Epilepsy in pregnancy is a chronic hereditary, congenital or acquired cerebral pathology that is caused by excessive neural activity and occurred before or during gestation. It is usually manifested by convulsive and convulsive paroxysms with or without loss of consciousness, less often by psychotic disorders in the form of twilight states, delirium, hallucinations, dysphoria. It is diagnosed using EEG, magnetic resonance imaging of the brain. For the treatment and prevention of possible complications, antiepileptic drugs, tranquilizers, folic acid, vitamins K1, D, B, sedative phytopreparations are used.
Epilepsy is one of the most common neurological disorders in women of reproductive age. The prevalence of the disease in the population reaches 0.5-3.0%. Thanks to the use of prolonged anticonvulsants of a new generation, most patients manage to achieve stable remission or subcompensation of the pathological process, which led to an increase in the frequency of pregnancies in women who have epilepsy. According to specialists in the field of obstetrics and gynecology, up to 0.3-0.5% of pregnant women suffer from epileptic disease. The disease is usually diagnosed in childhood or adolescence, but the onset of paroxysms and even the primary occurrence of epistatus is possible during pregnancy and childbirth.
Epileptic disease is a polyethological disease, and each of the factors plays only a predisposing role. In 86% of patients, paroxysmal syndrome develops before conception and is not associated with the effect of specific gestational changes. Epilepsy can occur in women with congenital failure of brain structures caused by defects in neuronal differentiation, impaired neuronal migration, cortical dysgenesis, dysontogenesis, intrauterine neuroinfections, birth trauma. Acquired predisposition is formed against the background of brain destruction after severe injuries, meningoencephalitis, strokes.
Two-thirds of cases are hereditary. In 98% of patients with idiopathic epileptic disease, the disorder has a polygenic basis and develops against the background of channelopathy, leading to instability of neuronal membranes. In 1-2% of sick women, convulsive syndrome is a manifestation of monogenic diseases in which protein, fat, carbohydrate metabolism is disrupted or degenerative changes of the nervous system occur: paroxysmal seizures are observed with lipofuscinosis, neurofibromatosis, progressive myoclonus epilepsy, tuberous sclerosis, phenylketonuria, etc.
In 14% of cases, convulsive seizures occur for the first time in pregnant women who have prerequisites for the development of paroxysms, and are repeated only in subsequent gestations, which makes it justified to isolate gestational epilepsy as a separate form of the disease. In such women, specific changes occurring during gestation contribute to the actualization of the clinical picture:
- Changes in water-electrolyte metabolism. In pregnant women, the volume of circulating blood increases and the permeability of membranes increases, which contributes to the accumulation of fluids in tissues, including the brain. A physiological increase in the level of ACTH contributes to the retention of sodium and chlorides. Against the background of hypersecretion of mineralocorticoids, the content of calcium and magnesium decreases. The result of these changes is an increase in the excitability of cell membranes.
- Hormonal restructuring. An increase in the convulsive readiness of brain tissue during gestation leads to a more than 30-fold increase in the concentration of estrogens. According to the results of research in the field of neurology, estrogenic stimulation increases the excitability of nerve cells. In some pregnant women, the anticonvulsive effect of progestins, the level of which increases 10-fold, is insufficient to compensate for the action of estrogens.
- Hyperventilation. Despite the high standing of the diaphragm, there is an increase in pulmonary ventilation in pregnant women — the volume of inhaled and exhaled air increases by 40%, alveolar gas exchange accelerates, the total lung resistance decreases by 2 times. Against the background of hyperventilation, the concentration of carbon dioxide in the blood decreases, which leads to narrowing of cerebral vessels, insufficient blood supply to brain cells and a decrease in their excitability threshold.
Often the situation is aggravated by stressful loads and emotional changes characteristic of pregnant women. Insufficient rest and sleep contribute to the accumulation of epileptogenic substances, and hormonal anxiety, irritability, a tendency to mood swings, panic reactions to changing well-being affect the reactivity of the central nervous system.
The mechanism of development of epilepsy in pregnancy is based on increased excitability of neuronal membranes and an imbalance of excitation-inhibition processes. Electrolyte shifts caused by gestational factors, disruption of membrane channels, sinuses, excitatory and inhibitory receptors affect neuronal activity and increase the convulsive readiness of brain tissues. The impact of super-threshold factors (strong emotional experience, peak increase in estrogen levels, other external and internal stimuli) causes periodic focal depolarization of the membranes of neurons with the formation of a focus of epileptic activity. Further generalization of the process leads to the occurrence of convulsive and convulsive seizures.
