Epilepsy

Definition

Epilepsy is a condition characterized by repeated (more than two) epileptic seizures not provoked by any immediately identifiable cause. An epileptic seizure is a clinical manifestation of abnormal and excessive discharge of brain neurons causing sudden transient pathologic phenomena (sensory, motor, mental, vegetative symptoms, and changes in consciousness). It should be remembered that several epileptic seizures provoked or caused by any distinct causes (brain tumor, traumatic brain injury) do not indicate the presence of epilepsy in a patient.

General information

Epilepsy – a condition characterized by repeated (more than two) epileptic seizures not provoked by any immediately identifiable causes. An epileptic seizure is a clinical manifestation of abnormal and excessive discharge of brain neurons causing sudden transient pathologic phenomena (sensory, motor, psychiatric, vegetative symptoms, changes in consciousness). It should be remembered that several epileptic seizures provoked or caused by any distinct causes (brain tumor, traumatic brain injury) do not indicate the presence of epilepsy in a patient.

Classification

According to the international classification of epileptic seizures, partial (local, focal) forms, and generalized epilepsy are distinguished. Focal epileptic seizures are subdivided into simple (without disturbance of consciousness)—with motor, somatosensory, vegetative, and mental symptoms—and complex—accompanied by disturbance of consciousness. Primary-generalized seizures occur with the involvement of both hemispheres of the brain in the pathological process. Types of generalized seizures are myoclonic, clonic, absences, atypical absences, tonic, tonic-clonic, and atonic.

There are unclassified epileptic seizures that do not fit any of the above types of seizures, as well as some neonatal seizures (chewing movements, rhythmic eye movements). There are also repeated epileptic seizures (provoked, cyclic, random) and prolonged seizures (status epilepticus).

Symptoms of epilepsy

The clinical picture of epilepsy has three periods: ictal (seizure period), postictal (after seizure), and interictal (between seizures). In the postictal period, there may be a complete absence of neurologic symptoms (except for symptoms of the disease-causing epilepsy—craniocerebral trauma, hemorrhagic or ischemic stroke, etc.).

There are several main types of aura that precede a complex partial seizure in epilepsy: autonomic, motor, mental, speech, and sensory. The most common symptoms of epilepsy include nausea, weakness, dizziness, tightness in the throat, numbness of the tongue and lips, chest pain, drowsiness, ringing and/or tinnitus, olfactory paroxysms, lump in the throat, and others. In addition, complex partial seizures, in most cases, are accompanied by automated movements that are seemingly inadequate. In such cases, contact with the patient is difficult or impossible.

A secondary generalized seizure usually begins suddenly. After the aura lasts for a few seconds (the course of the aura is unique in each patient), the patient loses consciousness and falls. The fall is accompanied by a peculiar scream caused by a spasm of the vocal cleft and convulsive contraction of the chest muscles.

The tonic phase of an epileptic seizure, named for the type of seizure, follows. Tonic convulsions—the torso and limbs are stretched in a state of extreme tension, the head is tilted and/or turned to the side contralateral to the lesion, breathing is held, neck veins swell, the face becomes pale with slowly increasing cyanosis, and the jaws are tightly clenched. The duration of the tonic phase of the attack is 15 to 20 seconds.

Then comes the clonic phase of an epileptic seizure, accompanied by clonic convulsions (noisy, hoarse breathing, foaming at the mouth). The clonic phase lasts from 2 to 3 minutes. The frequency of convulsions gradually decreases, followed by complete muscle relaxation; when the patient does not react to stimuli, pupils are dilated, their reaction to light is absent, and protective tendon reflexes are not evoked.

Diagnosis

Diagnosis of epilepsy should be based on history, physical examination of the patient, electroencephalography, and neuroimaging data (MRI and CT of the brain). It is necessary to determine the presence or absence of epileptic seizures according to the patient’s history, clinical examination, and results of laboratory and instrumental tests, as well as to differentiate epileptic and other seizures; to determine the type of epileptic seizures and the form of epilepsy; to familiarize the patient with the recommendations on the regimen, to assess the need for drug therapy, its nature and the likelihood of surgical treatment. 

