Anatomic and MRI bases for medullary infarctions with patients' presentation

OBJECTIVE

There is a low incidence of the medullary infarctions and sparse data about the vascular territories, as well as a correlation among the anatomic, magnetic resonance imaging (MRI) and neurologic signs.

MATERIALS AND METHODS

Arteries of the 10 right and left sides of the brain stem were injected with India ink, fixed in formalin and microdissected. The enrolled 34 patients with medullary infarctions underwent a neurologic, MRI and Doppler examination.

RESULTS

Four types of the infarctions were distinguished according to the involved vascular territories. The isolated medial medullary infarctions (MMIs) were present in 14.7%. The complete MMIs comprised one bilateral infarction (2.9%), whilst the incomplete and partial MMIs were observed in 5.9% and 8.9%, respectively. The anterolateral infarctions (ALMIs) were very rare (2.9%). The complete and incomplete lateral infarctions (LMIs), noted in 35.3%, comprised 11.8% and 23.6%, respectively, that is, the anterior (5.9%), posterior (8.9%), deep (2.9%), and peripheral (5.9%). Dorsal ischemic lesions (DMIs) occurred in 11.8%, either as a complete (2.9%), or isolated lateral (5.9%) or medial infarctions (2.9%). The remaining ischemic regions belonged to various combined infarctions of the MMI, ALMI, LMI and DMI (35.3%). The infarctions most often affected the upper medulla (47.1%), middle (11.8%), or both (29.5%). Several motor and sensory signs were manifested following infarctions, including vestibular, cerebellar, ocular, sympathetic, respiratory and auditory symptoms.

CONCLUSIONS

There was a good correlation among the vascular territories, MRI ischemia features, and neurologic findings regarding the medullary infarctions.

Pathological correlates of brain arterial calcifications

BACKGROUND

In clinical practice, calcifications seen on computed tomographic studies within the large brain arteries are often referred to as a surrogate marker for cholesterol-mediated atherosclerosis. However, limited data exist to support the association between calcification and atherosclerosis. In this study, we examined if intracranial arterial calcifications were associated with cholesterol-mediated intracranial large artery atherosclerosis (ILAA) within the arteries of the circle of Willis in an autopsy-based sample.

METHODS

We carried out a cross-sectional analysis of histopathological characteristics of brain large arteries obtained from autopsy cases. Brain large arteries were examined for evidences of calcifications, which were rated as macroscopic (coalescent) and microscopic (scattered). In addition to calcification, we also obtained measurement of the arterial wall and the presence of ILAA and nonatherosclerotic arterial fibrosis. We built hierarchical models adjusted for demographic and vascular risk factors to assess the relationship between calcification and ILAA.

RESULTS

In univariate analysis, the presence of any arterial calcifications was associated with cerebral infarcts (29% vs. 14%, P<.01). Multivariate analysis revealed that among all calcifications, coalescent calcifications were not associated with ILAA. In contrast, scattered calcifications were associated with ILAA (P<.001), decreased lumen diameter (-1.87 +/- 0.41 mm, P≤.001), and increased luminal stenosis (0.03% +/- 0.01%, P≤.006). These findings were independent of age, sex, or other vascular risk factors.

CONCLUSIONS

This study demonstrates that coalescent calcifications in brain large arteries, although associated with morbidity, are not synonymous with cholesterol-driven ILAA. Understanding the precise pathological components of cerebrovascular disease, including nonatherosclerotic arterial calcifications, will help develop individualized therapies beyond amelioration of traditional risk factors such as hyperlipidemia.