Abstract 20: Syndrome of the Trephined: Functional Improvement After Reconstruction of Large Cranial Vault Defects

Abstract

PURPOSE: Large decompressive craniectomies performed after trauma may be life-saving; however, they may result in ‘Syndrome of the Trephined.’ This post-recovery sequella is characterized by dizziness, fatigue, depression, weakness, speech slowing, gait disturbance, and impaired mentation. This entity is poorly understood. Therefore, we attempted to quantify the functional disturbance in patients with large cranial vault defects and changes after cranial vault reconstruction using accepted functional analysis. METHODS: Patients with large cranial vault defects (>50cm2) were studied preoperatively and postoperatively (6 months) after cranial vault reconstruction using both: 1) Cognistat Active Form and 2) The FIM instrument (Functional Independence Measure) (n=35). Cranial vault reconstructive techniques varied from split cranial bone to alloplastic implants (PEEK) to titanium implants. Complications, reoperations, and patient scores on both outcome instruments were recorded. RESULTS: Of the 140 patients treated with decompressive craniectomies, 35 with large cranial defects were studied. Defects ranged from 55cm2 to 110cm2 with a mean of 65cm2. Reconstructions were: Split cranial bone (74%); alloplastic implants (PEEK) (15%); titanium implants (11%). Timing of postoperative symptom improvement varied with a range of 1 week to 3 months. Cognisant assessment showed functional improvement in 85% of patients undergoing cranial vault reconstruction; mean preop score 38 ± 9 and postop score of 69 ± 11. FIM also showed improvement (score=16 meant total dependence and score 126 meant complete independence): when comparing total preoperative 38 ± 7 to postoperative 98 ± 1 scores. Cognitive scores improved from 11 ± 4 to 26 ± 10 and Motor from 27 ± 10 to 71 ± 10. Type of reconstruction was not a determinant for functional improvement. Split calvarium was the longest procedure but had the least complications. In 2 patients, implants were removed due to infection and Syndrome of Trephined returned. Symptoms once again resolved after the patients underwent a second cranial vault reconstruction. CONCLUSIONS: Syndrome of the Trephined occurs more frequently then previously described in post-traumatic patients with large cranial vault defects; Cranial vault reconstruction leads to symptomatic improvement in large number of patients.