Extrapontine Myelinolysis and Reversible Parkinsonism After Hyponatremia Correction in a Case of Pituitary Adenoma: Hypopituitarism as a Predisposition for Osmotic Demyelination

• Published in: World neurosurgery 2018-10, Vol.118, p.304-310
• Main Authors: Perikal, Parichay J., Jagannatha, Aniruddha Tekkatte, Khanapure, Kiran S., Furtado, Sunil Valentine, Joshi, Krishna Chaitanya, Hegde, Alangar Satyaranjandas
• Format: Article
• Language: English
• Subjects: Adenoma - complications; Adenoma - diagnostic imaging; Adenoma - therapy; Demyelinating Diseases - diagnostic imaging; Demyelinating Diseases - etiology; Demyelinating Diseases - therapy; Extrapontine myelinolysis; Female; Humans; Hydrocortisone - administration & dosage; Hyponatremia; Hyponatremia - diagnostic imaging; Hyponatremia - etiology; Hyponatremia - therapy; Hypopituitarism; Hypopituitarism - complications; Hypopituitarism - diagnostic imaging; Hypopituitarism - therapy; Levodopa - administration & dosage; Middle Aged; Myelinolysis, Central Pontine - complications; Myelinolysis, Central Pontine - diagnostic imaging; Osmotic demyelination; Parkinsonian Disorders - complications; Parkinsonian Disorders - diagnostic imaging; Parkinsonian Disorders - therapy; Parkinsonism; Pituitary adenoma; Pituitary Neoplasms - complications; Pituitary Neoplasms - diagnostic imaging; Pituitary Neoplasms - therapy; Saline Solution, Hypertonic - administration & dosage
• ISSN: 1878-8750; 1878-8769
• DOI: 10.1016/j.wneu.2018.07.115

Osmotic demyelination syndrome commonly follows rapid correction of hyponatremia. Although pons is a common location, extrapontine locations, such as striatum and thalamus, have been reported. A 48-year-old woman presented with masked facies, shuffling gait, and pill-rolling tremors suggestive of acute-onset parkinsonism. Hyponatremia was diagnosed following a bout of diarrhea, which was corrected with hypertonic saline. Magnetic resonance imaging of the brain showed a giant pituitary adenoma. Hyperintensities on T2-weighted imaging were also seen at the level of pons and bilateral striatum. Central pontine myelinolysis and extrapontine myelinolysis were diagnosed. Hormonal assay showed hypocortisolism, secondary hypothyroidism, and hypogonadism. The patient was started on levodopa-carbidopa, steroids, and thyroxine. She underwent transnasal pituitary adenoma excision. At 6 months postoperatively, she had recovered completely with normal gait. Repeat imaging showed complete resolution of myelinolysis. At 36 months, she continued to have hypocortisolism and hypothyroidism requiring replacement. Extrapontine myelinolysis with parkinsonism and asymptomatic central pontine myelinolysis is rare with few cases described in the literature. Our patient had a pituitary adenoma with hyponatremia requiring sodium correction, and we believe that hypopituitarism might have predisposed her to osmotic demyelination. We reviewed relevant literature on extrapontine myelinolysis in suprasellar tumors and the pathophysiology. Hypopituitarism is an underrecognized cause of hyponatremia. When treating a patient with hyponatremia, knowing the pituitary function status is a prerequisite for the physician to prevent osmotic demyelination syndrome. •ODS can occur with slow rates of sodium correction.•CPM and EPM can be morbid complications of sodium correction; rarely, EPM can manifest with acute-onset parkinsonism.•EPM associated with parkinsonism tends to have a better prognosis with levodopa-carbidopa therapy.•Hypopituitarism and hypoadrenalism can predispose to ODS in a patient with hyponatremia.•The treating physician needs to keep this predisposition in mind when treating patients with hyponatremia.