Case Presentation: A 64 year old female with history of insulin dependent type II DM presented with complaints of 6 weeks of involuntary right sided movements. She reported it as twitching/dancing of her right arm and leg accompanied by abnormal facial and tongue movements, as well as difficulty walking and maintaining her balance. Her symptoms worsened over a 6 week period. She also reported poor insulin compliance and high blood glucose for 3 months. Neurological examination revealed involuntary dance like movements of the right arm and leg, with normal muscle strength, tone, and reflexes. Laboratory tests showed random blood glucose of 380 and glycated hemoglobin was 10.7%. Her thyroid function, liver and kidney tests, ceruloplasmin, vitamin D, B12 and folic acid were all normal. A head computed tomography (CT) scan demonstrated asymmetric left striatal hyper attenuation and a brain magnetic resonance imaging (MRI) revealed left basal ganglia hyper density consistent with NKH. Her symptoms showed improvement with glycemic control and symptomatic treatment of chorea with risperidone for 5 days. She was discharged with noticeable improvement in her symptoms. Patient was advised to follow up at neurology clinic for symptom resolution and repeat imaging, however was lost to follow up.
Discussion: Hemichorea is the involuntary, rhythmic, and proximal jerking movement of a unilateral extremity. It is due to lesions in the caudate nucleus, globus pallidus, or putamen of the basal ganglia[1,3,5]. Hemichorea is a rare complication of NKH in poorly controlled diabetics[2], most often in elderly women over the age of 71 (especially of East Asian descent)[5,4]. Not fully understood, theories of the pathophysiology center around the depletion of the neurotransmitter GABA in a nonketotic hyperglycemic state and the loss of its’ inhibitory action on dopaminergic neurons[1,3]. Diagnosis includes the clinical hemichorea, significantly elevated blood sugar level, and basal ganglia lesions seen on T1-weighted MRI. Treatment hinges upon addressing the underlying NKH[2]. Basal ganglia lesions and the associated hemichorea have been known to reverse weeks after the resolution of NKH, however it’s often dependent upon the degree of glycemic control and the duration of the NKH episode[1]. Neuroleptic and Dopaminergic drugs have also been used for treatment of hemichorea[1]. Necessary rule outs include infectious, neoplastic, cerebrovascular, immunologic, and neurodegenerative disease. Future studies could include elucidating the etiology of NKH hemichorea in the absence of basal ganglia abnormalities on MRI, as well as the cause of continued hemichorea in the setting of resolved hyperglycemia.
Conclusions: Chorea is an abnormal involuntary movement disorder that results in abrupt, irregular movements. Metabolic disease is one of the few known secondary causes of chorea. Nonketotic hyperglycemic (NKH) chorea is most commonly reported in elderly patients of East Asian descent. Symptoms improve with better glycemic control and use of neuroleptic drugs