The National Heart Lung and Blood Institute estimated that nearly three out of four people with narcolepsy also have cataplexy, a major symptom of narcolepsy, which is characterized by a sudden, bilateral loss of muscle tone (and possible fall) with preserved consciousness. It is, however, easier to study cataplexy during status cataplecticus.' Picturing brain activity during cataplexy, a transient and unpredictable neurologic state, is challenging. The method used in this particular study analyzed functional features specifically related to the mechanisms of cataplexy. 'Previous imaging studies have failed to show structural changes in the brain of narcoleptic patients, but functional changes could be demonstrated. 'To my knowledge, this report is the first of imaging analysis comparing brain activation during a cataplectic episode with a nonsymptomatic state in the same subject,' said Chabas. There was, however, no hyperactivation of the pons, amygdale or occipital cortex, other imaging characteristics of normal REM sleep. Subtraction SPECT coregistered to magnetic resonance imaging (MRI)-determined anatomic areas differentially perfused during cataplexy and basal wakefulness state.Īccording to the results, the areas hyperactivated during cataplexy correspond on brain MRI with the cingular area, the left and right orbitofrontal cortex, the right temporal cortex and the right putamen, which are all activated during normal REM sleep. This image was compared with her brain SPECT during an intervening asymptomatic period. The woman underwent a 99mTc-ethylcysteinate dimmer brain SPECT during an episode of cataplexy. The study, conducted by Dorothée Chabas, MD, PhD, of Université Pierre et Marie Curie-Paris, and Assistance Publique Hôpitaux de Paris, focused on a 68-year-old woman with hypocretin-deficient narcolepsy-cataplexy, who suffered status cataplecticus after having stopped clomipramine. The first efforts to identify the neural structures and pathways underlying cataplexy during status cataplecticus in a narcoleptic patient, with the use of brain perfusion single photon emission computed tomography (SPECT), have led to the discovery that cataplexy during status cataplecticus, a case of prolonged cataplexy, partially resembles normal rapid eye movement (REM) sleep but without the other imaging characteristics of this state, according to a study published in the February 1st issue of the journal SLEEP. It suggests the widespread disruption of white matter integrity and prevalent brain degeneration of frontal lobes according to a depressive symptom in narcolepsy.īrain diffusion tensor imaging frontal lobe hypersomnia mood disorder.WESTCHESTER, Ill. This tract-based spatial statistics study demonstrated that drug-naïve patients with narcolepsy had reduced fractional anisotropy of white matter in multiple brain areas and significant relationship between increased mean diffusivity of white matter in frontal/cingulate and depression. Among patients, mean diffusivity values of white matter in the bilateral superior frontal gyri, bilateral fronto-orbital gyri and right superior parietal gyrus were positively correlated with depressive mood.

Patients and controls showed no differences in mean diffusivity. Compared with controls, patients showed significant decreases in fractional anisotropy of white matter of the bilateral anterior cingulate, fronto-orbital area, frontal lobe, anterior limb of the internal capsule and corpus callosum, as well as the left anterior and medial thalamus. Fractional anisotropy and mean diffusivity images were obtained from whole-brain diffusion tensor imaging, and tract-based spatial statistics were used to localize white matter abnormalities. To investigate brain white matter alterations in drug-naïve narcolepsy patients with cataplexy and to explore relationships between white matter changes and patient clinical characteristics, drug-naïve narcolepsy patients with cataplexy (n = 22) and healthy age- and gender-matched controls (n = 26) were studied. It also raised the necessity to evaluate white matter changes. Those distinct morphometric changes account for problems in wake-sleep control, attention and memory. Functional imaging studies and voxel-based morphometry analysis of brain magnetic resonance imaging showed abnormalities in the hypothalamus-thalamus-orbitofrontal pathway, demonstrating altered hypocretin pathway in narcolepsy.

A brain scan of narcolepsy cataplexy