A 13 year old male patient resident of UK came with complaints of Dystonic hand movements on activity, right more than Left.
No history of seizures. No obvious cognitive impairment. No prior investigations were done.
Routine MRI brain imaging
Arterial Spin Labelled Perfusion MRI images of Brain
What is Arterial Spin Labelled Perfusion MRI ?
• Uses magnetically labelled endogenous blood water.
• Ideal in brain as the arterial supply is well defined & perfusion to brain tissue is high.
• Higher magnet strengths give improved ASL
• Gives an idea of tissue perfusion without using contrast
• Estimates cerebral blood flow in ml/gm/min
Diffusion Tensor Imaging and Fibre Tracking images of Brain
What is Diffusion Tensor Imaging ?
• A form of diffusion-weighted imaging
• Analyzes the microstructural integrity of white matter
• Fractional anisotropy -The major index for this discrepant diffusion
• Higher FA values correlate with more ordered tissue containing a larger number of aligned axons
• Higher FA values reflect tissue integrity and coherence
Fractional Anisotropy Maps
Average fractional Anisotropy ( FA) values:
Putamen (Right) 0.293 (Left) 0.328
Posterior limb of IC (Right) 0.616 (Left) 0.709
Genu of IC (Right) 0.693 (Left) 0.637
Corpus callosum (Right) 0.697 (Left) 0.880
Thalamus (Right) 0310 (Left) 0.321
Thalamo cortical tract fibers appear relatively sparse on right side compared to left.
Corpus callosal and cortico spinal tract fibres appears more ore less symmetrical on both sides.
Interpretation:
Average fractional Anisotropy values are more in putamen, Posterior limb of left internal capsule, Corpus callosum and left thalamus.
In the genu of internal capsules, the values are greater on right side.
Segmented Brain Volumes
Volumetry was performed using 3DSPGR acquisition.
Whole brain and segmented brain volumes were calculated.
Left putaminal volume is approximately 13 % more than right.
MR Spectroscopy
To summarize the findings in this case..
• Structural MRI is normal.
• MR spectroscopy is normal.
• Arterial Spin Labelled MR Perfusion (ASL) show increased cerebral blood flow in left parietal cortex and caudate nuclei.
• DTI and FA maps show Relatively dense Thalamo cortical tracts on left.
• Segmented Brain Volume show 13 % increased putamen volume on left.
Review of Literature:
Primary Dystonias is a hyperkinetic movement disorder characterized by involuntary, repetitive twisting movements.
Early onset - prior to 26 years of age.
Associated with a known gene carrier status (e.g., DYT1).
Symptoms more likely begin in one extremity and have a tendency to be generalized.
Conventional MRI does not typically reveal brain abnormalities.
Segmented Brain Volumes
• Putamen has been predominantly involved in focal hand dystonias.
• The involved side show > 10% increase in putaminal volume.
• Other areas which may be involved are thalami and caudate nucleus.
Summarization of Literature…
• Gray matter changes are not restricted to the basal ganglia.
• Sensorimotor cortices, thalamus, and cerebellum may also be involved
• White matter aberrations mainly involve cortico-striato-pallido-thalamic and cerebello-thalamo-cortical pathways.
• Whether these changes are causative or compensatory remains unknown.
• Newer MRI sequences may provide an insight in understanding disease pathophysiology and intricate brain networks involved.
To conclude…
• Advanced MRI sequences like ASL, DTI, Segmented brain volumes may provide more comprehensive insight into pathophysiology of dystonia.
• Further studies in this regard are needed to understand these findings and link them to disorder-specific clinico-behavioral characteristics.
References:
• Newer advances in the pathophysiology of focal dystonias Brain (2006), 129, 6–7
• Thalamocortical Connectivity Correlates with Phenotypic Variability in Dystonia; May 2014 An Vo1,Wataru Sako1, Martin Niethammer1, Maren Carbon
• Primary Dystonia: Conceptualizing the Disorder Through a Structural Brain Imaging Lens Ritesh A. Ramdhani & Kristina Simonyan
• Cortical somatosensory reorganization in children with spastic cerebral palsy: a multimodal neuroimaging study Front. Hum. Neurosci., 12 September 2014 Christos Papadelis1,2*†, Banu Ahtam1,2†, Maria Nazarova
Contributors:
Dr.Deepak Patkar (HOD Radiology) Nanavati Superspeciality Hospital, Mumbai
Dr.Mitusha Verma SR DNB Radiology Nanavati.
