Dopamine Transporter maging with Tc-99m TRODAT-1 SPECT in Parkinson's isease and its orrelation with linical isease everity

Abstract

Objectives: To evaluate the role of Tc-99m TRODAT-1 Single Photon Emission Computed Tomography (SPECT) in Parkinson's Disease (PD) by assessing the correlation of clinical disease severity, disease duration and age at onset of disease with specific uptake ratio of Tc-99m TRODAT-1 in striatum.

Methods: The study included 63 patients in age range of 40-72 years with clinical diagnosis of PD and nine controls. Clinical history of patients was obtained regarding age at onset of disease and disease duration. Disease severity in each patient was assessed using H and Y stage and UPDRS. Tc-99m TRODAT-1 SPECT was performed and specific uptake ratios were calculated for six regions in bilateral striata, caudate nuclei and putamina. Difference in specific uptake ratios between different stages of disease was analyzed for statistical significance. Specific uptake ratios were correlated with UPDRS, motor score of UPDRS, duration of disease and age at onset of disease using Pearson's correlation co-efficient.

Results: Median specific uptake ratio was found to be least in contralateral putamen for all H and Y stages. There was a statistically significant difference between specific uptake ratios of controls vs stage 1, stage 1 vs 2, 1 vs 3, 1 vs 4, and 2 vs 4 for all 6 regions. The difference in uptake ratio between 3 and 4 H and Y stages was significant only for contralateral regions. There was no significant difference in uptake ratio between 2 and 3 H and Y stages. The uptake ratios showed a strong negative correlation with UPDRS and motor score, a weak negative correlation with duration of disease and no significant correlation with age at onset of disease.

Conclusion: We conclude that Tc-99m TRODAT-1 SPECT can be used to assess the disease severity in PD patients.

Keywords: H and Y scale; Parkinson’s disease; Severity; Tc-99m TRODAT-1 SPECT; UPDRS.

Figure 1

Image showing representation of manual ROI drawn over right striatum (grey), left caudate nucleus (blue), left putamen (black) and occipital region (red). Similar ROI were drawn over left striatum, right caudate nucleus and right putamen

Figure 2

Horizontal bar diagram depicting distribution of study population in different age groups

Figure 3

Tc-99m TRODAT-1 SPECT image of control (A) and patients belonging to different H and Y stages (B-F). B: stage 1, patient had history of rest tremors in left upper limb since 2 years; image shows reduced uptake in right putamen; C: stage 2, patient presented with difficulty in writing, rest tremor in bilateral upper limb, more on right side, image shows reduced ^99mTc-TRODAT-1 uptake in bilateral putamen (L<R) with preserved uptake in bilateral caudate nuclei; D: stage 3, patient had bilateral rest tremor and difficulty in walking; image shows no significant uptake in bilateral putamen, reduced uptake in right caudate nucleus. Uptake in left caudate nucleus is preserved; E: stage 4, patient presented with slowness of movements, rest tremors, difficulty in walking without support; image shows no significant uptake in bilateral putamen and reduced uptake in left caudate nucleus. Uptake in right caudate nucleus also appears reduced; F: stage 5, patient had rest tremors, was wheel chair bound, rigidity in all 4 limbs (R>L); image shows no significant uptake in bilateral putamen and right caudate nucleus, and reduced uptake in left caudate nucleus