The Correlation between Mild Head Injury and Positive CT scan of the Brain in the Patients with Moderate Risks at Naresuan University Hospital

Mild head injury is common reason for hospital admission after trauma. An increasing number of patients currently receive Computed tomography in addition to hospital observation. The definitive diagnosis of intracerebral hemorrhage was performed by CT brain scan which is available in only tertiary care centers. It has been suggested that patients can be screened for admission with an early CT scan, thereby avoiding unnecessary admissions when findings are normal. Because of the cost and requirement of the specialist who interpreted CT brain scan, that result in clinical characteristics were used to screen patients who have mild head injury, before sending them to perform CT brain scan. However a few studies have shown thatthe best clinical characteristic was used to screen patients.Therefore the purpose of this research was to find clinical characteristics in patients who had mild head injury that associated with abnormal CT brain finding.

In retrospective study, we collected the sample consisting of 109 patients who had mild head injury and got CT brain scan at Naresuan university hospital between 1st January 1999 to 31th May 2011 .In this study, we compared the patients with clinical characteristics and the patient without clinical characteristics. Main outcome measures were intracranial abnormal finding which detected on computed tomography. This research was analyzing by Chi-square test.

The result showed that indifference in sex and mean age between them. (29.07 years old in compared group and 29.93 years old in control group) Both group had 28 people shown abnormal finding in CT brain scan. The most common of head-traumatic mechanism is motorcycle accident by 74 people (67.89%). CT scan finding showed the brain lesion which consisted of subdural hematoma, traumatic subarachnoid hemorrhage, epidural hemorrhagic, hemorrhagic conclusion.The finding showed that patient with significant subgaleal swelling increased abnormal CT rate and operative intervention for head injury.

Patients with mild head injury and significant subgaleal swelling should be evaluated for CT brain scan.

Introduction

Casualty due to accident is the third cause of death following to cancer and cardiovascular disease respectively. Unfortunately it is the most common cause of death of people in working age. In 2007 there were 100,733 of total traffic related accidents with total number of death, severely injured and injured was 11,830, 14,733 and 61,742 respectively. It costs more than 4 billion baths which is more than any crime by 4-5 folds. Head injury is the most common site (30%) of all injuries. Mortality rate of severe head injury is 29% and is increasing steadily.

In western country, incidence of mild head injury 100-300 per 100,000 was found. Head injury patient is a patient who has definite history or physical exam of head trauma, mild alteration of consciousness (GCS 13-15)and with rare complications (6-12%).There is high mortality rate and needs surgical intervention among certain patient (0.4-1.0%).

CT brain is gold standard for diagnosis of intracerebral hemorrhage which requires specialized instruments and only available in tertiary center. Because of its availability, cost and specialist requirements, there is increasing trends of screening patient before perform CT brain base on clinical characteristics of patient. From SüleymanTüredi MD. and team study , there is a risk for patient who have mild head injury with nausea and vomiting with significant statistic ( odds ratio 4.61 , 95%CI 2.20-9.64 , p=0.0001 ) as in patient who was mild head injury with suspected skull fracture ( odds ratio 3.46 , 95%CI 1.52-7.91 , p=0.0032 )

This study is based on the fact that there are no definitive clinical characteristics associated with abnormal computed tomography scan finding in mild head injuries. The study objective is to define clinical characteristic criteria for screening patient who is at risk of intracerebral hemorrhage, which is insight for diagnosis, treatment, referral to reduce morbidity, mortality rate and cost for health on source section

Objective

  1. Define definitive clinical characteristics associated with abnormal computed tomographic scan finding in mild head injuries
  2. Guideline for appropriate requirement to perform CT brain
  3. Guideline for management and referral

Methods

We reviewed retrospectively hospital charts of 109 patients treated at the emergency department with mild head injury (GCS score of 13 to 15) between January 1, 2008 and May 31, 2011 were performed CT scan. The inclusion criteria, based on previously published material, were patients involved in traffic accidents with fatalities, significant subgaleal swelling, post traumatic seizure, retrograde amnesia, alcohol consumption, basal skull fractures,serious facial injury, a loss of consciousness, vomiting, progressive headache and multiple traumas. We excluded patients if they: had a bleeding disorder or used anticoagulants (i.e., Coumadin), had a risk factors present with respect to the spontaneous intracerebral hemorrhage (i.e., Idiopathic thrombocytopenic purpura, leukemia, and stroke)

Mild head injury is defined as blunt trauma to the head, after which the patient loses consciousness for < 15 min or has a short, post-traumatic amnesia of < 1 h, or both, as well as a normal or minimally altered mental status on presentation (a GCS score of 13-15)

Patients with no risk factors present were compared with patients with one or more risk factors with respect to abnormal CT rate and rate of operative intervention for head injury.

