[Pre-evening meal administration of tacrolimus improved refractory ocular symptoms in two young children with latent general myasthenia gravis].

We report two patients with latent general myasthenia gravis (MG) with refractory ocular symptoms who were successfully treated with pre-evening meal administration of tacrolimus. Patient 1 was a 4-year-old girl with persistent ocular symptoms despite high-dose steroid therapy and thymectomy. Oral tacrolimus was initiated at the age of 3 years, which was resulted in complete resolution of symptoms. After one year, hemilateral ptosis recurred. The plasma consentration of tacrolimus was very low, probably due to sudden weight gain. Increasing the dose and a change from post- to pre-evening meal administration of tacrolimus enabled maintenance of its concentration and complete control of ocular symptoms. Patient 2 was a 2-year-old boy whose symptoms were refractory to steroid therapy after his first relapse. Since post-meal administration of tacrolimus provided partial benefit, the closing schedule was changed to pre-evening meal administration, with good results. Neither patient had adverse effects of tacrolimus. It is difficult to maintain an effective tacrolimus concentration in children due to marked growth and rapid metabolic rates. Pre-evening meal administration of tacrolimus is an easy, safe and useful method of treatment in MG young children.

High-density areas on muscle CT in childhood-onset Pompe disease are caused by excess calcium accumulation.

We report two patients with childhood-onset Pompe disease showing striking changes with high-density areas on skeletal muscle CT, not seen in adult- or infantile-onset forms of this disease. While the anterior compartment of the thigh muscles was less affected in the adult-onset form, the rectus femoris and tibial muscles were preferentially involved from the early stage in the childhood-onset form of Pompe disease. The high-density areas became increasingly diffuse with disease progression, producing a marbled pattern and ultimately resulting in homogeneous high density and muscle atrophy. Muscle biopsy specimens from the high-density areas showed striking vacuolar changes with many dense globular bodies in lysosomes. High calcium signals were identified by X-ray microanalysis using energy-dispersive X-ray spectroscopy in these areas. Excess calcium accumulation in the vacuoles was also confirmed with the glyoxal-bis(2-hydroxyanil) (GBHA) staining. The high density on CT was slightly reduced together with clinical improvement after enzyme replacement therapy in patient 2. Our data demonstrate that in childhood-onset Pompe disease, high-density areas on skeletal muscle CT images are due to the accumulation of calcium in dense globular bodies formed by a chronic degenerative process affecting autophagic vacuoles.

[Treatment approach to congenital myasthenic syndrome in a patient with acetylcholine receptor deficiency].

Congenital myasthenic syndromes (CMS) are rare heterogeneous disorders of neurotransmission caused by genetic defects of neuromuscular junction molecules. While CMS patients have been reported worldwide, in Japan there have been only a few descriptions of adult CMS patients with acetylcholinesterase (AChE) deficiency and slow channel syndrome. Herein, we report a Japanese CMS patient with acetylcholine receptor (AChR) deficiency, diagnosed during childhood, and our treatment approach to the patient. This 13-year-old Japanese boy had had severe myasthenic symptoms since infancy. Ptosis, his first symptom, appeared at 5 months and nasal voice was recognized at 2 years of age. AchR and anti-muscle-specific tyrosine kinase (Musk) antibody remained negative. A positive tensilon test and decremental response on electromyogram supported the diagnosis of sero-negative myasthenia gravis. Despite thymectomy and strong immunosuppressive therapy including steroid pulse and FK 506, he gradually deteriorated and became wheelchair bound. Genetic analyses for AchR, Rapsyn, Musk and AChE were negative. At age 11 years, a muscle biopsy was performed in the deltoid muscle for neuromuscular junction sampling. Electron microscopic and confocal microscopic analysis of endplates showed almost complete loss of AChR and the diagnosis of CMS with AChR deficiency was confirmed. All immunosuppressive therapies were discontinued. Instead, we started Ubretide and 3,4-diaminopyridine (DAP) after obtaining informed consent. Although not approved in Japan for this use, 3,4-DAP is reportedly effective in refractory cases of CMS. The patient experienced no side effects. Despite all of the objective data were improving, his subjective symptoms and ADL remained poor. There are still many challenges in the treatment of the patient.

