Introduction: Syndrome of the Trephined (ST) is a post-craniectomy complication. It is characterized by the development of new neurological symptoms following the craniectomy that disappear after cranioplasty. The purpose of our work was: i) to identify imaging biomarkers of ST, and ii) to identify pathophysiological changes that occur after craniectomy.

Methods: We have retrospectively analyzed CT images of 32 patients that underwent craniectomy (ST=13, controls=19). The relative intracranial cerebrospinal fluid (CSF) volume was quantitatively measured using ITK snap software. Nine patients (ST=3, controls=6) had longitudinal CT scans. Patients with new intracranial hemorrhage, ischemia or hydrocephalus (treated by ventriculo-peritoneal shunt) were excluded of this study.

Results: We did not find significant differences between groups in the mean age or number of post-craniectomy days. ST was diagnosed during the 2nd post-craniectomy month. ST patients had significantly smaller relative intracranial CSF volume. Preliminary analysis of longitudinal data (ST and controls) showed that CSF volume declines with time following the craniectomy, and increases after cranioplasty (Figure 1).

Conclusions: Our preliminary results suggest that craniectomy alters biophysical properties of CSF that might underlie pathophysiology of ST.

Patient Care: Early detection of ST could lead to better care of craniectomised patients

Learning Objectives: Imaging biomarker of syndrome of the trephined Altered biophysical properties of CSF after craniectomy Altered biophysical properties of CSF after cranioplasty

References: Yamaura A, Makino H (1977) Neurological deficits in the presence of the sinking skin flap following decompressive craniectomy. Neurol Med Chir 17(1 Pt 1):43–53 Fodstad H, Love JA, Ekstedt J, Friden H, Liliequist B (1984) Effect of cranioplasty on cerebrospinal fluid hydrodynamics in patients with the syndrome of the trephined. Acta Neurochir 70(1–2):21–30 Grant FC, Norcross NC (1939) Repair of cranial defects by cranioplasty. Ann Surg 110(4):488–512