CMF fractures: clinical signs and examination
1. Clinical signs
The clinical signs of head fractures are manifold and depend on the location of the lesions. In addition to pain during palpation of the affected head region, there may be hemorrhage from the ocular, nasal or oral cavities, regardless of whether the neighboring soft tissues are affected. Occasionally emphysema may be palpated. Horses with head fractures often have an abnormal general demeanor, loss of appetite, drooling and/or a foul odor from the mouth. Fractures that involve the cerebral cranium usually lead to neurologic deficits such as ataxia or vestibular syndrome. A fracture should be suspected when there is asymmetry of the skull.
2. Clinical examination
A comprehensive assessment of a head fracture requires a thorough clinical examination. Of critical interest is whether the fracture involves soft-tissue structures, particularly the brain, but also the eyes or cranial nerves.
The clinical examination should be supplemented by endoscopy, ultrasonography, radiography, and computed tomography, if available.
3. Injury to the central nervous system
Depending on whether the central nervous system is involved, the patient is allocated to one of two groups, which have very different prognoses and require different treatment. If the nervous system is not affected, the demeanor, general condition and appetite are usually normal and there are no cranial nerve deficits. This is usually the case with trauma to the rostral part of the visceral skull.
The risk of injury to the central nervous system increases considerably with trauma and fractures located further caudally, and in these cases the immediate application of emergency measures is critical for a favorable outcome.
4. Imaging
A minimum of two radiographic views (a&b) must be taken in horses suspected of having a fracture. Additional views including oblique and intraoral radiographs (c) are recommended when a fracture is diagnosed. However, the diagnostic value of skull radiographs is limited, and many fractures cannot be definitively diagnosed, especially those of the cerebral cranium.
Computed tomography has become the diagnostic imaging method of choice for equine skull fractures and should be used in difficult cases.
