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 Table of Contents  
ORIGINAL ARTICLE
Year : 2015  |  Volume : 4  |  Issue : 2  |  Page : 45-50

Computed tomographic pattern of traumatic head injury at a tertiary hospital in Ibadan, South-Western Nigeria: A 10 year review


Department of Radiology, College of Medicine, University College Hospital, University of Ibadan, Ibadan, Nigeria

Date of Web Publication22-Mar-2016

Correspondence Address:
Dr. Adenike Temitayo Adeniji-Sofoluwe
Department of Radiology, College of Medicine, University College Hospital, University of Ibadan, Ibadan
Nigeria
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1597-1112.179215

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  Abstract 

Background: The World Health Organization has projected that by the year 2020, head trauma from Road Traffic Crashes (RTCs) alone will be the 3 rd leading burden of diseases in developing countries. Computed tomography (CT) is the imaging modality of choice in acute traumatic head injury evaluation and provides an excellent guide to the care of the head injured patient.
Aim: The aim of this study was to evaluate the computed tomographic pattern of head injury over a decade.
Materials and Methods: This is a 10 year retrospective and descriptive study carried out at the University College Hospital Ibadan, a premier tertiary health institution, which serves as a referral center for cities and towns in South-West Nigeria. All patients with head injury referred to the Radiology Department for cranial CT investigation between January 2003 and December 2012 were recruited into the study.
Results: Males accounted for 75.3% of the 2142 head trauma cases with an approximate male to female ratio of 3:1. The mean age of the patients was 34.4 years, and the median age was 32 years (age range: 1-92 years). Patients <39 years accounted for 64.4% of the cases. RTC was the most common etiologic factor accounting for 1,318 head injury cases. Cases due to assault were least seen in 131 (6.3%) of the study population. Abnormal CT findings were present in 77.6% of cases. Intracranial hemorrhage was demonstrated in 1390 patients and was the most common finding. Intraaxial bleeds were present in 60.9%, and the incidence of skull fracture was also high (50.9%).
Conclusion: RTC remains the leading cause of head injury but now occurring at an increasing and alarming rate. The most common abnormal CT finding is intraaxial bleeds, followed by skull fractures and extraaxial bleed in decreasing order. A combination of these findings was also frequently recorded.

Keywords: Computed tomography, head trauma, intracranial bleed, road traffic accident


How to cite this article:
Adekanmi AJ, Adeniji-Sofoluwe AT, Obajimi MO. Computed tomographic pattern of traumatic head injury at a tertiary hospital in Ibadan, South-Western Nigeria: A 10 year review. Afr J Trauma 2015;4:45-50

How to cite this URL:
Adekanmi AJ, Adeniji-Sofoluwe AT, Obajimi MO. Computed tomographic pattern of traumatic head injury at a tertiary hospital in Ibadan, South-Western Nigeria: A 10 year review. Afr J Trauma [serial online] 2015 [cited 2019 Jul 20];4:45-50. Available from: http://www.afrjtrauma.com/text.asp?2015/4/2/45/179215


  Introduction Top


Head trauma remains one of the most frequent causes of death and disability in children and adults worldwide. [1],[2] They results in lesions or functional damage of the scalp, the cranial bones, the meninges, and the brain itself. [1],[2] The 2010 report of the Centre for Disease Control and Prevention, National Centre for Injury Prevention and Control, USA, documented that an estimated 1.7 million people receive medical treatment for head trauma every year in the United States alone with high morbidity and mortality recorded. [3] Head injury from traumatic events is documented as one of the most common reasons for medical consultations and accounts for about 30% of all injury-related death in the USA. [3],[4] In Europe, the rate of hospitalization for head trauma, according to the meta-analysis study of 23 European countries by Tagliaferri et al. in 2006 was 235 cases per 100,000 persons per year. [5] In Nigeria, a staggering incidence rate of 2710 per 100,000 per year was reported by Emejulu et al. [6] Head injury is commonly seen in adults and shows a bimodal peak: First peak occurs between 15 and 24 years and the second peak in people above 50 years. [7] Head injury is twice more common in males than in females. [4] Head trauma is the cause of death in more than 50% of trauma patients. [8] Various etiological reasons result in head trauma in different parts of the world, although the most common causes include Road Traffic Crashes (RTCs), falls, and assault. [2],[5] Other documented causes are violence, sports, and recreation injuries. [2]

