Lactulose to the Rescue: A Case of Toxic Hepatic Encephalopathy Caused by Portosystemic Shunting and Epistaxis in a Patient with Hereditary Hemorrhagic Telangiectasia

Diffuse Cerebral Edema and Impending Herniation Complicating Hepatic Encephalopathy in Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disease characterized by the formation of cutaneous and visceral telangiectasias and arteriovenous malformations (AVM). Multiple organs may be affected, including the nasal mucosa, skin, lungs, gastrointestinal tract, and brain. The following case highlights a unique manifestation of HHT in a patient with a gastrointestinal hemorrhage and epistaxis, resulting in hyperammonemia and diffuse cerebral edema and herniation. Clinicians should be aware of this potential complication in such patients and initiate ammonia-reducing agents early to avoid this devastating consequence.

Minimal portosystemic encephalopathy: A new nosological entity in patients with hereditary haemorrhagic telangiectasia

BACKGROUND

Portosystemic shunts in Hereditary Haemorrhagic Telangiectasia (HHT) are often overlooked by conventional imaging although they could reduce hepatic clearance of gut-derived toxins.

AIMS

To evaluate, the presence of subclinical neurological alterations (SNAs), that we named "minimal portosystemic encephalopathy" (mPSE) in HHT patients without advanced liver disease (ALD).

METHODS

In this cross sectional study, consecutive HHT outpatients were firstly screened by critical flicker frequency (CFF) test (abnormal ≤39Hz), and the simplified animal naming test (S-ANT₁) (abnormal <15) was used to confirm the diagnosis of mPSE. Furthermore, we evaluated the effect of lactulose administration on mPSE. Multi-slice CT, cerebral dynamic magnetic resonance, laboratory analyses and transient elastography were also used.

RESULTS

None of the 37 enrolled patients showed portosystemic shunts at imaging techniques. However, 33 patients had normal CFF values (CFF-) and 4 displayed CFF alterations (37.0±0.7Hz, CFF+). The S-ANT₁ confirmed an impaired neurological performance (10.2±2.8) in CFF+ patients thus confirming the presence of mPSE. Noteworthy, lactulose administration determined a CFF increase (39.1±0.4Hz) and S-ANT₁ normalization in these patients. Neither mPSE- nor mPSE+ patients had ALD and showed similar demographic, clinical and laboratory parameters. Finally, no mPSE+ patient showed radiologically-detectable brain vascular malformations or other brain abnormalities at imaging.

CONCLUSIONS

HHT patients represent a human model of mPSE secondary to portosystemic shunts escaping radiological detection. mPSE evaluation should be incorporated in HHT surveillance protocols since it can affect both health-related/social aspects and pharmacokinetics of orally administered drugs with a narrow therapeutic index and high hepatic first-pass uptake.

Hereditary Hemorrhagic Telangiectasia Induced Portosystemic Encephalopathy: A Case Report and Literature Review

Hereditary hemorrhagic telangiectasia (HHT) is a rare disorder characterized by telangiectasias and arteriovenous malformations (AVMs), which can involve multiple organ systems. Although hepatic involvement is common, the development of portosystemic encephalopathy is extremely rare. We herein report a 72-year-old woman with HHT-induced portosystemic encephalopathy secondary to hepatic arteriovenous malformations. She presented with disturbance of consciousness, and her serum ammonia level was elevated at 270 mg/dL. Color Doppler ultrasonography and contrast-enhanced computed tomography showed hepatic AVMs and shunts, which were useful for making the definite diagnosis. Portosystemic encephalopathy should be considered as a differential diagnosis in HHT patients presenting with disturbance of consciousness.