Presentation
Bilateral ptosis and ophthalmoplegia upon awakening with mild altered mental status.
Patient Data
There are areas of moderately hypodensity at the paramedian sectors of the thalami as well as in the median-paramedian region of the midbrain.
Old small infarcts are also demonstrated in the parietal lobes, especially in the left.
There are areas of T2 and FLAIR hyperintense signal and restricted diffusion at the paramedian sectors of the thalami as well as in the median-paramedian and periaqueductal grey matter of the midbrain and along the pial surface of the midbrain interpeduncular fossa (the V-sign). Infarct in the Percheron’s territory is clearly demonstrated.
There are some small foci of restricted diffusion in the occipito-mesial region and at the right frontal lobe, in which focal cortical laminar necrosis is also present characterized by an intrinsic high T1 signal and corresponding susceptibility artifact. Old infarcts are also demonstrated in the parietal lobes. Some chronic ischemic changes of small vessels in the supratentorial white matter and at the middle right cerebellar peduncle are also evident. Discrete deposition of iron at the basal ganglia, red nuclei and dentate nuclei is appreciated. The ventricular system, the cerebrospinal fluid spaces and the basal cisterns are moderately dilated.
Case Discussion
Artery of Percheron is a rare anatomical variant that forms a single thalamic-perforating branch. Occlusion of this artery is rare.
The diagnosis of artery of Percheron territory infarct is made indirectly through findings of bilateral thalamic paramedial ischemia with or without involvement of the midbrain.
This case highlights a very high concordance between clinical manifestations and imaging findings; in fact, bilateral ptosis and ocular movement disorders found in our patient are the result of ischemic damage at the midbrain and in particular of a likely involvement of the oculomotor nerves.
Patient with arterial hypertension, type 2 diabetes, previous ischemic stroke and myocardial infarction; an unknown atrial fibrillation was also highlighted, likely to cause cardioembolic phenomena that triggered both infarct in the Percheron artery territory and other small ischemic insults detected by imaging.
Unable to process the form. Check for errors and try again.