In the developing nations, including Nigeria, head injury is on the increase due to increasing incidence of road traffic accidents. [8] In the World Health Organization (WHO) Geneva 2006 report, it was projected that by the year 2020, head trauma from RTCs alone will be the third leading burden of diseases in the developing countries. Head injury poses a tremendous health challenge with attendant huge socioeconomic impact from the head trauma itself or its squealae largely due to poverty and scanty infrastructures in most African countries. [9] In Nigeria, like other countries in the subregion, the advent of commercial motorcycles popularly called "OKADA" as a means of transportation particularly in areas with deplorable/non-motorable roads has significantly increased the incidence of head injuries. [10] This is partly due to reckless maneuverings of the commercial motorcycles and lack of appropriate protective wear for the motorcyclist and the "passenger." [11],[12],[13]

Head injury involves a wide spectrum of injuries which may be classified as primary or secondary traumatic lesions. Primary head injury is present at the time of trauma, it is transient and leads to an irreversible damage to the brain. Secondary brain injury usually result from the accompanying perilesional edema or raised intracranial pressure or parenchyma ischemia affecting different parts of the brain. These secondary changes can cause tonsillar herniation, especially in cases with raised intracranial pressure and may eventually culminate in the death of the patient. [14]

The current trend of evaluation of patients with head injury includes computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine. However, cranial CT has emerged as the mainstay in the diagnostic work-up of patients with head injury, particularly in the initial assessment of the head injured due to its availability, short image acquisition time and its accuracy in the detection of skull fractures and intracranial hemorrhage. [15],[16],[17]

CT is invaluable in the assessment of the brain parenchyma and the bony vault. It is used in the management of traumatic structural brain damage secondary to head trauma and has tremendously helped in the care of the head injured persons, particularly in instituting prompt surgical care. The CT features of head trauma have been described in some teaching hospitals in the country; however, most of these studies were conducted over a maximum period of -2 years. [18],[19],[20] This study involves head trauma patients over a 10-year period with the largest sample size in Nigeria and sub-Sahara Africa. This study is aimed at evaluating the epidemiological, demographic, and computed tomographic features of head trauma patients in Ibadan over a decade.


  Materials and Methods Top


This is a retrospective and descriptive study carried out over a 10 year period (2003-2013) at the Department of Radiology University College Hospital (UCH) Ibadan, Nigeria. It is a tertiary health institution which serves as a referral center for towns and cities in South-West Nigeria. All head injured patients referred to the Radiology Department for cranial CT during this period were included in the study. Their imaging records and the reports of all the 2143 patients were retrieved and evaluated.

Cranial CT examinations were done using the Toshiba Aquilion 64-slice and General Electric (GE) 8-slice multidetector CT scanners. A multislice protocol with 3-8 mm (5 mm) cuts from the base to the vertex was utilized. A range of 120-150 kvp and 250-300 mAs were used for the cranial CT scans. Images were acquired in the axial plane with multiplanar reformatted sagittal and coronal images.

A proforma was used to document the demographic information about the patients. The type of injury, as well as the imaging findings, was also documented in the proforma. Cranial CT findings documented include scalp injuries (swelling, laceration, subcutaneous emphysema, foreign bodies, and avulsion), intraaxial hemorrhage (intraparenchymal hemorrhage), extraaxial hemorrhage (subdural, epidural, and subarachnoid hemorrhage), cerebral edema/brain swelling, intracavitary hematoma, and skull vault fractures. Other documented findings are those of chronic head trauma like infarction. Due ethical considerations were adhered to but consent was not required as secondary data analysis was performed. However, all information obtained about the patients was kept confidential. All data was entered and analyzed using the statistical package Statistical Package for Social Sciences ( SPSS 22.0, Armonk, NY: IBM Corp.). Frequency distributions (proportions), graphs, and tables were constructed to present the data as appropriate.


  Results Top


A total of 2142 patients of all age groups, irrespective of their Glasgow Coma Score referred for cranial CT scan due to head injury, during the 10 years period were included in this study. 2086 (98.4%) had complete data. While 56 of the patients (2.6%) had some missing data on age and mechanism of injury. Males accounted for 75.3% (1612/2142) of all the head trauma cases, while females recorded 24.7% (530/2142) with an approximate male to female ratio of 3:1. The mean age of the patients was 34.4 years, and the median age was 32 years (age range: 1-92 years).