Benefits of FK 506 for refractory eye symptoms in a young child with ocular myasthenia gravis.

Recently, there have been many reports on the efficacy and safety of tacrolimus (FK506) treatment for adult patients with intractable generalized myasthenia gravis (MG). There have also been a few reports of successful FK506 therapy in patients with severe childhood-onset generalized MG involving a myasthenic crisis. Herein, we report the efficacy of FK 506 for refractory ocular symptoms in a 3-year-old girl with ocular type MG. Ptosis and alternating strabismus had appeared at 10 months of age. No bulbar signs, respiratory failure or generalized muscle weakness had been seen during her course. Her ocular symptoms had persisted despite repeated steroid pulse therapy, high dose oral prednisolone and thymectomy. Adverse effects of steroids, including obesity, growth retardation, osteoporosis, cataracts and hyperlipidemia, gradually worsened. After obtaining written informed consent from her parents, we started oral tacrolimus at a dose of 0.5mg/day and her symptoms resolved completely within 3 weeks at a maximum dose of 2.5mg/day. No adverse effects, such as renal failure or glucose intolerance, were seen. FK506 treatment allowed the steroid dose to be reduced, eliminating its adverse effects. In patients with intractable childhood-onset MG with ocular manifestations, FK506 is an alternative to steroid therapy or thymectomy.

[Carry over: practical experience of persons with severe motor and intellectual disabilities].

Tomo clinic is a special clinic for the handicapped. We have supported a day care center and a group home for persons with severe motor and intellectual disabilities (SMID) for over ten years. It seems that physical well-being declines dramatically in persons with SMID over 20-years old. We need special cooperation with the general hospital not only for the treatment of adult diseases including esophageal cancer, but also to backup the social activities of our clinic, because we support daily lives of persons with SMID and their families who want to live together in their own communities for as long as possible. The author reported the daily medical care activities in the day care center and the group home.

[A two-year-old infant with a myopathic form of very-long-chain Acyl-CoA dehydrogenase deficiency].

A two-year-three-month old girl was hospitalized for detailed examination following repeated hyper-creatine kinasemia and cervical muscle cramps induced by pyrexia and persistent hypertonicity of the cervical muscles. Physical examination showed mild hypotonia but no muscle weakness. Induction of symptoms by continuous cervical muscular exercise and the appearance of dicarboxylic aciduria during the fasting test indicated a disorder of fatty acid oxidation. Free fatty acid and acyl carnitine analyses using dried blood spots, and acyl-CoA dehydrogenase activity assays using cultured skin fibroblasts established a diagnosis of very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. Currently VLCAD deficiency has been divided into three phenotypes; a severe childhood form, a milder childhood form, and an adult form. However, we suggest that the severe and milder childhood forms would be better described as a systemic form, and the adult form and our infant case as a myopathic form. An early onset of the myopathic form within the first year of life, as well as its diagnosis in early infancy, has never been described in the literature.

A 1-year-old infant with McArdle disease associated with hyper-creatine kinase-emia during febrile episodes.

A 14-month-old girl was hospitalized due to repeated hyper-creatine kinase (CK)-emia during pyrexia. Mild hypotonia was observed, but other physical and neurological findings were unremarkable. The serum CK level was normal at rest or normothermia. Open muscle biopsy was performed on the rectus femoris, and showed glycogen storage and complete lack of phosphorylase activity histochemically and biochemically, establishing the diagnosis of McArdle disease. The diagnosis of McArdle disease in early infancy is uncommon. Until this study there have been no reports of clinical symptoms or muscle biopsy findings for McArdle disease in early childhood. This disease must be considered when transient hyper-CKemia is observed in infants, even if glycogen storage is unremarkable as compared with adult cases.

Hyperzincemia with systemic inflammation: a heritable disorder of calprotectin metabolism with rheumatic manifestations?

A boy had infantile-onset systemic inflammation, growth failure, hepatosplenomegaly, anemia, leukocytopenia, progressive muscular dystrophy, and hypercalprotectinemia, resulting in marked hyperzincemia. His mother had a history of chronic arthritis since childhood and also showed hypercalprotectinemia/hyperzincemia. We postulate an inherent defect in calprotectin metabolism.