Symptoms of epilepsy in pregnancy
The clinic of paroxysms during gestation depends on the localization of the epileptogenic focus and the characteristics of the propagation of the excitation wave to various structures of the brain. With classic generalized convulsive seizures lasting up to 3 minutes, the pregnant woman loses consciousness, falls, she has a strong tonic contraction of the muscles of the body with subsequent convulsive convulsions of the muscles of the extremities, possible tongue biting, involuntary urination, sometimes defecation. At the end of the attack, consciousness does not recover immediately, breathing remains intermittent for some time, cyanotic and skin moisture are characteristic, maximum pupil dilation without reaction to light. Often, after a convulsive paroxysm, sleep comes.
In some patients, the seizure is preceded by an aura in the form of dizziness, chest tightness, illusory or hallucinatory olfactory, tactile, sound, auditory, taste sensations, motor automatism (scratching, sorting things, stomping on the spot, etc.). Some components may be missing in the structure of epileptic paroxysm.
Thus, absences are manifested by short—term loss of consciousness without convulsive muscle contractions, and the most common partial seizures are tonic or clonic seizures, somatosensory disorders, vegetative-visceral manifestations (sweating, redness of the face, discomfort in the epigastrium, changes in pupil diameter) with preserved or altered consciousness. In rare cases, there are psychotic variants of epilepsy with a twilight state, hallucinations, delirium, dysphoric maliciously sad affect.
In 10-15% of pregnant women suffering mainly from post-traumatic and rheumatic epilepsy, seizures become more frequent, especially in the I and III trimesters. The progressive course of the disease is associated with the risk of developing an epileptic status, in which the maternal mortality rate reaches 16-20%, and perinatal mortality is 6.6%. 28.8% of patients with epilepsy develop late gestosis, including eclampsia, 4-11% have premature labor. With epileptic disease, the risk of stillbirth, spontaneous abortions, and violent labor increases. In 16.9% of cases, early postpartum bleeding develops and in 28.4% — late. Pregnant women with paroxysms are 1.5 times more likely to have a caesarean section.
Traumatization, the risk of which increases in the presence of generalized convulsive seizures, increases the likelihood of intracerebral hemorrhages and fetal hydrocephalus. Up to 6-8% of children have congenital malformations, which is associated with the teratogenic effect of antiepileptic drugs that affect the folate cycle. Cleavage of the palate (cleft lip), spine (spiha bifida), facial skull defects, heart defects are more common than others. Epileptologists have described a specific embryonic AEP syndrome in newborns, manifested by ptosis, strabismus, hypertelorism, epicanthus, flattened bridge of the nose, hypoplasia of nails and/or phalanges of fingers.
With the hereditary form of epilepsy in the mother, the probability of developing the disease in the child reaches 10%, with symptomatic forms of paroxysmal disease — 3-4% (against 1% on average in the population). Intrauterine hypoxia occurs in 10.4% of fetuses, up to 23.2% of children are born in a state of asphyxia. Sometimes, against the background of taking anticonvulsants, a child develops erythroblastosis. 7-10% of newborns have a weight of less than 2,500 g. Also, children carried out by women with epilepsy usually have lower indicators on the Apgar scale. Perinatal mortality is 1.2-2 times higher than the average.
Difficulties in making a diagnosis are possible with the onset of epilepsy during pregnancy, especially if the paroxysms are convulsive. In such cases, the diagnostic search is aimed at identifying pathological neuronal activity in the brain, detecting the organic substrate of the disease, and assessing the prevalence of the pathological process. The most informative methods are:
- Electroencephalography. EEG examination allows to identify characteristic focal complexes “peak wave” or asymmetric slow waves, as well as accurately localize the pathological cerebral focus. To increase the information content of the examination, it is possible to perform video EEG monitoring and assign functional tests (except hyperventilation).
- MRI. Layered scanning of brain tissues allows detecting structural changes (cerebral aneurysms, cavernous hemangiomas, arteriovenous malformations, cysts, neoplasia, hemorrhages, post-traumatic injuries) that contribute to the occurrence of paroxysms. MRI of the brain is effective for the diagnosis of symptomatic epilepsy.
