Clinical relevance of microhemorrhagic lesions in subacute mild traumatic brain injury
Clinical relevance of microhemorrhagic lesions in subacute mild traumatic brain injury
H. J. van der Horn 0 1 2
S. de Haan 0 1 2
J. M. Spikman 0 1 2
J. C. de Groot 0 1 2
J. van der Naalt 0 1 2
0 Department of Radiology, University of Groningen, University Medical Center Groningen , Groningen , The Netherlands
1 Department of Neuropsychology, University of Groningen, University Medical Center Groningen , Groningen , The Netherlands
2 Department of Neurology, University of Groningen, University Medical Center Groningen , Hanzeplein 1, 9700, RB Groningen , The Netherlands
Magnetic resonance imaging (MRI) is often performed in patients with persistent complaints after mild traumatic brain injury (mTBI). However, the clinical relevance of detected microhemorrhagic lesions is still unclear. In the current study, 54 patients with uncomplicated mTBI and 20 matched healthy controls were included. Posttraumatic complaints were measured at two weeks postinjury. Susceptibility weighted imaging and T2*-gradient echo imaging (at 3 Tesla) were performed at four weeks post-injury. Microhemorrhagic lesions (1-10 mm) were subdivided based on depth (superficial or deep) and anatomical location (frontal, temporoparietal and other regions). Twenty-eight per cent of patients with mTBI had ≥1 lesions compared to 0 % of the healthy controls. Lesions in patients with mTBI were predominantly located within the superficial frontal areas. Number, depth and anatomical location of lesions did not differ between patients with and without post-traumatic complaints. Within the group of patients with complaints, number of complaints was not correlated with number of lesions. In summary, microhemorrhages were found in one out of four patients with uncomplicated mTBI during follow-up at four weeks post-injury, but they were not related to early complaints.
Mild traumatic brain injury; MRI; Microhemorrhages; Microbleeds; Post-traumatic complaints
Introduction
Frequently, no abnormalities are found on computed
tomography (CT) in the acute phase after mild traumatic brain injury
(mTBI)
(G L Iverson et al. 2000)
. When patients suffer from
(persistent) cognitive complaints interfering with daily
activities, magnetic resonance imaging (MRI) is routinely
performed to assess traumatic parenchymal abnormalities.
However, studies have shown that the number of
selfreported symptoms (which we will refer to as post-traumatic
complaints) in the sub-acute phase after mTBI does not differ
between patients with and without lesions on admission CT
and/or follow-up MRI (i.e. complicated vs. uncomplicated
mTBI)
(Grant L. Iverson et al. 2012; Panenka et al. 2015)
.
Microhemorrhagic lesions are among the most frequently
found traumatic abnormalities in mTBI, especially due to the
sensitivity of susceptibility weighted imaging (SWI) and to a
lesser extent of T2*-gradient echo (GRE) imaging
(Huang
et al. 2015; Yuh et al. 2013)
. However, the clinical relevance
of these microhemorrhages in addition to other traumatic
lesions, with regard to post-traumatic complaints
(Hofman et al.
2001; Hughes et al. 2004)
, cognitive performance
(Hofman
et al. 2001; Huang et al. 2015; Hughes et al. 2004; Lee et al.
2008)
and outcome
(Yuh et al. 2013)
, is still unclear. Hence,
clear criteria to make a distinction between clinically relevant
and non-relevant lesions in mTBI are currently not available.
This pertains not only to the number of lesions, but also to
depth and anatomical location of these lesions.
The aim of the current study was to gain more insight into
t h e n u m b e r , d e p t h a n d a n a t o m i c a l l o c a t i o n o f
microhemorrhages on SWI and T2*-GRE in patients with
uncomplicated mTBI and healthy controls, and to find clues
for the interpretation in clinical practice, especially with
regard to the presence or absence of post-traumatic complaints
at two weeks post-injury.
Methods
Participants
This study is part of a larger prospective multicentre cohort
study on outcome post-mTBI (UPFRONT study) conducted
between March 2013 and February 2015. Patients were
included at the emergency department (ER) of the University
Medical Centre Groningen (a level I trauma centre). Inclusion
criteria for the MRI study were: age between 18 and 65, no
abnormalities on admission CT-scan (i.e. uncomplicated
mTBI), and the presence or absence of post-traumatic
complaints at two weeks post-injury. Exclusion criteria were:
major neurologic or psychiatric co-morbidity, admission for prior
TBI, drug or alcohol abuse, mental retardation. This
information was obtained from the patients’ history at the ER or
neurology ward, and through questionnaires at two weeks
postinjury. Contraindications for MRI were: implanted
ferromagnetic devices or objects, pregnancy or claustrophobia. Twenty
age, sex and education matched healthy controls without a
history of TBI were recruited among social contacts and via
advertisements.
The study was approved by the Medical Ethics C (...truncated)