Traumatic acute convexity interdural hematoma: a case report and literature review

The interdural hematoma: A subtype of convexity subdural/dural hematoma with specific radioanatomical characteristics

“…e nomenclature of IDH should be used carefully as this diagnosis relies on specific radiological patterns and the confirmation that the inner wall of the hematoma is of dural origin. [4][5][6]13,14,18,21,32,42,54] After reviewing the literature, we have identified the biconvex shape, the dural beak sign on the coronal plane, as well as the irregular thick inner wall as potential unique radiological characteristics of the IDH [Figure 1]. e IDH is a chimeric radiological entity as it is biconvex like the epidural hematoma but crosses the suture on the rostrocaudal axis like a SDH.…”

“…[32] 79 Male IDH CT Craniotomy Yes Yes No Eom et al 2009 [14] 79 Male aEDH CT Craniotomy No Yes No Prieto et al 2010 [42] 67 Female aEDH CT Craniotomy Yes Yes Yes Baharvahdat et al 2012 [6] 51 Male EDH CT Craniotomy Plasty No Yes Babayev et al 2015 [5] 61 Male n.a. MRI Craniotomy Plasty No No Yoo et al 2016 [54] 54 Female saEDH CT/MRI Craniotomy Yes Yes No Genc et al 2017 case A [18] 74 Male Meningioma CT/MRI Craniotomy Yes No No Genc et al 2017 case B [18] 53 Male Meningioma CT/MRI Craniotomy Yes Yes No Chen et al 2018 [13] 90 Male CSDH CT/MRI Burr-hole Yes Yes Yes Iranmehr and Namvar 2020 [21] 57…”

“…e aforementioned radiological characteristics were confirmed on most MRIs in those cases where additional imaging was performed. [4][5][6]13,14,18,21,32,35,42] Attempts were made to subclassify chronic SDH based on its internal radiological anatomy and volumetry at the moment of diagnosis and during its aging with the aim to define predicting factors of its recurrence, among them the Oslo Grading System. [3,8,[35][36][37]48] Radioanatomical analysis of the shape of the SDH was however rarely reported or analyzed and likely explains also why biconvex SDHs and among them, IDH are rarely recognized or reported.…”

“…In fact, a minority of all diagnosed SDHs have a biconvex shape with sometimes a very distinct dural beak and 11 cases of such biconvex hematomas were reported in ten publications as being strictly encapsulated between the outer periosteal and the inner thick meningeal layers of the convexity dura mater and named therefore interdural hematoma (IDH) [Table 1]. [2,[4][5][6]10,13,14,18,21,30,32,[41][42][43]54] In most of these cases, the collection was misdiagnosed as an epidural hematoma or a meningioma due to its biconvex shape and, therefore, managed invasively through a craniotomy with dural membrane excisions [Table 1]. [5,6,14,18,21,32,42,54] e diagnosis of IDH was made intraoperatively after unexpectedly finding a dural layer under the skull and visualizing a thick opaque inner membrane covering the arachnoid membrane confirmed histologically as being of dural origin [Table 1].…”

“…[2,[4][5][6]10,13,14,18,21,30,32,[41][42][43]54] In most of these cases, the collection was misdiagnosed as an epidural hematoma or a meningioma due to its biconvex shape and, therefore, managed invasively through a craniotomy with dural membrane excisions [Table 1]. [5,6,14,18,21,32,42,54] e diagnosis of IDH was made intraoperatively after unexpectedly finding a dural layer under the skull and visualizing a thick opaque inner membrane covering the arachnoid membrane confirmed histologically as being of dural origin [Table 1]. Altogether, these observations strongly point to the existence of a convexity subdural/dural hematoma spectrum.…”