PMC8219867_01
Consecutive brain 18F-FDG PET scans in a patient aged 16 y/o with seronegative AIE. Axial slices of 6 consecutive 18F-FDG PET scans (A-F) are displayed in radiological view with the French scale color. (A) First 18F-FDG PET: moderate mediofrontal and thalamic hypometabolism; 18F-FDG PET was performed after the first plasma exchange, when the patient's state was slowly improving. (B) Second 18F-FDG PET: moderate, bilateral parietotemporal hypometabolism (white arrow); bilateral striatal hypermetabolism; metabolism is significantly decreased compared with healthy controls in the posterior cingulate and parietotemporal cortices with Z-scores ranging from -2.1 to -2.9, and highly increased in the striatum (Z-score: +3.5) and cerebellar vermis (Z-score: +3.3) (G); 18F-FDG PET was performed after the second plasma exchange that was ineffective. (C) Third 18F-FDG PET: deeper and widespread metabolism decreases in posterior cortex spreading to the primary visual cortex with Z-scores ranging from to -2.1 to -5.1 [in blue (H)]; striatal hypermetabolism [in red (H)]; deterioration of patient state; 18F-FDG PET was performed after the third plasma exchange that was inefficient. (D) Fourth 18F-FDG PET: partial improvement in posterior (Z-score: -2.3) and primary visual area metabolism (Z-score of -2.1 vs. a previous score of -5.1); occurrence of moderate mediofrontal and hippocampal hypometabolism; 18F-FDG PET was performed when the patient improved after rituximab, levodopa, ECT, and benzodiazepine administration. (E) Fifth 18F-FDG PET: normalization of bilateral posterior associative metabolism; normalization of striatal metabolism; stability of mediofrontal and mesiotemporal hypometabolism; 18F-FDG PET was performed when the patient was much improved, showing minor frontal syndrome and little abnormal movement. (F) Last 18F-FDG PET: examination showing mild, persistent mediofrontal and mesiotemporal hypometabolism; normal metabolism in the posterior cortex [as shown on the statistical map (I)]. (G-I) Show 3D statistical maps of voxel-based analyses for 3 18F-FDG PET scans (B,C,F, respectively) in comparison with a control group <40 y/o (n = 23, mean age 30.9 +- 8.6 y/o; Scenium software, Siemens healthcare). Rainbow color scale indicates Z-score values. Medial and lateral 3D views of the right (R) and left (L) hemispheres are shown.
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F1
Shortly after this second-line treatment, he underwent an initial brain 18F-FDG-PET examination (2 MBq/kg, 10-min acquisition started 30 min post injection) which was the first abnormal paraclinical exam showing moderate mediofrontal and thalamic hypometabolism (Figure 1A). A second brain 18F-FDG-PET examination was performed and showed the appearance of a metabolic decrease in the parietotemporal associative cortex and a high metabolic increase in the striatum (Figure 1B). On brain 18F-FDG-PET performed 1 month later, the hypometabolism decrease worsened in the posterior areas and extended to the occipital cortex, including the primary visual cortex (Figure 1C). Another 18F-FDG-PET performed to monitor the treatment response revealed a partial improvement in posterior associative metabolism, with the emergence of moderate mesiotemporal and mediofrontal hypometabolism (Figure 1D). Figure 1E). Two months later, in August, a final cerebral 18F-FDG-PET scan was unchanged, with normal posterior associative cortex and mild medioprefrontal and mesiotemporal hypometabolism (Figure 1F).
Pediatric catatonia rating scale based on time and treatment during the 2-year follow-up. OCD, obsessive compulsive disorder; PE, plasma exchanges; 18F-FDG PET, 18-fluorodeoxyglucose positron emission tomography; IVIG, intravenous immunoglobin; ECT, electroconvulsive therapy.
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F2
Once again, the 18F-FDG-PET findings were correlated with the patient's condition (Figure 2). After 3 months, the improvement led to the recovery of eating, talking, catatonia (Figure 2) and Jason showed normal general behavior, although a slight frontal syndrome (lack of initiative and emotion, perseveration) and mild anosognosia persisted (cf.