Neuroacanthocytosis, a rare and challenging diagnosis

Abstract

Neuroacanthocytosis syndromes are a heterogeneous group of genetically defined neurological disorders characterized by progressive degeneration of the basal ganglia, along with red blood cell acanthocytosis. Despite its likelihood of being under-diagnosed, its reported prevalence is approximately 1–5 per 1,000,000 individuals. Its onset is usually by the third or fourth decade of life, and it's classically manifested by orolingual action-induced dystonia, generalised chorea, vocal tics, and stereotypies. Other manifestations include dysphagia, dysarthria, peripheral neuropathy, cognitive decline, areflexia, and parkinsonism. We herein report a rare case of neuroacanthocytosis in a 40 years old male who presented with a 3 years history of multiple falls, along with difficulty in swallowing and speaking that resulted in a weight loss of 71 kg. In addition, he suffered an apparent cognitive decline and some psychiatric disturbances, on top of his baseline obsessive-compulsive behavior. He was initially misdiagnosed and investigated for Huntington's disease, Huntington-like diseases, and malnutrition but the workup denied these diagnoses. The patient underwent several investigations including laboratory investigations, a brain MRI, and electrodiagnostic studies. His lab tests revealed red blood cell acanthocytosis of more than 5% on the peripheral smear, in addition to elevated lactate dehydrogenase and creatinine phosphokinase. His brain MRI was unremarkable. Nerve conduction studies and electromyography performed on all four limbs and paraspinal muscles revealed findings suggestive of chronic polyneuropathy. In view of the absence of targeted treatment for neuroacanthocytosis, the prognosis was explained to the family and the importance of follow-up was emphasized to optimize symptomatic management.