from the frontal lobes. Frequently, seizure types are focal onset with preserved or impaired awareness, often with progression to bilateral tonic-clonic activity.
Time of day is an important characteristic for seizures originating in the frontal lobe. Compared to temporal lobe seizures, seizures arising from the frontal lobe are more likely to occur between 12 am and 12 pm.[1] A frontal lobe seizure is often the seizure type most difficult to diagnose as it can be easily mistaken for a parasomnia or nonepileptic event. The following features help to distinguish frontal lobe seizures from nonepileptic events:
Other semiologic findings may vary according to the specific part of the frontal lobe involved at the onset:
Physical examination in focal lobe epilepsy is typically normal but may reveal signs suggestive of syndromes or structural lesions that may be associated with epilepsy, such as the following:
See Clinical Presentation for more detail.
For new-onset seizures, blood tests should be performed to rule out a metabolic cause (eg, hyperglycemia). For patients with an established diagnosis of epilepsy, blood testing for complications may include the following:
Brain imaging
Electroencephalography
See Workup for more detail.
Antiseizure therapy should be initiated once the diagnosis of epilepsy is established. Many nocturnal seizures with prominent motor manifestations respond extremely well to carbamazepine. Monotherapy is desirable, but some patients require polytherapy.
Patients with medically intractable epilepsy should be considered for resective epilepsy surgery. Other treatment options include the following:
See Treatment and Medication for more detail.
Frontal lobe epilepsy is characterized by recurrent seizures arising from the frontal lobes. Frequently, seizure types are focal onset with preserved or impaired awareness, often with progression to bilateral tonic-clonic activity. Clinical manifestations tend to reflect the specific area of seizure onset or early propagation and range from behavioral to motor or tonic/postural changes.
Frontal lobe epilepsy frequently overlaps with sleep-related hypermotor epilepsy (SHE; formerly known as nocturnal frontal lobe epilepsy), which is an epilepsy syndrome characterized by the occurrence of sleep-related hyperkinetic seizures with variable duration and complexity. However, SHE can occasionally arise from extrafrontal areas.[3]
Disease conditions commonly associated with frontal lobe epilepsy are frequently symptomatic, including congenital causes (such as cortical dysgenesis, gliosis, vascular malformations), neoplasms, head trauma, infections, and anoxia.
Owing to advances in genetic analysis, an expanded number of genetically inherited frontal lobe epilepsy syndromes have been described. Many of these syndromes are characterized by autosomal dominant inheritance.
Quality-of-life issues for patients with epilepsy can include the following:
For more information, see Status Epilepticus.
Go to Epilepsy and Seizures for an overview of this topic.
With improvements in neuroimaging, focal cortical dysplasias are increasingly being identified as epileptogenic lesions.[4] This is particularly true for patients who were initially assumed to be nonlesional. Other common developmental causes of frontal lobe seizures include hamartomas and nodular heterotopias.
Reviews indicate that the epileptogenic lesion in approximately one third of patients with refractory frontal lobe seizures is a tumor.
Common tumors causing frontal lobe epilepsy include gangliogliomas, low-grade gliomas, and epidermoid tumors.[5, 6] High-grade tumors more often present with headache or focal deficits, but many are associated with seizures at some time in their course.
Head trauma is a very frequent cause of damage to the frontal lobes.[7] Risk of later epilepsy depends largely on the severity of trauma. The first seizure usually occurs within months, but may not occur for many years.
Pathologic examination of the frontal lobe frequently reveals meningocerebral cicatrix.
Three main types are recognized: arteriovenous malformations, cavernous angiomas, and venous angiomas. Arteriovenous malformations and cavernous angiomas are more likely to cause seizures than are venous angiomas.[8]
Gliosis is identified in many pathologic specimens following surgical resection for frontal lobe epilepsy. It may follow head trauma, neonatal anoxia, or previous resection; often, no cause is identified.
Although encephalitis commonly produces temporal lobe epilepsy, frontal lobe seizures may occur.
The seizures of autosomal dominant sleep-related hypermotor epilepsy (SHE)(formerly known as ADNFLE for autosomal dominant nocturnal frontal lobe epilepsy), which are mostly originating in the frontal lobe, are clinically characterized by brief, nocturnal motor seizures that often occur in clusters, mainly during non-REM sleep. Seizures may also occur during daytime naps. Some patients may describe a brief aura, which is typically followed by hyperkinetic or tonic activity. Awareness is often preserved, and daytime seizures are rare. Seizure onset is typically in childhood, but can range from infancy to adulthood. Affected patients have normal neurologic exams and intellect. These seizures typically respond well to carbamazepine (often low doses) and are lifelong, though not progressive. Differentiation from parasomnias remains a challenge.
