Late whiplash syndrome: correlation of brain SPECT with neuropsychological tests and P300 event-related potential

BACKGROUND: The acceleration forces infringing the cervical spine in whiplash injury are frequently associated with multiple cerebral symptoms. The purpose of this study was to determine whether there is a correlation between cerebral perfusion findings, P300 recording (an electrophysiologic marker of cognitive ability), and neuropsychological tests in patients with whiplash injury. METHODS: Twenty patients with chronic whiplash injury underwent extensive clinical evaluation and neuropsychological testing. A brain single-photon emission computed tomography (SPECT) study using 99mTc-HMPAO was performed in all patients within 24 hours of neuropsychological evaluation. P300 event-related potentials were performed in 15 patients and in 9 normal volunteers. RESULTS: Thirteen of 20 patients had brain perfusion abnormalities on the SPECT studies, in one or more regions. Eight of 15 patients had abnormal P300 studies. Seven of eight patients with abnormal P300 had also an abnormal SPECT study. Seven of 15 patients had normal P300 results, 6 of them with a normal SPECT and 1 with SPECT abnormalities. There was no significant correlation between the SPECT findings or the P300 results and the scores of attention and working memory. There was, however, close agreement between the SPECT and P300. CONCLUSION: SPECT perfusion abnormalities in patients with chronic whiplash syndrome correlate well with P300 recording. The combination of these studies with neurocognitive and neurobehavioral tests may be useful in identifying a subgroup of patients having organic brain lesions.