Degeneration of nigrostriatal dopaminergic neurons in the early to intermediate stage of dementia with Lewy bodies and Parkinson's disease

• Published in: Journal of the neurological sciences Vol. 449; p. 120660
• Main Authors: Okitsu, Masato, Sugaya, Keizo, Nakata, Yasuhiro, Kawazoe, Tomoya, Ikezawa, Jun, Okiyama, Ryoichi, Takahashi, Kazushi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.06.2023
• Subjects: Corpus Striatum - diagnostic imaging; Corpus Striatum - metabolism; Dementia with Lewy bodies; Dopamine transporter scintigraphy; Dopaminergic Neurons - metabolism; Humans; Lewy Body Disease - diagnostic imaging; Lewy Body Disease - metabolism; Neurology; Neuromelanin-sensitive MRI; Nigrostriatal dopaminergic neuron; Parkinson Disease - diagnostic imaging; Parkinson Disease - metabolism; Parkinson's disease; Tomography, Emission-Computed, Single-Photon - methods; Dopamine transporter scintigraphy; R2; SBR; Parkinson's disease; Neuromelanin-sensitive MRI; MRI; CI; MMSE-J; NRCLC; ROC; NRCSN; SPECT; AUC; ET; Nigrostriatal dopaminergic neuron; PD; DAT; LC; DLB; SN; NRC; Dementia with Lewy bodies; magnetic resonance imaging; NRC LC; locus coeruleus; receiver-operating characteristic; neuromelanin-related contrast in the substantia nigra; NRC SN; substantia nigra; R 2; specific binding ratio; area under the curve; neuromelanin-related contrast in the locus coeruleus; dopamine transporter; Mini Mental State Examination-Japanese; neuromelanin-related contrast; essential tremor; coefficient determination; confidence interval; single-photon emission computed tomography
• ISSN: 0022-510X; 1878-5883; 1878-5883
• DOI: 10.1016/j.jns.2023.120660

To investigate differences in nigrostriatal dopaminergic neuron degeneration between dementia with Lewy bodies (DLB) and Parkinson's disease (PD) in the early to intermediate stage of these diseases. An integrative neuroimaging analysis was developed using 3-Tesla neuromelanin-sensitive MRI and 123I-FP-CIT dopamine transporter SPECT, and the relationship and laterality of three variables, including neuromelanin-related contrast in the substantia nigra (NRCSN) and locus coeruleus (NRCLC) and the specific binding ratio (SBR) in the striatum, were examined in detail. Patients with DLB and PD and control subjects (n = 29, 52, and 18, respectively) were enrolled. A significantly greater decrease in the SBR in the bilateral hemispheres was observed in DLB than in PD. After adjusting for the interhemispheric asymmetry in neuromelanin-related MRI contrast by using the Z-score, linear regression between the NRCSN and SBR was performed for the most-affected/least-affected sides of the hemispheres as defined by the interhemispheric differences in each variable (SBR, NRCSN, standardized [SBR + NRCSN]). In DLB, the highest, albeit statistically non-significant, correlation was observed in the SBR-based, most-affected side. In PD, the highest correlation was observed in the (SBR + NRCSN)-based, most-affected side, which approximated the value of the clinically-defined, most-affected side. A non-significant correlation was observed only in the (SBR + NRCSN)-based or clinically-defined, least-affected side. Loss of the soma and presynaptic terminals may occur independently in DLB with a large decrease in the presynaptic terminals. The close relationship observed between the degeneration of the soma and presynaptic terminals suggested that axon degeneration may dominate in PD. •An integrative neuroimaging study based on DAT SPECT and 3-Tesla neuromelanin-sensitive MRI was developed.•The correlation of NRCSN with SBR in patients with DLB and PD in the early to intermediate stage of the diseases was found.•Loss of the soma and presynaptic terminals occurred independently in DLB.•A close relationship was found between soma and presynaptic terminal degeneration in PD.