Spontaneous cranial cerebrospinal fluid leak (CSF liquorrhea)
Spontaneous cranial cerebrospinal fluid leak (CSF liquorrhea) — is outflow of cerebrospinal fluid (CSF) of the innate or formed due to various non-traumatic causes of defects, which are formed in the bones of the skull and the dura.
The outflow of cerebrospinal fluid (CSF) may be constant or intermittent, drip or spray. Strengthening of a liquorrhea is possible by changing the position of the head, straining. Sometimes spontaneous liquorrhea is hidden. In hidden spontaneous liquorrhea cerebrospinal fluid (CSF) flow into the nasopharynx or absorbed by subcutaneous tissue.
Spontaneous cranial cerebrospinal fluid leak (CSF liquorrhea) is about 20% of all cases liquorrhea. There are several types of spontaneous liquorrhea depending on cerebrospinal fluid (CSF) leak places of from the cranial cavity:
- nasal liquorrhea (most common form)
- ear liquorrhea
- orbital liquorrhea (very rare form)
Spontaneous liquorrhea divided according to its origin:
- primary (idiopathic) spontaneous liquorrhea - apparent cause can not be determined
- secondary spontaneous liquorrhea - the formation of cerebrospinal fluid (CSF) fistula leads some pathology
Spontaneous cranial cerebrospinal fluid leak (CSF liquorrhea) causes
Spontaneous CSF rhinorrhea
The most common congenital or acquired defect in the skull base bones (anterior cranial fossa) at the spontaneous nasal liquorrhea localized in following formation:
- sphenoid sinus (43%)
- ethmoid bone (29%)
- cribriform plate (29%)
More rarely the skull base defect located at the rear wall of the frontal sinus. Even rarer cerebrospinal fluid fistula can be placed in the pyramid of the temporal bone. In this case, the cerebrospinal fluid (CSF) first enters the cavity of the middle ear, and then through the auditory tube in the nose and nasal cavity.
Spontaneous CSF otorrhea
During spontaneous ear liquorrhea violated the integrity of the tympanic membrane and the bone defect is localized in the roof of the tympanic cavity (middle or posterior cranial fossa).
Predisposing factors for the spontaneous liquorrhea appearance:
- congenital malformations of the skull base (cribriform plate, ethmoid, sphenoid and frontal sinuses)
- large cell (hyper pneumatization) the sphenoid sinus
- empty sella turcica
Localization of spontaneous liquorrhea in the lateral parts of sphenoid bone and large bone defects of the skull base increase the likelihood of relapsing forms of spontaneous liquorrhea.
The basis of spontaneous liquorrhea may lie disease of the connective tissue, such as Marfan syndrome, in which there is thinning of the dura mater, hypermotility joints, increased skin elasticity, retinal detachment. Cause of spontaneous liquorrhea may also be pathological processes of the brain and skull bones (inflammatory, neoplastic or pathological embryogenetic origin). Several authors think that patients with spontaneous liquorrhea continuously or periodically have increased intracranial pressure. This prevents self-defect closure of the dura mater (fistula). Other authors suggest the development of a local tissue resorption of the anterior skull base with a normal intracranial pressure.
Most often defect of the dura mater (cerebrospinal fluid fistula) is formed in the arachnoid and dura mater, which is closely associated with the olfactory filaments, which pass through the thin cribriform plate. Here often may be congenital malformations that develop in the embryonic period.
Ear spontaneous liquorrhea has age differences. In children, the cause is a congenital malformation of the labyrinth, which contributes to recurrent meningitis and deafness. In adults, causes spontaneous liquorrhea be bulging arachnoid through the roof of a congenital defect of the tympanum, or acquired defect in the arachnoid because of dynamic factors (increased intracranial pressure). Defects in the roof of the tympanum are often multiple.
Spontaneous orbital CSF leak
Formation of spontaneous orbital liquorrhea associated with recurring inflammation of the frontal sinus (chronic sinusitis). Pathological process in spontaneous orbital liquorrhea is formed in the patient's orbit and anterior cranial fossa.
