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Biomedical subjects

B Mamoli

Publications and source records attributed to B Mamoli.

At least 37 records · Page 2Linked to original sources
PubMed1998

Genotype-phenotype correlation in myotonic dystrophy.

Myotonic dystrophy (DM) is caused by a mutation in the length of a trinucleotide (CTG) repeat in the 3' untranslated region of the myotonin protein kinase gene located on chromosome 19q13.3. The normal gene has between 5 and 36 CTG trinucleotide repeats, whereas minimally affected individuals have 50 copies and severely affected DM-patients have several thousands of such repeats. Since no information on a genotype phenotype correlation in Austrian DM-patients is available, we examined a small group of these patients for the unstable trinucleotide repeat. Molecular analysis was used to clarify equivocal clinical diagnoses and confirm clinical findings. We studied eight DM-families, a total of 57 individuals, of whom 18 were diagnosed with a trinucleotide repeat expansion. Twenty-six unrelated individuals served as a control. Clinical assessment was based on the muscular disability rating scale (MDRS) and a sum of symptoms score (SSS). There was a significant correlation between the clinical scores (MDRS: Spearman r = 0.51; p = 0.029: SSS: Spearman r = 0.538; p = 0.0259) used and the size of the amplification of the trinucleotide repeat. The largest expansion found in our group of patients was 6 kb. Furthermore, we observed both expansion and contraction of the enlarged fragment during transmission from one generation to the next.

Adolescent↗
PubMed1998

Motor evoked potentials in unilateral lingual paralysis after monohemispheric ischaemia.

OBJECTIVES: The occurrence of a lingual paralysis after unilateral upper motor neuron lesions is an infrequent clinical phenomenon, and the underlying pathophysiological mechanisms are poorly understood. We studied the cortical motor representations of ipsilateral and contralateral lingual muscles in healthy controls and in a selected group of stroke patients, to clarify the variable occurrence of a lingual paralysis after recent monohemispheric ischaemia. METHODS: A special bipolar surface electrode was used to record the ipsilateral and contralateral compound muscle action potentials (CMAPs) from the lingual muscles after transcranial magnetic stimulation (TMS) of the human motor cortex and peripheral electrical stimulation (PES) of the hypoglossal nerve medial to the angle of the jaw. Four patients with a lingual paralysis (group 1) and four patients with symmetric lingual movements (group 2) after monohemispheric first ever stroke were studied and compared with 40 healthy controls. RESULTS: In controls, TMS of either hemisphere invariably produces CAMPs in the ipsilateral and contralateral lingual muscles, elicited through crossed and uncrossed central motor pathways, respectively. In the 40 healthy controls, TMS of either hemisphere elicited CMAPs of significantly greater amplitudes and shorter onset latencies from the contralateral muscles compared with the ipsilateral responses (p<0.0001). In the patient groups, TMS of the affected hemisphere failed to evoke any CMAP from either lingual side; TMS of the unsevered hemisphere always produced normal ipsilateral and contralateral responses, irrespective of whether the ipsilateral muscles were paralysed or not. CONCLUSIONS: Bilateral crossed and uncrossed corticonuclear projections are invariably existent in humans. After unilateral interruption of these pathways, some people do exhibit a lingual paralysis whereas others do not. The development of a central lingual paralysis is most likely dependent on the ability of the unsevered hemisphere to utilise the pre-existent uncrossed motor projections. The variable availability of these pathways among individual subjects is in good agreement with the inconstant occurrence of a lingual paralysis after restricted monohemispheric lesions.

Adult↗
PubMed1998

Progression of cardiac involvement in patients with myotonic dystrophy, Becker's muscular dystrophy and mitochondrial myopathy during a 2-year follow-up.

