Distinct muscle imaging patterns in myofibrillar myopathies

OBJECTIVE

To compare muscle imaging findings in different subtypes of myofibrillar myopathies (MFM) in order to identify characteristic patterns of muscle alterations that may be helpful to separate these genetic heterogeneous muscular disorders.

METHODS

Muscle imaging and clinical findings of 46 patients with MFM were evaluated (19 desminopathy, 12 myotilinopathy, 11 filaminopathy, 1 alphaB-crystallinopathy, and 3 ZASPopathy). The data were collected retrospectively in 43 patients and prospectively in 3 patients.

RESULTS

In patients with desminopathy, the semitendinosus was at least equally affected as the biceps femoris, and the peroneal muscles were never less involved than the tibialis anterior (sensitivity of these imaging criteria to detect desminopathy in our cohort 100%, specificity 95%). In most of the patients with myotilinopathy, the adductor magnus showed more alterations than the gracilis muscle, and the sartorius was at least equally affected as the semitendinosus (sensitivity 90%, specificity 93%). In filaminopathy, the biceps femoris and semitendinosus were at least equally affected as the sartorius muscle, and the medial gastrocnemius was more affected than the lateral gastrocnemius. The semimembranosus mostly showed more alterations than the adductor magnus (sensitivity 88%, specificity 96%). Early adult onset and cardiac involvement was most often associated with desminopathy. In patients with filaminopathy, muscle weakness typically beginning in the 5th decade of life was mostly pronounced proximally, while late adult onset (>50 years) with distal weakness was more often present in myotilinopathy.

CONCLUSIONS

Muscle imaging in combination with clinical data may be helpful for separation of distinct myofibrillar myopathy subtypes and in scheduling of genetic analysis.

Distinct muscle imaging patterns in myofibrillar myopathies

OBJECTIVE

To compare muscle imaging findings in different subtypes of myofibrillar myopathies (MFM) in order to identify characteristic patterns of muscle alterations that may be helpful to separate these genetic heterogeneous muscular disorders.

METHODS

Muscle imaging and clinical findings of 46 patients with MFM were evaluated (19 desminopathy, 12 myotilinopathy, 11 filaminopathy, 1 alphaB-crystallinopathy, and 3 ZASPopathy). The data were collected retrospectively in 43 patients and prospectively in 3 patients.

RESULTS

In patients with desminopathy, the semitendinosus was at least equally affected as the biceps femoris, and the peroneal muscles were never less involved than the tibialis anterior (sensitivity of these imaging criteria to detect desminopathy in our cohort 100%, specificity 95%). In most of the patients with myotilinopathy, the adductor magnus showed more alterations than the gracilis muscle, and the sartorius was at least equally affected as the semitendinosus (sensitivity 90%, specificity 93%). In filaminopathy, the biceps femoris and semitendinosus were at least equally affected as the sartorius muscle, and the medial gastrocnemius was more affected than the lateral gastrocnemius. The semimembranosus mostly showed more alterations than the adductor magnus (sensitivity 88%, specificity 96%). Early adult onset and cardiac involvement was most often associated with desminopathy. In patients with filaminopathy, muscle weakness typically beginning in the 5th decade of life was mostly pronounced proximally, while late adult onset (>50 years) with distal weakness was more often present in myotilinopathy.

CONCLUSIONS

Muscle imaging in combination with clinical data may be helpful for separation of distinct myofibrillar myopathy subtypes and in scheduling of genetic analysis.

Desmin mutations in a St. Petersburg cohort of cardiomyopathies

Several desmin mutations have been described over the past few years in patients with dilated and restrictive cardiomyopathy, often in association with distal myopathy. However, the role of desmin mutations as a cause of various types of cardiomyopathy is still undetermined. The aim of this study was to analyse the frequency of desmin mutations in patients with cardiomyopathy identified and diagnosed in the St. Petersburg area of Russia. We screened 98 patients with dilated, 40 with hypertrophic and 4 with restrictive cardiomyopathy. All exons of the desmin gene were amplified by PCR and studied by sequencing. Two out of 98 patients showed the presence of desmin gene mutations, not previously described in dilated cardiomyopathy. A novel IVS2-2A-->G splice site mutation, presumably causing skipping of exon 3, was detected in a case of familial right ventricular dilated cardiomyopathy. An A213V mutation was associated with a case of late onset dilated cardiomyopathy. No desmin mutations were found in patients with hypertrophic or restrictive cardiomyopathy. Desmin mutations should be considered a relatively rare cause of dilated cardiomyopathy in this specific geographic area.

