Skull base fracture
| Classification according to ICD-10 | |
|---|---|
| S02.1 | Base of skull fracture |
| ICD-10 online (WHO version 2019) | |
A skull base fracture (or a skull base fracture ) occurs after very strong violence in the head area , most often as a result of traffic accidents, and is a life-threatening injury. Bony structures of the anterior, middle or, less often, the posterior fossa are injured at the base of the skull . The most important two types of fracture are the rhinobasal (nose and skull base) or frontobasal and the otobasal (ear and skull base) or laterobasal fracture. In the former, the fracture gap extends into the paranasal sinuses , the latter affects the temporal bone . The discharge of blood and cerebrospinal fluid from the nose or ears is typical . Either through the actual trauma or through secondary bleeding into the brain, there are occasional disturbances of consciousness or neurological deficits ( commotio cerebri ).
Emergence
The base of the skull is often broken in traffic accidents involving a car, motorcycle or bicycle. When the accident happened, there was often a frontal impact. The face of a driver or front passenger who is not wearing seat belts collides head-on against the steering wheel or dashboard. The break lines follow the weak points of the bony structure of the skull and run horizontally and upwards in the process described. In the anterior fossa, the sphenoid sinus , the frontal sinuses , the ethmoid cells and the roof of the eye socket are particularly affected. The middle fossa is adjacent to the temporal bone. A break can damage the internal and external structures of the ear.
Symptoms
If the rupture results in an open connection between the nasal cavity or the external auditory canal and the space between the meninges and the brain, where the cerebrospinal fluid ( liquor cerebrospinalis ) is located, cerebrospinal fluid leaks from the nose, mouth or ears ( liquorrhea ). Since the vessels rupture at the same time, blood is almost always mixed with the actually clear liquor.
The evidence of a fractured skull are similar to the midface fractures an eyeglass or monocular hematoma (a visible bleeding into the eye socket). If blood collects behind the eye, the eyeball can be pushed forward ( protrusio bulbi ). A pulsation in the eyeball is an indication of internal carotid artery rupture and hemorrhage into the cavernous sinus . The resulting carotid-sinus-cavernosus fistula is a life-threatening complication.
Decreased consciousness or unconsciousness indicate a brain injury or brain supplying vessels. If there is bleeding into the brain, symptoms of a stroke may occur.
Since the cranial nerves leave the base of the skull through small openings, entrapment can cause specific symptoms of failure. Entrapment of an optic nerve can lead to blindness of the eye. In the area of the ear, apart from injuries to the auditory ossicles, damage to the facial nerve with failure of the facial muscles ( facial paresis ) or the vestibulocochlear nerve with hearing loss and dizziness can occur. Loss of smell ( anosmia ) is occasionally the only indication of a skull base fracture.
Diagnosis
The diagnosis of a skull base fracture is based on imaging and laboratory methods. The classic skull x-ray in 3 planes is nowadays increasingly being replaced by computed tomography (CT), which can reliably show even very small cracks in the skull with high resolution. The magnetic resonance imaging (MRI) provides bony structures is worse than CT, it is therefore not performed by default, but is used, if the suspicion of a brain injury is.
If a carotid-sinus-cavernosus fistula is suspected, an X-ray contrast medium can be used to visualize the vessels ( angiography ).
A bloody, watery discharge from the nose, mouth or ear can be examined in a laboratory. In this case, on β 2 - transferrin tested, a substance only in the CSF from occurring in the blood β 1 produced transferrin. This test is quick and very specific. It provides information about whether liquor is leaking, i.e. whether there is an open connection to the space that surrounds the brain. An even more specific investigation has recently become available, the detection of prostaglandin D synthase (so-called beta trace protein), which is 35 times more concentrated in the CSF than in the blood serum.
The fluorescent test is occasionally used to find the exact source of the liquorrhea . A substance that shines under UV light is injected into the liquor via a lumbar puncture . With the help of a UV endoscope , the side and the exact location of the CSF outlet can be found.
The compress test is a quick but imprecise test that is particularly useful in an emergency to differentiate cerebral fluid from other clear fluids in the nose (such as mucus). In this test, the corner of a compress is held in the blood that is leaking out. The cerebrospinal fluid forms a pale halo outside the area taken up by the blood.
therapy
Not every fractured skull base requires therapeutic intervention. However, there are situations where you need to be in a hurry, for example:
- an open traumatic brain injury ,
- involvement of the eyes with impending blindness (possibly with pinched optic nerve)
- a stake from a foreign body
- massive loss of blood and cerebrospinal fluid
- a facial palsy with a possible pinched facial nerve
Surgical intervention usually consists of relieving trapped structures and covering the fracture gaps that have arisen. On the one hand, the resulting cracks in the hard meninges are sewn, and on the other hand, the bone defects are covered with the body's own materials ( e.g. fascia ) and fibrin glue . Small metal plates, so-called microplates, are also used in the area of larger defects.
The rhinobasal fractures often require surgical treatment, especially if there is a leakage of CSF. In otobasal fractures, provided that no nerves are pinched, one can often wait. Even eardrum defects and blood accumulations in the middle ear usually heal spontaneously.
The benefit of prophylactic antibiotics is discussed by some doctors. This is said to reduce the risk of the dangerous complication of meningitis.
Complications
- meningitis
- Increase in intracranial pressure (due to swelling or bleeding, thereby risk of unconsciousness, cramps, respiratory and circulatory arrest)
- Choking hazard (if unconscious in the supine position)
- Risk of infection with open injuries (especially with liquorrhea of the nose) with possible brain abscess as a late complication
- Pinching of the eye nerves with impending blindness
- Injury to the internal carotid artery
- Facial paralysis
- Disorders of hearing and balance
- persistent ringing in the ear ( tinnitus )
- Loss of smell
- Pneumatocele (air pockets inside the skull)
Individual evidence
- ↑ laborlexikon.de Laborlexikon.de, accessed on February 16, 2012, 11:30 p.m.
- ↑ S. Maibaum et al.: Therapielexikon der Sportmedizin. Springer, 2001, ISBN 3-540-66759-8 , p. 153, (online at: books.google.de )
literature
- Bernhard Weigel, Michael Nerlich: Practice book accident surgery. 2 volumes. Springer, Berlin / Heidelberg 2005, ISBN 3-540-41115-1 .
- Hans-Henning Horch, Jürgen Bier: Oral and maxillofacial surgery. 4th edition. Elsevier, Urban & Fischer, Munich / Jena 2007, ISBN 978-3-437-05417-4 .
