MR Imaging, Single-photon Emission CT, and Neurocognitive Performance after Mild Traumatic Brain Injury

• Published in: American journal of neuroradiology : AJNR Vol. 22; no. 3; pp. 441 - 449
• Main Authors: Hofman, Paul A.M, Stapert, Sven Z, van Kroonenburgh, Marinus J.P.G, Jolles, Jelle, de Kruijk, Jelle, Wilmink, Jan T
• Format: Journal Article
• Language: English
• Published: Oak Brook, IL Am Soc Neuroradiology 01-03-2001; American Society of Neuroradiology
• Subjects: Adolescent; Adult; Biological and medical sciences; Brain; Brain - pathology; Brain - physiopathology; Brain Injuries - diagnosis; Brain Injuries - physiopathology; Brain Injuries - psychology; Cognition; Cognition Disorders - etiology; Female; Follow-Up Studies; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Neuropsychological Tests; Reaction Time; Reference Values; Tomography, Emission-Computed, Single-Photon; Traumas. Diseases due to physical agents; Radionuclide study; Human; Nervous system diseases; Cognitive disorder; Craniocerebral; Diseases of the osteoarticular system; Psychometrics; Nuclear magnetic resonance imaging; Photon; Trauma; Cerebral disorder; Central nervous system disease; Skull disease; Medical imagery; Complication; Evolution; Emission tomography
• ISSN: 0195-6108; 1936-959X

Mild traumatic brain injury (mTBI) (Glasgow Coma Scale = 14-15) is a common neurologic disorder and a common cause of neurocognitive deficits in the young population. Most patients recover fully from mTBI, but 15% to 29% of patients have persistent neurocognitive problems. Although a partially organic origin is considered likely, little brain imaging evidence exists for this assumption. The aims of the present study were to establish the prevalence of posttraumatic lesions in mTBI patients on MR images and to assess the relation between these imaging findings and posttraumatic symptoms. Secondly, we explored the value of early posttraumatic single-photon emission CT (SPECT) for the evaluation of mTBI.
Twenty-one consecutive patients were included in the study. Patients underwent MR examination, technetium-99m hexamethylpropylene amine oxime SPECT, and neurocognitive assessment within 5 days after injury. Neurocognitive follow-up was conducted 2 and 6 months after injury, and MR imaging was repeated after 6 months. Lesion size and brain atrophy were measured on the MR studies.
Twelve (57%) of 21 patients had abnormal MR findings, and 11 (61%) of 18 had abnormal SPECT findings. Patients with abnormal MR or SPECT findings had brain atrophy at follow-up. The mean neurocognitive performance of all subjects was within normal range. There was no difference in neurocognitive performance between patients with normal and abnormal MR findings. Patients with abnormal MR findings only showed significantly slower reaction times during a reaction-time task. Seven patients had persistent neurocognitive complaints and one patient met the criteria for a postconcussional syndrome.
Brain lesions are common after mTBI; up to 77% of patients may have abnormal findings either on MR images or SPECT scans, and these lesions may lead to brain atrophy. The association between hypoperfusion seen on acute SPECT and brain atrophy after 6 months suggests the possibility of (secondary) ischemic brain damage. There is only a weak correlation between neuroimaging findings and neurocognitive outcome.