How should a 30-year-old woman at 21 weeks gestation with a brief, reversible neurological event be evaluated and managed?

Evaluation and Management of Transient Neurological Symptoms in a 30-Year-Old Woman at 21 Weeks Gestation

This patient requires urgent neurological assessment with brain imaging (MRI preferred) to exclude life-threatening conditions including cerebral venous thrombosis, stroke, and posterior reversible encephalopathy syndrome (PRES), as pregnancy—particularly the third trimester and postpartum—significantly increases risk for these neurovascular emergencies. 1

Immediate Clinical Assessment

Critical History Elements

• Symptom characterization: Determine if symptoms affected upper body/face/cranial nerves versus isolated lower extremity involvement 1
• Headache presence and severity: Severe headache accompanying neurological symptoms raises concern for cerebral venous thrombosis, PRES, or stroke 1, 2
• Seizure activity: Any convulsive activity suggests PRES or eclampsia spectrum 3, 4
• Blood pressure: Hypertension is the biggest risk factor for stroke in pregnancy and can indicate preeclampsia/PRES 3, 4, 2
• Recent procedures: Any neuraxial anesthesia or epidural placement (though unlikely at 21 weeks) 1

Physical Examination Priorities

• Complete neurological examination: Document any focal deficits, cranial nerve abnormalities, motor/sensory changes 1, 5
• Blood pressure measurement: Essential to identify hypertensive emergency 3, 4, 2
• Fundoscopic examination: Assess for papilledema or retinal changes 3, 4
• Mental status assessment: Altered consciousness suggests PRES or other serious pathology 3, 2

Differential Diagnosis by Symptom Distribution

Upper Body/Face/Cranial Nerve Involvement

The Association of Anaesthetists guidelines specifically identify these patterns as concerning for:

• Cerebral venous thrombosis: Pregnancy increases risk 35-fold, with mean 7-day delay from symptoms to diagnosis being dangerous 1, 2, 6
• PRES: Characterized by hypertension, seizures, altered mental status, headache, and vision changes 3, 4, 2
• Stroke (ischemic or hemorrhagic): Pregnancy-related hypercoagulability and hemodynamic changes increase third-trimester risk 2, 6, 5
• Reversible cerebral vasoconstriction syndrome: Often presents with severe headache and transient neurological deficits 1, 2
• Migraine with aura: Diagnosis of exclusion only after imaging excludes serious pathology 2, 6

Isolated Lower Body Symptoms

If symptoms were confined to lower extremities without upper body involvement:

• Peripheral nerve lesions: Lumbosacral nerve roots, sciatic nerve, femoral nerve, lateral cutaneous nerve of thigh 1
• Spinal cord pathology: Anterior spinal artery syndrome, cauda equina syndrome, direct trauma, compression, ischemia 1

Urgent Diagnostic Workup

Imaging Protocol

MRI brain without contrast is the preferred initial imaging modality for suspected neurovascular emergencies in pregnancy 1. The Association of Anaesthetists emphasizes that:

• MRI provides superior detection of cerebral venous thrombosis, PRES, and ischemic changes 1
• CT may be more accessible but is less sensitive for early changes 1
• Gadolinium contrast should be avoided unless absolutely necessary for fetal safety 1

Additional Diagnostic Studies

• Complete blood count with platelets: Assess for thrombocytopenia 1
• Coagulation studies: PT/PTT, fibrinogen if bleeding disorder suspected 1
• Comprehensive metabolic panel: Evaluate renal function, electrolytes 3, 4
• Urinalysis with protein: Screen for preeclampsia 3, 4, 2
• Blood cultures if febrile: Rule out infectious etiology 1

Advanced Imaging Considerations

If initial MRI is inconclusive but clinical suspicion remains high:

• MR venography or CT venography: Specifically evaluate for cerebral venous thrombosis 1
• Digital subtraction angiography: Gold standard for confirming isolated cortical vein thrombosis when other imaging is equivocal 1

Management Based on Findings

If Cerebral Venous Thrombosis Confirmed

• Immediate anticoagulation: Despite pregnancy, benefits outweigh risks for preventing progression 1, 2, 6
• Neurosurgical consultation: Particularly if intracranial hemorrhage present 1
• Close monitoring: Symptoms can progress rapidly; one case report showed deterioration despite anticoagulation requiring craniotomy 1

If PRES Identified

Research demonstrates 83% of severe preeclamptic women with headache show abnormal MRI findings, with 66% having cortical hyperintensities typical of PRES 4. Management includes:

• Blood pressure control: Aggressive antihypertensive therapy to prevent progression 3, 4, 2
• Seizure prophylaxis: Magnesium sulfate per eclampsia protocols 3, 4
• Delivery planning: Consider expedited delivery depending on gestational age and severity 3, 4, 5
• Serial neurological assessments: Monitor for progression to frank eclampsia 3, 4

If Imaging Normal

• Continued observation: Transient symptoms with normal imaging still require close follow-up 1, 2
• Repeat imaging if symptoms recur: Do not dismiss recurrent events 1, 5
• Neurology consultation: For persistent or recurrent symptoms despite normal initial workup 1, 5

Critical Pitfalls to Avoid

Do Not Delay Imaging

The Association of Anaesthetists emphasizes that hospitals must have protocols enabling rapid escalation and imaging access, including outside office hours 1. Mean time from symptom onset to diagnosis of isolated cortical vein thrombosis is 7 days—a dangerous delay 1.

Do Not Attribute to Benign Causes Without Imaging

While migraine and benign conditions are more common, the high morbidity and mortality of missed cerebral venous thrombosis, stroke, or PRES mandates imaging in pregnancy 1, 2, 6, 5. One case series showed that early MRI detection of PRES changes in preeclamptic women with headache prevented progression to eclampsia 4.

Do Not Assume Resolution Means No Pathology

Transient symptoms can represent:

• Transient ischemic attack: Requires urgent stroke workup 2, 6, 5
• Partial cortical vein thrombosis: May present with intermittent symptoms before complete occlusion 1
• Early PRES: Symptoms may fluctuate before full syndrome develops 3, 4

Pregnancy-Specific Considerations

Timing and Risk

• Third trimester and early postpartum carry highest risk for neurovascular events, but this patient at 21 weeks is not immune 1, 2, 6
• Pregnancy-related hypercoagulability begins in first trimester and progressively increases 2, 6
• Hemodynamic changes throughout pregnancy alter cerebrovascular dynamics 2, 6, 5

Treatment Modifications

• Anticoagulation is NOT contraindicated in pregnancy when cerebral venous thrombosis is diagnosed 1, 2, 6
• Aggressive blood pressure control is essential but must balance maternal and fetal perfusion 3, 4, 2
• Radiation exposure from CT should be weighed against diagnostic necessity, but MRI is preferred 1

Follow-Up Protocol

If Serious Pathology Excluded

• Neurology follow-up in 2-4 weeks: Assess for recurrent symptoms 7
• Patient education: Instruct to return immediately for recurrent neurological symptoms, severe headache, or seizure activity 1, 5
• Blood pressure monitoring: Continue surveillance for preeclampsia development 3, 4, 2

If Pathology Identified

• Multidisciplinary care: Neurology, maternal-fetal medicine, and potentially neurosurgery 1, 2, 6, 5
• Serial imaging: Monitor lesion evolution and treatment response 1, 3, 4
• Delivery planning: Coordinate timing and mode of delivery based on maternal and fetal status 3, 4, 5