Topodiagnostic implications of hemiataxia: An MRI-based brainstem mapping analysis

The topodiagnostic implications of hemiataxia following lesions of the human brainstem are only incompletely understood. We performed a voxel-based statistical analysis of lesions documented on standardised MRI in 49 prospectively recruited patients with acute hemiataxia due to isolated unilateral brainstem infarction. For statistical analysis individual MRI lesions were normalised and imported in a three-dimensional voxel-based anatomical model of the human brainstem. Statistical analysis revealed hemiataxia to be associated with lesions of three distinct brainstem areas. The strongest correlation referred to ipsilateral rostral and dorsolateral medullary infarcts affecting the inferior cerebellar peduncle, and the dorsal and ventral spinocerebellar tracts. Secondly, lesions of the ventral pontine base resulted in contralateral limb ataxia, especially when ataxia was accompanied by motor hemiparesis. In patients with bilateral hemiataxia, lesions were located in a paramedian region between the upper pons and lower midbrain, involving the decussation of dentato-rubro-thalamic tracts. We conclude that ataxia following brainstem infarction may reflect three different pathophysiological mechanisms. (1) Ipsilateral hemiataxia following dorsolateral medullary infarctions results from a lesion of the dorsal spinocerebellar tract and the inferior cerebellar peduncle conveying afferent information from the ipsilateral arm and leg. (2) Pontine lesions cause contralateral and not bilateral ataxia presumably due to major damage to the descending corticopontine projections and pontine base nuclei, while already crossed pontocerebellar fibres are not completely interrupted. (3) Finally, bilateral ataxia probably reflects a lesion of cerebellar outflow on a central, rostral pontomesencephalic level. © 2007 Elsevier Inc. All rights reserved

MOESM3 of Rationale, design, and baseline characteristics of the CArdiovascular safety and Renal Microvascular outcomE study with LINAgliptin (CARMELINAÂŽ): a randomized, double-blind, placebo-controlled clinical trial in patients with type 2 diabetes and high cardio-renal risk

Additional file 3. Baseline characteristics by established CV disease and prevalent kidney disease at baseline in CARMELINAÂŽ participants