Cerebral salt-wasting syndrome (CSWS) is a rare

Rare disease

A rare disease, also referred to as an orphan disease, is any disease that affects a small percentage of the population.Most rare diseases are genetic, and thus are present throughout the person's entire life, even if symptoms do not immediately appear...

 endocrine condition featuring hyponatremia

Hyponatremia

Hyponatremia is an electrolyte disturbance in which the sodium concentration in the serum is lower than normal. In the vast majority of cases, hyponatremia occurs as a result of excess body water diluting the serum sodium and is not due to sodium deficiency. Sodium is the dominant extracellular...

 (low blood sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 concentration) and dehydration

Dehydration

In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...

 in response to trauma/injury or the presence of tumors in or surrounding the brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

. This form of hyponatraemia is due to excessive renal sodium excretion resulting from a centrally mediated process.

The condition was initially described in 1950.

Symptoms

Primary symptoms include polyuria

Polyuria

Polyuria is a condition usually defined as excessive or abnormally large production or passage of urine . Frequent urination is sometimes included by definition, but is nonetheless usually an accompanying symptom...

 (at least 2.5 liters in the course of 24 hours, for adults) due to inadequate sodium retention in the body, polydipsia

Polydipsia

Polydipsia is a medical symptom in which the patient displays excessive thirst. The word derives from the Greek πολυδιψία, which is derived from πολύς + δίψα...

 (excessive thirst) due to polyuria, extreme salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

 cravings (e.g. desire to drink pickle juice), dysautonomia

Dysautonomia

Dysautonomia is a broad term that describes any disease or malfunction of the autonomic nervous system. This includes postural orthostatic tachycardia syndrome , inappropriate sinus tachycardia , vasovagal syncope, mitral valve prolapse dysautonomia, pure autonomic failure, neurocardiogenic...

, and dehydration

Dehydration

In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...

. Patients often "self-medicate" by naturally gravitating toward a high-sodium diet and by dramatically increasing their water intake. Advanced symptoms include muscle cramps, lightheadedness, dizziness or vertigo

Vertigo (medical)

Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...

, feelings of anxiety or panic (not mentally induced), tachycardia

Tachycardia

Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...

 (rapid heart rate) or bradycardia

Bradycardia

Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...

 (slow heart rate), hypotension

Hypotension

In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...

 and orthostatic hypotension

Orthostatic hypotension

Orthostatic hypotension, also known as postural hypotension, orthostasis, and colloquially as head rush or dizzy spell, is a form of hypotension in which a person's blood pressure suddenly falls when the person stands up or stretches. The decrease is typically greater than 20/10 mm Hg, and may be...

 sometimes resulting in syncope

Syncope (medicine)

Syncope , the medical term for fainting, is precisely defined as a transient loss of consciousness and postural tone characterized by rapid onset, short duration, and spontaneous recovery due to global cerebral hypoperfusion that most often results from hypotension.Many forms of syncope are...

. Other symptoms frequently associated with dysautonomia include: headaches, pallor

Pallor

Pallor is a reduced amount of oxyhaemoglobin in skin or mucous membrane, a pale color which can be caused by illness, emotional shock or stress, stimulant use, lack of exposure to sunlight, anaemia or genetics....

, malaise

Malaise

Malaise is a feeling of general discomfort or uneasiness, of being "out of sorts", often the first indication of an infection or other disease. Malaise is often defined in medicinal research as a "general feeling of being unwell"...

, facial flushing, constipation

Constipation

Constipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...

 or diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

, nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, acid reflux, visual disturbances, numbness, nerve

Nerve

A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...

 pain, trouble breathing, chest pains, loss of consciousness and seizures.

Causes and Diagnosis

CSWS is usually caused by brain injury/trauma or cerebral lesion, tumor, or hematoma. CSWS is a diagnosis of exclusion and may be difficult to distinguish from the syndrome of inappropriate antidiuretic hormone

Syndrome of inappropriate antidiuretic hormone

The syndrome of inappropriate antidiuretic hormone hypersecretion is characterized by excessive release of antidiuretic hormone from the posterior pituitary gland or another source. The result is hyponatremia and sometimes fluid overload...

 (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 hypovolemia

Hypovolemia

In physiology and medicine, hypovolemia is a state of decreased blood volume; more specifically, decrease in volume of blood plasma...

 whereas SIADH is consistent with a normal to hypervolemic range. Random urine sodium concentrations tend to be lower than 100 mEq/L in CSWS and greater in SIADH . If blood-sodium levels increase when fluids are restricted, SIADH is more likely.

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. While fluid restriction is used to treat SIADH, CSWS requires aggressive hydration and correction of the low sodium levels using sodium chloride tablets. Sometimes, fludrocortisone

Fludrocortisone

Fludrocortisone is a synthetic corticosteroid with moderate glucocorticoid potency and much greater mineralocorticoid potency. The brand name in the U.S. and Canada is Florinef.-Uses:...

 (a mineralocorticoid

Mineralocorticoid

Mineralocorticoids are a class of steroid hormones characterised by their similarity to aldosterone and their influence on salt and water balances.-Physiology:...

) improves the hyponatremia.