Classic neuroimaging findings of nonketotic hyperglycemia on computed tomography and magnetic resonance imaging with absence of typical movement disorder symptoms (hemichorea-hemiballism)

Abstract

While there are broad differential diagnoses for either the clinical finding of hemichorea-hemiballism or the imaging finding of lateralizing/asymmetric basal ganglia lesions (hyperdense on computed tomography, hyperintense on T1 magnetic resonance imaging), the presence of both findings is highly suggestive of nonketotic hyperglycemia. We present an unusual case of a patient with vague stroke-like complaints and imaging findings notable for lateralizing basal ganglia lesions. Laboratory analysis revealed nonketotic hyperglycemia and neurologic exam failed to elicit any findings of movement disorder. As far as we know, this is the first published case of a patient with typical neuroimaging manifestations of nonketotic hyperglycemia without associated hemichorea-hemiballism (a disorder of abnormal movements comprised of more proximal, higher amplitude movements-ballismus and lower amplitude, more distal movements-chorea). This finding suggests that radiologists should be alert to the possibility of nonketotic hyperglycemia in patients with asymmetric/lateralizing basal ganglia lesions even in the absence of a movement disorder.

Unilateral striatal CT and MRI changes secondary to non-ketotic hyperglycaemia

“…This characteristic basal ganglia lesion is hyperintense in T1W with no mass effect or perilesional oedema in the majority of reported cases in the literature 1–11. On T2W MRI, the signal changes are reported to be variable, with the lesions appearing either hypointense, isointense or hyperintense,1 7 with hypointensity predominating in many reports 8 10 11. The features of restricted diffusion7 8 10 and signal loss on gradient echo have also been reported 7.…”

“…The differential diagnosis of T1W hyperintense basal ganglia lesions includes deposition of paramagnetic substances namely iron, copper (Wilson's disease), melanin (malignant melanoma), manganese (chronic liver disease) and intracellular methaemoglobin in subacute haematoma 1 2. Other causes include chronic hepatic encephalopathy, postcardiac-arrest encephalopathy, hypoglycaemic coma and mild local ischaemia 4.…”

Diabetic striatopathy manifesting as severe consciousness disturbance with no involuntary movements

“…few cases of diabetic striatopathy without involuntary movements have been reported [3,4]. In addition, this is the first case of diabetic striatopathy manifesting purely as a severe consciousness disturbance.…”

Paediatric non-ketotic hyperglycaemic hemichorea–hemiballismus

“…Additional caudate nucleus or globus pallidus involvement may also be seen 9. T2WI may show variable results, either isointense or hypointense to the surrounding normal basal ganglia 11. Plain cranial CT images would show hyperattenuation on the same areas described above 12.…”

“…Plain cranial CT images would show hyperattenuation on the same areas described above 12. There are many hypotheses to explain the T1WI findings, but the most commonly promoted premise is the presence of a protein hydration layer in swollen gemistocytes 11. Gemistocytes are reactive astrocytes that are swollen and appear during acute injury.…”