Encephalopathy with cerebellar deficits in a context of hyponatremia.

Background: Hyponatremia can present with various neurological manifestations ranging from altered mental status to cerebral herniation and death. However, cerebellar symptomatology has been rarely reported.

Case presentation: A 53-year-old male with a history of diabetes mellitus type 2, hypothyroidism, and anxiety disorder presented with impaired level of consciousness and ataxia. His laboratory tests were consistent with sepsis (staphylococcus aureus in blood culture), hyponatremia with euvolemia, low serum and high urine osmolarity. Brain computerized tomography revealed diffuse cerebral edema. Antibiotics and sodium replenishment were initiated. A lumbar puncture and subsequent investigations ruled out alternative etiologies (metabolic, autoimmune, paraneoplastic and other infectious causes). Repeated brain magnetic resonance imaging excluded osmotic demyelination syndromes. After serum sodium restoration his symptoms gradually improved.

Discussion: We highlight reversible cerebellar ataxia as a rare manifestation of hyponatremia, in the context of sepsis and possible syndrome of inappropriate antidiuretic hormone ADH release. Extensive diagnostic work-up is essential for the exclusion of other diagnoses.