Merosin-deficient congenital muscular dystrophy: neuropathology case reports.

The aims of our study were: to present cases of congenital muscular dystrophy (CMD) with deficiency in merosin and the importance of immunohistochemistry in the diagnosis of merosin-deficient CMD. In four years (1997-2000), we found three patients with merosin-deficient CMD, one of them having an unusual clinical and pathological manifestation of the disease. Muscle biopsies of gastrocnemius or quadriceps muscles were investigated. In addition with the conventional HE staining, indirect immunohistochemistry for merosin, dystrophin, utrophin and for the proteins of the dystrophin associated complex (alpha-, beta-, gamma- sarcoglycans; beta-dystroglycan) was performed on cryosections. The findings suggest that there is no correlation between the clinical and histological picture of the disease and the expression of merosin in skeletal muscles. The degree of muscle involvment (assessed by histology) is parallel with the clinical neuromotor deficiency, but not with expression of merosin, which can be absent even in mild cases. The clinical investigations as well as current morphological techniques, only together with immunohistochemistry can differentiate between merosin - deficient CMD and other muscular dystrophy forms.

Skeletal muscle biopsy analysis in reducing body myopathy and other FHL1-related disorders.

FHL1 mutations have been associated with various disorders that include reducing body myopathy (RBM), Emery-Dreifuss-like muscular dystrophy, isolated hypertrophic cardiomyopathy, and some overlapping conditions. We report a detailed histochemical, immunohistochemical, electron microscopic, and immunoelectron microscopic analyses of muscle biopsies from 18 patients carrying mutations in FHL1: 14 RBM patients (Group 1), 3 Emery-Dreifuss muscular dystrophy patients (Group 2), and 1 patient with hypertrophic cardiomyopathy and muscular hypertrophy (Group 2). Group 1 muscle biopsies consistently showed RBs associated with cytoplasmic bodies. The RBs showed prominent FHL1 immunoreactivity whereas desmin, αB-crystallin, and myotilin immunoreactivity surrounded RBs. By electron microscopy, RBs were composed of electron-dense tubulofilamentous material that seemed to spread progressively between the myofibrils and around myonuclei. By immunoelectron microscopy, FHL1 protein was found exclusively inside RBs. Group 2 biopsies showed mild dystrophic abnormalities without RBs; only minor nonspecific myofibrillar abnormalities were observed under electron microscopy. Molecular analysis revealed missense mutations in the second FHL1 LIM domain in Group 1 patients and ins/del or missense mutations within the fourth FHL1 LIM domain in Group 2 patients. Our findings expand the morphologic features of RBM, clearly demonstrate the localization of FHL1 in RBs, and further illustrate major morphologic differences among different FHL1-related myopathies.

Carnitine deficiency.

We present the case of a female patient, aged 12 years, with fatigability and exertional myalgias, progressively developed within the last two years. Negative family history, as well as negative personal medical history, were found. At physical examination, short stature, proximal muscle weakness and mild hepatomegaly were noted. Urine ketones level was slightly decreased, serum transaminases, creatine kinase and lactate dehydrogenase levels were increased. Electromyographical examination showed a myopathic non-specific pattern. Deltoid muscle biopsy revealed: small, clear vesicles are present on Hematoxylin-Eosin and modified Gömöri trichrome stains; modified Gömöri trichrome stain also revealed muscle fibers (especially type I of muscle fibers) having mild to moderate mitochondrial proliferation (red rim and speckled sarcoplasm). The lipid storage has been well demonstrated by Sudan Black stain, which revealed small lipid droplets in type I muscle fibers. Abnormal internal architecture with a punctate pattern was showed by adenine dinucleotide tetrazolium reductase and succinate dehydrogenase stains. Electron microscopy showed small inter-myofibrillar accumulations of round, amorphous, homogeneous acellular substances that are not membrane bounded. These features indicate that these are neutral fat (lipid) droplets. Subsarcolemmal accumulations of mitochondria were also revealed. The differential diagnosis of this case is discussed, and the up to date general data concerning carnitine deficiency are presented. The aim of our case-report is to emphasize the role of muscle biopsy in carnitine deficiency, as well as to remind the necessity of keeping in mind such metabolic disorders when doing the differential diagnostic of a muscular weakness.

A diagnosis challenge-L4 nerve root compression as the initial presentation of chronic inflammatory demyelinating polyneuropathy.

The authors present the case of a 65-year-old woman who was admitted for paraparesis and paresthesias in the inferior limbs. The neurological examination revealed the difficulty in extension of the right foot and of the right toe, accompanied by paresthesias located in the anterolateral area of the right leg, dorsum and plantar area of the foot, the reduction of the right knee jerk, and of the ankle tendon jerk both sides. The vertebro-spinal MRI showed lumbar canal stenosis with L4 intraforaminal compression on the right, and L2-L3 on the left. CSF examination revealed mild increase in protein concentration. The morphological picture of the sural nerve biopsy was compatible with a chronic inflammatory neuropathy and severe muscular lesions of neurogenic origin were observed on right gastrocnemius muscle biopsy. The diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) was established. Solu-medrol (0.5 g/d)-5 days, then medrol (prednisolone) was done, followed by improving of the symptomatology. For the relapse of the disease intravenous immunoglobulins (IVIG)-0.4 g/kg/d-5 days was the elective treatment. Six months later she presented a new relapse. IVIG were administered with the remission of the sensitive symptoms. A chronic treatment with medrol was recommended. The diagnosis of L4 disc herniation was obvious in the studied case, but the electroneurographic examination brought extra data for the associated diagnosis of CIDP whose onset was asymmetrical and initially paucisymptomatic. Neither the electroneurographic examination nor the CSF examination were total relevant for CIDP, imposing the sural nerve biopsy. The diagnosis of CIDP involves a team-work composed of neurologist, electroneurophysiologist and neuropathologist.

Dermatomyositis and polyradiculoneuritis, a rare association.

The association between dermatomyositis and polyradiculoneuritis is rarely citated in the speciality literature. Our patient had at first a disorder that looked like dermatomyositis, then she associated polyradiculoneuritis. At the presentation to our hospital the two diseases were combined, being very difficult to differentiate. The discrimination between these two had been made by performing a muscular biopsy and EMG studies. This emphasizes once again their importance in defining the muscular impairment from the neurogenic one.

Value of immunohistochemical investigation in the diagnosis of neuromuscular diseases in children.

UNLABELLED: Neuromuscular diseases represent an important group in pediatric pathology. Immunohistochemistry together with clinical examination and morphologic exam are very important in the diagnosis of neuromuscular disorders. PATIENTS AND METHODS: One hundred children diagnosed with neuromuscular disorders were included in a prospective-retrospective study in 25 years. RESULTS: There were 58 neurogenic diseases and 42 muscular dystrophies. In positive and differential diagnosis very important were the morphologic and immunohistochemical investigations. Seventy-three percent had positive family history and 27% of dystrophic patients had "de novo" mutations. The most part of the neurogenic disorders were spinal motor atrophies, 91.38%. CONCLUSIONS: Neurogenic muscular diseases were the most common neuromuscular diseases in our patient group. The immunohistochemical investigation was very useful in diagnosing some of these cases.