[Figure 1] shows the distribution of the participants by age group and gender. The proportion of head injury was almost similar in the age group below 20 years and those between 30 and 39 years (20% and 20.2%, respectively). Those in the age group 20 and 29 years was about 22.5%, and 13.5% were seen among those aged 40-49 years, while 261 (12.4%) were in the age 60 years and above. The smallest proportion (150/2086) of 8.9% of head trauma patients was in the 50-59 years age group. In general, abnormal CT findings were present in 1662 patients out of the total 2142. While the remaining 480 (22.4%) showed normal cranial CT scan [Table 1]. Co-existence of various lesions was recorded on the cranial CT examinations. The etiological factors of head injury are depicted in [Figure 2]. The highest number of cases of head injury was from road traffic accident, accounting for 1318 cases. Cases of head trauma from assault were the least and accounted for only 6.3%.
Figure 1: Age group and Gender distribution in 2086 head trauma patients


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Figure 2: Documented mechanism of head trauma


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Table 1: Cranial CT findings among the head trauma study population


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Scalp injury was seen in 629 (29.3%) patients. The scalp injury recorded in this study ranged from soft tissue swelling to avulsion injuries. About 582 (92.5%) had scalp swelling, 93 (14.8%) had subcutaneous emphysema, 32 (5%) had scalp foreign body, and subgaleal hematoma was seen in 15 (2.4%) patients. Eight (1.3%) patients had scalp laceration while only five (0.8%) had avulsion injury. The region of soft tissue affectation was most frequent in both parietal regions. The frontal regions were the next most frequent site. Skull fractures were present in a total of 836 (835/2142) cases as shown in [Figure 3]. Blowout fracture of the orbital bones was the least common type of fracture and documented in 35 patients (4.2%). The highest number of fractures involved the frontal bone in 35.8% (299/836) of cases and parietal bones or 38.3% (320/836).
Figure 3: Types of skull fracture among the study population. *Total is more than 836 due to multiple cranial fractures in some participants. Other fractures included paranasal sinuses, mastoid, and nasal bone fractures


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Extraaxial hemorrhage was present in 547 patients accounting for 41.1% (547/1662). Out of these, subdural hemorrhage alone was the most common bleed and accounted for 65.3% (357/547). A combination of subarachnoid and epidural bleed was the least common and seen in only 3.1% (18/547). A significant contribution was also made by epidural hemorrhage alone in 19.7% (108/547) of cases as shown in [Figure 4]. Among these patients, 428 (77.3%) were acute bleed, 37 (6.7%) were subacute, chronic bleed was seen in 69 (12.5%) acute on chronic bleed in 18 cases (3.2%), and subacute on chronic seen in 2 cases (4%).
Figure 4: Frequency and distribution of extraaxial hemorrhage among the study population


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Intraaxial hemorrhagic contusion was observed in 846 (50.9%) patients out of the 1662 patients with abnormal CT findings with an affectation of different parts of the brain in varying degrees. The least common was cerebellar vermis bleed recorded only in one case. Most of the bleeds were located in the parietal and frontal lobes, followed by temporal and occipital lobes in decreasing order as shown in [Figure 5]. The cranial CT features of the intracranial bleed are shown in [Figure 6]. Intracavitary hematoma resulting from paranasal sinuses and mastoid bone fractures were demonstrated in 395 cases. The maxillary, ethmoidal, and sphenoidal sinuses were the most affected paranasal sinuses accounting for 27.1%, 28.4%, and 28.9%, respectively. While hematoma of the frontal sinuses was seen in 10.9%. The mastoid air cells were the least affected and documented in only 4.7% of those with intracavitary hematoma.
Figure 5: A plot chart showing the distributions and frequency of brain parenchymal bleed among the study population.*Note several patients recorded multiple brain parenchymal hemorrhage


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Figure 6: Cranial Computed Tomographic images of different intracranial bleeds in the study population. Non-contrast axial cranial computed tomography scan (brain window) showing different forms of intracranial bleed. (a) Extensive irregular right putaminal hyperdensity with perilesional edema and intraventricular extension into the posterior horns of both lateral ventricles. (b) Extensive left concavo-convex hyperdensity adjacent the frontoparietal skull vault's inner table in keeping with sudural bleed. Also note the left parietal lobe acute bleed, mass effect (obliteration of the sulci, ipsilateral lateral ventricle compression and midline shift to the right). (c) Biconvex hyperdensity adjacent the inner table of the right temporal lobe, indicating an acute epidural bleed. (d) Extensive hyperdensity in the sylvian fissures, anterior inter-hemispheric fissure, and basal cistern, in keeping with acute subarachnoid bleed


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Other CT findings in this study population were infarction of various part of the brain seen in 134 cases. Most of the recorded Infarction was in the cerebral hemispheres in 93.4%, the brain stem was involved in five patients (3.7%), cerebellum infarctions were seen in six cases (3.7%), and only two cases of vermin infarction (0.2%) were also documented.


