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Biomedical subjects

J Finsterer

Publications and source records attributed to J Finsterer.

At least 145 records · Page 8Linked to original sources

[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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

Needle EMG of the tongue: motor unit action potential versus peak ratio analysis in limb and bulbar onset amyotrophic lateral sclerosis.

OBJECTIVES: To find out if conventional and automatic needle EMG of the tongue can be helpful in the diagnosis and differentiation of limb and bulbar onset amyotrophic lateral sclerosis. METHODS: Motor unit action potential (MUAP) analysis and peak ratio interference pattern analysis were performed in the right genioglossus muscle of 30 healthy subjects aged 30-81 years, 10 patients aged 49-73 years with limb onset amyotrophic lateral sclerosis, and eight patients aged 52-75 years with bulbar onset amyotrophic lateral sclerosis. Electrical activity was sampled via standard concentric needle electrodes with a commercially available EMG recorder. RESULTS: Normal mean (2SD) MUAP duration was 6.6 (1.5) ms. Normal mean (2SD) MUAP amplitude was 224 (97.4) microV. Normal mean (2SD) peak ratio (PR), turns/second (T/s), amplitude/turn (A/T), and time intervals (TI1, TI2, TI3) were 1.68 (0.56), 732 (303.9), 446 (180.3) microV, 2.62 (0.34), 2.31 (0.14), and 1.01 (0.50) respectively. Mean MUAP duration and amplitude were significantly increased in limb onset (P=0.0001 and P=0.013) and bulbar onset amyotrophic lateral sclerosis (P=0.0001 and P=0.017). Peak ratio indices stayed unchanged in limb onset amyotrophic lateral sclerosis but were significantly decreased (PR, T/s, A/T, TI1, and TI2) or increased (TI3) in bulbar onset disease. The sensitivity of the MUAP analysis was 70% in limb and 75% in bulbar onset amyotrophic lateral sclerosis. The sensitivity of the peak ratio interference pattern analysis was 20% in limb and 100% in bulbar onset amyotrophic lateral sclerosis. Subclinical involvement of the tongue was found in 20% of the patients with limb onset amyotrophic lateral sclerosis and could be more accurately assessed with MUAP analysis than with automatic EMG. CONCLUSIONS: Both conventional and automatic needle EMG of the tongue are valuable electrophysiological devices to assess the clinical and subclinical involvement of the tongue in patients with limb and bulbar onset amyotrophic lateral sclerosis.

Action Potentials↗

Temperature dependency of turn/amplitude parameters.

OBJECTIVES: to assess the influence of the skin and muscle temperatures on the turns per second (T/s) and the amplitude per turn (A/T) and to find out whether turn/amplitude analysis requires temperature monitoring. SUBJECTS: ten healthy individuals (three women, seven men) aged 23 to 36 years. METHOD: recording of two electromyograms (EMGs) in the right biceps brachii muscle from ten locations each, during isometric contractions with 30% of the elbow flexors' maximum force. The first EMG was recorded after warming the muscle to at least 37 degrees C and the second EMG after cooling the muscle to at least 27 degrees C. RESULTS: lowering the muscle temperature by an average of 10.9 degrees C, the mean T/s decreased from 484 to 436 (P = 0.002), the mean A/T increased from 476 to 513 (P = NS) and the mean ratio T/s:A/T decreased from 1.1 to 0.91 (P =0. 0001). None of the individual results became patholgical after cooling the muscle. CONCLUSION: in a range of 27 to 37 degrees C, turn/amplitude analysis can be performed without temperature monitoring.

Adult↗

Anti-GM1 antibodies in polyneuropathies of unknown origin.

This study was undertaken to determine whether anti-GM1 titres are raised in polyneuropathies of unknown origin and whether determination of these titres is useful for diagnosing these conditions. The study population comprised 20 controls (aged 36-88 years), 12 patients with polyneuropathies of known origin (aged 31-81 years) and 15 patients with polyneuropathies of unknown origin (aged 40-77 years). Antibody levels were measured using a commercial GM1 enzyme linked immunosorbent assay kit (Buehlmann Laboratories). Mean anti-GM1 IgG and IgM antibody titres were not raised in patients with polyneuropathies of unknown origin. Anti-GM1 IgG antibody titres were raised in one and GM1 IgM antibody titres in none of the patients with polyneuropathies of unknown origin. In conclusion, GM1 antibody levels are rarely raised in polyneuropathies of unknown origin and probably play a minor role in the pathogenesis of these conditions.

Adult↗

Recovery from coma caused by primary CNS mantle cell lymphoma presenting as encephalitis.

We report a 74-year-old woman with progressive cognitial deterioration and changes in personality. She had no clinical signs of an inflammatory CNS process, but brain CT and MRI scans and cytologic examination of the CSF were initially indicative of encephalitis and ventriculitis. Antiviral and antibacterial therapy had no effect on the course of symptoms, and patient became comatose. We established the diagnosis of a primary CNS mantle cell lymphoma (PCNSL) and began corticosteroids. Within a few days the patient became alert and was able to walk again. Nonenhancing and non-space-occupying PCNSLs are rare but must be considered in the differential diagnosis of coma and encephalitis. Comatose PCNSL patients without radiographic evidence for herniation can be successfully treated with corticosteroids even if the EEG has a burst suppression pattern.

Adrenal Cortex Hormones↗

Yes/yes head tremor without appendicular tremor after bilateral cerebellar infarction.

We report a 67-year-old man who developed yes/yes head tremor without appendicular tremor six weeks after right occipital and bilateral cerebellar infarction. The tremor was resting-postural. Its activity increased with excitement, decreased either after ethanol, lateroflexion or rest and stopped at sleep. Four-vessel angiography revealed a well collateralised occlusion of both vertebral arteries. Needle-EMG recordings showed rhythmic, synchronous agonist/antagonist activity in both the splenius capitis and sternocleidomastoideus muscles at a frequency of 2-3 Hz. After administration of botulinum toxin A (DysportR), the tremor markedly improved and vanished completely after a booster. Since then the tremor did not reappear. Delayed-onset, yes/yes head tremor without appendicular tremor may be caused by bilateral cerebellar infarction and can be successfully relieved with botulinum toxin A.

Botulinum Toxins↗