The aim of this prospective noninvasive follow-up study was (1) to assess the progression of cardiac involvement (CI) in patients with myotonic dystrophy (MD), Becker's muscular dystrophy (BMD) and mitochondrial myopathy (MMP), (2) to find out if CI and neurologic impairment are related and (3) to determine how often cardiac investigations should be performed. Clinical, electrocardiographic, echocardiographic and 24-hour ambulatory electrocardiographic examinations were performed at yearly intervals. CI was assessed qualitatively by the presence of pathologic examinations and quantitatively by the number of pathologic examinations. Qualitatively, CI was present at baseline in 36 of the 38 cases (18-68 years) and the number of cases did not change. Quantitatively, CI progressed after 1 (2) year in 50% (50%) of patients with MD (n = 16), 0% (43%) of patients with BMD (n = 7) and 27% (27%) of patients with MMP (n = 15). CI and neurologic impairment were not related (p = 0.54). Cardiac investigations should be repeated at yearly intervals irrespective of whether there is neurologic deterioration or not.

Adolescent↗
PubMed1998

Hypervolemic hemodilution in acute ischemic stroke: the Multicenter Austrian Hemodilution Stroke Trial (MAHST).

BACKGROUND AND PURPOSE: Experimental studies suggest a beneficial effect of hemodilution on acute ischemic stroke. This was not proven by previous multicenter trials in the clinical setting. Various reasons have been suggested for the failure of these studies, which we attempted to consider in the Multicenter Austrian Hemodilution Stroke Trial (MAHST). METHODS: MAHST is a randomized, double-blind, placebo-controlled study of hypervolemic hemodilution (HHD) within 6 hours of a clinically first ischemic stroke localized in the middle cerebral artery territory. The treatment consisted of 10% hydroxyethyl starch 200/0.5 (HES) and was tested against pure rehydration with Ringer's lactate over a period of 5 days. Our primary outcome measure was clinical improvement within 7 days as measured by the Graded Neurologic Scale (GNS). We performed an adaptive interim analysis to reevaluate the study goal after entering half of the projected number of patients (n = 200). At least 600 patients per group would have been required for significant results, and therefore we decided to terminate the trial. RESULTS: Ninety-eight patients received HHD and 102 patients placebo. The baseline characteristics were comparable between both groups. In the HHD group the absolute reduction of the hematocrit was 2.5% on day 2 with a maximum of 3.7% on day 5, which compares with a reduction in the placebo group of 1% and 1.9%, respectively. Intention-to-treat analysis showed no significant difference of the change of the GNS scores between HHD-treated (median, -8.5; 95% confidence interval, -14.2 to -4.0) and placebo-treated patients (median, -6.0; 95% confidence interval, -11.0 to 0.0) on day 7, and GNS scores remained similar in both treatment groups throughout the trial. At 3 months, slightly more HHD patients showed complete independence on the Barthel Index (28 versus 24), and fewer HHD than placebo patients had died (13 versus 17), but these differences were not statistically significant. HHD treatment was not associated with any specific adverse event. CONCLUSIONS: Mild HHD is safe but failed to demonstrate a significant beneficial effect over the pure rehydration regimen in patients with acute ischemic stroke.

Aged↗
PubMed1998

Needle electromyography of bulbar muscles in patients with amyotrophic lateral sclerosis: evidence of subclinical involvement.

