Concepts and controversies in nonketotic hyperglycemia‐induced hemichorea: Further evidence from susceptibility‐weighted MR imaging

Abstract

Hyperglycemia-induced hemichorea can show T1 hyperintensity of the contralateral striatum on MRI. This is thought to be due to petechial hemorrhages or gemistocytic astrocyte accumulation. This study explores the utility of susceptibility-weighted imaging (SWI) and diffusionweighted imaging (DWI) in identifying the nature of these lesions. Three patients underwent MR imaging of the brain with SE T1, F SE T2, DWI, and SWI. T1 images showed hyperintensity predominantly involving the contralateral striatum, where mild (two cases) to moderate (one case) restricted diffusion (low apparent diffusion coefficient [ADC]) was detected on DWI. SWI demonstrated bilateral symmetrical hypointensities in the first two cases, suggesting age associated mineralization. In addition, increased susceptibility change (hypointensity) was also noted in the right putamen in the first and the third cases, suggesting paramagnetic mineral deposition. T1 hyperintensity may be from the protein hydration layer inside the cytoplasm of swollen gemistocytes appearing after an acute cerebral injury. These astrocytes also express metallothionein with zinc, which is thought to be the cause of asymmetric hypointensity of the posterior putamen on SWI. ADC values were thought to be useful for prognostication; however, they should be interpreted cautiously in the presence of susceptibility changes.

Neuroimaging in Patients with Abnormal Blood Glucose Levels

“…8 The abnormal movements are thought to be secondary to reduced cerebral perfusion, presumably caused by hyperviscosity secondary to hyperglycemia. 16,19 This is supported by recent observations that raised plasma glucose levels directly correlate with cerebral hypoperfusion. 22 Ensuing anaerobic metabolism leads to depletion of GABA, which is used as a metabolite to generate energy.…”

“…16,17 It most commonly results from a vascular insult involving the contralateral basal ganglia. [16][17][18] NKHG is the second most common cause for such presentation. 16 Occasionally, HC-HB may result from neoplastic or infective conditions involving the brain.…”

“…[16][17][18] NKHG is the second most common cause for such presentation. 16 Occasionally, HC-HB may result from neoplastic or infective conditions involving the brain. 17,19 HC-HB in association with hyperglycemia is well recognized.…”

“…19 Because GABA is an inhibitory neurotransmitter, its depletion causes increased thalamocortical drive, resulting in HC-HB. 16 The pathogenesis of the imaging findings in these patients is controversial and is further compounded by variable histopathology results from different studies. 8,16 Focal hemorrhage and calcification were initially proposed to explain the imaging pattern on CT and MR imaging.…”

Nichtketotische hyperglykämieinduzierte Hemichorea-Athetose

“…Die Befunde in den T2-Wichtungen variieren, wobei Hypointensitäten am häufigsten sind, isointense oder hyperintense Läsionen werden jedoch ebenfalls beschrieben [4,5]. In kleineren Fallserien zeigten Diffusionswichtungen (DWI/ADC) eine eingeschränkte Diffusion in den betroffenen Gebieten [3,5]. Frauen sind häufiger betroffen, und typisch ist ein höheres Erkrankungsalter.…”