Autosomal dominant SHE was the first focal epilepsy identified as a single gene disorder. Mutations in 3 nicotinic acetylcholine receptor genes (nAChR alpha-2, alpha-4 and beta-2 subunits) have been associated with this epilepsy syndrome.[9] Additional causative mutations in the following genes were later identified: CRH, DEPDC5, KCNT1. Penetrance is 70%, and there can be significantly clinical heterogeneity among affected individuals in the same family. The KCNT1 pathogenic variant has been associated with a more severe phenotype.[10]
The exact incidence of frontal lobe epilepsy is not known. In most centers, however, frontal lobe epilepsy accounts for 20–30% of operative procedures involving intractable epilepsy.
No significant sex-based frequency difference has been reported for frontal lobe epilepsy in epidemiologic studies. However, a comparison of frontal lobe versus temporal lobe seizures captured during epilepsy monitoring has suggested a male predominance in frontal lobe seizures.[11]
Symptomatic frontal lobe epilepsy may affect patients of all ages.
In a large series of cases, the mean subject age was 28.5 years, with the age of epilepsy onset 9.3 years for left frontal epilepsy and 11.1 years for right frontal epilepsy.
Complications of frontal lobe epilepsy may include status epilepticus or a comorbid psychiatric or behavioral disturbance.
The episodes of status epilepticus may be convulsive, nonconvulsive, or focal without impaired awareness.
As with all epilepsy patients, particularly those with medically intractable seizures, patients with frontal lobe epilepsy should be counseled on the risk of SUDEP (sudden unexpected death in epilepsy patients). However, patients with frontal lobe epilepsy do not appear to have a higher incidence of SUDEP compared to other epilepsy populations.[12]
Approximately 65–75% of patients with frontal lobe seizures respond to appropriate antiseizure medications and become seizure free. However, approximately 30% of patients will be intractable, many of whom will continue to have frequent nocturnal seizures.
The proportion of patients with medically refractory frontal lobe epilepsy who become seizure free from additional medications or surgical options is lower than in patients with temporal lobe epilepsy.
An important feature in prognosis is the early recognition of frontal lobe seizures as an epileptic syndrome rather than as a parasomnia or a psychiatric condition.
Patient education is important for all patients with epilepsy. Many patients benefit from joining one of the national or regional epilepsy support groups.
Patients with epilepsy who are not seizure free have the following restrictions:
The majority of frontal lobe seizures are thought to be due to underlying structural lesions, although many patients with frontal lobe seizures have no obvious lesions on magnetic resonance imaging (MRI) scans.
A careful history should focus on specific characteristics of seizure episodes, including a detailed description by eyewitnesses, patterns of occurrence, precipitating factors, and response to medication. Time of day is an important characteristic for seizures originating in the frontal lobe. Compared to temporal lobe seizures, seizures arising from the frontal lobe are more likely to occur between 12 am and 12 pm.[1] Awareness may appear unimpaired when seizures are brief, and patients may have absent or minimal post-ictal state.
