Irreversible striatal neuroimaging abnormalities secondary to prolonged, uncontrolled diabetes mellitus in the setting of progressive focal neurological symptoms

Abstract

Hemichorea-hemiballisum in patients with hyperglycemia and striatal hyperintensity on T1-weighted magnetic resonance imaging is now an accepted clinical entity. Usually, both the clinical syndrome and neuroimaging abnormalities are reversible. A transient, reversible metabolic impairment within the basal ganglion has been considered a possible cause of this disorder. However, the pathophysiology remains to be unclear. We report a 56-year-old man with a prolonged, uncontrolled hyperglycemia (HbA1C: 13.8%) and striatal hyperintensity on T1-weighted MR imaging presenting as reversible focal neurological deficit and irreversible neuroimaging abnormalities on the fourth month when blood sugar was under control (HbA1C 6.0 mg/dl). We hypothesize that neuroimaging abnormalities in our case may be a sequence of an "ischemic insult" caused by prolonged, uncontrolled hyperglycemia. Whether the signal abnormalities on neuroimaging studies or the clinical syndrome are reversible (patients with HCHB) or irreversible (such as in our case) are based on the degree of ischemic damage.

Irreversible Hemichorea–Hemiballism in a Case of Nonketotic Hyperglycemia Presenting as the Initial Manifestation of Diabetes Mellitus

“…Similarly, other researchers have reported cases of HCHB with irreversible clinical and/or imaging findings. 4 , 14 , 15 …”

“…Tung et al hypothesized that hyperglycemia can result in an ischemic penumbra and reversible clinical syndrome/neuroimaging abnormalities in patients with HCHB; however, prolonged hyperglycemia may result in true infarction with an irreversible clinical syndrome. 4 Lin et al studied stroke patients and postulated that decreased NAA/Cr and NAA/Cho ratios, as well as an increased Lac/Cr ratio often indicate irreversible infarction, and the monitoring of the NAA peak may be considered as an indicator for evaluating the effectiveness of treatment for cerebral infarction. 16 In the current case there was both decreased NAA/Cr and NAA/Cho ratios (NAA/creatine (Cr) ratio = 1.01 and NAA/Cho ratio = 0.78 as compared to other side) along with a Lac peak prompting towards an infarction.…”

Decreased Efferents of Mesencephalic Raphe Nuclei to Striatum in Animal Model of Streptozocin-Induced Diabetes

“…We observed a decrease in projections but it is difficult to distinguish serotonergic neurons from non-serotonergics in our study. Tung and colleagues claimed that hyperglycemia can cause transient and reversible effects to basal nuclei functions (24). Furthermore, previous studies showed axonal transport reduction and cell death following diabetes mellitus (3).…”

Irreversible Hemichorea–Hemiballism in a Case of Nonketotic Hyperglycemia Presenting as the Initial Manifestation of Diabetes Mellitus

“…3 Furthermore, HCHB due to NKH resolves after correction of hyperglycemia in the majority of cases; however, the time frame for improvement varies from case to case and may be as long as 6 months. 4 Other identified causes of bilateral chorea/ballism that are initially more unilateral include chorea associated with infections, sequela of rheumatic fever, thyrotoxicosis, systemic lupus erythematosus, systemic vasculitis (inflammatory), autoimmune etiologies, hypoxic encephalopathy, and drug-induced or substance abuse. Rarely, chorea associated with neuroacanthocytosis and Huntington disease may also start unilaterally.…”