Diabetic Hemichorea-hemiballism

Review Article

Austin J Clin Neurol 2015;2(4): 1037.

Diabetic Hemichorea-hemiballism

Ohara S*

Department of Neurology, Matsumoto Medical Center, Japan

*Corresponding author: Shinji Ohara, Department of Neurology, Matsumoto Medical Center, Chushin- Matsumoto Hospital, 811 Kotobuki, Matsumoto 399-0021, Japan

Received: February 05, 2015; Accepted: March 10, 2015; Published: April 09, 2015


Hemichorea/hemiballism (HC/HB) associated with nonketotic hyperglycemia (NKH) and hyperintense putamen on T1 weighted MRI has been recognized as a clinical entity, but the substrate responsible for the MRI signal changes and the pathogenesis of HC/HB remain unsettled. This syndrome is relatively rare, but its recognition is important because the correction of hyperglycemia usually leads to prompt clinical and radiological improvement, and occasionally to the detection of untreated diabetes mellitus. In this review, the clinical, radiological, and pathological features of this syndrome are extensively described with reference to possible underlying mechanisms.

Keywords: Nonketotic hyperglycemia; Hemichorea; Hemiballism; Diabetes mellitus; Magnetic resonance imaging


HC/HB: Hemichorea/hemiballism; DM: Diabetes Mellitus; NKH: Nonketotic Hyperglycemia; NPY: Neuropeptide Y


Hemichorea/hemiballism (HC/HB) is a continuous, arrhythmic hyperkinetic movement disorder occurring in a distal or proximal part of body. Chorea is characterized by jerky, forcible, often twisting movements of an arm or the trunk or facial grimacing, that can be incorporated into voluntary movements, and ballism is characterized by proximal dominant, often violent limb-throwing-like movement of the entire limb [1]. Chorea and ballism often coexist and blend with each other in a single patient, so that the difference may be due simply to the difference in the amount of movement and not in quality. The anatomical lesions responsible for HC/HB are generally found in the contralateral subthalamic nucleus and/or the basal ganglia. The varying etiologies include cerebrovascular, inflammatory, infectious, metabolic/toxic, and neurodegenerative etiologies, and those related to neoplasms or that are paraneoplastic. Autoimmune and infectious etiologies are more common among young individuals compared to the elderly, whereas cerebrovascular accidents are the most common etiology among the elderly, often with a background of concomitant hypertension and/or diabetes mellitus (DM).

Non-ketotic hyperglycemia (NKH) has been known to be associated with chorea and/or ballism [2-4]. However, NKH has gained increasing attention since Yahikozawa et al. reported a new syndrome in 1994 that they named “hemiballism with striatal hyperintensity on T1-weighted MRI in diabetic patients” [5]. At present, this syndrome is regarded as the second most common cause of HC/HB, following cerebrovascular accidents.

The clinical importance of this syndrome lies in the fact that it can be the first manifestation of DM, and that, in most cases; it can be improved simply by the correction of hyperglycemia and an intravenous administration of fluids. Because of the relatively benign course of the symptoms of this syndrome, the underlying pathogenesis of this condition has been unclear.

Clinical features

The ‘hemiballism with striatal hyperintensity on T1-weighted MRI in diabetic patients’ syndrome has been reported most often in patients from Japan and Asian countries and was found more commonly in elderly females with diabetes. Among 53 patients with this syndrome, Oh et al. reported that their mean age was 71 years, the female to male ratio was 1.8:1, and the mean hemoglobin A1C (HbA1C) was 14% [6].

The typical clinical course is as follows; an elderly patient with history of DM presents to an emergency room with an acute or subacute onset of HC/HB. Imaging studies of the brain to rule in/ out cerebrovascular stroke reveals high intensities on computed tomography (CT) and high signals in T1 MRI in the striatum contralateral to the side of the involuntary movement. Laboratory studies reveal NKH. After the correction of blood sugar, the involuntary movement as well as abnormal imaging resolves gradually [5-7].

The HC/HB is usually unilateral, but can involve both sides when striatal lesions are bilateral [6-8]. Once resolved following the correction of blood sugar, HC/HB may recur with resurgent hyperglycemia [9]. Correction of the hyperglycemia does not necessarily lead to abolishment of the involuntary movement and may lag for a few years [10,11].

