FDG Metabolism in Dementia With Lewy Body (DLB) Patients as Indicated by PET Dynamic Acquisition

Dementia with Lewy Body (DLB) is a common neurodegenerative disorder responsible to 15%-20% of the dementia cases in the elderly population. Dementia with Lewy Body (DLB) is a common neurodegenerative disorder responsible to 15%-20% of the dementia cases in the elderly population . This disorder belongs to the family of synucleinopathies, which are diseases characterized by the abnormal accumulation of the protein α-synuclein (α-syn) in neuronal and non-neuronal cells in the brain. The clinical symptoms of DLB include dementia with the presence of fluctuations in attention or alertness, recurrent visual hallucinations, spontaneous extrapyramidal motor features and REM sleep behavior disorder (RBD). Supportive clinical symptoms are severe sensitivity to antipsychotic agents, postural instability, repeated falls, syncope or other transient episodes of unresponsiveness, severe autonomic dysfunction e.g. constipation, orthostatic hypotension, urinary incontinence, hypersomnia, hyposmia, hallucinations in other modalities, systematized delusions, apathy, anxiety and depression. DLB differs from PD by the order of appearance of clinical symptoms. The diagnosis of DLB requires in addition to the clinical symptoms the existence biomarkers indicating the pathology. It is important to note that due to the complexity of DLB diagnosis, mainly due to the similarity of this syndrome to other dementia conditions, more than one biomarker is required to identify DLB \[6\]. The biomarkers contain indicative biomarkers and supportive biomarkers. Indicative biomarkers include a. Assessment of the integrity of dopaminergic system by either F-DOPA Positron Emission Tomography (PET) or by Ioflupane 123I (DaT) Single Photon Emission Tomography (SPECT) scans. b. Abnormal (low uptake) MIBG myocardial scintigraphy. c. Polysomnographic confirmation of REM sleep without atonia. Supportive biomarkers are: a. MRI/CT scans showing neuronal structural modifications with relative preservation of