Background: Since Whiplash-Associated Disorder (WAD) causes severe pain and even disability among patients, early diagnosis and therapy are essential to reduce personal and social costs. Traditionally, the diagnosis of WAD is mainly conducted through the examination of clinical symptoms and anatomical imaging with Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) but not Single-Photon Emission Computed Tomography (SPECT).

Case description: A 24-year-old woman reported having mild headaches and progressive left leg numbness six months after experiencing a whiplash injury during a rear-end motor vehicle crash. MRI, CT, and electromyographic examination of her left leg were all negative, but SPECT of her brain showed decreased activity in the right parieto-occipital lobes.

Conclusion: Our case highlights (1) the clinical significance of hypoperfusion in the parietal lobe inducing leg numbness instead of nerve dysfunction or nerve-to-muscle signal transmission, (2) the evolving usefulness of functional imaging patterns of SPECT, and (3) the concordance between clinical WAD symptoms and the functional imaging findings. We suggest that patients with WAD need study of nuclear scintigraphy of the brain for a more precise diagnosis.