[P3-76] A case of paroxysmal nonkinesigenic dyskinesia with symptom improvement by iron supplementation
[Introduction] Paroxysmal nonkinesigenic dyskinesia (PNKD) is a rare movement disorder with sudden attacks of involuntary movements at rest. PNKD causes episodes of treatment-resistant involuntary movements. Herein, I report a case of clinically confirmed PNKD with restless legs syndrome (RLS), the symptoms of which were improved by iron supplementation. [Case report] The patient was a 14-year-old girl. From 11 years of age, she exhibited involuntary movement involving stiffening of the trunk and bending of the arms, with appearance of knee shaking. We diagnosed her with PNKD by clinical features. Valproate sodium was relatively effective for attacks, although symptoms worsened when the dose was tapered or stopped. The patient noticed dysesthesia, with itching over her waist to lower limbs before sleep, in addition to the involuntary movement of the upper and lower limbs. As a low ferritin level (28 ng/ml) was observed by blood test, iron supplementation was started for RLS. The dysesthesia before sleep disappeared one month after starting iron treatment, and the involuntary movements of the upper and lower limbs also disappeared after two months. She was able to stop taking valproate sodium. [Conclusion] Iron plays an important role in catecholamine biosynthesis. Reduced iron levels in the central nervous system can result in dopaminergic dysfunction, with development of RLS. Thus, iron supplementation can be effective for treatment of RLS. Further, as dopaminergic dysfunction underlies symptoms of paroxysmal dyskinesia, iron treatment may also be usefull for PKND.