What neurological symptoms should be monitored after carotid stent (carotid artery stent) placement?

Neurological Symptoms to Monitor After Carotid Stent Placement

Monitor continuously for stroke symptoms (weakness, numbness, speech changes, vision loss), transient ischemic attacks, seizures, and altered consciousness during the procedure and for at least 48 hours post-procedure, as these represent the most critical neurological complications requiring immediate intervention. 1

Critical Periprocedural Monitoring (During and Immediate Post-Procedure)

Level of consciousness, speech function, and motor strength must be assessed continuously throughout the stent procedure by the physician or circulating nurse, avoiding excessive sedation to facilitate ongoing neurological assessment. 1

Acute Stroke Symptoms (0-48 hours)

• Hemispheric (cortical) ischemia: Weakness, paralysis, numbness, or tingling affecting one side of the body (contralateral to the stented carotid artery) 1
• Speech disturbances: Aphasia if the dominant hemisphere (usually left) is affected 1
• Neglect syndrome: If the non-dominant hemisphere (usually right) is affected 1
• Visual deficits: Temporary or permanent partial/total blindness in the ipsilateral eye (amaurosis fugax or retinal artery occlusion) 1
• Altered consciousness: Any change in mental status or level of alertness 1

Incidence and Timing

• Transient ischemic attacks (TIAs): Occur in 1-2% of patients, with some occurring between 1-14 days post-stenting 1, 2
• Minor strokes: 2.2% incidence, with 3 of 10 occurring >24 hours after stenting in one series 2
• Major strokes: 0.7% incidence 1
• Total stroke and death rate: Approximately 4.2% within 30 days 2

Rare but Critical Neurological Complications (<1% each)

Hyperperfusion Syndrome

• Presentation: Related to hypertension and anticoagulation 1
• Management priority: Maintain systolic blood pressure below 180 mm Hg to minimize risk of intracranial hemorrhage or hyperperfusion syndrome 1

Intracranial Hemorrhage

• Incidence: <1% of CAS procedures 1
• Risk factors: Hypertension and anticoagulation 1

Seizures

• Incidence: <1% of cases 1
• Mechanism: Related predominantly to hypoperfusion 1

Extended Monitoring Period (Up to 30 Days)

Continue neurological surveillance for the full 30-day periprocedural period, as late embolic phenomena can occur beyond the immediate post-procedure window. 2

• Late minor strokes: The occurrence of minor strokes >24 hours following stenting may indicate a possible late embolic phenomenon 2
• Delayed TIAs: Can occur up to 14 days post-stenting 2

Hemodynamic-Related Neurological Symptoms

Hypotension-Related Symptoms

• Sustained hypotension: Can persist for 18-33 hours after the procedure 3
• Associated bradycardia: May occur with or without third-degree atrioventricular block 3
• Neurological manifestations: Symptoms related to cerebral hypoperfusion 1

Continuous electrocardiogram and blood pressure monitoring has become routine during and after CAS due to frequent vasovagal and vasodepressor reactions. 1

Long-Term Follow-Up Considerations

Clinical Follow-Up

• Formal neurological examination: Plays an important part in assessment of peri-procedural complications and long-term efficacy 1
• Annual assessment: Check for neurological symptoms, cardiovascular risk factors, and treatment adherence at least yearly 1

Surveillance Imaging

• Duplex ultrasound (DUS): Recommended within the first month after ICA revascularization 1
• Annual DUS: Monitor for restenosis, which can manifest with recurrent neurological symptoms 1

Common Pitfalls to Avoid

1. Inadequate monitoring duration: Neurological deficits can occur up to 48 hours post-procedure, not just during the procedure 4
2. Excessive sedation: Prevents adequate neurological assessment during the procedure 1
3. Delayed recognition of late embolic events: Minor strokes occurring >24 hours post-stenting warrant investigation 2
4. Inadequate blood pressure control: Post-operative hypertension is a risk factor for stroke, TIAs, and intracranial hemorrhage 1

High-Risk Features Requiring Enhanced Vigilance

• Advanced age (≥80 years): Independent predictor of procedural stroke 5, 6
• Symptomatic lesions: 8.3-fold increased risk of periprocedural neurological deficits 4
• Long stenotic segments (≥11.2 mm): 5.2-fold increased risk 4
• Multiple or complex stenoses: Independent predictor of procedural stroke 5

Patients with these features require more intensive neurological monitoring and may benefit from prolonged observation periods.