Role of repeat CT in mild to moderate head injury: an institutional study

Patients with traumatic brain injury (TBI) often undergo repeat head CT scans to identify the possible progression of injury. The objective of this study is to evaluate the need for routine repeat head CT scans in patients with mild to moderate head injury and an initial positive abnormal CT scan.

This is a retrospective study of patients presenting to the emergency department from January 2016 to December 2017 with Glasgow Coma Scale (GCS) scores > 8 and an initial abnormal CT scan, who underwent repeat CT during their in-hospital medical management. Patients who underwent surgery after the first CT scan, had a GCS score < 9, or had a normal initial CT scan were excluded. Demographic, medical history, and physical examination details were collected, and CT scans were reviewed. Radiological deterioration, neurological deterioration, and/or the need for neurosurgical intervention were the primary outcome variables.

A total of 1033 patients were included in this study. These patients underwent at least two CT scans on an inpatient basis. Of these 1033 patients, 54.1% had mild head injury and 45.9% had moderate head injury based on GCS score at admission. The most common diagnosis was contusion (43.8%), followed by extradural hematoma (28.8%) and subdural hematoma (26.6%). A total of 2636 CT scans were performed for 1033 patients, with a mean of 2.55 per patient. Of these, 25 (2.4%) had neurological deterioration, 90 (8.7%) had a progression of an existing lesion or appearance of a new lesion on repeat CT, and 101 (9.8%) required neurosurgical intervention. Seventy-five patients underwent surgery due to worsening of repeat CT without neurological deterioration, so the average number of repeat CT scans required to identify one such patient was 21.3. On multiple logistic regression, GCS score at admission (p = 0.024), abnormal international normalized ratio (INR; p < 0.001), midline shift (p = 0.005), effaced basal cisterns (p < 0.001), and multiple hemorrhagic lesions (p = 0.010) were associated with worsening of repeat CT, neurological deterioration, and/or need for neurosurgical intervention.

The role of routine repeat head CT in medically managed patients with head injury is controversial. The authors have tried to study the various factors that are associated with neurological deterioration, radiological deterioration, and/or need for neurosurgical intervention. In this study the authors found lower GCS score at admission, abnormal INR, presence of midline shift, effaced basal cisterns, and multiple lesions on initial CT to be significantly associated with the above outcomes.