Multiple Sclerosis and other Neurological Conditions
Jennifer R. Codd, MD
PGY-1 Resident
Creighton University East Valley Arizona
Chandler, Arizona, United States
Brandon Poppe, DO
PGY-3 Resident
Creighton University East Valley Arizona
Chandler, Arizona, United States
Jennifer R. Codd
University of Arizona College of Medicine - Phoenix
Phoenix, Arizona, United States
A 34-year-old female presented for evaluation of diffuse myalgias and paresthesia in the bilateral lower extremities. Symptoms presented one week following a viral upper respiratory infection and progressed to include painful paresthesia in the distal bilateral upper extremities and lower extremities. Physical examination demonstrated decreased sensation in the distal extremities and decreased deep tendon reflexes in the ankles. Pertinent laboratory findings include serum sodium of 142 mmol/L on initial presentation, which decreased to 125 mmol/L four days later with low serum osmolality (257 mOsm/kg) and elevated urine osmolality and urine sodium (584 mOsm/kg and 54 mmol/L respectively), which corrected with fluid restriction and salt tablets. TSH and morning cortisol were within normal limits. Brain and spine MRIs were negative for demyelinating lesions. CSF analysis revealed cytoalbuminologic dissociation. The patient was diagnosed with Guillain-Barre Syndrome (GBS) with secondary Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH).
Discussions:
Given the low serum osmolality, elevated urine osmolality and urine sodium, and improvement with fluid restriction and salt tablets, she was diagnosed with SIADH secondary to Guillain-Barre Syndrome. SIADH is a rare complication of GBS, believed to be due to autonomic dysfunction that affects the hypothalamic regulation of antidiuretic hormone (ADH). The pathophysiology is believed to be due to inflammation and demyelination of autonomic nerve fibers, impairing the afferent nerve signaling to the central nervous system resulting in nonosmotic release of ADH. Hyponatremia due to GBS may increase patients’ risk for morbidity and mortality.
Conclusions:
SIADH is a rare complication of Guillain-Barre Syndrome that is likely caused by dysautonomia. Patients with SIADH in the setting of GBS are at higher risk for complications, therefore careful monitoring during recovery is essential.