OBJECTIVE: To determine if quantitative motor unit action potential (MUAP) analysis and peak ratio interference pattern analysis of the fifth, seventh, and eleventh cranial nerve innervated muscles are helpful in the assessment of subclinical bulbar involvement in ALS. METHODS: With both electromyographic (EMG) techniques, electrical activity was recorded via needle electrodes from the right frontalis, masseter, and sternocleidomastoideus muscles of nine ALS patients without clinical bulbar signs (Frenchay score >85%) aged 40 to 87 years; 21 healthy subjects aged 27 to 74 years; and five ALS patients with clinical bulbar signs (Frenchay score <85%) aged 53 to 69 years. RESULTS: The normal mean (2 SD) MUAP duration of the frontalis muscle was 7.4 (2.2) milliseconds; masseter muscle, 9.3 (3.1) milliseconds; and sternocleidomastoideus muscle, 10.9 (4.1) milliseconds. The normal mean (2 SD) peak ratio of the frontalis was 2.3 (1.1) milliseconds; masseter, 1.2 (0.4) milliseconds; and sternocleidomastoideus, 1.5 (0.7) milliseconds. Quantitative MUAP analysis was interpreted as neuropathic if MUAP duration, MUAP amplitude, or both exceeded the mean (+2 SD). Peak ratio interference pattern analysis was interpreted as neuropathic if the peak ratio, the number of small time intervals, or both were below the mean (-2 SD). If a result of either EMG technique was neuropathic in at least one of the three investigated muscles, bulbar involvement was assumed. Subclinical bulbar involvement could be detected by quantitative MUAP analysis in six ALS patients without clinical bulbar signs, and by peak ratio interference pattern analysis in two. CONCLUSIONS: Conventional needle EMG of the fifth, seventh, and eleventh cranial nerve innervated muscles shows subclinical bulbar involvement quite frequently. Peak ratio interference pattern analysis is largely not helpful in detecting this involvement.

Accessory Nerve↗
PubMed1998

Malnutrition-induced hypokalemic myopathy in chronic alcoholism.

CASE REPORT: A 42-year-old man with a history of Billroth II-gastrectomy, chronic alcoholism, and malnutrition developed acute tetraparesis, two days before admission. He presented with bilateral, proximal upper and lower limb weakness, limb girdle wasting, bilaterally reduced Achilles tendon reflexes, and bilateral stocking-type sensory disturbances. Laboratory data revealed hypokalemia (2.2 mmol/L), elevated creatine kinase (7282 U/L), metabolic alkalosis and reduced urine potassium, albumin, and total protein. Muscle biopsy showed atrophic, necrotic, and regenerating fibers, endomysial macrophages, and vacuolar degeneration, interpreted as hypokalemic myopathy. With the correction of the serum potassium, tetraparesis rapidly resolved. With other causes excluded, malnutrition and gastrectomy were considered responsible for hypokalemia in this patient with acute tetraparesis and chronic alcoholism.

Acute Disease↗
PubMed1998

[Electromyography in myopathies].

Despite increasing importance of molecular genetics, electromyography has preserved its place as a valuable tool in the diagnostic procedure of myopathies. Conventional electromyography allows the assessment of spontaneous activity, motor unit action potentials and interference patterns. In myopathies, fibrillations and positive sharp waves can be found in the majority of the cases. Motor unit action potentials are of short duration, low amplitude and may show increased polyphasia and number of satellite potentials. The interference pattern may be of low amplitude and compact already at submaximal contraction. Compared to conventional electromyography, automatic interference pattern analysis provides quantitative results and has the higher sensitivity and specificity. Normal conventional or automatic electromyography does not exclude a myopathy. For diagnostic purposes, electromyography will be followed by muscle biopsy and DNA analysis in most of the cases.

Diagnosis, Differential↗
PubMed1997

Light chain myeloma with oro-pharyngeal amyloidosis presenting as bulbar paralysis.

A 53-year old woman developed slowly progressive dysarthria, mild enlargement of the tongue and dysphagia since 1 year ago. All neurological differential diagnoses that could have explained the bulbar symptoms were excluded. The swallowing sequence was pathologic and immunoglobulins were markedly reduced. A bone marrow biopsy revealed light chain myeloma grade III. Amyloid deposits were found in the tongue but not in the kidneys. Oro-pharyngeal amyloidosis was held responsible for the described complaints. It is concluded that multiple myeloma must be considered in the differential diagnosis of bulbar paralysis and that biopsy of specific lesions is necessary to confirm local amyloidosis.

Amyloidosis↗
PubMed1997

Randomised placebo-controlled trial of monthly intravenous immunoglobulin therapy in relapsing-remitting multiple sclerosis. Austrian Immunoglobulin in Multiple Sclerosis Study Group.