Features that help to distinguish frontal lobe seizures from nonepileptic events include stereotyped semiology, occurrence during sleep, brief duration (often < 30 seconds), rapid bilateral evolution, prominent motor manifestations, and complex automatisms. Other features of frontal lobe seizures include significant voice alterations in ictal speech, with elevated pitch during verbal communication.[13]
Even when such characteristics are present, however, distinguishing frontal lobe seizures from nonepileptic events remains difficult based on history alone, and patients with frontal lobe epilepsy are often directed first to psychiatrists rather than to neurologists. Details obtained about the seizure semiology may help to identify the specific frontal region of onset.[14, 15] Neuropsychological evaluation is sensitive to network activity beyond the seizure onset zone and some patients with frontal lobe epilepsy demonstrate reduced learning capacity.[16]
The semiologic findings may vary according to the specific part of the frontal lobe involved at the onset:
Stereo EEG (SEEG) can be used to explore the seizure semiology in patients with frontal lobe epilepsy and can be grouped in motor signs (either elementary or complex) and emotional signs, with a rostrocaudal gradient of anatomical electroclinical correlations.[17]
In one study, SEEGs from 54 patients were analyzed, with clinical signs evident after ~3 seconds (0.5–10 seconds) from the first SEEG ictal discharges, which either remained local or propagated to more caudal premotor or precentral regions. Four partially overlapping anatomical/clinical groups of frontal lobe seizures were identified: (1) prefrontal/premotor regions, clinically characterized by elementary motor signs (clonic, tonic/dystonic, head/eye version) with no gestural motor behavior; (2) premotor/posterior prefrontal regions, clinically with nonintegrated gestural motor behavior (proximal tonic posturing and facial contraction, occasionally hyperkinetic), nonverbal vocalization; (3) lateral prefrontal cortex/frontal pole, with gestural motor behavior (distal stereotypies – reaching/tapping, kicking/pedaling) with either no emotional content or positive emotional content (singing/humming); and (4) ventromedial frontal cortex, clinically with gestural motor behavior (at times hyperkinetic) with fearful emotional expression.[18]
A general physical and thorough neurologic examination should be performed in all patients with epilepsy.
General examination may reveal signs suggestive of syndromes that may be associated with epilepsy, such as facial dysmorphisms. Skin abnormalities, such as cafe-au-lait spots, hypomelanotic macules, or neurofibromas suggesting neurocutaneous syndromes, may also be found.
Structural abnormalities may be identified in patients with frontal lobe epilepsy, including tumors, strokes or vascular malformations, focal cortical dysplasia, and other developmental brain abnormalities. Neurologic abnormalities may be seen in relation to the structural lesions. Pay particular attention to the motor examination.
Blood tests should be performed to rule out a metabolic cause of new-onset seizures, eg, hypoglycemia or hypomagnesemia. Once the diagnosis of epilepsy is established, blood testing remains important in the management of patients who are taking antiseizure medications. Blood monitoring should be guided by the likely complications of a given medication and, more importantly, by patient risk factors and symptoms. Blood tests include the following:
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and other sleep-related hypermotor/hyperkinetic epilepsy are characterized by brief seizures with motor manifestations that tend to occur in clusters at night. Mutations in DEPDC5, as well as KCNT1, CHRNA2, CHRNB2, CHRNA4, and PANX1 genes have been reported.[23] Autosomal recessive mutations also have been described (eg, mutations in GPR56 gene leading to bilateral frontoparietal polymicrogyria).[24]
The imaging modality of choice in patients with frontal lobe seizures is MRI. Advances in MRI have improved the identification of underlying lesions, which are reported to be present in up to 50% of patients with frontal lobe epilepsy.
Optimally, MRI should be obtained with high resolution, 1-mm thick slices, and multiple sequences. If EEG or other testing indicates a potential epileptogenic zone, thin slices through the area of interest should be requested to increase the likelihood of detecting a subtle lesion, such as a focal cortical dysplasia. A field strength of 3 Tesla (3T) can further increase the identification of lesions.[2]
PET scanning is being increasingly used in the presurgical evaluation of patients with extratemporal epilepsy.
Interictal hypometabolism, reflective of focal dysfunction and possibly the seizure onset zone, may be seen in areas that were normal on MRI, although this finding is better established for temporal than for frontal lobe epilepsy. The role of tracer-imaging functions other than glucose metabolism, such as benzodiazepine receptors, still is being defined.
Decreased thalamic metabolism ipsilateral to the seizure focus may be seen in nonlesional frontal lobe epilepsy, particularly in association with a long duration of intractability.
If the patient has very frequent seizures, and particularly if they do not recognize not all seizures, then consider performing an ambulatory EEG for the 48–72 hours leading up to the PET scan to establish whether the study was truly interictal.
Ictal single-photon emission computed tomography (SPECT) scans may be obtained during prolonged video-EEG monitoring.
Hyperperfusion seen on ictal SPECT scanning is suggestive of an area of seizure onset. The sensitivity of ictal SPECT scan hyperperfusion is reported to be higher in frontal lobe epilepsy than in temporal lobe epilepsy.
As seizures in patients with frontal lobe epilepsy are often brief and may generalize rapidly, obtaining an ictal SPECT scan is difficult.
Magnetic resonance spectroscopy (MRS), while still mainly an experimental testing modality, is being increasingly used in the presurgical evaluation of intractable epilepsy.
