Differences in Brain Activation Between Tremor- and Nontremor-Dominant Parkinson Disease

Prodoehl, Janey; Planetta, Peggy J.; Kurani, Ajay S.; Comella, Cynthia L.; Corcos, Daniel M.; Vaillancourt, David E.

doi:10.1001/jamaneurol.2013.582

Cited by 73 publications

(67 citation statements)

References 22 publications

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“…We used VBM analysis of the T1-weighted images and did not find macrostructural changes in the whole brain and substantia nigra consistent with most other VBM studies in non-demented PD (Price et al, 2004; Prodoehl et al, 2013b; Tessitore et al, 2012). This does not rule out the possibility that atrophy based neurodegeneration was occurring within the SN voxels because the free-water measurement could be more sensitive to neurodegeneration than VBM of the T1 image.…”

Section: Discussionsupporting

confidence: 69%

Increased free water in the substantia nigra of Parkinson's disease: a single-site and multi-site study

Ofori

Pasternak

Planetta

et al. 2015

Neurobiology of Aging

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137

158

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Measures from diffusion magnetic resonance imaging reflect changes in the substantia nigra of Parkinson’s disease. It is the case, however, that partial volume effects from free-water can bias diffusion measurements. The bi-tensor diffusion model was introduced to quantify the contribution of free-water and eliminates its bias on estimations of tissue microstructure. Here, we test the hypothesis that free-water is elevated in the substantia nigra for Parkinson’s disease compared with controls. This hypothesis was tested between large cohorts of Parkinson’s disease and control participants in a single-site study, and validated against a multi-site study using multiple scanners. The fractional volume of free-water was increased in the posterior region of the substantia nigra in Parkinson’s disease compared with controls in both the single-site and multi-site studies. We did not observe changes in either cohort for free-water corrected fractional anisotropy or free-water corrected mean diffusivity. Our findings provide new evidence that the free-water index reflects alteration of the substantia nigra in Parkinson’s disease, and this was evidenced across both single-site and multi-site cohorts.

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Section: Discussionsupporting

confidence: 69%

Increased free water in the substantia nigra of Parkinson's disease: a single-site and multi-site study

Ofori

Pasternak

Planetta

et al. 2015

Neurobiology of Aging

Self Cite

137

158

View full text Add to dashboard Cite

show abstract

“…This finding indicates that there may be more oscillations in the tremor dominant(TD) PD than the non-tremor dominant(NTD) PD. Furthermore, there is another evidence showing reduced blood oxygenation level dependent(BOLD) activity in the NTD PD patients compared to the TD PD patients in several areas(cortex, GPi, GPe and thalamus) [50]. Taking these results together, it is logical to hypothesize that more oscillatory activity in PD requires more energy, which is consistent with our theoretical predictions.…”

Section: Resultssupporting

confidence: 86%

Quantification of motor network dynamics in Parkinson’s disease by means of landscape and flux theory

Yan

Wang

2017

PLoS ONE

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The basal ganglia neural circuit plays an important role in motor control. Despite the significant efforts, the understanding of the principles and underlying mechanisms of this modulatory circuit and the emergence of abnormal synchronized oscillations in movement disorders is still challenging. Dopamine loss has been proved to be responsible for Parkinson’s disease. We quantitatively described the dynamics of the basal ganglia-thalamo-cortical circuit in Parkinson’s disease in terms of the emergence of both abnormal firing rates and firing patterns in the circuit. We developed a potential landscape and flux framework for exploring the modulatory circuit. The driving force of the circuit can be decomposed into a gradient of the potential, which is associated with the steady-state probability distributions, and the curl probability flux term. We uncovered the underlying potential landscape as a Mexican hat-shape closed ring valley where abnormal oscillations emerge due to dopamine depletion. We quantified the global stability of the network through the topography of the landscape in terms of the barrier height, which is defined as the potential difference between the maximum potential inside the ring and the minimum potential along the ring. Both a higher barrier and a larger flux originated from detailed balance breaking result in more stable oscillations. Meanwhile, more energy is consumed to support the increasing flux. Global sensitivity analysis on the landscape topography and flux indicates how changes in underlying neural network regulatory wirings and external inputs influence the dynamics of the system. We validated two of the main hypotheses(direct inhibition hypothesis and output activation hypothesis) on the therapeutic mechanism of deep brain stimulation (DBS). We found GPe appears to be another effective stimulated target for DBS besides GPi and STN. Our approach provides a general way to quantitatively explore neural networks and may help for uncovering more efficacious therapies for movement disorders.

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“…Their results suggest that dopamine loss in the striatum is not involved in determining motor phenotype, tremor in particular. This is consistent with research that implicates nonnigro-striatal systems in the manifestation of Parkinson's disease tremor [15,16].…”

Section: Understanding the Etiologic Or Physiological Basis Of Subtypessupporting

confidence: 90%

“…Further support for the tremor-dominant /PIGD distinction comes from Prodoehl et al [16] who studied patients using functional MRI during a grip task in tremor-dominant and nontremor-dominant Parkinson's disease. Reduced activation in the prefrontal cortex and globus pallidus of patients with nontremor-dominant Parkinson's disease compared with both patients with tremor-dominant Parkinson's disease and healthy controls was found, suggesting differences in brain activation patterns between the subtypes that extend beyond the occurrence of the tremor itself.…”

Section: Understanding the Etiologic Or Physiological Basis Of Subtypesmentioning

confidence: 99%

Subtypes of Parkinson's disease

Marras¹

2015

Current Opinion in Neurology

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It will be important to revisit PD-MCI classification to consider subtyping based upon data that relate cognitive phenotype to prognosis. Given the traction that traditional motor subtyping has had in the field it would be of value to consider how nonmotor symptom clusters can be used with or alongside the motor subtypes. Finally, incorporating subtypes into clinical trials remains a significant gap in Parkinson's disease research.

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Differences in Brain Activation Between Tremor- and Nontremor-Dominant Parkinson Disease

Cited by 73 publications

References 22 publications

Increased free water in the substantia nigra of Parkinson's disease: a single-site and multi-site study

Increased free water in the substantia nigra of Parkinson's disease: a single-site and multi-site study

Quantification of motor network dynamics in Parkinson’s disease by means of landscape and flux theory

Subtypes of Parkinson's disease

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