A change in the ratio of measurements of which structures on axial views of MRI brain are suggestive of this condition?
In Huntington disease, the frontal horn width to intercaudate distance ratio approaches 1 as the caudate heads reduce in volume. The normal ratio is 2.2-2.6. Conversely, the inner table to intercaudate distance ratio is increased in Huntington disease. The normal ratio is 0.09-0.12.
Reduced uptake is seen in the heads of the caudate nuclei, worse on the left side. In addition, hypoperfusion is seen in the parietal lobes particularly in the left superior parietal lobe. The perfusion is also mildly reduced in the mesial temporal lobes.