Cerebral salt-wasting syndrome (CSWS), also written cerebral salt wasting syndrome, is a
rare endocrine condition featuring a
low blood sodium concentration and
dehydration in response to injury (trauma) or the presence of tumors in or surrounding the
brain. In this condition, the kidney is functioning normally but excreting excessive sodium.
The condition was initially described in 1950. Its cause and management remain controversial.
In the current literature across several fields, including
neurology,
neurosurgery,
nephrology
Nephrology (from Greek'' nephros'' "kidney", combined with the suffix ''-logy'', "the study of") is a specialty of adult internal medicine and pediatric medicine that concerns the study of the kidneys, specifically normal kidney function (ren ...
, and
critical care medicine
Intensive care medicine, also called critical care medicine, is a medical specialty that deals with seriously or critically ill patients who have, are at risk of, or are recovering from conditions that may be life-threatening. It includes pro ...
, there is controversy over whether CSWS is a distinct condition, or a special form of
syndrome of inappropriate antidiuretic hormone secretion (SIADH).
Signs and symptoms
Signs and symptoms of CSWS include
large amounts of urination (polyuria, defined as over three liters of urine output over 24 hours in an adult), high amounts of sodium in the urine, low blood sodium concentration,
excessive thirst
Polydipsia is excessive thirst or excess drinking.Porth, C. M. (1990). ''Pathophysiology: Concepts of altered health states''. Philadelphia: J.B. Lippincott Company. The word derives from the Greek () "very thirsty", which is derived from (, "mu ...
(polydipsia), extreme
salt cravings,
dysfunction of the autonomic nervous system (dysautonomia), and
dehydration. Patients often self-medicate by consuming high amounts of sodium and by dramatically increasing their water intake. Advanced symptoms include
muscle cramps, lightheadedness, dizziness or
vertigo, feelings of anxiety or panic,
increased heart rate or
slowed heart rate,
low blood pressure and
orthostatic hypotension which can result in
fainting.
Other symptoms frequently associated with dysautonomia include
headaches,
pallor
Pallor is a pale color of the skin that can be caused by illness, emotional shock or stress, stimulant use, or anemia, and is the result of a reduced amount of oxyhaemoglobin and may also be visible as pallor of the conjunctivae of the eyes o ...
,
malaise
As a medical term, malaise is a feeling of general discomfort, uneasiness or lack of wellbeing and often the first sign of an infection or other disease. The word has existed in French since at least the 12th century.
The term is often used ...
, facial flushing,
constipation or
diarrhea,
nausea,
acid reflux, visual disturbances, numbness,
nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system.
A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the e ...
pain,
trouble breathing, chest pain, loss of consciousness, and
seizures.
Causes
Although the pathophysiology of CSWS is not fully understood, it is usually caused by neurological injury, most commonly
aneurysmal subarachnoid hemorrhage
Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consci ...
.
It is also reported after surgery for pituitary tumor, acoustic neuroma,
calvarial remodeling,
glioma and with infections including
tuberculous meningitis,
viral meningitis,
metastatic carcinoma, and
cranial trauma
A head injury is any injury that results in trauma to the skull or brain. The terms ''traumatic brain injury'' and ''head injury'' are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of inju ...
.
Diagnosis
CSWS is a
diagnosis of exclusion
A diagnosis of exclusion or by exclusion (''per exclusionem'') is a diagnosis of a medical condition reached by a process of elimination, which may be necessary if presence cannot be established with complete confidence from history, examination or ...
and may be difficult to distinguish from the
syndrome of inappropriate antidiuretic hormone
Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by excessive unsuppressible release of antidiuretic hormone (ADH) either from the posterior pituitary gland, or an abnormal non-pituitary source. Unsuppressed ADH c ...
(SIADH), which develops under similar circumstances and also presents with hyponatremia.
The main clinical difference is that of total fluid status of the patient: CSWS leads to a relative or overt
low blood volume[ whereas SIADH is consistent with a normal or high blood volume (due to water reabsorption via the V2 receptor).]
Treatment
While CSWS usually appears within the first week after brain injury and spontaneously resolves in 2–4 weeks, it can sometimes last for months or years. In contrast to the use of fluid restriction to treat SIADH, CSWS is treated by replacing the urinary losses of water and sodium with hydration and sodium replacement.
References
External links
{{Electrolyte abnormalities
Endocrine diseases
Electrolyte disturbances
Neurosurgery
Rare syndromes