Contrecoup Extradural Hematoma Without Fracture: A Case Report and Review of Literature

Introduction

An extradural hemorrhage is a collection of blood in the space between the inner table of calvarium and dura mater. It can occur in coup and countercoup injuries. Extradural hematomas (EDHs) due to coup type of head injuries are quite common and most often associated with overlying calvarium fractures, whereas contrecoup EDHs are very rare entities and are not associated with any overlying fractures. There are only a few reports of contrecoup EDHs published in the literature.

Case Report

A 28-year-old male alleged to have sustained head injuries in a road traffic accident by fall from a two-wheeler under the influence of alcohol presented to the emergency department with no complaints of loss of consciousness, vomiting, seizures, and ear/nose bleed. A laceration was noted on the right temporoparietal region which was immediately sutured. On examination, the patient was conscious and coherent with a Glasgow Coma Scale Score of 15/15 without any focal neurological deficits; all vitals were within normal limits. Computed tomography of the brain was done which revealed a 10 mm thick extradural hemorrhage in the left parieto-occipital region and soft tissue thickening in the right temporoparietal region [Figure 1]. No calvarial fractures were noted. A computed tomography scan of the brain was repeated after 24 h which revealed no increase in the thickness of extradural hemorrhage. The patient was managed conservatively, and the follow-up was uneventful.

Figure 1

Computed tomography scan of the brain shows a 10 mm thick hyperdense collection in the left parieto-occipital region with a subcutaneous swelling in the right temporoparietal region. No calvarial fracture noted

Discussion

At our center, we came across one such case where the patient had a contrecoup EDH without an overlying fracture of the calvarium, and a thorough review of literature reiterates the fact that this presentation is a rare variant and hence this case report. EDHs are one of the most common presentations in head injury. It accounts for 1%–3% of all the head injuries.[1] They are usually located at the site of impact and occur due to the rupture of a middle meningeal artery or calvarial fracture resulting in accumulation of blood in between the inner calvarium and dura mater due to the separation of dura mater from the calvarium. These types of EDHs are referred to as coup EDHs and are more commonly noted.[2] They develop below the impact point and are accompanied by the linear fracture in most of the cases.[134]

Contrecoup EDHs, however, are a rare variant those not associated with a fracture are extremely rare, and only 21 cases have been previously reported in the literature.[5] They are not associated with any overlying fractures and are usually found at a location opposite to the site of impact. Contrecoup EDHs are more commonly seen in the females in the fifth to sixth decade.[6] They are more commonly seen in the frontal regions, which can be explained by the fact that the dura mater can easily be detached from the inner table of the lateral frontal region.[1]

Contrecoup acute epidural hemorrhage without fracture in the occipital region is considered due to the skull development. The occipital bone develops from two types of tissues membranous and cartilaginous tissues, and the transverse sinus is present in the boundary between these tissues. Thus, this region is easily deformed and reported to be a region with reduced resistance against external forces.[7]

Cavitation effect and inertia loading at the countercoup site may be the reason for countercoup hematomas.[8] The negative pressure created at the opposite site may cause the cavitation and the tensile strain in the angular movement of the head may cause vascular injury.[9] Both of these mechanisms explain the genesis of contrecoup intraparenchymal hematomas. However, mechanism of contrecoup EDH remains unclear.

Few have proposed that it might be generated by the buckling effect of the skull exactly opposite to the site of impact.[10] Others have proposed that compression wave from the site of impact produces a relative movement in between the dura mater and skull bone resulting in the stripping of dura mater and collection of EDH at the diagonally opposite side.

Here, we report a case of the left parieto-occipital EDH in a 28-year-old male who was managed conservatively with a good outcome. Few other cases reported by others have been noted below.

Okamoto reported a case of the left frontal contrecoup hematoma in a 51-year-old female due to fall which was surgically treated.[11] Balasubramaniam and Ramesh reported a case of a 21-year-old male patient with a contrecoup EDH at the left frontal region which was managed surgically. Miyazaki et al. reported a case of right frontal contrecoup EDH in a 52-year-old female who was managed surgically.[3] Motohashi reported a case of a 59-year-old female patient with a left frontal contrecoup EDH who was managed conservatively.[4] Mitsuyama et al. reported a case of a 50-year-old female patient with right frontal contrecoup EDH who was managed conservatively.

Conclusion

EDH is a neurosurgical emergency. Contrecoup variants of EDH are a rare entity, and those not associated with fracture are extremely rare. Hence, careful observation and timely management are required. Here, we report a case of contrecoup variant of EDH which is not associated with fracture.