Cerebrospinal fluid rhinorrhoea (CSF rhinorrhoea) refers to the drainage of

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

through the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes th ...

(

rhinorrhoea Rhinorrhea, rhinorrhoea, or informally runny nose is the free discharge of a thin mucus fluid from the nose; it is a common condition. It is a common symptom of allergies (hay fever) or certain viral infections, such as the common cold or COVID-1 ...

). It is typically caused by a basilar skull fracture, which presents complications such as infection. It may be diagnosed using brain scans (prompted based on initial symptoms), and by testing to see if discharge from the nose is cerebrospinal fluid. Treatment may be

conservative Conservatism is a cultural, social, and political philosophy that seeks to promote and to preserve traditional institutions, practices, and values. The central tenets of conservatism may vary in relation to the culture and civilization i ...

(as many cases resolve spontaneously), but usually involves

neurosurgery Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty concerned with the surgical treatment of disorders which affect any portion of the nervous system including the brain, spinal cord and peri ...

Classification

CSF rhinorrhoea may be spontaneous, traumatic, or congenital. Traumatic CSF rhinorrhoea is the most common type of CSF rhinorrhoea. It may be due to severe

head injury 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 ...

, or from complications from

. Spontaneous CSF rhinorrhoea is the most common acquired defect in the skull base bones (

anterior cranial fossa The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting frontal lobes of the brain. It is formed by the orbital part of frontal bone, orbital plates of the Frontal bone, frontal, the cribriform plate ...

) causin
spontaneous nasal liquorrhea
Defects are often localized in the

sphenoid bone The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of occipital bone, basilar part of the occipital bone. The sphenoid bone is one of the seven bones ...

and the

ethmoid bone The ethmoid bone (; from grc, ἡθμός, hēthmós, sieve) is an unpaired bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a ...

. * sphenoid sinus (43%). * ethmoid bone (29%). * cribriform plate (29%). Congenital CSF rhinorrhoea is the least common type of CSF rhinorrhoea. It may be caused by problems in the

embryological development Prenatal development () includes the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal deve ...

of bones of the skull.

Signs and symptoms

CSF rhinorrhoea involves drainage of

through the

. This appears as a clear, colourless liquid. *Aldroubi sign "The liquid in CSF rhinorrhea is thin and clear, and an affected person might notice a sweet or salty taste due to the increased glucose and electrolytes present in cerebrospinal fluid so some affected toddlers and young children tend to lick their nose frequently".

Causes

Traumatic

CSF rhinorrhoea may be a sign of a

basilar skull fracture A basilar skull fracture is a break of a bone in the base of the skull. Symptoms may include bruising behind the ears, bruising around the eyes, or blood behind the ear drum. A cerebrospinal fluid (CSF) leak occurs in about 20% of cases and m ...

. Other signs of a basilar skull fracture include CSF otorrhoea (drainage of CSF through the

ear An ear is the organ that enables hearing and, in mammals, body balance using the vestibular system. In mammals, the ear is usually described as having three parts—the outer ear, the middle ear and the inner ear. The outer ear consists of ...

). It can have devastating complications in some patients, as the communication between the nasal cavity, the cerebrospinal fluid and the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...

can result in severe bacterial infections. CSF rhinorrhoea may be a complication of

, such as

functional endoscopic sinus surgery Functional endoscopic sinus surgery (FESS), or functional endoscopic sinus surgery, is a procedure that is used to treat sinusitis and other conditions that affect the sinuses. Sinusitis is an inflammation of the sinuses that can cause symptoms su ...

, and hypophysectomy (partial or complete removal of the

pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...

Non-traumatic

CSF rhinorrhoea may be caused by the growth of certain

cancers Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Poss ...

(such as

pituitary adenoma Pituitary adenomas are tumors that occur in the pituitary gland. Most pituitary tumors are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas.

Diagnosis

Radiology

If a patient has clear, colourless liquid leaking from the

, then

radiographs Radiography is an imaging technology, imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnos ...

or CT scans may be used to look for a

Biochemistry

Measures of CSF components, such as

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using ...

, have been used in the past, but are neither sensitive nor specific. Beta-2 transferrin has a high

positive predictive value The positive and negative predictive values (PPV and NPV respectively) are the proportions of positive and negative results in statistics and diagnostic tests that are true positive and true negative results, respectively. The PPV and NPV descr ...

of CSF rhinorrhoea. It has also been noted to be characterized by unilateral discharge.

Treatment

Surgery

Neurosurgery Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty concerned with the surgical treatment of disorders which affect any portion of the nervous system including the brain, spinal cord and peri ...

is usually necessary to prevent the spread of infection to the meninges. Minimally invasive techniques tend to have fewer complications compared to open techniques.

Conservative management

Conservative management Conservative management is a type of medical treatment defined by the avoidance of invasive measures such as surgery or other invasive procedures, usually with the intent to preserve function or body parts. For example, in appendicitis, conservati ...

includes

watchful waiting Watchful waiting (also watch and wait or WAW) is an approach to a medical problem in which time is allowed to pass before medical intervention or therapy is used. During this time, repeated testing may be performed. Related terms include ''expec ...

, as some minor CSF leaks often stop spontaneously.

References

External links

{{CNS diseases of the nervous system Body fluids