What is the appropriate management for a patient with Hereditary Hemorrhagic Telangiectasia (HHT) who presents with a decrease in sensorium?

Management of Decreased Sensorium in Hereditary Hemorrhagic Telangiectasia

A patient with HHT presenting with decreased sensorium requires immediate neuroimaging to evaluate for cerebral arteriovenous malformation hemorrhage, brain abscess from paradoxical embolism through pulmonary AVMs, or ischemic stroke from paradoxical embolism, followed by urgent screening for pulmonary AVMs if not previously performed. 1, 2

Immediate Diagnostic Evaluation

Emergent Neuroimaging

• Obtain urgent brain MRI or CT to identify the specific CNS pathology, as decreased sensorium in HHT can result from three distinct mechanisms: intracerebral hemorrhage from cerebral AVM rupture, brain abscess from paradoxical septic emboli through pulmonary AVMs, or ischemic stroke from paradoxical thromboemboli 1, 2
• Cerebral AVMs occur in up to 11% of HHT patients and can present with hemorrhage or mass effect causing altered mental status 3
• Brain abscess is a well-recognized complication in HHT patients with pulmonary AVMs, as right-to-left shunting allows bacteria to bypass pulmonary capillary filtration 1, 2

Pulmonary AVM Screening

• Perform urgent contrast echocardiography or chest CT if pulmonary AVMs have not been previously screened, as pulmonary AVMs occur in up to 33% of HHT patients and are the primary source of paradoxical emboli causing stroke or brain abscess 4, 3
• Pulmonary AVMs create right-to-left shunts that allow septic or thrombotic emboli to bypass the pulmonary capillary bed and reach the cerebral circulation 4, 1

Additional Metabolic Evaluation

• Assess for hepatic encephalopathy if hepatic AVMs are known or suspected, as symptomatic liver involvement can cause encephalopathy through portal hypertension and portosystemic shunting 5
• Check complete blood count, as severe anemia from chronic bleeding affects approximately 50% of HHT patients and can contribute to altered mental status 4, 6

Management Based on Neuroimaging Findings

If Cerebral AVM Hemorrhage Identified

• Consult neurosurgery immediately for evaluation of surgical evacuation or endovascular embolization, as cerebral AVMs in HHT can cause life-threatening hemorrhage 7, 2
• Endovascular therapies are very effective and safe in experienced hands for hemorrhagic lesions in HHT 7

If Brain Abscess Identified

• Initiate broad-spectrum antibiotics immediately and consult neurosurgery for potential drainage, as brain abscess in HHT results from paradoxical septic embolism through pulmonary AVMs 1
• Perform percutaneous transcatheter embolization of pulmonary AVMs regardless of feeding artery size to prevent recurrent paradoxical embolism and future neurological complications 4, 6

If Ischemic Stroke from Paradoxical Embolism

• Treat the acute stroke according to standard protocols, then perform pulmonary AVM embolization to prevent recurrent paradoxical embolic events 4, 1
• Anticoagulation is not an absolute contraindication in HHT despite bleeding risks, with heparin agents and vitamin K antagonists preferred over direct oral anticoagulants 4, 6

If Hepatic Encephalopathy Identified

• Treat with intensive medical therapy including salt restriction, diuretics, and standard encephalopathy management (lactulose, rifaximin) as recommended for cirrhotic patients 5
• Approximately 63% of patients show complete response and 21% show partial response to intensive medical therapy for complicated liver VMs 5
• Consider liver transplantation only after 6-12 months of failed intensive medical therapy, as post-operative mortality is 7-10% but long-term survival reaches 82-92% 5

Critical Pitfalls to Avoid

• Never perform liver biopsy in HHT patients due to catastrophic hemorrhage risk, even when investigating hepatic involvement as a cause of encephalopathy 5, 8
• Do not dismiss neurological symptoms as benign in HHT patients with epistaxis or known pulmonary AVMs, as nearly one in five HHT patients develop stroke or cerebral abscess 8
• Recognize that cerebral or spinal arteriovenous fistulas may be present in patients with epistaxis or pulmonary AVMs, requiring high clinical suspicion 7

Long-Term Prevention

• All HHT patients should undergo screening for pulmonary AVMs with contrast echocardiography or chest CT, as these can be treated presymptomatically to prevent stroke and cerebral abscess 4, 8
• Screen for cerebral AVMs with brain MRI in all HHT patients, particularly those with HHT1 (ENG mutations) where cerebral AVMs are more common 8
• Ensure family members undergo screening given the 50% inheritance risk with autosomal dominant transmission 6, 8