Interactive Transcript
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This is a 66-year-old man known
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to me on Parkinson's therapy,
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switched to another therapy upon which the
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diagnosis of a possible stroke was entertained,
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and therefore he got diffusion imaging,
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which was negative, by the way,
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did not show evidence of a stroke.
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And most likely his symptoms were related to
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tardive dyskinesia with the development of
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choreoathetosis, secondary to the new medication.
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Now, on the EPI image,
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you can see very close opposition of the
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red nuclei to the substantia nigra.
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And the substantia nigra is thickened from
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anterior to posterior due to accumulation
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of iron in the compacta region.
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Now, this is not as easily appreciated
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or not as specifically identified as it
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is in the middle image,
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which is a blood iron-sensitive sequence
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known as blood-sensitive imaging,
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BSI, SWAN, or SWI,
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susceptibility-weighted imaging.
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When we look at this image,
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we see right there that there is a paucity
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of iron in the red nucleus.
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So there's depigmentation of the red nucleus.
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The compacta stripe is very thin on one cut
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and on the next cut, the two absolutely,
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positively bleed together.
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Then in the lateral aspect of the nigra,
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maybe there's a little bit of a swallowtail here,
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but there's not much of a swallowtail on the
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patient's right side, the viewer's left.
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And the iron distributions and stores
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are completely blunted.
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Now, on the diffusion tensor image,
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attenuation of the white matter tracks posteriorly
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due to visual spatial agnosia and loss of visual
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spatial function is not specific
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to Parkinson's disease.
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It's seen in dementia with Lewy bodies,
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as well as classic Parkinson's disease,
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although some have described it as a more
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severe attenuation seen in LBD.
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So we've got three findings here, at least.
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Attenuation of the white matter tracks in the
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visual spatial pathway,
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bleeding together of the rubro nigral interface
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with loss and thinning of the compacta zone,
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and loss of iron in the outer half
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to outer third of the substantia
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nigra with loss of the normal wispy swallow
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tail in the lateral aspect of the midbrain.
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