Effects of Early and Late Cranioplasty on Neurocognitive Outcome and Cerebral Glucose Metabolism using PET Scan - A Comparative Study.

Background: Brain protection and cosmetic aspects are the major indications of cranioplasty (CP) after decompressive craniectomy. CP can avoid the recurrence of brain damage, achieve the plastic effect, protect the patient from seizures, and relieve the syndrome of trephine.

Materials and methods: This was a prospective, observational study done over a period of 2 years from April 2017 to April 2019 in the Department of Neurosurgery at Sri Venkateswara Institute of Medical Sciences (SVIMS), Tirupati. Patients of age group 20-60 years who underwent CP after decompressive craniectomy for traumatic brain injury or cerebrovascular accidents with refractory intracranial hypertension were included. The study population was divided into two groups: early and late CP groups. Neurocognitive assessment was done 72 h before and 3 months after CP by mini-mental state examination (MMSE), Glasgow outcome score (GOS), and PGI battery of brain dysfunction (PGIBBD) scores. Cerebral glucose metabolism was assessed by 18F-FDG PET scan.

Results: In both early and late CP groups, there was a highly significant difference between the mean pre- and postoperative values of MMSE, GOS, and PGIBBD, suggesting significant improvement in neurocognitive parameters of patients postoperatively. There was no significant difference between early and late CP groups for mean standard uptake values (SUVs) on PET scan for both affected (P-value- 0.40) and nonaffected (P-value- 0.30) sides.

Conclusion: CP improves the cerebral metabolism and neurocognitive outcome, weather it is done early or late.