Post-Traumatic Gliosis Presenting as Facial Sensory Disturbances in a Child: A Diagnostic Pitfall

Significance Statement

In this case, a lesion that can easily be confused with various brainstem pathologies is presented. Among the most common differential diagnoses are neoplastic processes when appearing as a mass lesion and demyelinating or infectious etiologies when enhancement is present. Misdiagnosis can lead to unnecessary treatments or surgical interventions, potentially resulting in adverse outcomes for patient well-being.

A 14-year-old boy presented to the otolaryngology clinic with complaints of facial numbness, pain, and sensory loss. On physical examination, there were no deficits in various motor functions such as closing his eyes, raising his eyebrows, or smiling. He only described sensory symptoms. The initial history obtained from the patient and his parents did not reveal any additional significant findings.

To investigate potential central causes, cranial magnetic resonance imaging (MRI) was performed. Imaging revealed a hyperintense, nonspecific focus in the right half of the pons, at the origin of the trigeminal nerve, on T2-weighted images (Figure 1a). This focus demonstrated contrast enhancement in post-contrast sequences. Initially, a low-grade tumor was suspected.

Figure 1.

(a) Axial FLAIR MRI image demonstrating a hyperintense focus (p) at the origin of the right trigeminal nerve within the right half of the pons. In addition, mild thickening and increased signal intensity are noted in the ipsilateral trigeminal nerve, with its course through the pc visible. (b) Schematic magnified illustration highlighting anatomical details and emphasizing the lesion (p). The pons is shaded for clarity. n, trigeminal nerve; pc, prepontine cistern; v, fourth ventricle; c, cerebral hemisphere; t, temporal lobe.

Upon further, more detailed questioning, it was revealed that the patient had struck his head forcefully against a wall during a fight with his friends at school 2 weeks earlier. He had concealed this information in the initial history out of fear of his parents. In light of this new information, the nonspecific focus observed on imaging was primarily considered to represent a gliotic area secondary to trauma.

However, due to the uncommon localization of the lesion, a neoplastic process could not be completely excluded, and the patient was scheduled for close follow-up at short intervals. At the first-, third-, and sixth-month follow-up evaluations, the size of the lesion remained stable, and its contrast enhancement disappeared. During this period, the patient was treated with nonsteroidal anti-inflammatory drugs for pain management. At his most recent follow-up visit, it was noted that all of his initial complaints had completely resolved. A follow-up evaluation, including imaging, was recommended in 6 months.

Changes following traumatic brain injury are highly complex and represent a cascade of events involving cellular responses and neuronal inflammation, which can persist from minutes to several years. Gliosis refers to structural and functional alterations of glial cells in response to such injuries. ¹ On MRI, gliosis typically appears as a hypo- or isointense signal on T1-weighted images and a hyperintense signal on T2-weighted images; it is usually non-enhancing and may present as a mass with ill-defined margins, potentially mimicking low-grade tumors. In addition, secondary to trauma, disruption of the blood-brain barrier may occur, and enhancement can occasionally be observed. ² The radiological findings in our case were consistent with these characteristics. Moreover, the patient’s facial symptoms, in line with trigeminal nerve dysfunction, further supported a local pathology in this region.

Initially, due to the absence of a reported trauma history, a neoplastic process was considered. However, with detailed anamnesis and careful clinical follow-up, this diagnosis was excluded. We emphasize that, especially in pediatric patients, thorough and patient-centered history-taking is crucial, even if challenging. Identifying even the smallest clue can provide substantial benefits for achieving an accurate diagnosis.