The Facioscapulohumeral muscular dystrophy region on 4qter and the homologous locus on 10qter evolved independently under different evolutionary pressure

BACKGROUND: The homologous 4q and 10q subtelomeric regions include two distinctive polymorphic arrays of 3.3 kb repeats, named D4Z4. An additional BlnI restriction site on the 10q-type sequence allows to distinguish the chromosomal origin of the repeats. Reduction in the number of D4Z4 repeats below a threshold of 10 at the 4q locus is tightly linked to Facioscapulohumeral Muscular Dystrophy (FSHD), while similar contractions at 10q locus, are not pathogenic. Sequence variations due to the presence of BlnI-sensitive repeats (10q-type) on chromosome 4 or viceversa of BlnI-resistant repeats (4q-type) on chromosome 10 are observed in both alleles. RESULTS: We analysed DNA samples from 116 healthy subiects and 114 FSHD patients and determined the size distributions of polymorphic 4q and 10q alleles, the frequency and the D4Z4 repeat assortment of variant alleles, and finally the telomeric sequences both in standard and variant alleles. We observed the same frequency and types of variant alleles in FSHD patients and controls, but we found marked differences between the repeat arrays of the 4q and 10q chromosomes. In particular we detected 10q alleles completely replaced by the 4q subtelomeric region, consisting in the whole set of 4q-type repeats and the distal telomeric markers. However the reciprocal event, 10q-type subtelomeric region on chromosome 4, was never observed. At 4q locus we always identified hybrid alleles containing a mixture of 4q and 10q-type repeats. CONCLUSION: The different size distribution and different structure of 10q variant alleles as compared with 4q suggests that these loci evolved in a different manner, since the 4q locus is linked to FSHD, while no inheritable disease is associated with mutations in 10qter genomic region. Hybrid alleles on chromosome 4 always retain a minimum number of 4q type repeats, as they are probably essential for maintaining the structural and functional properties of this subtelomeric region. In addition we found: i) several instances of variant alleles that could be misinterpreted and interfere with a correct diagnosis of FSHD; ii) the presence of borderline alleles in the range of 30–40 kb that carried a qA type telomere and were not associated with the disease

Health-related quality of life in patients with myasthenia gravis and the relationship between patient-oriented assessment and conventional measurements

We assessed the health-related quality of life (HRQoL) of patients with myasthenia gravis (MG) and correlated it with the physician's measurements of MG. Patients with MG were evaluated by means of (1) self-administered questionnaires, (2) clinical examination, (3) Osserman classification, (4) anti-AChR antibody, and (5) neurophysiology. Relationships between patient-oriented assessment and conventional clinical-neurophysiological and serological findings were evaluated. A total of 46 patients, inpatients and outpatients (mean age 50.7 years, range 11-77 years, 17 males, 29 females) with MG diagnosis were studied. The Osserman scale and clinical examination findings were significantly related to the physical aspects of HRQoL. Mental aspects of the quality of life were not progressively involved as muscle deficit progressed, but even in a mild clinical picture, the mental aspects were deteriorated. Patient-oriented measures proved that the patient's quality of life was impaired especially with regard to physical aspects. Our data demonstrated that clinical measurements are related to the HRQoL. The results may be useful in developing a disease-specific patient-oriented tool

Myasthenia gravis self-administered questionnaire: development of regional domains

The objective was to develop regional domains from the Myasthenia Gravis Questionnaire (MGQ) to better assess generalised, bulbar and ocular involvement in patients with myasthenia gravis (MG) and to evaluate their responsiveness. Some items from the MGQ were aggregated into 3 domains: bulbar, generalised and ocular. The study was carried out at the Institute of Neurology, EMG Service, Universita Cattolica, Rome, and the Department of Neurology, University Hospital, Modena, Italy. Ninety-three MG patients were prospectively enrolled in two neurological departments; furthermore, outcome after treatment was studied in 23 patients to evaluate responsiveness. Disease severity was scored according to a modified version of the Osserman classification and MGQ. The questionnaire appeared more sensitive than clinical examination and history to assess bulbar and ocular involvement. For example, according to the bulbar domain, 67 patients experienced bulbar symptoms whereas on clinical examination 51 of 67 were completely normal in the bulbar region. The MGQ domains appeared reliable and sensitive. Results of global MG score (GMG) and of domains appeared reliable. Domains were able to better assess the functional involvement of anatomical regions than main GMG, clinical examination and history