No history of seizures. No obvious cognitive impairment. No prior investigations were done.
Routine MRI brain imaging
Conventional MRI Brain normal
What is Arterial Spin Labelled Perfusion MRI ? • Uses magnetically labelled endogenous blood water.
• Ideal in brain as the arterial supply is well defined & perfusion to brain tissue is high.
• Higher magnet strengths give improved ASL
• Gives an idea of tissue perfusion without using contrast
• Estimates cerebral blood flow in ml/gm/min
Diffusion Tensor Imaging and Fibre Tracking images of Brain
• A form of diffusion-weighted imaging
• Analyzes the microstructural integrity of white matter
• Fractional anisotropy -The major index for this discrepant diffusion
• Higher FA values correlate with more ordered tissue containing a larger number of aligned axons
• Higher FA values reflect tissue integrity and coherence
Fractional Anisotropy Maps
Putamen (Right) 0.293 (Left) 0.328
Posterior limb of IC (Right) 0.616 (Left) 0.709
Genu of IC (Right) 0.693 (Left) 0.637
Corpus callosum (Right) 0.697 (Left) 0.880
Thalamus (Right) 0310 (Left) 0.321
Thalamo cortical tract fibers appear relatively sparse on right side compared to left.
Corpus callosal and cortico spinal tract fibres appears more ore less symmetrical on both sides.
Interpretation:
Average fractional Anisotropy values are more in putamen, Posterior limb of left internal capsule, Corpus callosum and left thalamus.
In the genu of internal capsules, the values are greater on right side.
Segmented Brain Volumes
Volumetry was performed using 3DSPGR acquisition.
Whole brain and segmented brain volumes were calculated.
MR Spectroscopy
To summarize the findings in this case..
• Structural MRI is normal.
• MR spectroscopy is normal.
• Arterial Spin Labelled MR Perfusion (ASL) show increased cerebral blood flow in left parietal cortex and caudate nuclei.
• DTI and FA maps show Relatively dense Thalamo cortical tracts on left.
• Segmented Brain Volume show 13 % increased putamen volume on left.
Review of Literature:
Primary Dystonias is a hyperkinetic movement disorder characterized by involuntary, repetitive twisting movements.
Early onset - prior to 26 years of age.
Associated with a known gene carrier status (e.g., DYT1).
Symptoms more likely begin in one extremity and have a tendency to be generalized.
Conventional MRI does not typically reveal brain abnormalities.
Segmented Brain Volumes
• Putamen has been predominantly involved in focal hand dystonias.
• The involved side show > 10% increase in putaminal volume.
• Gray matter changes are not restricted to the basal ganglia.
• Sensorimotor cortices, thalamus, and cerebellum may also be involved
• White matter aberrations mainly involve cortico-striato-pallido-thalamic and cerebello-thalamo-cortical pathways.
• Whether these changes are causative or compensatory remains unknown.
• Newer MRI sequences may provide an insight in understanding disease pathophysiology and intricate brain networks involved.
To conclude…
• Advanced MRI sequences like ASL, DTI, Segmented brain volumes may provide more comprehensive insight into pathophysiology of dystonia.
• Further studies in this regard are needed to understand these findings and link them to disorder-specific clinico-behavioral characteristics.
References:
• Newer advances in the pathophysiology of focal dystonias Brain (2006), 129, 6–7
• Thalamocortical Connectivity Correlates with Phenotypic Variability in Dystonia; May 2014 An Vo1,Wataru Sako1, Martin Niethammer1, Maren Carbon
• Primary Dystonia: Conceptualizing the Disorder Through a Structural Brain Imaging Lens Ritesh A. Ramdhani & Kristina Simonyan
• Cortical somatosensory reorganization in children with spastic cerebral palsy: a multimodal neuroimaging study Front. Hum. Neurosci., 12 September 2014 Christos Papadelis1,2*†, Banu Ahtam1,2†, Maria Nazarova
Contributors:
Dr.Deepak Patkar (HOD Radiology) Nanavati Superspeciality Hospital, Mumbai
Dr.Mitusha Verma SR DNB Radiology Nanavati.
No comments:
Post a Comment