First epileptic seizure in an adult

The first epileptic seizure does not always mean the debut of epilepsy as a disease. According to some researchers, 5-9% of people in the general population suffer at least one non-febrile seizure at some point in their lives. However, the first seizure in adults should give rise to a search for organic, toxic or metabolic diseases of the brain or extracerebral disorders that can cause seizures. Epilepsy, in its etiopathogenesis, is a multifactorial condition. Therefore, a patient with epilepsy should undergo mandatory electroencephalographic and neuroimaging, and sometimes general somatic examination.

When the first attack occurs in adulthood, the list of diseases presented below should be taken very seriously, which implies repeated examinations of the patient if the first series of examinations was uninformative.

First, of course, it is necessary to clarify whether the attacks are truly epileptic in nature.

Syndromic differential diagnosis includes fainting, hyperventilation attacks, cardiovascular disorders, some parasomnias, paroxysmal dyskinesias, hyperekplexia, facial hemispasm, paroxysmal vertigo, transient global amnesia, psychogenic seizures, and less commonly with conditions such as trigeminal neuralgia, migraine, and some psychotic disorders.

Unfortunately, very often there are no witnesses to the seizure, or their description is not informative. Such valuable symptoms as biting the tongue or lip, leaking urine or increasing the level of serum creatine kinase are often absent, and the EEG sometimes records only non-specific changes. Video recording of the seizure (including at home) can be very helpful in recognizing the nature of the seizure. If the epileptic nature of the first seizure is not in doubt, then it is necessary to consider the following range of underlying diseases (epileptic seizures can be caused by almost all diseases and injuries of the brain).

The main causes of the first epileptic seizure in adults:

1. Withdrawal syndrome (alcohol or drugs).
2. Brain tumor.
3. Brain abscess and other space-occupying lesions.
4. Traumatic brain injury.
5. Viral encephalitis.
6. Arteriovenous malformation and brain malformations.
7. Thrombosis of the cerebral sinuses.
8. Cerebral infarction.
9. Carcinomatous meningitis.
10. Metabolic encephalopathy.
11. Multiple sclerosis.
12. Extracerebral diseases: cardiac pathology, hypoglycemia.
13. Idiopathic (primary) forms of epilepsy.

Withdrawal syndrome (alcohol or drugs)

So far, the most common causes of the first epileptic seizure in adults remain alcohol or tranquilizer abuse (as well as a brain tumor or abscess).

Alcohol-related ("toxic") seizures usually occur during the withdrawal period, indicating a long period of regular use of large doses of alcohol or drugs.

A valuable withdrawal symptom is the fine tremor of the outstretched fingers and hands. Many patients report an increase in amplitude (not frequency) of the tremor in the morning after an overnight break from taking another drink and a decrease during the day with the alcohol or drug. (Familial or "essential" tremor is also reduced by alcohol, but it usually appears coarser and is often hereditary; EEG is usually normal.) Neuroimaging often reveals global hemispheric volume loss and also cerebellar "atrophy." The volume loss suggests dystrophy rather than atrophy and is reversible in some patients with continued alcohol use.

Withdrawal attacks may be a precursor to psychosis, which will develop within 1-3 days. This condition is potentially dangerous and intensive medical care should be provided early enough. Drug withdrawal syndrome is more difficult to recognize both by history and physical examination, and, in addition, treatment here is longer and requires intensive care in full.

Brain tumor

The next condition to consider in a first epileptic seizure is a brain tumor. Since the majority of histologically benign, slowly growing gliomas (or vascular malformations) are present, the history is often of little help, as is the routine neurological examination. Contrast-enhanced neuroimaging is the adjuvant method of choice, and should be repeated if the initial findings are normal and no other cause for the seizures is found.

Brain abscess and other space-occupying lesions (subdural hematoma)

A brain abscess (like a subdural hematoma) will never be missed if neuroimaging is performed. The necessary laboratory studies may not indicate the presence of an inflammatory disease. An EEG will usually show focal abnormalities in the very slow delta range plus generalized abnormalities. At a minimum, an ear, nose, throat examination and a chest X-ray are required. Blood and CSF studies may also be helpful.

Traumatic brain injury

Epilepsy following a traumatic brain injury (TBI) may reappear after many years, so the patient often forgets to inform the doctor about this event. Therefore, collecting anamnesis in these cases is especially important. However, it is useful to remember that the occurrence of epileptic seizures after a TBI does not mean that the injury is the cause of epilepsy; this connection must be proven in doubtful cases.

