Acute symptomatic hypoglycaemia mimicking ischaemic stroke on imaging: a systemic review

Abstract

Background: Acute symptomatic hypoglycaemia is a differential diagnosis in patients presenting with stroke-like neurological impairment, but few textbooks describe the full brain imaging appearances. We systematically reviewed the literature to identify how often hypoglycaemia may mimic ischaemic stroke on imaging, common patterns and relationships with hypoglycaemia severity, duration, clinical outcome and add two new cases.

Methods: We searched EMBASE and Medline databases for papers reporting imaging in adults with symptomatic hypoglycaemia. We analysed the clinical presentation, outcome, brain imaging findings, duration and severity of hypoglycaemia, time course of lesion appearance, including two new cases.

Results: We found 42 papers describing computed tomography or magnetic resonance imaging in 65 patients, plus our two cases with symptomatic hypoglycaemia. Imaging abnormalities on computed tomography and magnetic resonance were uni or bilateral, cortical or sub-cortical. Thirteen (20%) mimicked cortical or lacunar stroke. Acute lesions had restricted diffusion on magnetic resonance or low attenuation on computed tomography, plus swelling; older lesions showed focal atrophy or disappeared, as with ischaemic stroke. The association between the depth or duration of hypoglycaemia, the severity or extent of neurological deficit, and the imaging abnormalities, was weak.

Conclusion: Imaging abnormalities in patients with hypoglycaemia are uncommon but very variable, weakly associated with neurological deficit, and about a fifth mimic acute ischaemic stroke. Blood glucose testing should be routine in all patients with acute neurological impairment and hypoglycaemia should be included in the differential diagnosis of imaging appearances in patients presenting with acute stroke.

Figure 1

86 year old female in hypoglycaemic coma, computed tomography on Day 14 after onset of hypoglycaemia. There is a large area of low attenuation involving grey and white matter in the right temporal and parietal lobes. Differential diagnosis for this imaging appearance would be acute right middle and posterior cerebral artery territory infarction.

Figure 2

78 year old female in hypoglycaemic coma, computed tomography performed approximately 9 hours after onset of hypoglycaemia. There are areas of cortical low attenuation and swelling in the temporal and parietal lobes bilaterally.

Figure 3

The patterns of abnormality which have been described in cases of acute symptomatic hypoglycaemia with poor outcome (death, persistent vegetative state, or severe long-term neurological deficit) – 3c is similar to New Case 1, the hypoattenuation being predominantly unilateral. All used with permission: a[39], b[15], c [3], d[33], e[5].

Figure 4

The patterns of abnormality seen in cases of symptomatic acute hypoglycaemia with good outcome (complete recovery) – b and c mimic lacunar stroke on imaging. All used with permission: a[29], b[31], c[25].