[A case of Parkinson's disease with marked head drop after administration of donepezil hydrochloride].

A 76-year-old woman with a 2-year history of Parkinson's disease presented with dropped head, which had developed rapidly after she had been prescribed donepezil hydrochloride (DNP) at 3 |mg/day. After one month of medication, the extent of the head drop reached 90°. Examination revealed hypertrophy of the left sternocleidomastoid muscle, but no weakness of the extensor muscles in the cervical region. Surface electromyography demonstrated co-|contraction of the sternocleidomastoid and splenius capitus muscles during head flexion and extension. DNP was withdrawn, resulting in immediate amelioration of the head drop, and complete resolution was achieved after two months. Although head drop is often seen in patients with Parkinson's disease, few previous reports have documented DNP as a causative factor. If patients with Parkinson's disease develop head drop, it is important to investigate any history of DNP medication.

[Juvenile-onset anti-nuclear matrix protein 2 (NXP-2) antibody-positive dermatomyositis with joint contractures before manifestation of myositis: a case report].

A 23-year-old man was admitted to our hospital with a one-year history of muscle weakness and atrophy. He had noticed contractures of the fingers of both hands from the age of 18. Examination revealed a skin rash including heliotrope rash and Gottron's sign, joint contractures in the extremities, dysphagia, extensive muscle weakness and marked muscle atrophy. The serum creatine kinase level was 272 |IU/l and muscle biopsy showed typical perifascicular atrophy but little lymphocyte invasion. There was no interstitial pneumonia or malignancy, but muscle tendons showed elevated CT values suggesting calcification or fibrosis. Anti-nuclear matrix protein 2 (NXP-2) antibody-positive dermatomyositis was diagnosed on the basis of the serum antibody level. Methylprednisolone pulse therapy ameliorated the skin rash and bulbar palsy, but muscle weakness, atrophy and joint contractures were resistant to the treatment. There have been no previous reports of young adults with anti-NXP-2 antibody-positive dermatomyositis in whom joint contracture became evident as early as 4 years beforehand, which is a important feature for differential diagnosis of dermatomyositis.