Taste disorder as a sole manifestation of syndrome of the trephined

Abstract

Syndrome of the trephined, or sinking skin flap syndrome, is a rare complication following craniectomy, showing a variety of neurological symptoms that improve after cranioplasty. Taste disorders can be induced by a variety of causes, while those due to central lesions are rare. We report a case of syndrome of the trephined that developed a taste disorder as a sole manifestation. A 61-year-old man underwent enlarged left craniectomy due to bacterial infection after surgical resection of a convexity meningioma. In six weeks, the patient complained of taste abnormalities. Visual analog scale score, electrogustometry, and a whole-mouth gustatory test revealed impairment of taste perception. As other possible causative factors were excluded, and the symptom improved after the cranioplasty, we made the diagnosis of syndrome of the trephined. Gustatory information from one side of the tongue enters the nucleus of the solitary tract of the medulla, and reaches insular-operculum ipsilaterally through the ventroposterior medial nucleus of the thalamus. Additionally, it is speculated that gustatory information from the left side of the tongue directly reaches the left insula, while information from the right side may also reach the left insula through the right insula. Disturbance of the left hemisphere including the insula due to a skull defect may have caused impairment of taste perception. A taste disorder should bear in mind in the treatment of central nervous system diseases and taken into account as a manifestation of syndrome of the trephined.

Keywords

• Taste disorder
• Syndrome of the trephined
• Sinking skin flap syndrome
• Skull defect