Category: Rare Neurometabolic Diseases
Objective: To describe the investigation of ataxia in a patient with primary biliary cholangitis (PBC) despite ursodeoxycholic acid (UDCA) treatment.
Background: PBC is an autoimmune condition that results in destruction of the intrahepatic bile ducts, often causing fatigue and pruritus and sometimes progressing to cirrhosis. Other long-term complications may include fat-soluble vitamin deficiencies, hyperlipidemia, and osteoporosis. Although there is no cure for PBC, UDCA is the first-line treatment, reducing hepatocyte apoptosis and fibrosis. Adjuvant treatment may involve fat-soluble vitamin repletion, cholestyramine for pruritis, and oral vitamin D and calcium for osteoporosis prevention [1].
Method: A 74-year-old gentleman with a 19-year history of PBC presented with ataxia. He reported a 9 month history of recurrent episodes of ataxia in the setting of hyperammonemia. These episodes resolved when his hyperammonemia was treated with UDCA. However, for around a month before his clinic visit, he observed persistent balance issues despite his normal ammonia levels. Neurologic exam during this visit was significant for slight dysarthria, clumsiness with finger taps, decreased vibration sensation in the bilateral feet, truncal ataxia with standing, ataxic gait, and unsteady turns. There was no asterixis.
Results: Nine months prior, MRI brain showed mild cerebellar atrophy, and MRI spine demonstrated multilevel cervical changes with mild canal stenosis and heterogenous appearance of the liver consistent with cirrhosis. Ammonia level was normal at 52, despite elevated levels during prior episodes of ataxia. Antibody studies of gliadin, TTG, ANA, SSA/SSB, and anti-TPO were negative. Levels of B1, B12, and TSH were normal. Vitamin E was notably low at <0.5, and vitamin B6 was mildly low at 15.1. We diagnosed ataxia secondary to Vitamin E deficiency in the context of malabsorption due to PBC. The patient was treated with vitamin E 400 units daily with symptomatic improvement.
Conclusion: Although hyperammonemia is a common cause of ataxia in patients with PBC, fat-soluble vitamin deficiency may also be a contributing factor. Patients with PBC are at an elevated risk for other autoimmune conditions that may result in ataxia or other symptoms such as thyroid dysfunction, systemic sclerosis, and Sjögren’s syndrome [2]. This case highlights the importance of a thorough workup to treat symptoms in their entirety.
References: 1. Pandit S. Primary Biliary Cholangitis. StatPearls, 2023.
2. Chalifoux SL. Extrahepatic Manifestations of Primary Biliary Cholangitis. Gut and Liver, 2017.
To cite this abstract in AMA style:
M. Rajani, P. Prakash. Ataxia in PBC: The Overlooked Role of Fat-Soluble Vitamin Deficiency [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/ataxia-in-pbc-the-overlooked-role-of-fat-soluble-vitamin-deficiency/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/ataxia-in-pbc-the-overlooked-role-of-fat-soluble-vitamin-deficiency/