Cribriform Plate Fractures

The cribriform plate is a portion of the ethmoid bone located at the base of the skull. The base of the skull is the term used to describe the most inferior portion of the skull. It is comprised of portions of the frontal bone, ethmoid bone, sphenoid bone, temporal bone, and occipital bone. The base of the skull is divided into three sections: the anterior fossa, the middle fossa, and the posterior fossa. Within the center of the anterior fossa sits the ethmoid bone. This bone is located in the midline and extends from the medial wall of the orbits over the nasal septum, and comprises the roof of the nasal cavity. This narrow bony structure contains deep grooves known as olfactory fossa, which support the olfactory bulbs. It is perforated by numerous small openings, known as olfactory foramina, through which the olfactory nerve fibers enter into the roof of the nasal cavity to allow olfaction.   The cribriform plate is the thinnest portion of the base of the skull and is, therefore, susceptible to fracture in cases of facial trauma. Fractures can lead to partial or complete anosmia secondary to a severing of the olfactory nerves or due to contusion of the olfactory bulb itself. The dura overlying the cribriform plate is thin and tightly adherent to the skull; thus, fractures of the cribriform plate can easily tear the dura and lead to leakage of cerebral spinal fluid (CSF) into the nasal cavity. Once the dura is compromised, the patient is at risk for complications such as pneumocephalus, encephalocele, and ascending infections leading to meningitis.  Prompt evaluation and diagnosis can facilitate early treatment and reduce the risk of developing these potentially life-threatening complications. Diagnosis of cribriform plate fractures and dural fistulas can be difficult; thus, clinicians must maintain a high index of suspicion when evaluating a patient with facial trauma to allow early diagnosis and prevention of serious complications.