Key-words:
Contrecoup - extradural - hemorrhage - trauma - without fracture
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.[[1]],[[3]],[[4]]
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.
Declaration of patient consent
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understand that their names and initials will not be published and due efforts will
be made to conceal their identity, but anonymity cannot be guaranteed.