Corticospinal volleys evoked by transcranial stimulation of the brain in conscious humans

The direct recording in conscious humans of corticospinal volleys evoked by different magnetic and electric techniques of transcranial stimulation demonstrates that it is possible to activate neurones of the motor cortex in several different ways. Lateral electrical stimulation of the motor cortex preferentially activates the axons of corticospinal neurones in the subcortical white matter, and evokes a D-wave in pyramidal tract. The way of activation of corticospinal neurones using magnetic stimulation depends on the direction of the electrical current induced in the brain and on the shape of the coil. Monophasic magnetic stimulation with a focal figure-of-eight coil inducing posterior-anterior current in the brain activates corticospinal neurones trans-synaptically recruiting an 11-wave, with later I-waves appearing in sequence at higher intensities and a D-wave at very high intensities. If the induced current is rotated to the anterior-posterior direction late I-waves are preferentially recruited and when a D-wave is recruited, it has a later onset than the electrical D-wave, suggesting an activation nearer the cell body of the pyramidal neurones. A latero-medial induced current activates both corticospinal axons at the same point as electrical stimulation evoking a D wave and cortico-cortical axons evoking I-waves. A nonfocal large circular coil centered at the vertex is capable of activating pyramidal neurones both at the initial segment and trans-synaptically evoking a D wave with a longer latency than the electrical D-wave and I-waves. Using a biphasic magnetic stimulation, both phases of the biphasic pulse are capable of activating descending motor output and the pattern of recruitment of descending activity depends on the intensity of the stimulus and the relative threshold of each volley to each direction of current flow

Peroneal mononeuropathy: predisposing factors, and clinical and neurophysiological relationships

The most common mononeuropathy in the lower extremity involves the nerve. We retrospectively evaluated the etiological predisposing factors and clinical-neurophysiological features of 36 patients affected by peroneal mononeuropathy (PM). In 30 patients, a clear predisposing factor was identified. PM was more frequently perioperative (11 cases), associated with axonal involvement. Unexpectedly, PM was not only due to surgery close to the peroneal region, but was mostly associated with hip surgery and, rarely, with thoracic-abdominal surgery. A postural predisposing factor of PM was also frequently observed, usually associated with a pure conduction block. Conversely, most patients with bedridden predisposing factor presented axonal involvement, which was rarely associated with conduction block. In 25 of 36 PM cases, a long-term follow-up lead to an improvement (12 cases) or to good recovery (13 cases) of PM. In conclusion, our study shows that: (1) in most PM cases it is possible to identify a predisposing factor; (2) there is a good correlation between predisposing factor and neurophysiological involvement, and (3) PM usually has usually a good prognosis

Determinants of change in Quality of Life from 1 to 6 months following acute stroke - a comment

Comment on Determinants of change in quality of life from 1 to 6 months following acute stroke. [Cerebrovasc Dis. 2008

Use of transcranial magnetic stimulation of the brain in stroke rehabilitation

Preliminary studies suggest that stimulation of the motor cortex enhances motor recovery after stroke. Most of these studies employed transcranial magnetic stimulation of the brain and two different approaches have been evaluated. The first approach is based on the use of protocols of stimulation that increase cortical excitability, targeting the hemisphere in which the stroke occurred in order to enhance the output of the motor cortex and the response to physiotherapy. The second approach is based on the use of protocols of stimulation that suppress cortical excitability, targeting the intact hemisphere in order to counteract the imbalance due to the increased interhemispheric inhibition onto the lesioned cortex, and reducing the potential negative interference of the intact hemisphere with the function of the affected one. Cumulatively, preliminary studies suggest that transcranial magnetic stimulation might be a suitable method to combine with physiotherapy and improve recovery of useful limb function in stroke patients. However, further studies are needed to determine the best stimulation parameters and how to select patients who are likely to respond to this treatment