Ipsilateral mamillary body atrophy after infarction of the posterior cerebral artery territory: MR imaging

Abstract

We describe herein magnetic resonance (MR) features of ipsilateral mamillary body atrophy after infarction of the posterior cerebral artery (PCA) territory. During the period May 2000 through July 2004, 13 patients with infarction of the PCA territory underwent cranial MR imaging in the chronic stage. Two 1.5-T scanners were used to obtain axial T1- and T2-weighted images with conventional spin-echo and fast spin-echo pulse sequences, respectively. The slice thickness was 6 mm, with a 2-mm interslice gap. Five of the 13 patients with PCA territory infarction had ipsilateral mamillary body atrophy. However, this asymmetry of the mamillary bodies was unclear in two of the five patients because of the thickness of the axial image slices. All five patients had a temporo-parieto-occipital infarction. The remaining eight patients had a parieto-occipital or an occipital infarction. Unilateral transneuronal mamillary body degeneration after infarction of the ipsilateral PCA territory including the posteromedial temporal lobe can be detected on conventional thick axial MR images.

Ipsilateral atrophy of the mammillary body and fornix after thalamic stroke: evaluation by MRI

“…In addition, secondary degeneration of the MB or Fx caused by PCA infarction could also be considered as differential diagnosis. Uchino et al reported five cases with ipsilateral MB atrophy after infarction of the PCA territory, all of which involved hippocampus (28). Careful evaluation of the vascular changes and existing cerebral infarction must be undertaken.…”

“…Those small structures will sometimes be located in the interslice gap and the findings can easily be modified by the partial volume effect. Uchino et al reported that the tortuous and elongated basilar artery and crural segment of the PCA could compress the MB, resulting in asymmetry (28). Some other possible causes that influences those structures include compression by the edema following a large thalamic stroke, asymmetric positioning, and motion artifact or noise artifact.…”