Ictal alteration of 99mTc ECD SPECT imaging in a patient with secondary paroxysmal kinesigenic dyskinesia caused by hyperglycemia.

We described a 61-year-old man with diabetes mellitus who presented with hyperglycemia related paroxysmal kinesigenic dyskinesia (PKD) with sudden development of paroxysmal unilateral involuntary movements (IMs) of his neck and the left extremities. Ictal 99mTc-ethylcysteinate dimer SPECT (ECD-SPECT) revealed a hyperperfusion over the contralateral frontal cortex and a hypoperfusion over the contralateral basal ganglia. Immediate correction of hyperglycemia after admission resulted in a marked improvement of IMs and a return to normal cerebral blood flow on interictal ECD-SPECT imaging. These findings suggest that dysfunction of the indirect pathway through the basal ganglia lead to an imbalance of the cortico-striato-thalamo-cortical circuit and may have contributed to the cause of PKD in this case.