Neurologists and epileptologists diagnose epilepsy. The main method of examination of patients diagnosed with epilepsy is electroencephalography, which is performed on all patients without exception to detect epileptic activity. Modern methods of computer EEG analysis allow for determining the localization of the source of pathological bioelectrical activity. When EEG is performed during an attack, epileptic activity is registered in most cases; in the interictal period, EEG is normal in 50% of patients.

EEG, in combination with functional tests (photostimulation, hyperventilation), reveals changes in most cases. However, the absence of epileptic activity on EEG (with or without functional tests) does not exclude the presence of epilepsy. 

In the diagnosis of epilepsy, brain MRI is the most valuable among neuroimaging methods, which is indicated for all patients with local onset of epileptic seizures. MRI reveals diseases that have influenced the provoked nature of seizures (aneurysm, tumor) or etiological factors of epilepsy (mesial temporal sclerosis). Patients diagnosed with pharmacoresistant epilepsy in connection with a subsequent referral for surgical treatment also undergo an MRI to determine the localization of the CNS lesion. In some cases (elderly patients), it is necessary to conduct additional studies: biochemical blood analysis, ocular fundus examination, and ECG.

Epileptic seizures should be differentiated from other paroxysmal conditions of non-epileptic nature (syncope, psychogenic seizures, vegetative crises).

Epilepsy treatment

Conservative therapy

All epilepsy treatments are aimed at stopping seizures, improving quality of life, and stopping medication (in remission). In 70% of cases, adequate and timely treatment leads to the cessation of epileptic seizures. 

One of the principles of drug treatment of epilepsy is monotherapy. The drug is prescribed at the minimum dose and then increased until the seizures cease. In case of insufficient dose, it is necessary to check the regularity of drug administration and determine whether the maximum tolerated dose has been reached. The use of most antiepileptic drugs requires continuous monitoring of their blood concentrations. 

Treatment of newly diagnosed epilepsy is started with both traditional (carbamazepine and valproic acid) and newer antiepileptic drugs (topiramate, oxcarbazepine, levetiracetam) registered for monotherapy. When choosing between traditional and newer drugs, individual patient characteristics (age, gender, comorbidities) should be considered. Valproic acid is used to treat unidentified epileptic seizures.

When prescribing a particular antiepileptic drug, the lowest possible frequency of its administration (up to 2 times/day) should be aimed for. Due to stable plasma concentrations, prolonged-acting drugs are more effective. The drug should bediscontinued gradually, taking into account the form of epilepsy, its prognosis, and the possibility of seizure recurrence.

Surgical treatment

Drug-resistant epilepsies (ongoing seizures, ineffectiveness of adequate antiepileptic treatment) require additional examination of the patient to decide on surgical treatment. The preoperative examination should include registering seizures and obtaining reliable data on the localization, anatomical features, and the nature of the spread of the epileptogenic zone (MRI).

Based on the results of the above studies, the nature of surgical intervention is determined: surgical removal of epileptogenic brain tissue (cortical topectomy, lobectomy, hemispherectomy, multilobectomy); selective surgery (amygdalo-hippocampectomy in temporal lobe epilepsy); callosotomy and functional stereotactic intervention; vagusstimulation.

Each of the above surgical interventions has strict indications. They can be performed only in specialized neurosurgical clinics with appropriate equipment and with the participation of highly qualified specialists (neurosurgeons, neuroradiologists, neuropsychologists, neurophysiologists, etc.).

All these treatment options are available in more than 310 hospitals worldwide (https://doctor.global/results/diseases/epilepsy). For example, Deep brain stimulation (DBS) can be performed in 18 clinics across Germany for an approximate price of $33.6 K (https://doctor.global/results/asia/turkey/all-cities/all-specializations/procedures/deep-brain-stimulation-dbs). 

Prognosis and prevention

The prognosis for workability in epilepsy depends on the frequency of seizures. In the remission stage, when seizures occur less frequently and at night, the patient’s ability to work is preserved (excluding night shift work and business trips). Daytime epileptic attacks accompanied by loss of consciousness limit the patient’s ability to work.

The vast majority of patients who receive proper treatment lead an everyday life without seizures.

Epilepsy prophylaxis includes possible prevention of traumatic brain injury, intoxication, and infectious diseases, prevention of possible marriages between patients with epilepsy, and adequate fever reduction in children to prevent fever, the consequence of which may be epilepsy.