Manifestation and course of the disease
Epilepsy incidence exhibits a characteristic age-related dynamic: it gradually decreases by the age of 18, but then sharply increases in patients over 60 years old. In elderly patients, manifestation is most commonly due to various cerebrovascular disorders.
The first epileptic paroxysm in a person's life is often triggered by external factors. Key triggers include alcohol intake, severe psychological trauma, or a serious somatic illness. However, as the disease progresses, seizures begin to occur spontaneously, without any link to initiating triggers.
It is important to note that epilepsy rarely has its onset in the acute period of traumatic brain injury (TBI). Seizures typically develop several months or even years after brain damage. Meanwhile, in approximately a quarter of patients (about 25%), the disease is idiopathic in nature—no obvious preceding pathogenic factors that provoked the disease can be identified. Seizure frequency varies from rare (several times a year) to multiple times a day, and tends to increase over time.
Prodromal period and precursors
Long before the manifestation of the disease, the patient may exhibit early precursors. These are isolated paroxysms (both convulsive and non-convulsive) developing against the background of various exogenous influences. Such triggers include infectious fever, vaccination reactions, severe fright, toothache or dental treatment, staying in a stuffy room, or overheating in the sun.
Directly in the prodromal period preceding the seizure, patients often report nonspecific malaise. Frequent phenomena include:
- Paroxysmal headaches.
- Sleep disturbances: stereotyped nightmares, somniloquy (sleep-talking), somnambulism (sleepwalking), frequent myoclonic jerks during sleep.
Shortly before the onset of the disease itself, a feeling of pronounced fatigue (asthenia) and a marked decrease in working capacity come to the forefront. It is important to remember that classic precursors and aura do not occur in primary generalized paroxysms.
Clinical variants of seizures
The clinical picture of epileptic paroxysms is extremely polymorphic. The most frequent forms are major convulsive seizures (grand mal) and absence seizures (petit mal). In addition, psychosensory seizures, dysphoria, and twilight states of consciousness are distinguished.
State of consciousness during a seizure directly depends on its type:
- Completely absent (e.g., comatose state in grand mal).
- Clouded to varying degrees (observed in ambulatory automatisms).
Memory for seizure events is also impaired in various ways. Complete amnesia is characteristic of grand mal, absences, and twilight states of consciousness. Partial amnesia accompanies psychosensory seizures and altered states of consciousness. In dysphoria, amnesia is completely absent; the patient remembers everything.
Focal seizures, aura, and equivalents
Unlike primary generalized forms, focal (partial) seizures always begin with an aura. Its symptomatology is strictly specific for each patient, has a stereotyped (recurring) character, and allows for the localization of the epileptogenic focus.
The aura may manifest as isolated motor acts, sharp mood swings, complex actions, or ideational phenomena (hallucinations, visceral sensations, rushes or sudden stopping of thoughts). If a classic convulsive seizure does not develop after the aura, so-called equivalents occur.
Equivalents include:
- Twilight states of consciousness: trances, fugue states, somnambulism, ambulatory automatisms.
- Psychosensory seizures: altered states of consciousness considered as an analogue of an aura. They include emotional disorders (ecstasy, anxiety, euphoria), sensory phenomena (body schema disturbances), derealization (déjà vu and jamais vu episodes), as well as thought disorders (feeling of passivity and control). Due to the unusual nature of psychological experiences, such conditions require rigorous differential diagnosis with schizophrenia.
Briefly: answers to topical questions
What EEG changes are characteristic of typical absence seizures?
Typical absence seizures are characterized by the sudden appearance on the EEG of an episode of paroxysmal epileptic discharge that replaces background activity. Three sequential periods are distinguished:
- Pre-seizure — recording of normal background brain bioelectrical activity.
- During the seizure — a generalized discharge occurring synchronously across all leads. Its morphology represents a specific pattern consisting of a combination of spikes (sharp peaks) and slow waves.
- Post-seizure — a sharp cessation of epileptiform activity and return to the initial background pattern.
What drugs are used to terminate status epilepticus?
To abort status epilepticus, the following are used:
- Benzodiazepines — first-line drugs: diazepam, lorazepam, clonazepam.
- Barbiturates — phenobarbital.
- Hydantoins — phenytoin.
To abort the most dangerous generalized tonic-clonic status, the drugs of choice are diazepam and phenytoin, administered intravenously.
What are the main causes of epilepsy development in old age?
The main cause of epilepsy development in older age (after 60 years) is cerebrovascular disease. In addition, the onset of epileptic paroxysms over the age of 30 often acts as the first symptom of other severe pathologies:
- Space-occupying lesions — intracranial tumors, metastases, cysts, hematomas, and cysticercosis.
- Extracerebral causes — hormonally active tumors (e.g., insulinoma).
- Late stages of diseases — cerebral atherosclerosis, Alzheimer's disease, cerebral syphilis, and general paresis of the insane.
What is the clinical picture of a typical absence seizure?
The clinical picture of a typical absence seizure (petit mal) is characterized by a sudden onset without an apparent cause and occurs as a generalized non-convulsive epileptic seizure. At the moment of the seizure, the patient experiences an immediate and complete loss of consciousness. After the paroxysm ends, complete amnesia is observed—the patient has no memory of what happened. During the seizure, bilateral synchronous epileptic activity is recorded on the EEG, while in the interictal period, abnormalities are absent.
To memorize the depth of amnesia: "CAP". C — Complete (with Loss of consciousness: grand mal, petit mal). A — Partial (with Affective/psychosensory). P — Present / None (with Irritability/dysphoria) [Note: Translated conceptually to English mnemonic].
Class and exam questions
Is there an aura before a major convulsive seizure?
If the seizure is primarily generalized, there are no auras or prodromal symptoms preceding it. An aura precedes only focal (partial) seizures.
What is the reason for the high incidence of epilepsy in the elderly?
The significant increase in incidence after 60 years of age is typically due to various cerebrovascular lesions that form epileptogenic foci.
What is an equivalent of a convulsive seizure?
These are non-convulsive paroxysms that replace a classic seizure. They include variants of twilight states of consciousness (trances, fugues, automatisms) and psychosensory seizures.
What else to study on this topic
- Differential diagnosis of psychosensory seizures and schizophrenia
- Types of aura and topical diagnosis of the cortical epileptogenic focus
- Clinical picture of twilight states of consciousness: trances, fugues, automatisms
- Features of the course of idiopathic epilepsy without identified triggers
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