Taking into account the possible violation of the folate cycle, pregnant women taking anticonvulsants are recommended to evaluate the content of folic acid, vitamin B12, homocysteine in the blood serum in dynamics. To exclude fetal development abnormalities, prenatal screening is required: genetic ultrasound, a geneticist’s consultation no later than the 17th week of gestational age, according to indications, the use of invasive diagnostic methods: chorion biopsy, cordocentesis, amniocentesis. Taking into account the risk of intrauterine hypoxia and delayed development of the child, ultrasound of uteroplacental blood flow, fetometry, CTG, phonocardiography of the fetus are recommended.
Epilepsy in pregnancy is differentiated from:
- symptomatic paroxysms in exogenous intoxication encephalitis, after acute brain injury;
- syncopal states;
- crumpy syndrome;
- febrile convulsions;
- hysterical attacks;
- migraine attacks;
- extrapyramidal disorders;
- paroxysmal dissomnia (sleepwalking, narcolepsy);
- vestibular crises;
- paroxysmal myoplegia, etc.
According to the indications, the patient is consulted by an epileptologist, neuropathologist, psychiatrist, neurosurgeon, oculist, otorhinolaryngologist, phthisiologist, rheumatologist, oncologist.
Epilepsy in pregnancy treatment
When developing medical tactics, the risk of aggravation of epilepsy in pregnancy, the mutagenic and teratogenic potential of prescribed anticonvulsants, and the age of the patient are taken into account. Indications for medical abortion are a pharmacoresistive form of the disease with frequent paroxysms, a status type of epilepsy, pronounced characterological changes or psychotic disorders in which there is a threat to the woman and fetus. The issue of termination of pregnancy is decided on a commission by an obstetrician-gynecologist and a neuropathologist-epileptologist, taking into account the opinion of the patient.
When deciding to continue gestation, women with compensated epilepsy in remission are recommended to be examined by an epileptologist every 2 months, in the presence of partial seizures, a consultation is held at least 1-2 times a month. At the 19th-20th week, a pregnant woman is usually hospitalized in a hospital for a comprehensive examination and preventive therapy. The standard treatment regimen for active epilepsy usually includes:
- Anticonvulsive drugs. Basic monotherapy with retarded antiepileptic drugs is carried out in the minimum effective dosage with the use of therapeutic drug monitoring. Derivatives of carboxamide and valproic acid are recommended. With an increase in seizures, it is possible to prescribe tranquilizers.
- Folic acid preparations. To reduce the risk of teratogenesis and spontaneous miscarriage, provoked by violations of the folate cycle under the influence of anticonvulsants, folic acid is prescribed to pregnant women before the 13th week of gestation. Even more effective is the use of combined drugs, which also include iron and cyanocobalamin.
- Vitamin K1. Funds with phylloquinone are used from the 36th week to prevent erythroblastosis of newborns. Due to the effect on the synthesis of prothrombin, factors VII, IX, X, proteins C, S, Z, vitamin K increases blood clotting. Phylloquinone also improves the interaction of vitamin D and calcium, which helps strengthen bones and prevent osteoporosis.
Therapy is supplemented with phytosedatives, vitamin and mineral complexes containing B vitamins, zinc, selenium, magnesium, omega-3 acids. Surgical methods of treating the disease during pregnancy are not used.
Childbirth with epilepsy
Patients suffering from epilepsy are recommended to be hospitalized in a specialized obstetric hospital at 38-39 weeks of gestational age. With complete clinical and electroencephalographic remission, the preferred method of delivery is natural childbirth with epidural anesthesia and control of the concentration of antiepileptic drugs in the blood. Indications for caesarean section, in addition to obstetric complications, are an increase in convulsive seizures at the end of pregnancy and the occurrence of epileptic status.
Due to changes in metabolism and a decrease in a woman’s weight in the early postpartum period and during the first 3 months after childbirth, antiparoxysmal therapy needs to be adjusted. In the absence of skin rashes, pronounced sedation, irritability, and other complications, breastfeeding is allowed against the background of antiepileptic treatment.
Prognosis and prevention
With adequate antiparoxysmal therapy, pregnancy in patients suffering from epilepsy has a favorable outcome. Before conception, it is recommended to achieve at least a 3-year drug remission, which allows you to gradually cancel treatment. The minimum condition for gestation planning is the absence of generalized paroxysms for more than six months or subcompensation of the disease with rare attacks (no more than 4 per year). During 2-3 months before pregnancy, prophylactic folic acid intake is indicated. Specific prevention of epilepsy during gestation has not been proposed due to the polyetiological nature of the disease.