cerebrospinal fluid leak in brain after head trauma

20 Some surgeons also use CSF diversion as part of routine postoperative management after repair of skull base defects. The addition of CSF diversion to nonsurgical treatment raises the success rate to approximately 90%. 22 CSF hypovolemia can result in severe headache, pneumocephalus (from retrograde airflow through the fistula), or even brainstem herniation. 7 8 Optimal CSF drainage (∼10 mL/hour) should reduce pressure on the fistula without resulting in CSF hypovolemia. 2 20 A lumbar drain is the most common technique however, an external ventriculostomy can be used for patients with traumatic brain injury, low Glasgow coma scale scores, or a requirement for intracranial pressure monitoring. 21 Persistent CSF rhinorrhea after conservative management can be successfully treated with CSF diversion for 7 to 10 days. 20 Mincy found that 68% of the posttraumatic CSF fistulas closed spontaneously within 48 hours and 85% closed within 7 days of initial injury. Bell et al reviewed 34 cases of traumatic skull base CSF fistulas treated medical management and found resolution of CSF leak in 85% of the patients. Most posttraumatic CSF fistulas will resolve with medical management, particularly after surgical fracture reduction.

These include the following: Elevation of the head of bed ≥ 30 degrees, routine use of stool softeners, and avoidance of straining/Valsalva maneuver (i.e., nose blowing, sneezing, straining at stool, incentive spirometry, etc.).

Nonsurgical management of CSF rhinorrhea consists of bed rest with maintenance of strict precautions to reduce or eliminate increases in intracranial pressure. It should be noted, however, that gadolinium is not approved for intrathecal use in the United States. Other anatomic abnormalities such as an encephalocele or meningocele would also warrant MRI. Given these limitations, both MRI and magnetic resonance cisternography are generally reserved for patients who have already undergone high-resolution CT and the presence of location of a CSF leak still remains in question. It also requires a lumbar puncture with its associated risks (bleeding, infection, spinal headache, neurologic injury) as well as the need for active CSF flow to identify the leak. 16 Magnetic resonance cisternography is again more time consuming, costly, and physically more difficult to obtain (due to gantry size and patient tolerance) than high-resolution CT. 13 The sensitivity of this image modality for detection of CSF leak is approximately 85 to 92% and specificity of 100%. The risk of neurological changes or seizure activity with the use of gadolinium is extremely low. This can enhance the detection of CSF within the nasal cavity. Magnetic resonance cisternogram: Magnetic resonance cisternography is similar to CT cisternography and is performed with an intrathecal injection of gadolinium contrast material via lumbar puncture. A low index of suspicion and delay in diagnosis can increase the risk of meningitis or brain abscess. There are often no associated findings, and the drainage may be confused with other sinonasal disorders such as allergic, vasomotor, and nonallergic rhinitis. Chronic CSF leaks are typically more difficult to diagnose.

If CSF is present, it will diffuse faster than blood and result in a clear halo around the blood. Clear drainage suspicious for CSF can be grossly tested for a “halo sign.” The bloody nasal drainage is allowed to drip onto filter paper. Posttraumatic leaks may be more readily recognized due to associated findings such as epistaxis, periorbital ecchymosis, visual changes, anosmia, cranial nerve deficits, and pneumocephalus. Patients may note salty or sweet tasting postnasal drainage. It is classically positional in nature and exacerbated by dependent head positioning (i.e., “reservoir sign”). The most common clinical presentation of CSF rhinorrhea is intermittent, unilateral, clear, watery drainage.

Cerebrospinal fluid leak in brain after head trauma