MRS may demonstrate decreased NA/Cr ratios in the frontal epileptogenic zone, consistent with abnormalities of energy metabolism. However, there are no published studies examining this imaging modality specifically for frontal lobe epilepsy.
All patients with frontal lobe epilepsy should undergo EEG evaluation. Patients with intractable epilepsy, or in whom the diagnosis is doubtful, should undergo prolonged video-EEG monitoring. If the events are primarily or exclusively nocturnal, additional polysomnography should be considered, with extended EEG montages if available. Electroencephalography is discussed further in the subsections below.
Magnetoencephalography (MEG) is a functional neuroimaging modality that uses the brain’s magnetic fields to map brain activity. One study found that source localization using MEG provided important localization information and impacted surgical outcome in patients with frontal lobe epilepsy.[25]
Tissue from surgical resections for intractable frontal lobe epilepsy may demonstrate evidence of a developmental lesion, tumor, gliosis, or vascular malformation. However, the histologic findings may be confounded by post-surgical changes.
There are no pathognomonic EEG findings for frontal lobe epilepsy. In fact, interictal EEGs may be normal. Spikes or sharp waves may be absent; may appear maximal unilaterally (frontal or frontopolar), bilaterally, or in the midline (vertex); or may appear generalized due to secondary bilateral synchrony.[26] Multifocal spikes may be associated with a higher tendency for a history of bilateral evolution to tonic-clonic seizures.[27]
Background rhythm abnormalities, with or without focal slowing, may be present and usually depend on the presence of a structural lesion.
Ictal onset often is seen poorly from the scalp and is highly variable in appearance. EEGs can also be affected by muscle artifact, which may obscure the findings. Ictal onset most often appears as a low-voltage, high-frequency discharge (ie, buzz). Because of rapid bilateral synchrony, discharge on scalp recording may appear bilateral.
Closely spaced frontal electrodes can enhance localization in ictal EEGs. Rapid propagation of ictal discharges also poses a diagnostic challenge with frontal lobe seizures.
Lack of ictal discharge in the temporal lobes may suggest a frontal onset, if the semiology is consistent with frontal lobe seizures.
Video analysis of seizure semiology is crucial and may suggest frontal lobe epilepsy when the EEG is unrevealing. Fencing posturing and lack of postictal confusion are highly suggestive of frontal lobe seizures.[9]
Clinical semiology can provide lateralization information, with many unilateral movements or postures predicting a contralateral seizure onset.[28]
Mesial frontal lobe seizures may be characterized by generalized epileptiform discharges at onset , which are maximal at vertex. Dorsolateral frontal lobe seizures are frequently characterized by focal rhythmic activity, and non-localizable seizures may manifest as diffuse attenuation of the background activity and non-localized rhythmic theta or delta at onset.[26]
Postictal slowing also can be confirmatory, and at times, localizing or lateralizing.
Go to EEG Video Monitoring for complete information on this topic.
High-density (HD) EEG and electrical source imaging (ESI) are additional neurophysiologic modalities that can aid in localization, particularly for patients undergoing surgical work-up. HD EEG refers to using 64 or more electrodes, which can improve the accuracy of localization compared to standard EEG arrays. ESI uses mathematical algorithms to plot the interictal epileptiform discharges or initial ictal discharge on MRI images. Using the patient’s MRI, as opposed to an MRI template, leads to more accurate localization. Of note, these modalities are only useful if the patient’s interictal and/or initial ictal discharges are well-visualized on scalp EEG.
Patients with suspected frontal lobe epilepsy frequently require invasive EEG monitoring. Intracranial EEG is used for localizing the epileptogenic region and for functional mapping prior to resection when seizures arise close to eloquent cortex (eg, motor or language functional areas). Electrode coverage of frontal and temporal (and/or parietal) lobes may be needed.[29]
Stereotactically placed depth electrodes have the greatest accuracy if the area of interest is well defined, but records from a small anatomic area. Frequently, multiple electrodes are needed to sample different regions of the frontal lobe, and pre-implant hypothesis is very important.[30]
Subdural strips and grids sample more broadly, and can be used to perform cortical mapping, but they have higher infection risk and less anatomic specificity.
Interictal high-frequency oscillations (HFO) have localizing value in frontal lobe epilepsy, with their pre-resection presence predicting a postoperative seizure-free outcome.[26, 31]
While a first seizure may not warrant treatment, antiseizure medications should be initiated once the diagnosis of epilepsy is established.[32] Many nocturnal episodes with prominent motor manifestations respond extremely well to carbamazepine.