Spontaneous liquorrhea more common in obese women (94%). The average age of patients with spontaneous liquorrhea 49.6 years, and body mass index of 35.9 kg/m2.
Spontaneous cranial liquorrhea clinical signs and symptoms
For spontaneous liquorrhea characterized by headaches when changing body position (orthostatic headaches). This may be due to decreasing intracranial pressure (intracranial hypotension). There are cases when the headaches in patients with spontaneous liquorrhea appear at minimum load, and not a change in body position. These headaches are antiorthostatic character, can be explained by increased intracranial pressure.
In the case of long and abundant liquorrhea may experience symptoms of general weakening (asthenia) and dehydration - dry skin and visible mucous membranes, weight loss. In the case of latent or insignificant liquorrhea complaints will be absent.
Night cough can be formed in marked nasal liquorrhea due to the impact of cerebrospinal fluid (CSF) in the trachea and bronchus, when a patient lying on his back. This may result in the subsequent development of bronchitis.
An important symptom of spontaneous nasal liquorrhea is pathology sense of smell (anosmia, hyposphresia). The pathology sense of smell occurs most often on one side. Visual impairment indicate injury of the anterior skull base.
Otorrhea (leak of cerebrospinal fluid from the ear) is characterized by hearing loss. Hearing loss is directly proportional to the intensity of liquorrhea, because the cerebrospinal fluid (CSF) is connected to the perilymph through the cochlear aqueduct.
Among other serious complications of liquorrhea is bronchitis and bronchopneumonia due to leaking of the cerebrospinal fluid (CSF) in the respiratory tract. If the cerebrospinal fluid (CSF) accumulates in large volume in the patient's stomach, it can cause gastritis.
Risk of serious intra- and extracranial complications necessitates prompt diagnosis and treatment tactics in case of spontaneous liquorrhea. Spontaneous liquorrhea is a life-threatening disease because of the chance of infection liquor system (purulent meningitis) when cranial cavity in contact with the external environment.
Spontaneous cranial liquorrhea diagnosis
If the patient had a history of an episode of non-meningococcal meningitis, especially recurrent character, this may indicate the presence of liquorrhea.
Diagnosis obvious liquorrhea is not too difficult for the doctor. At the nasal spontaneous liquorrhea when tilted head down from the nose starts to drip clear and bright liquid. Distinguish nasal discharge in a patient with liquorrhea from vasomotor and allergic rhinitis can be achieved by determining the level of glucose in the fluid released from the nose. In cerebrospinal fluid is significantly higher than in the discharge of rhinitis. When wetted liquor wipes or a handkerchief last dries and do not becomes solid, unlike discharge in rhinitis. Developed as an alternative method for the differential diagnosis of spontaneous liquorrhea. It consists of two-dimensional electrophoresis analysis of the products of nasal discharge. With little or periodical of liquor expiration in a patient diagnosis of spontaneous liquorrhea becomes difficult.
Depending on the cause (etiology), clinical signs, symptoms and treatment facility for detection of spontaneous liquorrhea in a patient following techniques are applied:
- β-2-transferrin assay
- endoscopic examination
- radioisotope methods of diagnosis
- tests with medical dyes
- radiologic diagnosis - MRI, CT, skull radiography with contrast in liquor
Endoscopic examination of the nasal cavity is most often used to visually identify the flow of cerebrospinal fluid (CSF) and / or the place of leak. Endoscopic examination of the nasal cavity in the blue light more effectively. At long existing the nasal liquorrhea in some cases can be defined atrophic changes of the mucosa with thinning of the surface epithelium and maceration.
Radioisotope method is sensitive enough to diagnose liquorrhea in general, but not to localize of liquor fistula. Are also used tests with the medical dyes - indigo carmine, fluorescent substances, methylene blue.
Determination of β-2 fractions of transferrin (tau protein) in the discharge from the nose is now the gold standard for confirming the diagnosis of spontaneous liquorrhea. β-2 transferrin fraction (tau protein) is a specific protein that is found only in cerebrospinal fluid.
