Correlation of clinical features with neuroimaging in children with mild head injury

INTRODUCTION

Mild head injury is defined as a pediatric Glasgow Coma Scale (GCS) score of 13–15 at admission following trauma to the head.^[1] Such children are usually conscious with a few common symptoms. Although children rarely develop intracranial complications, those who do so can have rapid clinical deterioration. The chances of positive computed tomography (CT) scan finding in mild head injury is 15%, with <1% requiring any neurosurgical intervention.^[2] Such children, therefore, pose a dilemma to the attending pediatrician regarding the need to subject these children to a CT scan.

Several clinical decision rules aid in this decision-making, such as Canadian assessment of tomography for childhood head injury,^[3] Children’s Head Injury Algorithm for the Prediction of Important Clinical Events,^[4] Paediatric Emergency Care Applied Research Network,^[5] and National Institute for Health and Care Excellence (NICE)^[6] guidelines. The NICE guidelines, updated in 2014, recommend CT scan to be done in any child with presence of risk factors such as suspected non-accidental injury, post-traumatic seizure without history of prior seizures, GCS score of <14 (GCS <15 in an infant), or GCS <15 at 2 h following injury, if suspected open or depressed skull fracture or presence of tense fontanelle. Neuroimaging is also recommended in the presence of signs of basal skull fracture, focal neurological deficit, presence of any bruise, or swelling or laceration of more than 5 cm on the head of an infant. The presence of any of the following clinical symptoms such as loss of consciousness (LOC) >5 min, abnormal drowsiness, and three or more discrete episodes of vomiting also warrants a CT scan according to the guidelines.

Although imaging studies help detect a significant intracranial lesion which will facilitate the clinician regarding prognostication of the injury and discharge, they may expose the patient to radiation which may be a slight risk for cancer.^[7] In addition, neuroimaging adds to the financial burden and there are also issues with availability in remote areas in developing countries. At present, there are no clear-cut guidelines that are followed for neuroimaging among children with head injury in most countries. Hence, there is a need to identify symptoms that can predict clinically significant CT scan findings among children with a mild head injury.

This study aims to analyze the association of common clinical symptoms as per NICE guidelines with CT scan findings in children with mild head trauma. This study may help guide practitioners to judiciously advise CT scans in children with mild head injury, especially in resource-limited settings and help to reduce exposure to radiation.

MATERIALS AND METHODS

A retrospective and observational study was conducted in a tertiary health-care center after obtaining clearance from the Institutional Ethics Committee. Children in the age range of 1 month to 18 years with mild head injury presenting to the hospital during the study period between January and December 2022, in whom CT scan reports were available, were included in the study. Records of all the children fulfilling the inclusion criteria were retrieved. Demographic details such as age, gender, and clinical data such as type of injury (hit by a blunt object, fall from height, and road traffic accident), presence and frequency of vomiting, period of LOC if present, presence of drowsiness, headache, and giddiness if any were also noted. History of seizures, presence of focal deficits, and the GCS score were recorded in a predesigned proforma. The CT scan findings were noted and the report was considered abnormal if any of the following such as fracture of skull, cerebral edema, epidural, subdural and intracerebral hematoma, cerebral contusion, and subarachnoid hemorrhage were present. Neurosurgical intervention if done was also noted.

RESULTS

A total of 134 children presented with mild head injury during the period of the study. The median (interquartile range) age was 5 (2, 8) years. The demographic profile of the children is given in [Table 1]. The children were predominantly male, with a M: F ratio of 1.8:1.

The most common cause of injury present in 34.3% of the cases was road traffic accidents, followed by fall from a height of < 3 feet (31.3%). Majority of the children (92.7%) presented with a GCS of 15. The common symptoms were vomiting in 43.6%, abrasions on the head/face in 37.3%, LOC in 31.9%, and ear/nosebleed or cerebrospinal fluid (CSF) otorrhea/rhinorrhea in 21.9%. An abnormal CT scan was seen in 53.7% (n = 72), of which the most common abnormality was skull fracture (35.1%, n = 47), followed by cerebral edema (13.4%, n = 18). Four children required neurosurgical intervention.

