Cerebrospinal fluid (CSF) mainly occurs with traumatic brain injuries, less often the cause is cerebral tumors, birth defects, complications of neurosurgical interventions. With cerebrospinal fluid, a clear, odorless liquid flows out of the ear or nose, often accompanied by disturbances of consciousness and signs of focal damage to the structures of the central nervous system. CT and MRI of the brain, echoencephalography, and X-ray contrast studies are performed to diagnose the disease. Treatment is carried out conservatively and / or surgically.
ICD 10
G96.0 Cerebrospinal fluid leak
General information
Cerebrospinal fluid occurs in 2-3% of people with head injuries and in 5-11% of cases with a fracture of the base of the skull. With severe injuries of the facial skeleton and the nasoethmoidal orbital complex, the complication rate reaches 40%. Pathology is of great clinical importance in clinical neurology, as it indicates extensive traumatization of intracranial structures and requires urgent complex treatment. The efforts of doctors are aimed at improving the diagnosis of cerebrospinal fluid, which is important for its timely and adequate therapy.
Causes
The main etiological factor of the pathological condition is called TBI, which are accompanied by damage to bone structures and the underlying membranes of the brain. Most often, the problem develops with injuries to the base of the skull, the pyramid of the temporal bone, the frontal sinus. According to the biomechanics of damage, TBI of the following types are distinguished: shock-shock, acceleration-deceleration and combined. Other causes of cerebrospinal fluid:
- Volumetric neoplasms. Tumors of the brain and bone structures that have an invasive type of growth are capable of damaging the membranes and forming a defect for the expiration of the cerebrospinal fluid. Pathology is observed in advanced stages, when the neoplasm reaches a large size.
- Congenital malformations. With craniocerebral and spinal hernias, pathological ways of outflow of cerebrospinal fluid (CSF) develop. Pathology manifests itself from early childhood, accompanied by other neurological disorders.
- Latrogenic factors. Secondary cerebrospinal fluid occurs as a complication of neurosurgical operations in which the dura mater is accidentally injured. Such a situation is possible with severe head injuries, a shortage of modern equipment for intraoperative neuroimaging.
Pathogenesis
In skull fractures, displaced bone fragments damage the meninges, resulting in the expiration of the cerebrospinal fluid. There are 3 leading mechanisms of damage: infringement by bone fragments, perforation of cerebral membranes, extensive ruptures without signs of regeneration. The prolapse of the brain membranes into bone defects prevents their infection and contributes to the formation of a hernia containing elements of brain matter.
The high frequency of cerebrospinal fluid is due to the peculiarities of the anatomical structure of the base of the skull. Bones have a heterogeneous structure, contain a large number of air-bearing cavities and openings for neurovascular bundles. The meninges are tightly attached to solid structures, so their ruptures are observed even with minimal head injuries and displacement of intracranial contents.
Classification
According to the time of development, there is a primary (early) cerebrospinal fluid that appears in the first 24 hours after the injury, and a secondary (late) one that occurs a few days or even weeks later. A separate option is hidden cerebrospinal fluid, when patients do not notice CSF discharge from the nose or ear canal. In practical neurology and neurosurgery, the classification of the disease by localization is important:
- Nasal – the outflow of cerebrospinal fluid from one or both nasal passages.
- Otoliquorrhea is the outflow of cerebrospinal fluid from the external auditory canal.
- Postoperative – pathological secretion of cerebrospinal fluid after cranial trepanation and other neurosurgical manipulations.
Symptoms
In 97% of cases, there is a leakage of clear fluid from the nasal or auditory passage. Cerebrospinal fluid is permanent or intermittent, the volume of secretions varies from 1 to 30 ml per day. When the body position changes and the head tilts, the amount of discharge increases. The liquid has no odor and foreign inclusions, with nasal form, patients may take it for the first symptom of a runny nose or respiratory allergy.
In a horizontal position, especially during sleep, the cerebrospinal fluid flows from the nasal cavity into the throat and irritates the mucous membranes. Patients are worried about painful coughing attacks, which decrease in the half-sitting position. Profuse cerebrospinal fluid is accompanied by CSF ingestion into the stomach. At the same time, there is a clinic of acute non-infectious gastritis: pain and pain in the epigastrium, discomfort after eating, nausea and vomiting.
The clinical picture of posttraumatic cerebrospinal fluid is often accompanied by signs of concussion or brain injury. Patients complain of headaches, weakness, dizziness and severe nausea. Symptoms worsen when trying to get out of bed and active movements. Vegetative reactions also occur: flushes of blood to the face, excessive sweating, cardiac arrhythmias.
Neurological manifestations include asymmetry of tendon reflexes, anisocoria, nystagmus. With more serious brain injuries, motor dysfunction occurs, moderate meningeal symptoms. Patients report short-term memory loss at the time of injury, retrograde and antegrade amnesia are less common.