Weakness or paresthesias may precede the appearance of HC/ HB on the same side of the body [12,13]. The level of consciousness usually maintained, though in rare cases, alteration in consciousness, generalized seizures, or changes in the personalities may precede the appearance of HC/HB [10]. The latter may be associated with a disturbance of striatal-frontal projections, which may represent a non-motor feature of this syndrome [14].

Typically, T1 weighted MRI reveals high signals in the striatum of patients with this syndrome. However, cases presenting with hyperglycemia and acute onset chorea but with normal MRI imaging have been reported [11,14,15]. Cases presenting hyperglycemia and typical T1 MRI imaging abnormalities without involuntary movement have also been reported [16,17]. Imaging abnormalities on MRI or CT may precede the appearance of HB/HC [18,19]. It is possible that these variances reflect differences in the stage and/or degree of a common underlying pathology.

It is important to note that the appearance of hemiballism/ hemichorea may be the first manifestation of diabetes [20,21].

The previous reports of this syndrome have been mostly of elderly patients with poorly controlled type II diabetes. However, cases of previously healthy adolescents presenting with hemichorea as an initial manifestation of type I diabetes have been reported with or without MRI abnormalities, suggesting that this syndrome could also occur in childhood [15, 22].

Imaging studies

The characteristic MRI feature of this syndrome is high and relatively uniform signal intensity of the putamen conforming to the anatomical contour on T1 weighted images. Generally, this is not accompanied by mass effect or contrast enhancement. In majority of cases, T2 weighed MRI revealed low signals in the striatum. CT scans reveals high-intensity of the putamen. But it is less conspicuous than that on T1-MRI. Less often, the globus pallidus and caudate nucleus are involved, though internal capsules are generally spared from signal abnormalities. Patients presenting with hemichorea may show bilateral abnormal signals on T1 MRI.

Typical chronological changes of this syndrome on CT, MRI and single-photon emission computed tomography (SPECT) are as follows [6,23]. In the acute stage, there are no apparent edematous changes of the striatum itself and no surrounding edema. Following recovery, abnormal signals improve first with CT, followed by MRI. There is no conversion of signals from high to low or vice versa during the follow-ups. Unless the recovery is protracted, atrophic changes are not generally apparent after the disappearance of highintensity signals on T1-weighted MRI. SPECT studies may reveal hyperperfusion of the basal ganglia on the contralateral side in the acute stage and hypo-perfusion in the late stage.

With regard to T2-weighted gradient-echo MRI findings, in which hemorrhagic lesions can be depicted as low signals, there have been conflicting reports. Some groups reported that there were no abnormalities [24,25] and others described low signals [26-28]. The findings on diffusion MRI have been variable; some researchers reported increased signals in the putamen [9,12,16], whereas others did not [12,27].

It is noteworthy that hyperglycemic hemiballism may reveal lesions not only in the striatum but also the subthalamic nucleus at contralateral side of the involuntary movement. Kim et al. reported that a patient who presented with hemiballism and nonketotic hyperglycemia showed a localized subthalamic lesion on MRI imaging [29]. In this patient, only the subthalamic nucleus appeared high on T1 and low on T2. On the other hand, Maeda et al. reported an autopsied case of hyperglycemic hemiballism with negative MRI findings. The autopsy revealed a localized lesion in the contralateral subthalamic nucleus.


There have been only a few autopsy [30-32] and biopsy [12,18,33] reports of patients with hyperglycemic HC/HB associated with characteristic T1 MRI findings in the putamen. In the first autopsy report, the characteristic T1 MRI hyperintensity in the putamen was recognized 18 days prior to the patient’s death [30]. The autopsy revealed an increased number of reactive astrocytes and the presence of scattered small foci of fresh tissue necrosis. This was associated with enhanced neuropeptide Y (NPY) immunoreactivity of the interneurons. The contralateral putamen revealed only old lacunar infarctions which had been apparent on MRI images. No hemorrhagic changes, either fresh or old, could be identified histologically.

Citation: Ohara S. Diabetic Hemichorea-hemiballism. Austin J Clin Neurol 2015;2(4): 1037. ISSN : 2381-9154