Recurrent flaccid paraparesis due to acquired distal renal tubular acidosis and coexistent Devic’s disease: The “double trouble”

Abstract

ABSTRACT Renal tubular acidosis (RTA) consists of a group of disorders, caused by impaired distal renal tubular acid (hydrogen ion; H+) secreting ability, impaired proximal renal tubular reabsorption of filtered bicarbonate ion (HCO32 −), or both, resulting in hyperchloremic normal anion gap metabolic acidosis. Distal RTA (dRTA) occurs due to impaired acid-secreting ability of the alpha intercalated cells. Primary (inherited) dRTA, encountered mostly in children, is due to various mutations, whereas secondary (acquired) dRTA, which may manifest at any age, develops secondary to various autoimmune systemic conditions, with Sjogren’s syndrome reported to be the leading cause. In this study, we report a case of dRTA secondary to neuromyelitis optica, diagnosis, management, and long-term outcomes, with an aim of shedding light on this rare association, which quite often could be missed.