Patients with medically intractable epilepsy should be considered for resective epilepsy surgery. If resective surgery is not possible, other surgical options include responsive neurostimulation, deep brain stimulation, corpus callosotomy, multiple subpial transections, or vagus nerve stimulation.
While a first seizure may not warrant treatment, antiseizure medications should be initiated once the diagnosis of epilepsy is established.[32] Many nocturnal episodes with prominent motor manifestations respond extremely well to carbamazepine.
An increasing number of antiseizure medications for use in focal epilepsies are available and may be used as monotherapy or in combination.
While monotherapy is desirable to limit adverse effects, some patients require polytherapy for adequate seizure control. The choice of therapy may be influenced by factors such as tolerability of side effects, potential teratogenicity, and interactions with other medications. Older antiseizure medications include phenytoin, carbamazepine, valproic acid, and barbiturates. Newer antiseizure medications include gabapentin, lamotrigine, topiramate, levetiracetam, zonisamide, oxcarbazepine, pregabalin, lacosamide, clobazam, eslicarbazepine, brivaracetam,clobazam, and cenobamate.[33, 34]
Approximately 30% of patients with frontal lobe epilepsy will be refractory to multiple medications, and they may require evaluation for resective surgery. Other options include dietary therapy (ketogenic diet or modified Atkins diet), disconnection surgery, vagal nerve stimulation, deep brain stimulation, or responsive neurostimulation.
Go to Antiepileptic Drugs for complete information on this topic.
Folate should be added to the antiseizure medication regimen of female patients of childbearing age to reduce the risk of neural tube defects.[35]
Frontal cortical resection is the most commonly performed extratemporal cortical resection for intractable epilepsy.[36] Although it is less successful than temporal lobe surgery, advances in presurgical evaluation continue to improve the outcome of frontal resections. A systematic review and meta-analysis of 1199 patients who underwent resection for intractable frontal lobe epilepsy found that 45% of patients have postoperative seizure freedom. Significant predictors of long-term seizure freedom were an identifiable lesion and total resection.[37]
In a case series of patients with posttraumatic epilepsy, 57% had temporal lobe epilepsy and 35% had frontal lobe epilepsy (FLE). The overall poorer epilepsy surgical outcomes for FLE when compared with temporal lobe epilepsy (similar in posttraumatic and nontraumatic cases) may be related to a larger epileptogenic zone in FLE, with difficult-to-define margins (especially in nonlesional cases), which results in inadequate resection.[38]
Go to Epilepsy Surgery for complete information on this topic.
Prognostic factors for good long-term outcome following surgery include no history of febrile seizures, neuroimaging detection of a potentially epileptogenic lesion, and focal beta (fast) ictal discharge on scalp EEG.[36]
Factors predictive of poor outcome include incomplete resection, tonic seizures, and interictal spikes on follow-up EEG.[39]
In general, the prognosis is best if a lesion is present and can be resected completely along with the adjacent cortex if it is a part of the epileptogenic zone. The utility of resecting areas of interictal spiking is controversial. Most recurrences occur early, typically within 6 months of resection.[40]
Intraoperative electrocorticography has prognostic significance, especially if spikes are continuous or nearly so, as is often the case when cortical dysplasia is present. In these instances, absence of postresection epileptiform activity is a strong predictor of a favorable outcome. Although acute postoperative seizures are compatible with long-term seizure recurrence following surgery, early postoperative seizure control is a significant prognostic factor for an excellent outcome.
Besides the risk of cranial surgery, potential complications include motor weakness and behavioral changes. With dominant frontal lobe seizure, there may also be a risk of postoperative expressive aphasia.
Corpus callosotomy is aimed at prevention of bilateral synchrony, thus preventing convulsions and/or falls. Focal seizures that do not evolve to bilateral tonic clonic seizures often do not improve and may worsen. With the advent of improved surgical techniques, this procedure is now rarely performed for well-defined frontal lobe epilepsy.
In this procedure, multiple vertical transections are created, thus interrupting the pathways for horizontal ictal spread while preserving projection fibers important for function. Along with corpus callosotomy, this is one type of procedure referred to as disconnection surgery.
Multiple subpial transections is typically considered to be a palliative procedure and is performed in some centers, often in conjunction with resection, for epileptogenic zones that overlap with eloquent cortex.
