Can Diabetes Impair Stroke Recovery?

Patients with diabetes may experience reduced neuroplasticity that impairs recovery from stroke, researchers reported.

To further examine this possibility, investigators used threshold-tracking transcranial magnetic stimulation to non-invasively index neuroplasticity by measuring cortical excitability. Researchers evaluated a cohort of 57 patients.

Both the ipsilateral and contralesional hemispheres were examined and compared in 7 stroke patients with diabetes and 12 stroke patients who did not have diabetes. In the diabetic group, there were 3 cortical and 4 subcortical infarcts, while in the nondiabetic group there were 6 cortical and 6 subcortical infarcts.

Cortical function assessment also included 8 patients with diabetes without stroke and 30 control participants who did not have a history of stroke.

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Results showed that there were changes in cortical excitability (reduction in intracortical inhibition) between the groups. Stroke patients without diabetes had reduced short-interval intracortical inhibition (SICI) over both motor cortices, compared with normal controls. However, stroke patients with diabetes only had reduced SICI over the contralesional cortex and not the ipsilesional cortex, compared with control patients with diabetes. Among control patients, there was a significant reduction in SICI in control patients with diabetes versus normal control patients.

“These results have demonstrated the absence of ipsilesional cortical excitability change after diabetic strokes, suggesting impaired capacity for neuroplasticity over this hemisphere as a consequence of a “double-hit” phenomenon because of preexisting alterations in cortical function in nonstroke patients with diabetes,” the researchers stated.

They added that the research may have implications for poststroke recovery, though the cross-sectional design and the small cohort of patients with diabetes limited the study. Larger, longitudinal studies will be needed to confirm the findings, they said.

—Lauren LeBano

Reference

Huynh W, Kwai N, Arnold R, et al. The Effect of Diabetes on Cortical Function in Stroke: Implications for Poststroke Plasticity. Diabetes. 2017;66(6):1661-1670.