Neuroradiology Case of the Week

Case 27

Manoj Ketkar, MD, Ramon deGuzman, MD, Henry Wang, MD, PhD,
and P-L Westesson, MD, PhD, DDS

Clinical Presentation: A 26-year-old male was referred for CT scan of head following a blunt head trauma.

Radiological Findings: No acute intracranial abnormality was noted. There is evidence of bilateral prominence of the temporalis muscle, which was seen as bilaterally symmetrical soft tissues in the region of the temporalis fossa (Fig. 1A & B).

Figure 1A	Figure 1B
Figure 1A & B: Axial CT scan of the head demonstrates prominence of the temporalis muscles bilaterally (arrows).

Diagnosis: Temporalis muscle hypertrophy.

Discussion:
   Temporalis muscle elevates the mandible. It arises from the floor of the temporal fossa. It is inserted over the anterior margin of the coronoid process and anterior margin of the ramus. There are deep temporal branches of the mandibular division of trigeminal nerve (V3) supply muscle.
   Exact etiology of the prominence of the temporalis muscle bilaterally remains unknown; bruxism could be one of the causes. It can be idiopathic or could be a normal variant.