Pregnancy and Neurologic Disorders

Seizures

• Epilepsy refers to recurrent seizure activity in the absence of a metabolic disorder or acute brain disease.
• Seizures can be focal, generalized, or a combination of both.
• Parturients who were seizure-free prior to their pregnancy are unlikely to have a seizure during their pregnancy.¹
• Seizure frequency may increase during pregnancy for several reasons (Table 1).

Antiepileptic Drugs and Their Effects on the Fetus (Figure 1)

Anesthetic Considerations of Seizure Disorder in Parturients¹

• Antiepileptic drugs can induce CYP450 enzymes, which can affect the plasma concentrations of several classes of medications, including neuromuscular blockers, beta blockers, and calcium channel blockers.
• Hypoxia and acidosis during a seizure may lead to placental abruption and subsequent fetal compromise, with increased risk for cesarean delivery.
• Small doses of propofol or benzodiazepine arrest most seizures.
• Seizures after induction are most likely due to the administration of etomidate or ketamine.

Myasthenia Gravis (MG)

• MG is a chronic autoimmune disorder characterized by antibodies that target the nicotinic acetylcholine receptor on skeletal muscle, resulting in skeletal muscle weakness that worsens with activity. It can be treated with anticholinesterase drugs (e.g., pyridostigmine), steroids (e.g., prednisone), and other immunosuppressants (e.g., azathioprine).² Early age of onset and isolated ocular myasthenia are good prognostic signs.
• See the OA summary on MG for more details. Link
• Two types of crises can occur with MG:

• Obstetric and anesthetic considerations for the management of the parturient with myasthenia gravis are listed in Table 2.¹

Spinal Cord Injury

• Patients with spinal cord injury can have varying presentations depending on the level of the initial injury as well as the severity of the insult. Patients with severe injury to the spinal cord may experience spinal shock, which is a temporary areflexia/hyporeflexia and transient sensorimotor dysfunction that usually resolves within 24-48 hours, or they may have permanent neurologic deficits.¹
• Parturients with spinal cord injury may require special considerations depending on the level of the lesion and expected mode of delivery (Table 3).

• AH is the absence of central inhibition on the sympathetic neurons in the cord below the injury, such that noxious stimuli to pelvic viscera may result in extreme sympathetic hyperactivity, leading to severe hypertension and reflexive bradycardia (Figure 2).
• See the OA summary on autonomic dysreflexia for more details. Link

• Obstetric and anesthetic considerations for a parturient with spinal cord injury are listed in Table 4.³

MS

• MS is a demyelinating condition with variable neurologic disabilities, including motor weakness, impaired vision, ataxia, and bladder and bowel dysfunction.¹

• Patients with MS can experience abrupt attacks and go into remission, and some patients may experience progressive worsening of symptoms.
• Treatment for acute attacks includes immunosuppressive agents or intravenous immunoglobulin/plasmapheresis for severe relapses. Pregnant patients have lower rates of relapse compared to patients with MS who are not pregnant or postpartum patients with MS.⁵
• See the OA summary on MS for more details. Link
• Both neuraxial and general anesthesia are considered safe, paying special attention to respiratory function and temperature regulation (avoiding hyperthermia). Although there is a higher incidence of relapse in the several months postpartum, neither pregnancy nor anesthesia worsens long-term MS progression.¹

Subarachnoid Hemorrhage

• Intracerebral hemorrhage during pregnancy is most associated with an arteriovenous malformation or aneurysm1. Anesthetic considerations vary depending on whether the lesion has been treated or untreated, as well as whether the management of the parturient involves non-obstetric surgery or labor and delivery.
• See the OA summary on intracranial lesions in pregnancy for more details. Link

GBS

• GBS, also known as acute idiopathic polyneuritis, is an inflammatory demyelinating illness often preceded by a viral infection, presenting with distal-to-proximal muscle weakness. Symptoms peak at 2-3 weeks, and most patients make a complete recovery. Autonomic nervous system involvement, loss of reflexes, total paralysis, and respiratory failure can occur, and treatment is largely supportive. Plasmapheresis can be used to reduce the duration of illness.¹
• See the OA summary on GBS for more details. Link
• Pregnancy does not affect disease course; however, the incidence of GBS is higher in the first few months postpartum. Neuraxial techniques have been used in parturients with GBS. Still, there is insufficient evidence to conclude their safety/potential harmful effects, and succinylcholine should be avoided in patients with acute muscle wasting because of the risk for hyperkalemia. Parturients with a history of GBS may have persistent diminished respiratory reserve; thus, pulmonary evaluation during pregnancy should be considered.¹