A stimulator is implanted surgically, which provides stimulation of the left vagus nerve at a preset rate, typically 30 seconds every 5 minutes, and also may be activated by a hand-held magnet.
This technique allows for patient self-activation of the device during an aura, which may, in some patients, terminate the seizure. The programmed stimulations may improve seizure control even in patients with no aura, allowing self-activation of the device.
Newer models of the vagus nerve stimulator have an “autostimulation” mode, in which additional stimulation is given in response to a rapid increase in heart rate, as this may indicate that the patient is having a seizure. This feature makes the new VNS device a closed-loop system.
A systematic review found that 56% of patients who underwent VNS placement had > 50% seizure reduction.[41]
Go to Vagus Nerve Stimulation for complete information on this topic.
Responsive neurostimulation (RNS) is a newer device that should be considered when seizure onset is in/near eloquent cortex or bilateral. It is a closed-loop system with two electrodes implanted in the suspected seizure-onset zone(s) that are programmed to detect seizures and then stimulate to abort ictal activity. In one study, patients with frontal lobe epilepsy experienced a median percent seizure reduction of 70%, and treatment response was significantly better in those with an MRI lesion compared to those who were nonlesional.[42] A 9-year follow-up study demonstrated that the medical percent reduction in seizure frequency was 75%, and there were sustained improvements in quality of life and cognition.[43]
Deep brain stimulation (DBS) is a closed-loop system that has been used in the treatment of movement disorders for many years. In 2018, DBS targeting the anterior nucleus of the thalamus was approved by the FDA for the treatment of drug-resistant focal epilepsy. The initial study (the SANTE trial) found that the response increased over time, with the median percent seizure reduction increasing from 41% at 1 year to 69% at 5 years.[44]
This high-fat diet, typically with a fat-carbohydrate ratio of 3-4:1, induces ketosis. The ketogenic diet has been used as an effective antiseizure therapy since the 1920s, and there are multiple proposed antiseizure mechanisms. Considerations include the following:
The modified Atkins diet has been under investigation as an alternative to the ketogenic diet in patients with intractable epilepsy. This diet is not as restrictive and does not require initial fasting, and thus may be better tolerated. Other alternatives to the ketogenic diet include the medium chain triglyceride diet and the low glycemic index treatment. Results have been encouraging, but data on its efficacy specifically for frontal lobe epilepsy are limited.[46, 47]
Frontal lobe epilepsy may be an early or late sequela of head trauma. Measures should be taken to prevent head injury, including mandatory use of seat belts and bicycle helmets.
Use of prophylactic anti-seizure medications following head trauma has not been demonstrated to reduce the chance of epilepsy development.
Patients with epilepsy, particularly those with intractable epilepsy and frequent seizures, should be counseled regarding the risk of sudden unexplained death in epilepsy patients (SUDEP).
Patients with frontal lobe seizures should be evaluated by a neurologist. Patients with medically intractable frontal lobe epilepsy should be considered for referral to a comprehensive epilepsy center.
Psychiatric or neuropsychiatric consultation may be useful if there is widespread frontal lobe dysfunction, as can be seen following traumatic brain injury or in the setting of neurodevelopmental disorders, stroke, neurodegenerative disease, or tumors. Frontal lobe dysfunction can manifest as disinhibition and/or impaired executive function.
Depression is often a comorbid condition with intractable epilepsy.
Patients require frequent office visits while their antiseizure medications are being titrated and adjusted. Examination should include evaluation for excessive nystagmus, tremor, and ataxia. Baseline and follow-up blood testing may be needed.
When seizure free on a maintenance dose of medication, patients may be asked to come for follow-up 1–3 times a year.
Patients who are seizure free for 2–5 years may be considered for a trial of medication withdrawal, depending on the individual case.
Antiseizure medications indicated for use in focal seizures are the medical treatment of choice. An increasing number of antiseizure medications for use in focal epilepsies are available and may be used as monotherapy or in combination.[48, 49] Patients generally require many years of treatment, so consideration of side effects is important.
Although the effect of antiseizure medications in pregnancy may be unfavorable, the risk of medication to the fetus must be weighed against the risk of maternal seizures to the fetus. All antiseizure medications confer an elevated risk of suicidal ideation and behavior.
