Abstract
Hyponatremia is the most common electrolyte abnormality seen in hospitalised patients and is also the most common electrolyte imbalance seen in critically ill neurologic patients. It can significantly alter the morbidity, short and long term mortality of the underlying disease.
The causes of hyponatremia are varied, but in neurologically ill patients, are most commonly attributed to Syndrome of Inappropriate Anti-diuresis and Cerebral Salt Wasting. Both these entities are cerebral in origin but have distinct pathophysiology, prognosis and treatment options.
In stroke SIADH (euvolemichyponatremia) occurs due to AVP secretion inappropriate to the osmotic threshold. The suppressed proximal renal tubular transport in this condition can lead on to bicarbonaturia and hypouricemia. The effective treatment is fluid restriction. Hypertonic saline therapy is reserved for cases of severe hyponatremia.
CSW, on the other hand, is essentially a volume depleted state, which occurs due to the combined effects of decreased sympathetic outflow and increased natriuretic peptides. This resultant natriuresis leads to volume depletion and an appropriate AVP response. So the treatment for CSW includes an aggressive volume replacement regimen with isotonic saline or in severe cases, hypertonic saline.
Thus most CSW patients meet the criteria for SIADH and have elevated AVP levels but worsen with the treatment protocol given for SIADH. This observation lead to the description of CSW as a separate entity and widespread studies were carried out to distinguish the two entities.
Hyponatremia, especially Cerebral Salt Wasting, occurring in the setting of stroke has been shown to worsen the prognosis of stroke, increase morbidity, short and long term mortality, and cause a poorer discharge disposition.
References
- McCance RA: Experimental sodium chloride deficiency in man. Proc R Soc Lond 119: 245–268, 1936
- Peters JP, Welt LG, Sims EA, Orloff J, Needham J: A salt-wasting syndrome associated with cerebral disease. Trans Assoc Am Physicians63: 57–64, 1950
- Cort JH: Cerebral salt wasting. Lancet 266: 752–754, 1954
- Leaf A, Bartter FC, Santos RF, Wrong O: Evidence in man that urinary electrolyte loss induced by Pitressin is a function of water retention. J Clin Invest 32: 868–878, 1953
- Schwartz WB, Bennett W, Curelop S, Bartter FC: A syndrome of renal sodium loss and hyponatremia probably resulting from inappropriate secretion of antidiuretic hormone. Am J Med 23: 529–542, 1957
- Nelson PB, Seif SM, Maroon JC, RobinsonAG: Hyponatremia in intracranial disease: perhaps not the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). J Neurosurg 55: 938–941, 1981
- Wijdicks EF, Vermeulen M, ten Haaf JA, Hijdra A, Bakker WH, van Gijn J: Volume depletion and natriuresis in patients with a ruptured intracranial aneurysm. Ann Neurol 18: 211–216, 1985
- Wijdicks EF, Ropper AH, Hunnicutt EJ, Richardson GS, Nathanson JA: Atrial natriuretic factor and salt wasting after aneurysmal subarachnoid hemorrhage. Stroke 22: 1519–1524, 1991
- Damaraju SC, Rajshekhar V, Chandy MJ: Validation study of a central venous pressure based protocol for the management of neurosurgical patients with hyponatremia and natriuresis. Neurosurgery 40: 312–316; discussion 316–317, 1997
- Tisdall M, Crocker M, Watkiss J, Smith M: Disturbances of sodium in critically ill adult neurologic patients: a clinical review. J Neurosurg Anesthesiol 18:57-63, 2006
- Flear CT, Gill GV, Burn J: Hyponatraemia: mechanisms and management. Lancet 2:26-31, 1981
- Waikar SS, Mount DB, Curhan GC: Mortality after hospitalization with mild, moderate, and severe hyponatremia. Am J Med 122:857-865, 2009
- Hasan D, Wijdicks EF, Vermeulen M: Hyponatremia is associated with cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage. Ann Neurol 27:106-108, 1990
- Karandanis D, Shulman JA: Recent survey of infectious meningitis in adults: review of laboratory findings in bacterial, tuberculous, and aseptic meningitis. South Med J 69: 449-457, 1976
- Sheikh Saleem et al :Hyponatremia in Stroke . Ann Indian Acad Neurol 2014;17:55-7
- Sane T, Rantakari K, Poranen A, Tahtela R, Valimaki M, Pelkonen R: Hyponatremia after transsphenoidal surgery for pituitary tumors. J Clin Endocrinol Metab 79:1395-1398, 1994