Complications
With cerebrospinal fluid, the subarachnoid space has a direct communication with the external environment, so there is a constant threat of infection. When pathogens enter the structures of the central nervous system, meningitis, encephalitis, and cerebral abscesses may develop. There is still a risk of other complications of TBI: pneumocephaly, post-traumatic epilepsy, chronic encephalopathy and post-concussion syndrome.
Diagnostics
The primary assessment of the condition of patients with suspected cerebrospinal fluid is carried out by a neurologist. The degree of impaired consciousness is determined using the Glasgow Coma Scale, followed by a full neurological examination. To examine patients with combined injuries, a neurosurgeon, an anesthesiologist-resuscitator, and a traumatologist are involved. The comprehensive diagnostic program includes the following methods:
- CT scan of the brain. X-ray diagnostics with high accuracy shows bone defects that can cause damage to the dura mater. Additional information for neurosurgery is provided by cerebral MRI, aimed at visualizing the contents of the cranial box.
- CT-cisternography. Neuroimaging with endolumbal administration of radiopaque substances is the “gold standard” in the diagnosis of cerebrospinal fluid. The technique determines the localization of liquor fistulas, the state of the bone structures of the affected area.
- Echoencephalography. Cerebral sonography is used for rapid and non-invasive diagnosis of intracranial neoplasms, visualization of indirect signs of brain damage. The most important indicator of EchoEG is the state of the median structures (M–echo).
- ENT examination. Rhinoscopy determines hyperemia and swelling of the mucous membrane, the outflow of watery fluid through the nasal passages. To clarify the topic of the pathological process, a nasal endoscopy is performed. With otoliquorrhea, traumatic perforation of the eardrum is visualized.
- Analysis of the cerebrospinal fluid. Microscopic and microbiological examination of the leaking fluid is necessary to confirm the cerebrospinal fluid. If signs of purulent inflammation are detected in the cerebrospinal fluid, an extended diagnosis is carried out to determine the pathogenic pathogen.
Differential diagnosis
In non-severe variants of TBI, it is important to distinguish nasal cerebrospinal fluid from serous rhinitis, since the released fluid has no pathognomonic signs. CSF contains a lot of glucose (2.3-4 mmol / l) and little protein (0.1-0.22 mmol / L), which differs from inflammatory exudate, which is formed in ENT diseases. Differential diagnosis is also performed with benign tumors of the nasal cavity that produce mucus.
Treatment
Conservative therapy
The main task is to create favorable conditions for the closure of the defect of the meninges and the formation of a scar at the site of the expiration of the cerebrospinal fluid. Patients are prescribed strict bed rest, lifting the head end of the bed by 30-70 °. During the treatment period, any physical exertion, straining, emotional overstrain are excluded. Complex therapy for cerebrospinal fluid includes the following areas:
- Dehydration. Diuretics are used to reduce intracranial pressure and normalize the circulation of the cerebrospinal fluid. This accelerates the closure and regeneration of damage to the cerebral membranes.
- Antibacterial therapy. Preventive administration of antimicrobials is necessary for the prevention of purulent meningitis. Medications suppress bacteria that colonize the upper respiratory tract and prevent their spread to the structures of the central nervous system.
- CSF drainage. The procedure is performed when other conservative methods of treatment are ineffective. The liquor receiver is installed at the level of the patient’s head to avoid secondary intracranial hypotension.
Surgical treatment
The help of neurosurgeons is required for cerebrospinal fluid lasting more than 7 days. To eliminate the defect and stop the flow of cerebrospinal fluid, open transcranial or mini-invasive transnasal interventions are performed. Advantages of endoscopic surgery: minimal tissue injury, no risk of postoperative anosmia. The technique of the operation is selected individually, taking into account the nature and severity of the injury.
There are 2 points of view regarding the timing of neurosurgical intervention. Proponents of early operations (in the first 1.5 weeks after injury) report that the risk of developing meningitis increases over time, which makes adequate treatment more difficult. Physicians who prefer delayed operations emphasize the high frequency of spontaneous cessation of cerebrospinal fluid during 2-3 weeks of conservative therapy.
The effectiveness of surgical intervention depends on the location of the liquor fistula, the accuracy of preoperative diagnosis, and the experience of the neurosurgeon. Most patients require a single operation. If the lateral wall of the sphenoid sinus is damaged, repeated intervention may be required, since intraoperative visualization of such defects is difficult.
Rehabilitation
The recovery period after operations in neurosurgery takes about 6 weeks. Patients are prescribed complex medical treatment: antibacterial, dehydration and symptomatic drugs. Lumbar drainage is installed for no more than 2-3 days. Gradual activation of patients begins on the second day of the postoperative period, while it is important to avoid head tilts, lifting weights, and increased intra-abdominal pressure.
Prognosis and prevention
The effectiveness of neurosurgical treatment is 80-98% on the first attempt and 98-100% in case of repeated surgery. A less favorable prognosis is for patients with large defects in the bones of the base of the skull, with the development of meningoencephalocele, with long-lasting intracranial hypertension. To reduce the frequency of cerebrospinal fluid, comprehensive prevention of domestic, industrial and road traffic injuries is necessary.