Cerebral perfusion changes during cataplexy in narcolepsy patients.

To localize cerebral perfusion differences during cataplexy, brain SPECT subtraction was performed between cataplexy and baseline awake period or REM sleep in patients with narcolepsy. During cataplexy, subtracted SPECT showed hyperperfusion in right amygdala, bilateral cingulate gyri, basal ganglia, thalami, premotor cortices, sensorimotor cortices, right insula, and brainstem, and hypoperfusion in prefrontal cortex and occipital lobe. This result suggests that cataplexy is produced by the activation of amygdalo-cortico-basal ganglia-brainstem circuit.