BACKGROUND: Multiple sclerosis is an autoimmune disorder characterised by the repeated occurrence of demyelinating lesions within the central nervous system. Uncontrolled studies and experimental evidence suggest beneficial effects of repeated administration of intravenous immunoglobulin (IVIg) by immunomodulating mechanisms and induction or remyelination. We aimed to investigate the efficacy of IVIg in a randomised double-blind multicentre study. METHODS: Patients with relapsing-remitting multiple sclerosis were randomly assigned a monthly dose of IVIg (0.15-0.2 g/kg bodyweight) or placebo. Duration of treatment was 2 years. The primary outcome measures were the effect of treatment on clinical disability-measured by the absolute change in Kurtzke's expanded disability status scale (EDSS) score- and the proportion of patients with improved, stable, or worse clinical disability (> or = 1.0 grade on EDSS score). FINDINGS: Of the 243 patients screened, 150 met our eligibility criteria and were randomly assigned to IVIg or placebo. Before the start of treatment two patients in the placebo group dropped out, so there were 75 patients in the IVIg group and 73 in the placebo group. Intention-to-treat analysis showed that IVIg treatment had a beneficial effect on the course of clinical disability. The EDSS score decreased in the IVIg-treated patients and increased in the placebo group (-0.23 [95% CI -0.43 to -0.03] vs 0.12 [-0.13 to 0.37], p = 0.008). In the IVIg group, the numbers of patients with improved, stable, or worse clinical disability were 23 (31%), 40 (53%), and 12 (16%) compared with ten (14%), 46 (63%), and 17 (23%) in the placebo group. Side-effects were reported in three (4%) IVIg-treated patients and in four (5%) placebo-group patients, but were not directly linked to study medication. INTERPRETATION: Monthly IVIg is an effective and well-tolerated treatment for patients with relapsing-remitting multiple sclerosis.

Adult↗
PubMed1997

Satellite potentials as a measure of neuromuscular disorders.

The study was carried out to investigate the characteristics of satellite potentials and their validity in clinical electromyography. Conventional needle electromyography was applied to the right biceps brachii and tibialis anterior muscles of 41 controls, 22 neuropathies, and 17 myopathies. Satellites were defined as small extrapotentials, preceding/following the main motor unit action potential (MUAP) component and separated from it by an isoelectrical interval of > 1 ms. The normal mean satellite rate was 1.6% (biceps brachii) and 1.2% (tibialis anterior). In the biceps brachii (tibialis anterior) muscle it was 5 (5) times higher for neuropathies (P = 0.005, P = 0.006) and 5 (6) times higher for myopathies (P = 0.006, P = 0.003). MUAP parameters were not significantly different, whether satellites were considered or ignored. Evaluation of the satellite rate increased detection rates of neuromuscular disorders by up to 13%. The satellite rate proved a valuable and easily available, supplemental electromyographic parameter for the discrimination and detection of neuromuscular disorders.

Adult↗
PubMed1997

ECG abnormalities in myopathies, coronary heart disease and controls.

The aim of the study was to compare the prevalence of predefined ECG abnormalities, compiled from the literature, and of increased electrocardiographic myopathy indices (QT/PQs, P/PQs, R/S) among myopathy patients, patients with coronary heart disease and healthy subjects. ECGs from 27 myopathy patients, 35 patients with coronary heart disease and 36 healthy subjects were investigated. ECG abnormalities most often observed in myopathy patients were ST-abnormalities, T-wave abnormalities and tall R and/or S-waves. At least one increased electrocardiographic myopathy index was observed in 19% of the myopathy patients, 20% of the patients with coronary heart disease and 19% of the healthy subjects. At least one predefined ECG abnormality was found in 78% of the myopathy patients, 86% of the patients with coronary heart disease and 33% of the healthy subjects. In conclusion, ECG abnormalities frequently occur in myopathy patients and nearly as often as in patients with coronary heart disease. Electrocardiographic myopathy indices lack specificity and are thus of minor help in assessing myocardial alterations in myopathy patients.