Data were collected on patient and trauma characteristics (age, sex time of injury, and presentation), accompanying symptoms, physical and neurological examination, CT scan findings. Selection of these items was based on a literature review of published risk factors for intracranial complications after mild head injury.

Chi-squared test was used to compare the groups with normal and abnormal CT scan regarding sex, trauma mechanism, age, moderate risks, and outcome. Statistical significance was considered present for P values less than .05.

The research ethics committees of the study hospitals approved the protocol without the need for informed consent.

Results

Medical charts of 64 males and 45 females, with average age of 17-60 years, were reviewed. The age distribution of patients with abnormal CT scan finding is shown in Table 2; there were no statistically significant differences between the age group.

Mechanisms of trauma were motorcycle accident, 74; fall 21; and other, 12.Initial CT scan was performed on all 109 patients investigated within the first 3 hour. As a result of this initial CT scan, abnormal findings were identified in 28(25.7%). Their types were as follows: 17 (60.7%) subdural hematoma, 5 (17.9%) traumatic subarachnoid hemorrhage, 4 (14.3%) epidural hematoma, and 2 (7.1%) hemorrhagic contusion.

The correlation between moderate criteria and abnormal CT scan was analyzed. These findings are shown in Tables 4 and 5. There was a significant correlation of abnormal CT scan with significant subgaleal swelling, but no significant correlation with post traumatic seizure, retrograde amnesia, alcohol consumption, basal skull fractures, serious facial injury, a loss of consciousness, vomiting, progressive headache and multiple traumas.

The first risk factor, significant subgaleal swelling, was present in 20 patients. There were abnormal CT scan findings in 9 of these. This correlation between significant subgaleal swelling and abnormal CT scan was significant.

Post traumatic seizure was suspected in 3 patients. Abnormal CT scan findings were observed in only 1 of these. This correlation between posttraumatic seizure and abnormal CT scan was not significant.

Retrograde amnesia was suspected in 65 patients. Abnormal CT scan findings were observed in 14 of these, and no significant correlation was found between retrograde amnesia and abnormal CT. One additional risk factor was present in 11 of our patients presenting with retrograde amnesia, and 3 of these patients presented with isolated retrograde amnesia, CT scan being normal in both.

The correlation between serious facial injuryand abnormal CT scan was not significant. Serious facial injury was present in 15 of our cases, and abnormal CT scan was determined in only 1 of these. Only 1 of these 15 cases had serious facial injury as an isolated complaint, and CT scan was normal.

Alcohol consumption was present in 35 patients, and abnormal CT scan findings were in 9 of them. The number of patients presenting with isolated alcohol consumption was 3, and CT scan was normal in all of them. Our study found no significant between alcohol consumption and abnormal CT scan findings.

The number of patients with basal skull fractureswas16, and abnormal CT scan findings were present in 7 of these. One patient had basal skull fractures and no other risk factors, and CT scan was normal. Statistically, there was no correlation between basal skull fractures and abnormal CT scan.

Loss of consciousness was present in 68 patients. There were abnormal CT scan findings in 21 of these. Five of these cases had loss of consciousness as an isolated complaint, and there was an abnormal CT scan finding in only 1 of these. Our study found no significant between loss of consciousness and abnormal CT scan findings.

The correlation between vomiting and abnormal CT scan was not significant. Vomiting was present in 27 of our cases, and abnormal CT scan was determined in 9 of these. Two of patients had vomiting as an isolated complaint, and CT scan was normal.

Progressive headache was present in 41 patients, and abnormal CT scan findings were in 12 of them. The number of patients presenting with isolated alcohol consumption was only one, and CT scan was normal. Our study found no significant between progressive headache and abnormal CT scan findings.

Multiple traumas were suspected in 14 patients. Abnormal CT scan findings were observed in 6 of these, and no significant correlation was found between retrograde amnesia and abnormal CT.