The following evidence supports the traumatic genesis of epilepsy:

1. severe TBI; the risk of epilepsy increases if the duration of loss of consciousness and amnesia exceeds 24 hours, there are depressed skull fractures, intracranial hematoma, focal neurological symptoms;
2. the presence of early seizures (occurring within the first week after injury);
3. partial nature of seizures, including those with secondary generalization.

In addition, the period from the moment of injury to the subsequent occurrence of seizures is important (50% of post-traumatic seizures occur within the first year; if seizures appear after 5 years, their traumatic genesis is unlikely). Finally, not every paroxysmal activity on the EEG can be called epileptic. EEG data should always be correlated with the clinical picture.

Viral encephalitis

Any viral encephalitis may begin with seizures. The most characteristic is the triad of seizures, generalized slowness and irregularity on the EEG, disorientation, or frank psychotic behavior. The cerebrospinal fluid may contain an increased lymphocyte count, although protein and lactate levels are normal or slightly elevated (lactate levels rise when the bacteria "lower" glucose). A rare but very dangerous condition is encephalitis due to the herpes simplex virus (herpes simplex encephalitis). It usually begins with a series of seizures followed by confusion, hemiplegia, and aphasia if the temporal lobe is involved. The patient's condition rapidly deteriorates to coma and decerebrate rigidity due to massive swelling of the temporal lobes, which puts pressure on the brainstem. Neuroimaging examination reveals decreased density in the limbic region of the temporal and later frontal lobes, which become involved after the first week of the disease. During the first few days, nonspecific disturbances are recorded on the EEG. The appearance of periodic high-voltage slow complexes in both temporal leads is very characteristic. Cerebrospinal fluid examination reveals marked lymphocytic pleocytosis and increased protein levels. Searches for herpes simplex virus in the cerebrospinal fluid are justified.

Arteriovenous malformation and brain malformations

The presence of an arteriovenous malformation may be suspected when contrast-enhanced neuroimaging reveals a rounded, heterogeneous area of hypodensity on the convexital surface of a hemisphere without edema of surrounding tissues. The diagnosis is confirmed by angiography.

Brain malformations are also easily detected using neuroimaging methods.

Thrombosis of the cerebral sinus(es)

Thrombosis of the cerebral sinuses may be the cause of epileptic seizures, since hypoxia and diapedetic hemorrhages develop in the area of the hemisphere where venous outflow is blocked. Consciousness is usually impaired before focal symptoms appear, which to some extent facilitates the recognition of thrombosis. The EEG shows a predominance of generalized slow activity.

Cerebral infarction as the cause of the first epileptic seizure occurs in approximately 6-7% of cases and is easily recognized by the accompanying clinical picture. However, single and multiple (repeated) "silent" infarctions are possible with cerebrovascular infarction, which sometimes lead to the appearance of epileptic seizures ("late epilepsy").

Carcinomatous meningitis

In cases of unexplained headache and mild neck stiffness, a lumbar puncture should be performed. If the CSF analysis shows a slight increase in the number of atypical cells (which can be detected by cytology), a significant increase in protein levels, and a decrease in glucose levels (glucose is metabolized by tumor cells), then carcinomatous meningitis should be suspected.

Metabolic encephalopathy

The diagnosis of metabolic encephalopathy (usually uremia or hyponatremia) is usually based on a characteristic pattern of laboratory findings that cannot be described in detail here. It is important to suspect and screen for metabolic disorders.

Multiple sclerosis

It is important to remember that in very rare cases, multiple sclerosis can debut with epileptic seizures, both generalized and partial, and, after excluding other possible causes of epileptic seizures, it is necessary to conduct clarifying diagnostic procedures (MRI, evoked potentials, immunological studies of cerebrospinal fluid).

Extracerebral diseases: cardiac pathology, hypoglycemia

Epileptic seizures may be caused by transient disturbances in the oxygen supply to the brain due to cardiac pathology. Recurrent asystole, as in Adams-Stoke disease, is a familiar example, but there are other conditions, so careful cardiac examination is useful, especially in older patients. Hypoglycemia (including hyperinsulinism) may also be a factor in triggering epileptic seizures.

Idiopathic (primary) forms of epilepsy usually develop not in adults, but in infancy, childhood or adolescence.

Epileptic syndromes in some degenerative diseases of the nervous system (eg, progressive myoclonus epilepsies) usually develop against the background of progressive neurological deficit and are not discussed here.

Diagnostic tests for the first epileptic seizure

General and biochemical blood analysis, urine analysis, screening for metabolic disorders, identification of toxic agent, cerebrospinal fluid analysis, MRI of the brain, EEG with functional loads (hyperventilation, sleep deprivation; use of sleep electropolygraphy), ECG, evoked potentials of different modalities.