Introduction
Neurological diseases are quite rare among women of childbearing age. However, several diseases can occur during pregnancy or postpartum; preeclampsia and delivery-associated neurological conditions are very common. Approximately 50 % of critically-ill obstetric patients have neurologic involvement.
Neurologic manifestations may result from obstetric illnesses, including eclampsia, acute fatty liver of pregnancy, and amniotic fluid embolism. In some patients, pre-existing medical disorders such as hypertension, rheumatological disorders, or intracranial neoplasms may worsen during pregnancy or puerperium. In addition, pregnancy itself may predispose to some medical conditions.
A few other diseases that can be associated with pregnancy are ischemic stroke, cerebral venous thrombosis, and intracerebral hemorrhage. They are quite difficult to treat and pose a high risk of morbidity and mortality. If these neurological diseases are not recognized and treated, they can lead to fatal consequences. In addition, during pregnancy, many medications and diagnostic aids are avoided as they can cause harm to the fetus. Therefore, identifying such patients at the earliest is very important.
How Does Stroke Affect Pregnancy?
A stroke can be defined as the abrupt onset of focal neurological deficit due to vascular cause. It can be classified as ischemic and hemorrhagic, which majorly contribute to morbidity and mortality during pregnancy and the puerperium.
An ischaemic stroke can be due to obstruction to the blood flow, whereas a hemorrhagic stroke is the rupture of blood vessels. The physiologic and hemodynamic changes in pregnancy promote a state of relative hypercoagulability, increased cardiac overload, and altered vascular tone to meet the physiologic needs of the growing fetus and decrease hemorrhage during delivery. Also, there are high chances of recurrent strokes in the subsequent pregnancy or later in life.
The nonfocal symptoms include headache and altered consciousness. A seizure may complicate the clinical presentation and is more common in patients with venous thrombosis and subsequent venous infarctions. The main aim for the clinician is to differentiate stroke from stroke mimics and also further differentiate between ischemic and hemorrhagic events.
Laboratory Diagnosis: Ideally, a non-contrast head computerized tomography (CT) with appropriate fetal shielding or magnetic resonance imaging (MRI) of the brain is recommended. It greatly facilitates diagnosis with minimal risk to the fetus.
Treatment: Administration of tissue plasminogen activator is recommended in case of ischemic stroke. The major adverse effect of this drug is hemorrhage or, more specifically, intracerebral hemorrhage.
How Does Cerebral Venous Thrombosis Affect Pregnancy?
Cerebral venous thrombosis, usually associated with dural sinus thrombosis, affects approximately 12 % of pregnancies. There is a 300 % increase in clotting factors circulating during pregnancy. Levels of factors II, VII, and X are also increased. Although protein S is decreased, protein C remains unchanged.
Clinical Presentation:
Headache is the most common symptom of cerebral venous thrombosis and occurs in all patients. Other manifestations include
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Focal seizures.
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Paresis.
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Altered consciousness.
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Isolated intracranial hypertension.
Treatment: The management of cerebral venous sinus thrombosis with unfractionated heparin, or low molecular weight heparin (LMWH), has been proven safe and effective, even in patients with a preexisting intracranial hemorrhage. The activated partial thromboplastin time is maintained at twice the baseline value. Recombinant tissue-type plasminogen activator or urokinase has been used with variable success.
How Does Seizures Affect Pregnancy?
Approximately 0.5 % of all pregnancies are estimated to be complicated by epilepsy. Status epilepticus is associated with high maternal as well as fetal mortality.
Effects on the patient:
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Lactic acidosis.
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Increased cardiac output.
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Transient elevation of blood pressure.
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Increased intra-abdominal pressure.
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Redistribution of blood flow to the brain and muscles, with a consequent decrease in visceral and uterine flow.
The risk of developing a seizure during labor is nine times that during the rest of pregnancy.
Effects on the fetus:
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Perinatal mortality is three times higher.
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Prematurity.
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Perinatal death.
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Congenital anomalies associated with antiepileptic drugs.
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Hemorrhagic diseases of the newborn.
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Intracranial hemorrhage.
Treatment: Proper measures to prevent seizures during pregnancy must be emphasized. The benefits of seizure prevention must be balanced against the teratogenic risk of antiepileptic drugs. They should preferably be on a single antiepileptic agent. Regular therapeutic drug monitoring of antiepileptic drug levels is highly recommended. Sleep deprivation should be avoided. Folate supplements before pregnancy are recommended. Regular prenatal monitoring for fetal malformations should be done.
If seizures occur during pregnancy, they should be treated aggressively. The patient is asked to lay on the left lateral position to increase uterine blood flow and prevent aspiration. Oxygen should be administered if required. Intravenous Lorazepam 2 mg bolus should be repeated every five minutes. Alternatively, diazepam is given in 5 to 10 mg boluses. Check for blood glucose, electrolytes, and calcium levels. Intravenous magnesium is preferred if the seizures are due to eclampsia. Patients may normally deliver or have a cesarean section because of the risk of fetal hypoxia.
How Does Myasthenia Gravis (MG) Affect Pregnancy?
It is an autoimmune neuromuscular disease characterized by weakness and fatigue of the skeletal muscles of the face and extremities. It is always advisable for women to delay the pregnancy for at least two years following diagnosis as mortality is highest in this disease. Exacerbations of symptoms are most likely to occur in the first trimester or following delivery.
Management: Acetylcholinesterase inhibitors, such as Pyridostigmine and Neostigmine, are frequently being used in the treatment of myasthenia gravis, in addition to corticosteroids. Vaginal delivery is recommended for women with myasthenia. Assistance might be necessary for the second stage with the help of forceps or vacuum extraction, as striated muscles are involved. Cesarean section should be performed only for obstetric indications.
How Does Multiple Sclerosis (MS) Affect Pregnancy?
It is a central nervous system disease involving the brain and spinal cord. Both neuroinflammation, as well as neurodegeneration characterizes it. It is usually diagnosed between twenty to fifty years of age. So women with MS will therefore become pregnant relatively early in their illness and usually have correspondingly little associated disability.
Management: Relapsing and remitting cases are treated with disease-modifying drugs. Although the risk of relapse is reduced during pregnancy, this protective effect is less pronounced during the first and second trimesters. If relapse occurs, management is the same as for non-pregnant women. Mild relapses require no treatment at all.
Conclusion
Pregnancy will always elevate the challenges in managing neurologic diseases. It affects many neurological diseases, whereas some neurological diseases or their treatment may negatively impact pregnancy, labor, or delivery. Therefore, it is important to diagnose and provide early intervention in such cases as it has a high probability of complicating further and risking the life of the fetus and the mother.