Because of the risk of level fluctuations, patients in general should not switch between brand and generic anticonvulsants, and if a generic is used, patients should receive the same generic formulation consistently.
Clinical Context: This is a relatively newer agent indicated for partial-onset seizures that also inhibits synaptic vesicle protein SV2A. May cause psychiatric adverse reactions. Coadministration of brivaracetam with carbamazepine may increase exposure to carbamazepine-epoxide, the active metabolite of carbamazepine. Brivaracetam can also increase plasma concentrations of phenytoin.
Clinical Context: This is a first-line agent for partial seizures with or without secondary generalization. Carbamazepine is particularly effective in the treatment of nocturnal motor/dystonic frontal lobe seizures. However, it carries a potential for hematologic and other adverse effects; blood monitoring is recommended. Carbamazepine is available in the form of tablets, extended release tablets, extended release capsules, and a suspension. Patients who are not using the extended release form often require dosing 3 times a day.
Clinical Context: Cenobamate is a newer antiseizure medication indicated for treatment of partial-onset seizures as either monotherapy or adjunctive therapy. The exact mechanism of action is unknown, but it is thought to work by enhancing the rapid and slow inactivation of sodium channels and by positive allosteric modulator of the GABA-A ion channel. Given its long half-life of 50–60 hours, it is administered daily. Drug reaction with eosinophilia and systemic symptoms (DRESS) has been reported, as well as hepatic failure. Cenobamate has complex interactions with other antiseizure medications: it decreases plasma levels of lamotrigine and carbamazepine, and increases plasma levels and the effects of clobazam, lacosamide, phenytoin, and phenobarbital.
Clinical Context: Clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome. It is a 1,5-benzodiazepine and potentiates GABAergic neurotransmission by binding to GABA-A receptor. Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Somnolence, sedation, and serious skin reactions (Stevens-Johnson syndrome and toxic epidermal necrosis) have been reported and physical dependence can occur.
Clinical Context: Eslicarbazepine is indicated for partial-onset seizures as monotherapy or adjunctive therapy. Eslicarbazepine acetate is a prodrug that is activated to eslicarbazepine, the major active metabolite of oxcarbazepine. Due to a longer half-life of 13–20 hours, eslicarbazepine acetate is usually administered in daily dosing. Rare cases of anaphylaxis and angioedema have been reported, as well as hepatic effects with elevated transaminases and hyponatremia.
Clinical Context: Gabapentin is indicated for use in partial seizures with or without secondary generalization. It has relatively few drug interactions and adverse effects.
Clinical Context: This is a newer agent; it is effective for partial seizures with or without secondary generalization. Levetiracetam has few adverse effects and no drug-drug interactions. It does not require blood monitoring, although slight decreases in red blood cell (RBC) and white blood cell (WBC) counts have been reported.
Clinical Context: Perampanel is indicated for partial seizures, either as monotherapy or adjunctive therapy, as well as for primary generalized tonic-clonic seizures. Serious or life-threatening psychiatric and behavioral adverse reactions including aggression, irritability, and homicidal ideation have been reported in patients taking perampanel, with or without prior psychiatric history or abnormal behavior. Closely monitor patients particularly during the titration period and at higher doses. Perampanel is a selective noncompetitive antagonist of AMPA glutamate receptor and has a long half-life of ~105 hours.
Clinical Context: Phenytoin is available as tablets, capsules, Infatabs, and suspension. It is a first-line agent for partial seizures. The advantages of phenytoin include an ability to quickly achieve a therapeutic level and the possibility of once-daily dosing (Dilantin Kapseals), which increases compliance.
Clinical Context: Topiramate is indicated for the adjunctive treatment of partial seizures with or without secondary generalization, and for tonic-clonic seizures. It is approved for adults and for children aged 2–16 years. Topiramate has multiple mechanisms of action.
Clinical Context: This is available in the form of tablets, capsules, solution, and sprinkles and is also available in injectable form. Although it is considered a first-line agent for the treatment of primary generalized epilepsy, the drug is indicated for partial seizures as well, particularly for patients with secondary generalization. It must be used cautiously in women of childbearing age. The drug has limited use in young children because of a risk of potentially fatal hepatic failure.
Clinical Context: This drug is indicated for adjunctive treatment of partial seizures with or without secondary generalization. Evidence exists that zonisamide is effective in myoclonic and other generalized seizure types as well.
These agents prevent seizure recurrence and terminate clinical and electrical seizure activity.