G.P.12.04 Clinical features, particularly those of the central nervous system of patients with Becker muscular dystrophy, including autopsied cases

There are no detailed reports about the clinical and pathological findings in the central nervous system (CNS) of patients with Becker’s muscular dystrophy (BMD), although dysfunctions of the skeletal and cardiac muscles are well known in BMD. Since dystrophin is present in the CNS, and usual medical treatment is often influenced by CNS manifestations in patients, we studied the clinical and pathological features of BMD, with particular focus on the CNS manifestations, and also examined the relationships of these features with skeletal and cardiac muscle dysfunctions. We examined eight BMD patients aged 24-77 years who were admitted to our hospital, and six autopsied BMD patients aged 39-58 years. In addition to family histories of the patients, clinical findings, and disease progression, BMD was diagnosed based on the presence of dystrophin revealed by immunohistochemical examination and examination of the dystrophin gene. Brain computed tomography (CT), magnetic resonance imaging (MRI), and CNS pathohistology were also performed. Gene analyses by multiplex PCR revealed that exons 3-4, 3-6, 12-19, 45-47,45-49, and 45-52 were deleted; all the deletions occurred in hot spots in the dystrophin gene. With regard to the clinical CNS manifestations of BMD, 2 of the 14 patients experienced hallucinations, but there was no patient with severe mental retardation. Brain CT and MRI scans revealed various grades of mild atrophy of the front-parietal lobe for all the patients. Low-magnification microscopy images of the brain of three autopsied patients with mild BMD showed that the gyri of the brain were separated, suggesting brain atrophy. The nerve cells of the frontal lobe, however, seemed to be unaffected histologically. These results show that there are mild abnormalities in the CNS of BMD patients. It is well known that BMD patients demonstrate different levels of skeletal and cardiac muscle dysfunctions. In the current study as well, the BMD patients demonstrated CNS abnormalities, although these abnormalities were mild compared to the skeletal and cardiac muscle dysfunctions.