Table 1: Correlation between initial abnormal CT scan with sex and age in all patients

Factor / Positive CT brain
(n=28) / Negative CT brain
(n=81) / Risk ratio / 95% CI / p value
Number / Percent / Number / Percent
Age / 1 / 50 / 1 / 50 / 1.903 / 0.46- 7.91 / 0.465
0-2 years
3-60years / 26 / 26.26 / 73 / 73.74 / 1.00
> 60years / 1 / 12.5 / 7 / 87.5 / 0.476 / 0.073- 3.07 / 0.676
Sex / 11 / 24.44 / 34 / 75.56 / 1.00
Female
Male / 17 / 24.56 / 47 / 73.44 / 1.05 / 0.74-1.49 / 0.803

Table 2: Mechanisms of injury in the studies cases

Data / Number / %
Mechanisms of injury / Fall / 21 / 19.27
Road accident (RTA) / Motorcycle accident / 74 / 67.89
Others / 12 / 14.84

Table 3: Traumatic findings at CT

Traumatic findings at CT / Number of patients (%)
Hemorrhagic contusion / 2 (7.1)
Traumatic subarachnoid hemorrhage / 5 (17.9)
Subdural hematoma / 17 (60.7)
Epidural hematoma / 4 (14.3)

Table 4: Correlation between moderate-risk criteria and initial abnormal CT scan in all patients (n=109)

Moderate-risk criteria / Number of patients and percentage / Abnormal CT scan number / Abnormal CT scan percentage / p Value
Significant subgaleal swelling / 20 (18.35%) / 9 / 45% / 0.0451*
Post traumatic seizure / 3 (2.75%) / 1 / 33.33% / 1.000
Retrograde amnesia / 65 (59.63%) / 14 / 21.54% / 0.267
Alcohol or drug intoxication / 35 (32.11%) / 9 / 25.71% / 1.000
Basal skull fractures / 16 (14.68%) / 7 / 43.75% / 0.117
Serious facial injury / 15 (13.76%) / 3 / 20 % / 0.756
Loss of consciousness / 68 (62.39%) / 21 / 30.88% / 0.121
Vomiting / 27 (24.77%) / 9 / 33.33% / 0.317
Progressive headache / 41(37.61%) / 12 / 29.27% / 0.508
Multiple trauma / 14 (12.84%) / 6 / 42.86% / 0.186

P values less than .05

Table 5: Moderate-risk criteria and initial abnormal CT scan findings: Results of cohort study

Moderate-risk criteria / Initial abnormal CT scan findings / RR / 95% CT / P Value
Significant subgaleal swelling / Yes / 9 / 2.367 / 1.10-5.11 / 0.0451*
No / 11
Post traumatic seizure / Yes / 1 / 1.446 / 0.14-15.34 / 1.000
No / 2
Retrograde amnesia / Yes / 14 / 0.794 / 0.53-1.19 / 0.267
No / 51
Alcohol or drug intoxication / Yes / 9 / 1.00 / 0.54-1.86 / 1.000
No / 26
Basal skull fractures / Yes / 7 / 2.25 / 0.92-5.48 / 0.117
No / 9
Serious facial injury / Yes / 3 / 0.72 / 0.22-2.38 / 0.756
No / 12
Loss of consciousness / Yes / 21 / 1.29 / 0.97-1.72 / 0.121
No / 47
Vomiting / Yes / 9 / 1.45 / 0.74-2.84 / 0.317
No / 18
Progressive headache / Yes / 12 / 1.20 / 0.72-2.00 / 0.508
No / 29
Multiple trauma / Yes / 6 / 2.17 / 0.82-5.71 / 0.186
No / 8

RR = risk ratio; CI = confidence interval, P values less than .05.

Discussion

Clinical characteristics which had risk for intracranial hemorrhage were studied by previous researches. These were significant subgaleal swelling, post traumatic seizure, serious facial injury, retrograde amnesia, alcohol consumption, basal skull fracture, loss of consciousness, vomiting, progressive headache and multiple traumas.

Univariable analysis from this study was found that age and sex were not significant risk factor associated with intracranial hemorrhage. Theseresults were concurrent with SuleymanTuredi’s research finding which studied in Karadeniz hospital.

Clinical characteristics that had significant associated with abnormal CT brain scan (p<0.05) was significant subgaleal swelling. This result was different from other studies. The Stiell’sstudy found basal skull fractures and retrograde amnesia associated with abnormal finding in CT brain scan. The Falimirski’s study found loss of consciousness symptom associated with abnormal CT brain scan. The Murshid’sstudy found progressive headache symptom associated with abnormal CT brain scan. All patients who had significant subgaleal swelling were found that accompanied with other symptoms. Therefore, we used the Crude analysis to find the potential confounder by choose co-symptoms which had p-value<0.2. These were loss of consciousness, basal skull fracture, and multiple traumas. But, from analysis, these symptoms did not affect the relation between significant subgaleal swellings with abnormal CT brain scan.

