FP-CIT- and IBZM-SPECT in Corticobasal Syndrome: Results from a Clinical Follow-Up Study

Abstract

Objective: To evaluate the striatal presynaptic dopamine transporter (FP-CIT-SPECT) and postsynaptic D₂ receptor (IBZM-SPECT) binding in patients with corticobasal syndrome (CBS). Background: FP-CIT and IBZM are commercially available and approved SPECT tracers for in vivo molecular imaging of pre- and postsynaptic nigrostriatal neuronal degeneration, but only few data for CBS are available. Methods: 23 patients meeting clinical criteria for early- to mid-stage CBS (disease duration ≤4 years) were examined with SPECT radiotracers FP-CIT and IBZM. All suspected CBS patients underwent a clinical follow-up examination and were re-evaluated after 19.7 ± 15.2 months (mean ± SD). Postmortem diagnosis was available for 2 patients. In patients who met research criteria for probable CBS at the final follow-up visit (n = 19; disease duration: 1.95 ± 0.91 years), SPECT binding values were compared to those of age- and gender-matched Parkinson's disease (PD) patients (n = 18, disease duration: 1.92 ± 0.91 years; clinical follow-up: 32 ± 29.6 months) and neurologically normal control subjects (n = 19). Results: In comparison to the healthy control subjects, both patient groups showed significant and asymmetric reduction of the striatal presynaptic dopamine transporter binding, but PD patients had significantly lower FP-CIT binding ratios than probable-CBS patients. FP-CIT binding values of probable-CBS patients and healthy controls demonstrated marked overlaps, and in 7 patients (39%) scans revealed no dopaminergic deficit. IBZM uptake did not show significant between-group differences. Conclusion: Our data indicate that in the early- to mid-stage CBS the degree of nigrostriatal impairment is only mild with a significant proportion of preserved dopamine transporter binding.

A posterior variant of corticobasal syndrome: Evidence from a longitudinal study of cognitive and functional status in a single case

“…alien hand, early non-fluent aphasia, behavioral disturbances, personality changes). Moreover, basal ganglia were apparently not involved, which was found in previous CBS cases (Ceravolo et al, 2013;Cilia et al, 2011;Hammesfahr et al, 2016;Homma et al, 2014). Thus, CG's case study further supports the clinical heterogeneity of CBS's presentation.…”

Dopamine transporter imaging with [18F]FE-PE2I PET and [123I]FP-CIT SPECT—a clinical comparison

“…The fourth patient was clinically diagnosed with CBS at follow-up. It is known that CBS does not always show any signs of dopaminergic deficit in an early-stage disease [ 20 , 21 ], and none of the imaging methods detected any DAT reduction in this patient, who had less than 1 year of symptoms’ duration at the time of imaging. The fifth patient with normal DAT availability has not yet been reassessed clinically.…”

FDG-PET patterns associated with underlying pathology in corticobasal syndrome

“…1 18 Fluorodeoxyglucose PET (FDG-PET) 4 has been used to aid in CBS diagnosis, commonly showing an asymmetric frontoparietal pattern of cortical metabolism in many, 5,6 but not all studies. 7 The application of FDG-PET to try to differentiate the underlying pathologic substrata of CBS in vivo, however, has not been extensively explored, 6,8 even if available evidence suggests that different pathologies might show distinctive patterns of brain metabolism in CBS.…”