(123)I-meta-iodobenzylguanidine (MIBG) cardiac scintigraphy in α-synucleinopathies

Area of Science:

• Neurology
• Nuclear Medicine
• Cardiology

Background:

• Lewy body diseases, including Parkinson's disease (PD) and dementia with Lewy bodies (DLB), are characterized by the presence of Lewy bodies in the nervous system.
• Cardiac sympathetic denervation, indicated by reduced meta-iodobenzylguanidine (MIBG) uptake, is a known feature of Lewy body diseases.
• Previous research suggests cardiac MIBG uptake can help differentiate PD from other parkinsonian syndromes and DLB from Alzheimer disease (AD).

Purpose of the Study:

• To evaluate the utility of (123)I-MIBG cardiac scintigraphy as a biomarker for Lewy body presence.
• To explore the diagnostic value of reduced cardiac MIBG uptake in distinguishing specific neurological disorders.

Main Methods:

• Utilized (123)I-MIBG cardiac scintigraphy to assess cardiac MIBG uptake.
• Correlated scintigraphy findings with pathological confirmation of Lewy body disease in postmortem studies.
• Compared cardiac MIBG uptake patterns in patients with PD, DLB, pure autonomic failure, and AD.

Main Results:

• Cardiac MIBG uptake was significantly reduced in patients diagnosed with Lewy body diseases (PD, DLB, pure autonomic failure).
• Postmortem analysis confirmed decreased cardiac tyrosine hydroxylase (TH)-immunoreactive nerve fibers in pathologically confirmed Lewy body disease.
• Reduced cardiac MIBG uptake demonstrated potential in differentiating PD from other parkinsonian syndromes and DLB from AD.

Conclusions:

• Reduced cardiac MIBG uptake on (123)I-MIBG scintigraphy serves as a potential imaging biomarker for the presence of Lewy bodies.
• This non-invasive imaging technique can aid in the clinical diagnosis and differentiation of Lewy body diseases.