Major myofibrillar changes in early onset myopathy due to de novo heterozygous missense mutation in lamin A/C gene

Mutations in the lamin A/C gene (LMNA) have been associated with neuromuscular diseases and more complex syndromes, involving bone and adipose tissue. We report on a case of early onset myopathy due to a heterozygous LMNA mutation in exon 9, characterized by the presence of a marked number of cytoplasmic bodies with extensive myofibrillar abnormalities and Z-disk disruption in skeletal muscle. This case suggests there is a need to increase the list of genes to be screened in patients with myofibrillar myopathy.

Structural and functional analysis of a new desmin variant causing desmin-related myopathy

Desmin-related myopathy is a familial or sporadic disease characterized by skeletal muscle weakness and cardiomyopathy as well as the presence of intracytoplasmic aggregates of desmin-reactive material in the muscle cells. Previously, two kinds of deletions and eight missense mutations have been identified in the desmin gene and proven to be responsible for the disorder. The present study was conducted to determine structural and functional defects in a pathogenic desmin variant that caused a disabling disorder in an isolated case presenting with distal and proximal limb muscle weakness and cardiomyopathy. We identified a novel heterozygous Q389P desmin mutation located at the C-terminal part of the rod domain as the causative mutation in this case. Transfection of desmin cDNA containing the patient's mutation into C2.7, MCF7, and SW13 cells demonstrated that the Q389P mutant is incapable of constructing a functional intermediate filament network and has a dominant negative effect on filament formation. We conclude that Q389P mutation is the molecular event leading to the development of desmin-related myopathy.

Reducing body myopathy with cytoplasmic bodies and rigid spine syndrome: a mixed congenital myopathy

At the age of five years a male child started to develop a progressive rigid spine, torsion scoliosis, and flexion contractures of his elbows, knees, hips, and ankles owing to severe proximal and distal muscle weakness. He had three muscle biopsies from three different muscles at ages 7, 11, and 14 years, respectively. Myopathologically, these muscle tissues contained numerous inclusions which, at the ultrastructural level, turned out to be reducing bodies and cytoplasmic bodies, often in close spatial proximity. Similar histological inclusions, although not further identified by histochemistry and electron microscopy, were seen in his maternal grandmother's biopsied muscle tissue who had developed weakness of the legs and hands after the age of 50 years. The patient's parents were healthy, but the mother's quadriceps muscle showed an increased spectrum of muscle fibre diameters. Our patient, thus, had a neuromuscular disorder, perhaps familial, presenting as a mixed congenital myopathy, i.e., reducing body myopathy with cytoplasmic bodies, of which the morphological lesions could be consistently documented over several years in his different limb muscles. While other mixed congenital myopathies had shown cores and rods, both related to sarcomeres and thus possibly morphogenetically related, cytoplasmic bodies thought to be related to Z-bands and reducing bodies dissimilar to any muscle fibre constituent do not share any common denominator. Therefore, we suggest that this neuromuscular disorder may be a unique mixed congenital myopathy, either sporadic or genetic. In the latter case, the transmission pattern suggested X-linked recessive inheritance, but an autosomal-dominant transmission with variable penetrance could not be ruled out.

Late-onset muscle weakness in partial phosphofructokinase deficiency: a unique myopathy with vacuoles, abnormal mitochondria, and absence of the common exon 5/intron 5 junction point mutation

Three patients (ages 51, 59, and 79) from two generations of an Ashkenazi Jewish family had partial (33% activity) phosphofructokinase (PFK) deficiency that presented with fixed muscle weakness after the age of 50 years. MR spectroscopy revealed accumulation of phosphomonoesters during exercise. Muscle biopsy showed a vacuolar myopathy with increased autophagic activity and several ragged-red and cytochrome c oxidase-negative fibers. The older patient, age 79 at biopsy, had several necrotic fibers. Electron microscopy revealed subsarcolemmal and intermyofibrillar glycogen accumulation and proliferation of mitochondria with paracrystalline inclusions, probably related to reduced availability of energy due to impaired glycolysis. The common point mutation of exon 5/intron 5 junction seen in Jewish Ashkenazi patients with PFK deficiency was excluded. We conclude that late-onset fixed muscle weakness occurs in partial PFK deficiency and it may represent the end result of continuing episodes of muscle fiber destruction. Partial enzyme deficiency in two successive generations suggests a unique molecular mechanism.