However, we cannot certainly conclude that the patients who had subgaleal swelling symptom were also associated with abnormal CT brain scan everyone. Because of small sample size and incomplete medical records, which included history, physical examination, and management, these factors had an effect on the study analysis about the relation between clinical characteristics that associated with abnormal CT brain scan. Some physician did not record the data in three conditions: patients had no the symptoms, physicians had not done examination, and physicians found the symptoms but they did not record it. Finally, other factor that affected study analysis was that some patients did not perform the CT brain scan but they may have mild type of intracranial hemorrhage and did not get the treatment. So, these data was not collected for analysis.

Suggestion

  1. This research was studied only at Naresuan university hospital that can not refer to another population of patients with mild head injury.
  2. Design of this study would be better in prospective cohort study design because, in prospective cohort study, we can plan to collect the sample, which had more reliability and can refer to apply the real management. It can be reduce prejudice such as small size of the sample and remove the confounder before the study. Example; the patient who had underlying with anticoagulant drug taking has more chance to be intracranial hemorrhage. Moreover, we will completely receive the correct data that reduce the errors. However, this study design spends more time and money to study and difficultly finds the sample.

Conclusion

Patients with mild head injury who had significant subgaleal swelling and other symptoms which were risk to intracranial hemorrhage should perform computed tomography brain scan. Current study findings demandfuture researches in larger population by prospective cohort study design in the future.

Acknowledgement

Study group thanked

- Professor Supasitpannarunothai (MD), Dean of the faculty of medicine
- Doctor Suwitletkajornsin , Epidemiologist of CFOM department who is statistic adviser
- Radiologic officer who comfortably support for collect the data

for supportive data that help this research to accomplished.

Reference

1.Bahner J, Don R, Stein S, Ross S. The value of computed tomographic scans in patients with low-risk head injuries [Online]1990 [cited 29 July 2554 ]. Available from:

2.Cattamanchi S, Siva A, Raja A, Thiagarajan NR, Trichur RV. 86: Comparison of the Canadian CT Head Rule and the New Orleans Criteria In Minor Head Injury Patients With Glasgow Coma Scale 15/15.[Online]2010 [cited 29 July 2554 ]. Available from:

3.de Andrade AF, de Almeida AN, Bor-Seng-Shu E, Lourenço L, Mandel M, Marino JR. The value of cranial computed tomography in high-risk, mildly head-injured patients.[Online]2006 [cited 29 July 2554 ]. Available from:

4.Falimirski ME, Gonzalez R, Rodriguez A, Wilberger J. The need for head computed tomography in patients sustaining loss of consciousness after mild head injury. [Online] 2003 [cited 29 July 2554]. Available from: 2003

5.Havdel M, Preston C, Mills T, al. e. Indications for computed tomography in patients with minor head injury [Online]2001 [cited 29 July 2554 ]. Available from:

6.Miller EC, Holmes JF, Derlet RW. Utilizing clinical factors to reduce head CT scan ordering for minor head trauma patients.[Online]1997 [cited 29 July 2554 ]. Available from:

7.Murshid WR. Management of minor head injuries: admission criteria, radiological evaluation and treatment of complications.[Online]1998 [cited 29 July 2554 ]. Available from:

8.Ratanalert S, Kornsilp T, Chintragoolpradub N and Kongchoochouys. The impacts and outcomes of implementing head injury guidelines: clinical experience in Thailand. [Online] 2007 [cited 29 July 2554]. Available from:

9.Royal college of surgeons of Thailand. Head injury. [Online] 2008 [cited 29 July 2554]. Available from:

10.Smits M, Dippel DW, de Haan GG, Dekker HM, Vos PE, Kool DR, et al. External validation of the Canadian CT Head Rule and the New Orleans Criteria for CT scanning in patients with minor head injury.[Online]2005 [cited 29 July 2554 ]. Available from:

11.Stein SC, Ross SE. Mild head injury: a plea for routine early CT scanning.[Online]1992 [cited 29 July 2554 ]. Available from:

12.Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. . [Online] 2001 [cited 29 July 2554]. Available from:

13.SüleymanTürediMD ,AltugHasanbasoglu MD, AbdulkadirGunduz MD ,Mustafa Yandi MD. Clinical Decision Instruments for CT scan in Minor Head Trauma. [Online] 2008 [cited 29 July 2554]. Available from:

14.Voss M, Knottenbelt J, PEEDEN M. Patients who reattend after head injury: A high-risk group [Online]1995 [cited 29 July 2554 ]. Available from:

15.Yavuz MS, Asirdizer M, Cetin G, GunayBalci Y, Altinkok M. The correlation between skull fractures and intracranial lesions due to traffic accidents.[Online]2003 [cited 29 July 2554 ]. Available from: