Seizure syndrome in children

Pathogenesis and age-related features

The younger the child, the higher the risk of paroxysms. The high frequency of convulsive states in childhood is due to the anatomical and physiological characteristics of the central nervous system:

• Morphological and functional immaturity of nerve fibers and brain structures.
• High permeability of the blood-brain barrier (BBB).
• The tendency of the child's nervous system toward generalized processes.
• Neurotransmitter imbalance: the predominance of excitatory glutamatergic influences over inhibitory ones (mediated by gamma-aminobutyric acid, or GABA).

Clinical classification of seizures

The semiology of seizures is divided into four main types, each of which may indicate a specific cause:

1. Tonic seizures: prolonged muscle spasm. Pathognomonic posture: head thrown back, arms flexed at all joints, legs extended. Frequently observed in febrile states (manifesting as tonic-clonic paroxysms).
2. Clonic seizures: a series of rapid rhythmic or arrhythmic muscle contractions.
3. Myoclonic seizures: focal muscle twitches (typical of hypoglycemic states).
4. Atonic seizures: sudden limpness with complete loss of tone. This is a prognostically unfavorable marker of severe CNS damage.

Based on topography, seizures are divided into generalized and local (focal). Important clinical rule: focal seizures are always of epileptic origin.

Etiological structure

Overall, seizures are classified as epileptic (recurrent, unprovoked discharges in the gray matter) and non-epileptic/symptomatic (secondary in response to a trigger).

For convenience, causes are divided into two groups:

• Primary neurological (CNS damage): malformations, neuroinfections, trauma, hypoxic injury, tumors, genetic disorders, cerebrospinal fluid circulation disorders (hydrocephalus), and cerebral vasculitis.
• Extracerebral (triggering): febrile hyperthermia, acute childhood infections, severe somatic diseases (congenital heart disease, leukemias, hemophilia), toxic syndromes, metabolic disorders (hypocalcemia, hypoglycemia, phenylketonuria), vaccine reactions, hemolytic disease of the newborn (HDN), and psychogenic factors.

Diagnostic algorithm

The basis of differential diagnosis is identifying the root cause. For newly onset or provoked seizures, the focus is on laboratory methods (identifying the trigger).

For recurrent unprovoked seizures, instrumental methods are used:

• Electroencephalography (EEG): the "gold standard." It allows differentiation of an epileptic seizure, localization of the focus, and confirmation of generalization (EEG video monitoring and sleep deprivation are used).
• Neuroimaging: CT, MRI, or neurosonography (NSG). Indicated for any unclear or recurrent seizures to search for a structural substrate (symptomatic epilepsy).
• Additionally: blood flow assessment (TCD), fundus examination, cerebrospinal fluid analysis.

Therapeutic tactics and status management

Treatment is based on two approaches: etiotropic (for non-epileptic syndrome) and pathogenetic (administration of anticonvulsants).

Metabolic disorders:

• Hypocalcemia: 10% calcium gluconate intravenously (1 mg/kg in 5% dextrose).
• Hypomagnesemia: 25% magnesium sulfate intramuscularly (0.4 ml/kg).
• Hypoglycemia: 10–20% dextrose solution (10–15 ml/kg, blood glucose monitored).

Management of febrile seizures: Antipyretics are used (paracetamol 15 mg/kg, ibuprofen 6–10 mg/kg). For refractory fever, a lytic cocktail is used (metamizole sodium + chloropyramine). Important: metamizole sodium is dangerous due to the risk of bone marrow suppression. Modern practice indicates that antipyretics do not prevent seizures; specific anticonvulsant therapy is required (diazepam, 25% magnesium sulfate, sodium oxybate).

Intensive care for status epilepticus: Performed strictly in the ICU:

1. Maintenance of airway patency and oxygen therapy.
2. Intravenous administration of diazepam (first-line drug).
3. Intravenous administration of phenytoin, valproic acid, or sodium oxybate.
4. In refractory cases, transfer to mechanical ventilation and drug-induced coma (propofol or sodium thiopental).

Class and exam questions

What else to study on this topic

• Features of convulsive syndrome in hemolytic disease of the newborn (HDN).
• Genetic testing when idiopathic epilepsy is suspected.
• Criteria for selecting anticonvulsants depending on the clinical type of seizures.
• Differential diagnosis of breath-holding spells and syncopal episodes.
• Antibiotic therapy regimens for neuroinfections complicated by convulsive syndrome.

Other topics in "Chapter 13. Main syndromes requiring emergency care"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.