片側性持続性のChorea様不随意運動を呈した特発性副甲状腺機能低下症

Unilateral Choreic Movements in Idiopathic Hypoparathyroidism

　左半身の持続性chorea様不随意運動と四肢のテタニーを主徴とし，白内障を伴う66歳の女性例を報告する。本症例は低カルシウム血症，高リン血症，Ellsworth-Howardテスト陽性を示し，特発性副甲状腺機能低下症と診断された。頭部CT像にて右被殻，淡蒼球の石灰化，頸椎レ線像にて後縦靱帯の骨化が認められ，ともに副甲状腺機能低下によるカルシウム代謝異常に起因すると考えられた。本症例では特発性副甲状腺機能低下症に伴い片側性不随意運動がみられたことが特徴である。一般に副甲状腺機能低下に伴う不随意運動は発作性に出現し，血清カルシウム濃度の低下が原因と考えられている。しかし，本症例では持続性に出現，カルシウム濃度正常化後も引き続き認められた。また，CT上対側被殻，淡蒼球の石灰化が認められた。以上から，本症例の不随意運動は先ず副甲状腺機能低下のため大脳基底核に石灰化を生じ，神経細胞の機能が障害されて発現したと推測された。

We report a patient with idiopathic hypopara-thyroidism associated with unilateral calcification of the basal ganglia and contralateral choreic move-ments.

A 66-year-old woman was admitted to our hospi-tal because of involuntary movements of the left limbs. Two years before the present admission, she had operations for bilateral cataracts. Eight months before admission, she had an onset of severe carpal spasms and pain in both arms and legs. These symp-toms improved after one month's rest in a hospital.

About a month before admission, she noted progres-sive difficulty in using her left hand, followed by difficulty in walking due to the abnormal involun-tary movement of the left lower limb. Two weeks before admission her carpal spasms appeared again, bilaterally.

On admission, she was alert. The general physical examination was normal. Neurological examina-tion revealed choreic movements in the left hand, arm, leg and neck, and grimacing of the left face. She also complained of the spasms and pain in her hands, dysarthria and shortness of the breath. Chvostek and Trousseau signs were positive. Labo-ratory examination revealed marked decrease in serum calcium level (2.57 mEq/m /) and increase in inorganic phosphorus level (6.40 mEq/m /). Serum level of parathyroid hormone was less than 10 pg /m /. Ellthworth-Howard test was positive, inthat the infusion of parathyroid hormone (100 u) elicited a marked increment of the urinary excre-tions of phosphorus and cAMP. X-ray examination of the spine revealed ossification of the posterior longitudinal ligament in the cervical region. CT-scans of the brain revealed calcification in the region of right globus pallidus and putamen.

The bilateral spasms of hands and legs, dysarth-ria and shortness of the breath are thought to be the symptoms of tetany produced by idiopathic hypoparathyroidism. The unilateral choreic move-ment appear to be a result of calcification in the contralateral globus pallidus and putamen. The disturbed calcium metabolism seems to be respon-sible for her calcification of the basal ganglia and the abnormal ossification of the longitudinal liga-ment.