Among the clinical symptoms, ear/nosebleed or CSF otorrhea/rhinorrhea had a statistically significant association with an abnormal CT scan with P = 0.05 and an odds ratio (OR) of 1.4 (95% confidence interval [CI], 1–1.9) [Table 2]. Other symptoms such as drowsiness, headache, focal deficits, and vomiting (>3 episodes) had a high OR for an abnormal radiologic report, but none was statistically significant. The presence of vomiting and abrasions together was the most common combination of symptoms, but did not have statistically significant correlation with the CT scan findings.

Neuroimaging was indicated in 120 out of the 134 cases according to the NICE guidelines, out of which CT scan abnormality was seen in 68 cases. An abnormal CT scan would be missed in four cases that did not satisfy the NICE guidelines indication for neuroimaging. However, none of those cases required neurosurgical intervention. Having a positive indication for CT scan according to the NICE guidelines had an OR of 1.9 (95% CI: 0.9–4.6, P = 0.046) for detecting an abnormality.

DISCUSSION

Children presenting to the casualty with mild head injury pose a dilemma to the attending pediatrician regarding the need for a CT scan. During a 12-month follow-up of children with mild head injury, it was found that neuropsychological improvement was related with abnormal CT.^[8] It was also found that performance in cognitive domains was poorer in children with abnormal CT as opposed to those with normal or linear skull fracture on CT scan.^[8] On the other hand, the radiation from the CT scan may carry a marginal risk for cancer.^[7] Many children with history of mild head injury are hospitalized for neurologic observation even though they have a normal CT scan, which may not be required.^[9] Hence, the benefits must outweigh these small absolute risks to justify using a CT scan. We attempted to find any correlation between the standard clinical features and abnormality in the CT scan.

The cases were predominantly males, as seen in other studies.^[10,11] Road traffic accident (RTA) and fall from height formed the principal mechanism of head injury in our study. Similar observations were made in other studies^[12-14] on head injury in pediatric patients. Children are common among pedestrians who form a significant group involved in injury during an RTA.^[15] Children have relatively larger and heavier heads than the rest of the body. With increasing motor ability and the head being the center of gravity in children, any fall directly impacts the head. Hence, the chance of injury to the head is more in any form of trauma.

The predominant symptoms in our study were vomiting followed by scalp and facial abrasions and LOC. Headache, scalp hematoma, and nausea with or without vomiting were the three main symptoms in one study.^[11] In contrast, vomiting, LOC, and ear/nose bleeding were the chief symptoms in another study.^[10]

Positive findings in CT scan were seen in 50% of the cases, with skull fracture being the predominant finding, followed by epidural hematoma (EDH) in a study.^[11] This was similar to our CT scan results. Another study also observed similar results with EDH and fracture hematoma as common findings on neuroimaging.^[16] The higher incidence of abnormality in CT scan in our study is probably because only cases in which neuroimaging was done were included.

On analyzing the symptoms, it was found that those presenting with features such as ear/nosebleed and CSF otorrhea/ rhinorrhea were more likely to have an abnormality on a CT scan. In another similar study^[15] where clinical features were compared between normal and abnormal CT scans, ear and nose bleeds had the highest OR for an abnormal CT scan. However, it was not found to be statistically significant. Scalp hematoma, nausea with or without vomiting, and ear/ nose bleeds or soft-tissue contusion in the periorbital region were found to have independent association with abnormality on CT scan in children with mild traumatic brain injury and GCS of 15.^[11] Absence of vomiting, headache, scalp hematoma, clinical signs suggestive of fracture of the skull, and abnormality in mental status identified children at low risk for traumatic brain injuries on CT scans following blunt head trauma in another study.^[17] Differences in study settings and inclusion criteria are probably the reasons for this variance in the risk factors.

Our study has certain limitations, one being that it is a retrospective study. Second, we included only inpatients who underwent CT scans. Further studies on prospectively collected data on all minor head injuries would help identify those clinical symptoms that can be predictors of abnormal neuroimaging.

CONCLUSION

A child following mild head injury presenting with signs of fracture of the base of the skull such as bleeding from the ear or nose and CSF otorrhea/rhinorrhea should be advised a CT scan by the attending pediatrician as it is more likely to be abnormal. Hence, such children require close neurological observation and prompt intervention if necessary. However, abnormality on CT scan cannot be reliably ruled out based on the symptoms alone.