Spirituality and the treatment of the dually diagnosed: an investigation of patient and staff attitudes

Spirituality is a neglected area of study and research in the treatment of addictions. The role of spirituality in the treatment of the dually diagnosed has received particularly scant attention. One hundred and one patients on an in-patient dual-diagnosis unit, as well as the 31 members of the nursing staff who treat them were surveyed. Patients and staff were questioned about their spiritual beliefs and what was the role of spirituality in the patients' recovery from addiction. Staff were questioned about their own spirituality and what they think the patients' level of spirituality is. In addition the staff were asked what they think the patients' view of spiritually is. Results indicate that the patients and staff are equally spiritually oriented. The patients view spirituality as essential to their recovery and value spiritual programming in their treatment more than some concrete items. The nursing staff underestimated both the patients' level of spirituality and this importance placed on spiritual issues. The authors suggest that more attention should be given by staff to spirituality in the treatment of this population.

Use of buspirone for treatment of cerebellar ataxia. An open-label study

OBJECTIVE

To evaluate the efficacy of buspirone hydrochloride, a serotonin (5-hydroxytryptamine1A) agonist, in treating patients with cerebellar ataxia.

DESIGN

Open-label study in which 20 patients (14 with cerebellar cortical atrophy and six with olivopontocerebellar atrophy) received buspirone hydrochloride, up to 60 mg/d, for 8 weeks.

SETTING

Research hospital.

MAIN OUTCOME MEASURES

Clinical, physiological, and psychological assessment.

RESULTS

Nine patients with mild or moderate cerebellar dysfunction who completed the study showed significant improvement in clinical and self-assessment ratings, but not in a motor performance test, posturography (data were incomplete), State-Trait Anxiety Inventory, and Beck Depression Inventory. Seven patients with severe cerebellar dysfunction who completed the study had no improvement on any measure.

CONCLUSIONS

Buspirone may be effective in treating mild to moderate cerebellar ataxia. A double-blind study of the efficacy of buspirone in cerebellar ataxia is warranted.

Mitochondrial aldehyde dehydrogenase polymorphism in Asian and American Indian populations: detection of new ALDH2 alleles

Genetic deficiency of the mitochondrial aldehyde dehydrogenase (ALDH2) is frequent in Asian peoples where it is an important factor negatively regulating drinking behavior. To obtain additional information on gene geography of known ALDH2 alleles, and look for new variants, ALDH2 genes were evaluated in a Chinese population from Taiwan, a Yakut population of Siberia, and in five North American Indian populations. A novel approach based on a single-strand conformation polymorphism assay, and polymerase chain reaction-directed mutagenesis was developed for genotyping. In the Taiwan Chinese population, the ALDH2(2) allele frequency was 0.319 +/- 0.025, and this allele was not detected in the Yakut population nor in the five North American Indian populations. However, a new allele, ALDH2(3), was detected in Pima Indians at a frequency of 0.044 +/- 0.022, and this allele was also observed in 1 of 49 Pueblo samples. ALDH2(3) is a silent transition 1464 G-->A, and it possibly has a wide distribution among North American Indians. A new subtype of the ALDH2(2) allele, designated as ALDH2(2Taiwan), was found in 1 of 174 Chinese from Taiwan. ALDH2(2Taiwan) is characterized by two G-->A transitions at bases 1486 and 1510, resulting in Glu-->Lys substitutions at both the 479 and 487 positions. Thus, this second nonconservative ALDH2 substitution occurs within the sequence of the already inactive ALDH2(2) allele.

