[Delineation of the anatomical relationship of innominate artery and trachea by respiratory-gated MR imaging with true FISP sequence in patients with severe motor and intellectual disabilities].

Tracheoinnominate artery fistula is a well-known complication that arises on using a cannula. Therefore, routine examination of the anatomical relationship of the innominate artery and trachea should be carried out. We evaluated the usefulness of magnetic resonance imaging in 5 patients with severe motor and intellectual disabilities (SMID) using a combination of true-fast imaging of steady-state precession (true-FISP) sequences and two-dimensional prospective acquisition correction (2D-PACE). For all patients, the trachea and the innominate artery were identified without sedation and contrast media. In one patient, the innominate artery was observed to be pressing on the trachea. In three patients, the trachea and innominate artery were brought very close each other, and in the other patient the anatomical relationship of the trachea and surrounding structure was delineated before tracheotomy. The validity of true-FISP sequences combined with the respiratory-gated technique was confirmed useful for the patients who are difficult to lie quietly and to hold their breath voluntarily.

[Recurrent fever related to dantrolene sodium in a girl with sequelae of acute encephalopathy].

A fever of unknown origin developed in a patient with sequelae of acute encephalopathy who had received dantrolene for severe spasticity. A chronic subdural hematoma was found on MRI, and initially it was suspected that the patient had an intracranial infection. However, close investigation ruled out the chronic subdural hematoma as the source of infection. The patient's fever continued in spite of administration of antibiotics and antimycotics. We suspected that the fever was drug-induced and discontinued the use of dantrolene. As a result, the patient's fever promptly went down. After discontinuation of dantrolene the patient experienced increased muscle tone, vomiting and sleep disturbances. Dantrolene was readministered with the consent of the patient's family, but the fever returned. When dantrolene was once again discontinued, the fever immediately went down. We concluded that the fever of the patient was induced by dantrolene.

[Two boys with non-progressive unilateral atrophy of the calf muscles].

We report here two boys who presented with atrophy of the right calf muscle. The onset was insidious and the symptom was found in infancy in case 2. They were followed for more than 5 years and no progression was seen. No sensory disturbances or autonomic nervous system symptoms were observed. Although needle electric myograph and muscle biopsy findings showed a neurogenic pattern, no cause was confirmed. Recently, a new disease concept of "benign monomelic amyotrophy of lower limb" was established and this could be applied to these patients. This disorder is rare and it is seen in young adults. It is characterized by non-progressive unilateral calf muscle atrophy. There is almost no possibility that this disorder is a variant of spinal muscular atrophy. When a patient presents with unilateral calf muscle atrophy, the treatable causes of the atrophy, including spinal cord disorders or peripheral nerve disorders, should be excluded first. If a confirmed cause cannot be found, then there should be a careful follow-up of the patient, even if the symptoms are stable.