Adolescent↗
PubMed1997

Cardiac involvement in patients with myotonic dystrophy, Becker's muscular dystrophy and mitochondrial myopathy.

The aim of this prospective study was to classify cardiac involvement in myopathies by means of a comprehensive cardiac investigation, to determine the rate of cardiac involvement in myopathies according to this classification and to compare the validity of previously reported electro-cardiographic myopathy indices (QT/PQs, P/PQs, R/S) with that of the comprehensive cardiac investigation. We included 14 patients with myotonic dystrophy, 6 patients with Becker's muscular dystrophy and 10 patients with mitochondrial myopathy. Cardiac involvement was classified as either "definite", "equivocal" or "absent" by assessing cardiovascular history, physical examination, electrocardiography, echocardiography and 24-hour ambulatory electrocardiography. "Definite"/"equivocal"/"absent" cardiac involvement was found in 12/2/0 myotonic dystrophy, 3/3/0 Becker's muscular dystrophy and 6/3/1 mitochondrial myopathy patients. Electrocardiographic myopathy indices were pathologic in 3 Becker's muscular dystrophy, 6 mitochondrial myopathy but in none of the myotonic dystrophy patients. The proposed comprehensive cardiac investigation is simple, inexpensive and effective in assessing cardiac involvement in patients with myotonic dystrophy. Becker's muscular dystrophy and mitochondrial myopathy. In case of cardiac involvement, cardiac therapy might be one of the few therapeutic options for these patients.

Adolescent↗
PubMed1997

Reliability of automatic and visual analysis of interictal spikes in lateralising an epileptic focus during video-EEG monitoring.

We evaluated 2 h of two night recordings of surface EEG of 10 patients with drug-resistant focal epilepsy using video-EEG monitoring, giving 40 h of EEG. The raw data of the automatic spike analysis according to the Gotman algorithm was visually corrected by rejecting false detections. Furthermore, the complete EEG recordings were analysed independently visually by two experienced electroencephalographers. For each method we analysed the total count of detections and the topographical distribution (left-right) of spikes. The total number of detections was significantly higher (243%) in the raw data and significantly lower after elimination of false detections (57%) in comparison to conventional analysis (100%). Lateralisation was concordant between the methods in 9/10 patients. The extent (< 75%, 75-90%, > or = 90%) was concordant in 80% between the two human raters. The automatic analysis with elimination of false detections was concordant with each of the human raters in 60% of patients. Extent of concordance was dependent of the total number of spikes with patients having more spikes being more reliably lateralised. Our results suggest that visually corrected automatic spike analysis is an economical method to use interictal epileptogenic activity as an independent indicator of the side of the epileptogenic focus in the setting of non-invasive presurgical evaluation. This is especially true in patients with many spikes.

Action Potentials↗
PubMed1997

Peak-ratio interference pattern analysis in the detection of neuromuscular disorders.

Peak-ratio interference pattern analysis (peak-ratio method) is said to have a high sensitivity and to be independent of sex and age. This study was carried out to prove or disprove these findings. The peak-ratio method and qualitative motor unit action potential (MUAP) analysis were applied to the right brachial biceps and anterior tibial muscles of 44 healthy subjects, aged 23-87 years, 25 neuropathy patients, aged 21-83 years, and 29 myopathy patients, aged 19-70 years. Peak-ratio parameters were independent of sex and age. They tended to be lower in the anterior tibial muscle than in the brachial biceps muscle. Neuropathy patients typically showed decreased peak-ratio, short time intervals and increased amplitude/turn. Myopathy patients typically showed increased peak-ratio, turns/s and short time intervals. The sensitivity of the peak-ratio method was 72% for neuropathy patients and 59% for myopathy patients. The sensitivity of the peak-ratio method was similar to that of the MUAP analysis in neuropathy patients and higher than that of the MUAP analysis in myopathy patients. The specificity of the peak-ratio method was 80%. The peak-ratio method proved to be a valuable, supplementary electromyographic tool for the detection of neuromuscular disorders.

