Introduction

   Moyamoya disease is characterized by chronic progressive stenosis of the arteries of the circle of Willis. Involuntary movements in moyamoya disease are an unusual manifestation caused by cerebral ischemia and occur in about 3-6% of moyamoya patients.⁹⁾ Such involuntary movements may be caused by alterations in the balance between the basal ganglia and the cerebral cortices.^1)2)6)7)8) We report a child patient with moyamoya disease who had hemichoreoathetosis. Magnetic resonance imaging(MRI) showed a small infarction in the left subcortical area and single photon emission computed tomography (SPECT) also revealed a perfusion defect in the same lesion. After a superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and an encephalo-duro-arterio-myo-synangiosis(EDAMS), SPECT finding was normalized and the hemichoreoathetosis disappeared.

Case Report

   A 7-year-old boy was admitted to our hospital presenting with sudden right hemichoreoathetosis for one week. He had no specific past medical history. He had no family history of involuntary movement. His choreic movement was dominant on the right side, especially in the upper distal extremity and nearly continuous without any trigger factors. According to his mother, his attention span progressively decreased and his behavior became more aggressive and was characterized by abusive language or grumbling.
   On admission, he was alert and well oriented. Physical examination was unremarkable except for the right hemichoreoathetosis. No motor weaknesses or sensory dysfunction.
   Brain magnetic resonance imaging showed a small infarction in the left frontal subcortical white matter but no other area was affected including the basal ganglia (Fig. 1). Transfemoral cerebral angiography(TFCA) revealed severe stenosis of both distal internal carotid arteries, middle cerebral arteries and anterior cerebral arteries. In addition, many arteries and collaterals were perforated (Fig. 2). [Tc99m]-brain SPECT with acetazolamide showed a perfusion defect in left frontal subcortical region and decreased vascular reserve (Fig. 3). These findings were compatible with moyamoya disease. There were no specific results from laboratory findings and specialized tests；the following tests were done：routine blood tests, Anti-cardiolipin IgG, Anti-cardiolipin IgM, Anti-Ro antibody, Anti-La antibody, rheumatoid factor, Lupus anticoagulant, anti-streptokinase antibody, Anti-DNA antibody, Antinuclear antibody, electrocardiography, electroencephalography and thyroid function test.
   The patient underwent a left superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and an encephalo-duro-arterio-myo-synangiosis (EDAMS). Choreic movement improved immediately over the next few days and the characteristic behavior also improved over the next few weeks. Three months after surgery, cerebral angiography demonstrated bypass flow and increased collateral flows (Fig. 2). Postoperative SPECT showed normal brain perfusion and the vascular reserve (Fig. 3).

Discussion

   Clinical symptoms of moyamoya disease vary widely, and can include transient ischemic attack, seizure, headache, visual or speech disturbance, intellectual impairment, mental retardation and involuntary movement. Involuntary movement such as chorea is an uncommon manifestation, and chorea has been reported with stroke involving the basal ganglia and adjacent white matter.⁶⁾⁹⁾ Involuntary movements in moyamoya disease usually wax and wane and have trigger factors such as excitement, emotional strain or hyperventilation.⁶⁾ The pathophysiological mechanism is still uncertain, but subcortical white matter lesion without direct involvement of the basal ganglia or the subthalamic nucleus has been suggested as a cause.²⁾⁵⁾ The basal ganglia is concerned with controlling movement, so involuntary movement due to a lesion in the basal ganglia is relatively well known in the literature. However, other structures are also related to the pathogenesis of involuntary movement.^1)2)3)6) Hypoperfusion in the basal ganglia and its adjacent white matter caused by reversible, transient ischemia under some conditions is thought to induce involuntary movement. In other words, it is probable that any lesion that interrupts the cortical-striatalpallidal-thalamic-cortical circuits are a potential cause of an involuntary movement.^1)2)6)7)8) But, reports of involuntary movement with corticosubcortical lesions that do not affect the basal ganglia have been less common.^2)4)6)8)
   In our case, a frontal subcortical infarction on MR images and perfusion defect of the frontal lobe on SPECT images were observed but the basal ganglia was spared. Disappearance of hemichoreoathetosis with normalization of perfusion of the frontal subcortical area after revascularization procedure was observed, and it suggests the frontal subcortical hypoperfusion was related to the genesis of hemichoreoathetosis. This finding suggests that the involuntary movements were probably caused by a complex alteration in the balance between the basal ganglia and the cerebral cortices without directly involving the basal ganglia.⁸⁾ Involuntary movements may appear as a result of interruptions of the interactions between basal ganglia-thalamus-cortex circuits by focal subcortical dysfunction. These movements could be treated successfully with the revascularization surgery. This indicates that ischemia-induced functional disorder involving chorea in basal ganglia and its related structures may be reversible.

Conclusion

   Hemichoreoathetosis is a rare initial manifestation of moyamoya disaese and direct and indirect revascularization is an effective treatment of this rare symptom.

REFERENCES

1. Abbruzzese G, Berardelli A. Sensorimotor integration in movement disorders. Mov Disord 18:231-40, 2003

2. Barinagarrementeria F, Vega F, DelBrutto OH. Acute hemichorea due to infarction in the corona radiata. J Neurol 236:371-2, 1989

3. Bhatia KP, Marsden CD. The behavioral and motor consequences of focal lesions of the basal ganglia in man. Brain 117(Pt 4):859-76, 1994

4. Ferbert A, Rickert HB, Biniek R, Bruckmann H. Complex hyperkinesia during recovery from left temporoparietal cortical infarction. Mov Disord 5:78-82, 1990

5. FuKui T, Hasegawa Y, Seriyama S, Takeuchi T, Sugita K, Tsukagoshi H. Hemibalism-hemichorea induced by subcortical ischemia. Can J Neurol Sci 20:324-8, 1993

6. Ghika-Schmid F, Ghika J, Regli F, Bogousslavsky J. Hyperkinetic movement disorders during and after acute stroke: the Lausanne Stroke Registry. J Neurol Sci 146:109-16, 1997

7. Im SH, Oh CW, Kwon OK, Cho BK, Chung YS, Han DH. Involuntary movement induced by cerebral ischemia: pathogenesis and surgical outcome. J Neurosurg 100:877-82, 2004

8. Shintani S, Shiozawa Z, Tsunoda S, Shiigai T. Paroxysmal choreoathetosis precipitated by movement, sound and photic stimulation in a case of arterio-venous malformation in the parietal lobe. Clin Neurol Neurosurg 93:237-9, 1991

9. Watanabe K, Negoro T, Maehara M, Takahashi I, Nomura K, Miura K. Moyamoya disease presenting with chorea. Pediatr Neurol 6:40-2, 1990