Chromosome 14-encoded Alzheimer's disease: genetic and clinicopathological description

A family of Finnish descent with very-early-onset Alzheimer's disease has been identified. Genetic analysis of this family eliminated the amyloid precursor protein gene as the pathogenic locus, but strongly implicated a locus on chromosome 14q23.4 between D14S52 and D14S55. The early age at onset of the disease (average, 36 years; range, 35-39 years), the rapid progression, and the early and prominent myoclonus, while they appear to be frequent findings in the chromosome 14-encoded form of Alzheimer's disease, raised the clinical suspicion of prion disease. However, sequencing the prion gene-coding region of 2 affected members of the pedigree failed to show any abnormality. Apart from the presence of modest cortical vacuolar change, the pathological features of our index patient appeared typical of Alzheimer's disease with abundant senile plaques immunoreactive with beta-amyloid, but not with prion protein antibodies.

Molecular and clinical correlations in spinocerebellar ataxia type I: evidence for familial effects on the age at onset

The spinocerebellar ataxias are a group of debilitating neurodegenerative diseases for which a clinical classification system has proved unreliable. We have recently isolated the gene for spinocerebellar ataxia type 1 (SCA1) and have shown that the disease is caused by an expanded, unstable, CAG trinucleotide repeat within an expressed gene. Normal alleles have a size range of 19-36 repeats, while SCA1 alleles have 42-81 repeats. In this study, we examined the frequency and variability of the SCA1 repeat expansion in 87 kindreds with diverse ethnic backgrounds and dominantly inherited ataxia. All nine families for which linkage to the SCA1 region of 6p had previously been established showed repeat expansion, while 3 of the remaining 78 showed a similar abnormality. For 113 patients from the families with repeat expansion, inverse correlations between CAG repeat size and both age at onset and disease duration were observed. Repeat size accounted for 66% of the variation in age at onset in these patients. After correction for repeat size, interfamilial differences in age at onset remained significant, suggesting that additional genetic factors affect the expression of the SCA1 gene product.

Apolipoprotein E epsilon 4 allele distributions in late-onset Alzheimer's disease and in other amyloid-forming diseases

The frequency of the allele for apolipoprotein E type 4 (epsilon 4) is increased in late-onset familial and sporadic Alzheimer's disease (AD). We have examined epsilon 4 frequencies in four distinct, normal, elderly control groups and, most importantly, in patients with amyloid-forming diseases whose epsilon 4 distributions were not previously known (Creutzfeldt-Jakob disease, familial amyloidotic polyneuropathy, Down's syndrome). There were no differences between any of these controls and published control series, cementing the relevance of epsilon 4 for late-onset AD. The increase in late-onset AD was confirmed in two new series.

Attitudes toward sex, arousal, and the retention of contraceptive information

Previous research has suggested that women with a negative emotional orientation toward sexuality (i.e., erotophobia) have difficulty learning and retaining sexually relevant material such as contraceptive information. It has been hypothesized that these women become aroused by this material and that this arousal interferes with their ability to learn it. The importance of this issue led us to conduct the current study. Erotophobic and erotophilic women viewed presentations about contraception while their physiological responses were being monitored. In addition, they were tested on the information contained in the presentation before, immediately after, and again 4-6 weeks after the presentation. The results indicated that the erotophobic women knew less contraceptive information before the presentation and were more aroused by the presentation. This arousal, however, did not interfere with retention of the material. These results are discussed in terms of individual differences in reactions to sexual material and the ability to learn, retain, and use contraceptive information.

Attitudes toward sex, arousal, and the retention of contraceptive information

Previous research has suggested that women with a negative emotional orientation toward sexuality (i.e., erotophobia) have difficulty learning and retaining sexually relevant material such as contraceptive information. It has been hypothesized that these women become aroused by this material and that this arousal interferes with their ability to learn it. The importance of this issue led us to conduct the current study. Erotophobic and erotophilic women viewed presentations about contraception while their physiological responses were being monitored. In addition, they were tested on the information contained in the presentation before, immediately after, and again 4-6 weeks after the presentation. The results indicated that the erotophobic women knew less contraceptive information before the presentation and were more aroused by the presentation. This arousal, however, did not interfere with retention of the material. These results are discussed in terms of individual differences in reactions to sexual material and the ability to learn, retain, and use contraceptive information.