To clarify the localization of liquor fistulous used modern radiologic diagnosis:
Efficiency and sensitivity of CT cisternography in the diagnosis of spontaneous liquorrhea reaches 71-87%. If CT imaging accurately determined damage to bones of the skull base, then with a clear clinical picture of spontaneous liquorrhea the need for other diagnostic methods is eliminated.
MRI exceeds CT scans in detecting encephalocele (hernial protrusion of the brain in the skull defect clearance). But MRI worse than the CT scans can imaging reveals bony injuries of the skull base. Efficiency and sensitivity of MR cisternography in spontaneous liquorrhea reaches 78%. Sensitivity combined MRI methods: spin-echo (SE) T1W1 in the axial and sagittal projections, SE T2W1 in the axial and coronal projections, FLAIR is 100% with spontaneous cerebrospinal fluid (CSF) liquorrhea.
Spontaneous cranial liquorrhea treatment
Spontaneous cranial liquorrhea treatment in a patient begins with conservative therapy. Conservative treatment of spontaneous liquorrhea in a patient will be directed to:
- reduced secretion of cerebrospinal fluid
- reduction of cerebrospinal fluid pressure
- creating favorable conditions for ending liquorrhea
With the ineffectiveness of conservative treatment then performed surgery. Surgical treatment of spontaneous liquorrhea accompanied liquor hypertension begins with bypass surgery (overlay lumboperitonal shunt). If the cerebrospinal fluid (CSF) bypass surgery is not effective, neurosurgeons applied to transcranial and transnasal approach.
During transcranial surgery for spontaneous liquorrhea performed osteoplastic craniotomy. Next, the plastic of cerebrospinal fluid fistulas by epidural or subdural access, depending on its location.
At transnasal surgery performed plasty of cerebrospinal fluid (CSF) fistula through the nasal cavity under the control of the endoscope or microscope.
With the localization of the skull base defect in the area of cribriform plate and sphenoid sinuses are often used transnasal endoscopic techniques to close it. Transnasal endoscopic techniques are most effective, minimally invasive and less traumatic compared with intracranial interventions. Restrictions for the use of surgical techniques of endoscopic transnasal access are:
- localization of fistula within the rear wall of the frontal sinus, pyramid of temporal bone
- the size of the bone defect of skull more than 15 mm
- defects of other sites that are inaccessible by the transnasal endoscope surgery
- the inability to determine the location cerebrospinal fluid fistula before surgery
Traditional transcranial access gives an excellent review for the neurosurgeon. Disadvantage of this method of operation is the retraction of the frontal lobes of the brain with a possible rupture of the olfactory filaments (anosmia or hyposphresia after surgery comes to 100%) and prolonged hospitalization.
Endoscopic techniques are generally applicable in the surgical treatment of ear liquorrhea because defect of a bone or dura mater is not available to the endoscope.
n the case of liquorrhea from ear for closing the defects roof of the tympanum (the most common site of the defect) using access through the mastoid process. Common complication of access through the mastoid process is hearing loss. In case of multiple defects in the roof of the tympanum is recommended access to the middle cranial fossa with or without access through the mastoid process. To close the defect in the dura of the posterior cranial fossa is also possible to use the access through the mastoid process.
To close the defect in the bones of the skull base and depending on the surgical approach using different patient's tissues (periosteum, fascia lata, adipose tissue, cartilage of the nasal septum), adhesive compositions (Tissukol, Tachocomb), as well as their combinations.
Recovery and prognosis after spontaneous cranial liquorrhea surgical treatment
Recovery of patients after extracranial operations (transnasal endoscopic method) is faster than after intracranial surgery.
Unsuccessful outcome of endoscopic surgery for cerebrospinal fluid fistula can be associated with:
- with inaccurate localization of a liquorrhea
- the presence of multiple fistulas
- displacement of transplant
- unsuccessful juxtaposition of the graft and the dura mater
- poor healing of the wound
- acceded infection
- increased intracranial pressure
Possibility of recurrencein comparison with other types of liquorrhea, higher. Relapses of spontaneous liquorrhea after endonasal operations are 3-14%, and after transcranial - 10-27%. If the patient has recurrent spontaneous liquorrhea, it requires reoperation.