Action Potentials↗
PubMed1997

Quantitative electromyography-guided botulinum toxin treatment of cervical dystonia.

The purpose of this study was to investigate the clinical and electromyographic effect of turn/amplitude analysis (TAA)-guided botulinum toxin administration in patients with cervical dystonia. Involuntary electromyographic activity was recorded from both sternocleidomastoidei, both splenii capites, and both trapezii muscles of 13 torticollis patients, aged 34-73 years, before and after botulinum toxin A (Dysport) application. Dystonic muscles were selected for the injection if mean turns/s exceeded a level of 200. Four weeks after treatment with a mean dose of 223 mu/subject, clinical improvement was observed in 12 patients (92%) and only one patient reported no effect. Electromyographic improvement could be observed in 10 patients (77%). Both turns/s and the amplitude/turn decreased by 27% on the average after treatment. The electromyographic toxin effect showed a good correlation with the clinical toxin effect (r = 0.6). No dose dependency of the changes in turn/amplitude parameters could be observed. We found TAA a valuable modality for targeting and selecting dystonic muscles and for assessing the therapeutic benefit of the toxin.

Adult↗
PubMed1997

Automatic EMG-guided botulinum toxin treatment of spasticity.

Conventional electromyographic (EMG) guidance in botulinum toxin therapy can localize a muscle, but the amount of electrical activity is assessed only subjectively. We wanted to introduce a quantitative EMG criterion, according to which the decision for/against toxin application could be made. Turn/amplitude analysis (TAA) was applied to nine patients with severe paraspasticity (n = 5), right upper or lower limb spasticity (n = 3), or tetraspasticity (n = 1) before and after toxin administration. Muscles were selected for toxin application if both mean turns/second and mean amplitude/turn exceeded the level of 150. A mean Dysport dose of 116 mouse units (mu) (range 40-240 mu) was administered to each of the 26 muscles that met the EMG criterion. Thirty days after the injection, activities of daily living, pain, and TAA count improved in 89%, tone in 78%, and range of motion in 56% of the patients by at least 1 point on corresponding 5-point rating scales. TAA provides a useful EMG criterion for/against botulinum toxin application. Muscle selection according to this criterion leads to a significant subjective and objective toxin effect. TAA is a valuable tool to determine the benefit of single and subsequent botulinum toxin injections in the treatment of spasticity.

Adult↗
PubMed1997

Turn/amplitude-analysis in subclinical myogenic lesions.

OBJECTIVES: To investigate the accuracy of the turn/amplitude-analysis (TAA) in the detection of subclinical myogenic lesions, for which Duchenne (DMD) carriers were taken as a model. MATERIALS AND METHODS: Conventional EMG (MUAP analysis) and the TAA with/without force monitoring were applied to the right brachial biceps and femoral rectus muscles of 26 healthy subjects, 11 possible DMD carriers and 5 obligate DMD carriers. RESULTS: Conventional EMG was unspecifically abnormal in 4 possible and 2 obligate DMD carriers, neurogenic in 1 possible DMD carrier and myogenic in none of the DMD carriers. Mean turns/s (T/S), amplitude/turn (A/T) and the ratio (T/S:A/T) were not significantly different between controls and possible or between controls and obligate DMD carriers. With force monitoring, the ratio (T/S:A/T) was myogenic in 1 obligate DMD carrier at 20% of maximum (brachial biceps). One possible DMD carrier showed a neurogenic distribution of the single T/S-A/T pairs around the normal cloud at 60% of maximum (brachial biceps). Without force monitoring, the TAA was normal in all DMD carriers. CONCLUSIONS: TAA is of limited help in demonstrating subclinical myopathy, irrespective of whether it is carried out with or without force monitoring.

Adult↗