- Olson BR, Gumowski J, Rubino D, Oldfield EH: Pathophysiology of hyponatremia after transsphenoidal pituitary surgery. J Neurosurg 87:499-507, 1997
- Adrogue HJ, Madias NE: Hyponatremia. N Engl J Med 342:1581-1589, 2000
- Boulard G, Marguinaud E, Sesay M: Osmotic cerebral oedema: the role of plasma osmolarity and blood brain barrier. Ann Fr Anesth Reanim 22:215-219, 2003
- Wijdicks EF, Vermeulen M, Hijdra A, van Gijn J: Hyponatremia and cerebral infarction in patients with ruptured intracranial aneurysms: is fluid restriction harmful? Ann Neurol 17:137-140, 1985
- Rabinstein AA, Wijdicks EF: Hyponatremia in critically ill neurological patients. Neurologist 9:290-300, 2003
- Maesaka JK, Imbriano LJ, Ali NM, Ilamathi E: Is it cerebral or renal salt wasting? Kidney Int 76:934-938, 2009
- Nolph, K.D. and Schrier, R.W. (1970) Sodium, potassium and water metabolism in the syndrome of inappropriate antidiuretic hormone secretion. Am. J. Med. 49, 534–545
- Biff F. Palmer: Hyponatremia in patients with central nervous system disease: SIADH versus CSW. TRENDS Vol.14 No.4 May/ june 2014
- Dong Ki Kim et al.: Hyponatremia in patients with neurologic disorders. Electrolytes Blood Press 7:51-57, 2009ㆍdoi: 10.5049/EBP.2009.7.2.51
- Wijdicks, E. et al. (1985) Volume depletion and natriuresis in patients with a ruptured intracranial aneurysm. Ann. Neurol. 18, 211–216
- Levine, J.P. et al. (2001) Hyponatremia in the postoperative craniofacial pediatric patient population: a connection to cerebral salt wasting syndrome and management of the disorder. Plast.Reconstr. Surg. 108, 1501–1508
- Ganong, C.A. and Kappy, M.S. (1993) Cerebral salt wasting in children. The need for recognition and treatment. Am. J. Dis. Child. 147, 167–169
- Berendes, E. et al. (1997) Secretion of brain natriuretic peptide in patients with aneurysmal subarachnoid haemorrhage. Lancet 349, 245– 249
- Levin, E.R. et al. (1998) Natriuretic peptides. N. Engl. J. Med. 339,321– 328
- Maesaka, J.K. et al. (1999) Cerebral salt-wasting syndrome: does it exist? Nephron 82, 100–109
- Maesaka, J.K. and Fishbane, S. (1998) Regulation of renal urate excretion: a critical review. Am. J. Kidney Dis. 32, 917–933
- Bitew S, Imbriano L, Miyawaki N, Fishbane S, Maesaka JK: More on renal salt wasting without cerebral disease: response to saline infusion. Clin J Am Soc Nephrol 4:309-315, 2009
- Wijdicks, E. et al. (1985) Hyponatremia and cerebral infarction in patients with ruptured intracranial aneurysms: is fluid restriction harmful? Ann. Neurol. 17, 137–140
- Albanese, A. et al. (2001) Management of hyponatremia in patients with acute cerebral insults. Arch. Dis. Child. 85, 246–251
- Kinik, S.T. et al. (2001) Fludrocortisone treatment in a child with severe cerebral salt wasting. Pediatr.Neurosurg. 35, 216–219
- Rabinstein AA: Vasopressin antagonism: potential impact on neurologic disease. ClinNeuropharmacol 29:87-93, 2006
- Laureno R, Karp BI: Myelinolysis after correction of hyponatremia. Ann Intern Med 126:57-62, 1997
- Ellison DH, Berl T: Clinical practice. The syndrome of inappropriate antidiuresis. N Engl J Med 356:2064-2072, 2007
- Saleem et al: Hyponatremia in stroke : Ann Indian AcadNeurol 2014; 17:55-57
- Bussmann C, Bast T, Rating D. Hyponatraemia in children with acute CNS disease: SIADH or cerebral salt wasting? Childs Nerv Syst. 2001;17:58–62
- Dalal PM etal.Population based stroke survey in Mumbai, India: incidence and 28-day case fatality. Neuroepidemiology.2008;31:254-261
- Rodrigues B et al. Hponatremia in the orognosis of acute ischemic stroke. J stroke cerebrovasc Dis. 2014 May-Jun 23(5): 850-4
- Kuramatsu et al. Hyponatremia is an independent predictor of In-Hospital Mortality in Spontaneous Intracerbral Hemorrhage AHA journal. doi:10.1161/strokeaha.113.004136/-/DC1.
- Soiza R L et al. Hyponatremia predicts mortality after stroke. International Journal of Stroke.2015;doi:10.1111/ijs.12564.
- Huang WY et al. Association of hyponatremia in acute stroke stage with three-year mortality in patients with first-ever ischemic stroke. Cerebrovasc Dis.2012;34:55-62.
Corresponding Author
Dr M. Ramesh M.D
DOI: https://dx.doi.org/10.18535/jmscr/v8i1.63