  Discussion Top


Head trauma is one of the leading causes of death worldwide and road traffic accident in particular is responsible for the majority of recorded cases in the literature. [1],[7],[8],[10],[21] To our knowledge, this study population of 2142 is the largest head trauma study carried out in the West African sub-region and spanning the duration of 10 years as well. Head trauma has been documented to be more prevalent in the male gender. Expectedly, more males had a head injury as compared to females in this study. This relatively high number of males appears to be in agreement with findings in other climes. [20],[21],[22] This may be attributed to more preemptive nature of men who do the driving of cars, motorcycles and bicycles. The young adults were the most affected in this study, also in consonance with previous studies. [20],[21],[22] Again, young men are likely to be more adventurous and travel more. Most of the cases of head injury documented in this study are due to road traffic accidents accounting for 61.5%; this is in agreement with the rising incidence of head injury from RTCs from other parts of the World. [8],[10],[21] Studies in other parts of Africa also corroborate this high rate of head trauma from RTCs, which is also in tandem with the projected increase in cases of head trauma from RTC by the WHO report. [12],[23],[24] Several reasons may be proffered for this in Nigeria. They include bad roads, poorly maintained vehicles, lack of appropriate government policies on road safety rules and adherence to safety rules by road users, and passengers as well as mass influx of used cars into the country. Abnormal cranial CT findings were documented in 77.6% of the patients evaluated. This is higher and at variance with the 60.62% previously documented in Ibadan by  Ogunseyinde et al. in 1999. [19] However, this is in agreement with recent studies in Ife and Benin, Nigeria by Ashaleye et al. in 2005 and  Adeyekun et al. in 2013, respectively. [18],[20] This may be due to the increasing number of vehicles on our roads and the collapse of the previously compulsory driving test before the issuance of drivers' license as well as the lack of enforcement of traffic regulations by the relevant governmental agencies.

The most common cranial CT abnormality found in this study was intracranial hemorrhage seen in 1390 patients (65%). This is in agreement with the findings on CT of head injured patients in some recent research work in Nigeria. [20],[22] However, the frequency of cases in our study is higher than those documented by other researchers in Nigeria. [18],[20] This variation in numbers may possibly be due to the considerable smaller sample size employed in the other studies. This form of bleed is also a pointer to the severity of these cases.

In this study, intraaxial bleed is the leading form of intracranial bleed contrary to the previously reported findings of  Ogunseyinde et al.[18] in Ibadan, which documented subdural hematoma (extraaxial bleed) as the most common CT finding (28.7%). While intracerebral bleed was documented in 26.3% and skull fractures as demonstrated in 17.42% of the patients studied. [19]   Ashaleye et al. [19] also documented subdural hemorrhage (80%) as the most common finding among the 57 patients evaluated in their study. [20] This finding is however in agreement with the work of  Adeyekun et al. [17] The figures recorded in this present study were, however, about 1.52 times higher than what was reported in Benin. [18] The sample size employed in the other studies may be responsible for this significant disparity. Furthermore, we consider that this might also be attributable to lack of enforcement of safety rules in driving, the absence of road signs and severe head injuries from unprotected OKADA drivers and passengers seen over this study period. In the last decade, Nigeria and indeed West African countries have experienced an influx of more and newer models of more versatile vehicles, and the ease of access, due to increased pay packages, to these vehicles may have also contributed to an increase in the number of vehicular accident with higher impact injuries when compared to 20 years back when such did not exist.

From our study, 39.1% (544/1390) of bleeds were extraaxial and were mostly due to subdural bleed while epidural bleed accounted for about 20%. The incidence of skull fracture of 50.9% was documented among the cases with abnormal CT findings. Moreover, affirming the severity of the head injury cases seen at the UCH CT suite. Cranial bone fractures were mostly recorded than the base of the skull, orbital fractures and others like paranasal sinus fractures in decreasing order. This we believe is due to the cranial convexities being more vulnerable to traumatic impact during head trauma.

In addition, 33.5% of the patients with abnormal findings had various degrees of cerebral edema, indicative of the severity of the head trauma cases in this study.

Features of chronic head injury were also documented in this study, possibly due to late presentation or affected patients seeking medical treatment from the clinical symptoms of the squealae of head injury. Infarctions in various part of the brain were the most common chronic head injury feature seen in this study, with cerebral infarction accounting for most of the cases. This is possibly the result of severe head injury with accompanying resolved intraparenchymal bleed.


  Conclusion Top


Road traffic accident remains the leading cause of head injury, and there is an alarming increase in the number of patients with a head injury resulting from RTC. Head injury is commoner in males with a ratio of 3:1 and more so in the males aged 40 years and below. The most common abnormal CT finding is intraaxial bleed followed by skull fractures and extraaxial bleed in decreasing order, a pointer to more severe cases of injury and at variance with previous study 15 years ago in Ibadan. This trend calls for concern of all stakeholders as well as urgent governmental intervention of policies to stem the tide and protect our workforce.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

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