123I-Ioflupane dopamine transporter imaging (DaTSCAN) appearances in relation to emotional responsiveness, impulsivity and olfaction in suspected Parkinsonian syndrome

Abstract

Objective The aim of our study was to ascertain relationships between DaTSCAN, olfactory loss, behavioural and subjective measurements of impulsivity and emotional responsiveness in patients with clinically suspected Parkinsonian syndrome (PS). Methods A prospective study of 20 drug-naive patients with parkinsonism, underwent the University of Pennsylvania Smell Identification Test, impulsivity measurements and mood-state-questionnaires before visual and semi-quantitative DaTQUANT analyses. There were two subgroups: nine patients with scans without evidence of dopaminergic deficit (SWEDD – controls) and 11 patients with PS. Results The PS group reported lower non-planning impulsivity than the SWEDD group (P = 0.039). A positive correlation was found between the non-planning impulsivity ratings and right anterior putamen/background (bck) ratio in PS group (r = 0.598, P = 0.068). Higher ratings of anger (r = 0.575, P = 0.016), fatigue (r = 0.746, P = 0.001), confusion (r = 0.561, P = 0.019) and depression were positively correlated with putamen/caudate ratios (R > L) on DaTSCAN. Higher self-reported arousal was associated with lower right putamen/caudate ratio (P = −0.581, P = 0.014). Only fatigue was positively correlated with putamen/bck (r = 0.564, P = 0.018). The degree of smell deficit correlated negatively with performance on reflection impulsivity tasks (r = −0.470, P = 0.049). Conclusion DaTSCAN appearances correlated with emotional dysfunction and self-reported impulsivity in patients with PS. Olfactory impairment was associated with increased reflection impulsivity and the age of patients. Higher DaTSCAN putamen/caudate ratios were associated with higher emotional responsiveness and higher non-planning impulsivity in PS patients. These preliminary findings may be relevant in clinical practice in differentiating PS from SWEDD and identifying susceptibility to impulse control disorder although larger studies are warranted.

Dopamine Transporter Imaging, Current Status of a Potential Biomarker: A Comprehensive Review

“…Several DAT imaging studies revealed an association between decreased striatal DAT availability and non-motor symptoms in PD including anxiety [ 251 ], depression [ 252 , 253 , 254 ], apathy [ 255 ], impulsivity [ 239 , 256 ], fatigue, constipation [ 240 ], hyposmia [ 257 , 258 , 259 , 260 ], autonomic symptoms [ 261 , 262 , 263 , 264 , 265 , 266 ], sleep disturbances, daytime sleepiness [ 267 ], body weight loss [ 268 ] and visual hallucinations [ 241 ], in support of a partial dopaminergic pathogenesis [ 269 ] ( Table 1 ). In a recent study using data from sequential DAT-SPECT imaging in 344 PD patients from the PPMI dataset, Liu and colleagues demonstrated a significant association between DAT binding both at baseline and at follow-up scans and several baseline non-motor symptoms, with RBD showing the strongest association with concurrent and future DAT binding [ 270 ].…”

Quantitative [123]I-Ioflupane DaTSCAN single-photon computed tomography-computed tomography in Parkinsonism

“…DATs are located densely in the striata, which consists of the caudate nucleus and putamen. DaTSCAN can be conducted in vivo using single-photon emission computed tomography (SPECT) imaging to visualize and assess dopaminergic activity within this area [5,6]. This can assist in diagnosis when the clinical evaluation is inconclusive [1,5].…”

“…Moreover, between four to fifteen percent of patients with clinical suspicion of idiopathic Parkinson’s disease (IPD) and 10% of patients with corticobasal degeneration, both of which are types of neurodegenerative Parkinsonian syndromes, demonstrate a normal uptake of DaTSCAN [10,11]. This has led to the use of the acronym SWEDD, scans without evidence of dopaminergic deficit, to classify these patients [5].…”