Syndrome of the trephined revealed by vertical diplopia

Excerpt

A 29 year-old man underwent a bi-frontal decompressive craniectomy to drain a life-threatening post-traumatic intraparenchymal hematoma. The bone flap became infected and had to be removed 13 months after the initial surgery. Seven months later, the patient complained of vertical diplopia which was more prominent in the evening and disappeared upon awakening, suggesting posture-related occurrence of symptoms. Ophthalmologic examination revealed a limitation of the upward gaze of the left eye with upbeat nystagmus, and a bilateral horizontal gaze evoked nystagmus associated with irregular dysmetric saccades. Ophthalmological examination suggested a midbrain dysfunction. MRI revealed an impingement of the mesencephalon by brain shift after craniectomy suggesting syndrome of the trephined (ST)/sinking skin flap syndrome. Cranioplasty was performed, and symptoms disappeared shortly after. A follow-up MRI 2 months later showed a normalized shape of the previously impinged mesencephalon. …