Elzbieta Szmidt-Salkowska

The value of quantitative EEG in differential diagnosis of Alzheimer's disease and subcortical vascular dementia

OBJECTIVE To investigate whether quantitative EEG may be useful in differential diagnosis of AD and SVD and to determine the correlation between dementia and abnormalities in EEG. MATERIALS AND METHODS The group under study was consisted of 62 patients with AD (mean age: 73.6 yrs; M 51%), 31 with SVD (mean age: 75.2 yrs, M 43%) and a control group of 14 healthy subjects (mean age: 69.5 yrs, M 43%). The patients were divided into subgroups of those with mild, moderate and marked dementia. EEG findings were classified using eight-degree scale according to the presence of slow waves, and then quantitative analysis was carried out by calculating the alpha/slow wave power ratios and the mean frequencies in all and some selected derivations. RESULTS A significant difference between visual EEGs and QEEGs in AD and SVD was found. Only QEEG parameters differed in AD and SVD subgroups with the same degree of cognitive impairment: the mean wave frequencies of waves in temporal derivations in subgroups with mild and moderate dementia and alpha/delta waves power ratio in subgroups with moderate dementia. CONCLUSIONS Visual EEGs and QEEGs could be used in addition to the differential diagnosis between AD and SVD, but only selected parameters of QEEG could be useful in differentiating between AD and SVD subgroups with the same degree of dementia.

Atypical motor unit potentials in Emery-Dreifuss muscular dystrophy (EDMD)

OBJECTIVE The aim of the study was to analyse electromyographic changes in Emery-Dreifuss muscular dystrophy (EDMD) that are atypical for myopathy. Our special interest was focused on high amplitude polyphasic motor unit potentials (MUPs), also termed irregular MUPs. METHODS We studied 21 EDMD patients with the diagnosis based on clinical data, DNA analysis and immunohistochemical muscle studies. Rectus femoris muscle biopsies were investigated in all affected patients. Electrophysiological investigations involved quantitative concentric needle electromyography (CNEMG) of biceps brachii (BB) and rectus femoris (RF) muscles. Simulation studies were performed to approximate the number, diameter and distribution of muscle fibers, which contribute to irregular MUPs. RESULTS The EMG data in EDMD were compatible with myopathy. Irregular MUPs showed longer duration, larger area, size index and higher amplitude then simple ones (P < 0.05). The approximation of features of muscle fibers contributing to irregular MUP also indicated smaller (<45 microm) and larger (>55 microm) diameters than normal (50 +/- 5 microm). Muscle biopsy specimens revealed the variable muscle fiber size due to atrophy, hypertrophy, and muscle fiber splitting. CONCLUSIONS Irregular MUPs recorded in EDMD are due to hypertrophied and atrophied fibers as well as increased fiber density. They reflect reorganization of the motor unit in a slow progression myopathic process (muscle fiber hypertrophy and splitting). SIGNIFICANCE Irregular MUPs in EDMD most probably reflect increased variability of the muscle fiber size.

Does EEG (visual and quantitative) reflect mental impairment in subcortical vascular dementia

UNLABELLED The aim of this study was to determine if the results of visual and quantitative EEG (QEEG) parameters reveal a correlation with mental impairment in subcortical vascular dementia (SVD), one of the most frequent causes of cognitive impairment in the elderly. In SVD, like in Alzheimers disease disturbances were found in cholinergic transmission. The cholinergic deficit as manifested in changes of synaptic potentials is reflected in EEG signals. MATERIAL 31 patients with probable SVD (according to NINCDS-AIREN and T. Erkinjuntiis criteria) and mean age 72.3 yrs;(M--43%, F--57%) and 14 healthy control subjects with mean age of 72.3 yrs (M-57%, F-43%). According to the Mini Mental Scale Examination (MMSE) the SVD group was divided into two subgroups with mild and moderate dementia, their EEGs being recorded with a Medelec and Neuroscan 4.2 system. Visual EEG findings were classified with the use of eight-degree scale of pathological changes by the presence of slow waves. Then QEEGs were made. The following parameters were calculated: alpha/slow wave power ratios, the mean wave frequency in all and in some selected derivations. RESULTS A significant difference was found between QEEGs in SVD subgroups with mild and moderate dementia (p<0.05), but there was no significant difference between visual EEGs. A significant correlation between QEEG parameters such as alpha/slow wave ratio or mean wave frequency and mental impairment (according to MMSE results) was found (p<0.001), but there was no significant correlation between degree of EEG abnormalities in visual analysis and MMSE results. CONCLUSION Only QEEGs are correlated with mental impairment in SVD. Visual EEG technique as a less precise tool does not reflect the mental impairment in SVD due to cholinergic deficit.

Are we really closer to improving the diagnostic sensitivity in ALS patients with Awaji criteria

Abstract The Awaji criteria, recently introduced to increase diagnosis sensitivity in amyotrophic lateral sclerosis (ALS), equate the diagnostic significance of neurogenic electrophysiological changes to clinical signs of lower motor neuron dysfunction. They also increase the electrophysiological significance of fasciculation potentials (FPs). The aim of our study was to analyse whether the new parameters improve diagnostic sensitivity in ALS patients primarily diagnosed with the El Escorial criteria. Medical and electrophysiological records of 135 consecutive patients with ALS and 25 patients with progressive muscular atrophy (PMA) who underwent electrophysiological examination of at least three anatomical regions were analysed retrospectively. Results showed that implementation of the Awaji criteria increased the level of ALS diagnosis sensitivity in 5.9% of cases – 1.5% due to the new role of FPs potentials and 4.4% because of equalization of clinical and EMG findings. In 4% of patients the ALS diagnosis was, however, changed from laboratory-supported probable ALS to possible ALS. In conclusion, our study confirms that Awaji modifications are able to improve the diagnostic certainty in a few ALS cases. Although the new approach to FPs markedly increases the number of involved muscles, it only slightly raises the number of involved regions.

Motor unit number estimation as a complementary test to routine electromyography in the diagnosis of amyotrophic lateral sclerosis

Electromyographic (EMG) abnormalities that reveal denervation and reinnervation caused by lower motor neuron degeneration do not reflect the number of motor units that determines muscle strength. Consequently, motor unit activity potential (MUAP) parameters do not reflect muscle dysfunction. The aim of the study was to compare the value of motor unit number estimation (MUNE) and MUAP parameters as indicators of clinical muscle dysfunction in patients with amyotrophic lateral sclerosis (ALS), and to analyze the role of MUNE as a supplement to the EMG criteria for the diagnosis of ALS. In 25 patients with ALS, MUNE by the multipoint incremental method in the abductor digiti minimi (ADM) and quantitative EMG in the first dorsal interosseous (FDI) were obtained. The Medical Research Council (MRC) scale was used to evaluate clinical muscle dysfunction. A strong correlation between the number of motor units evaluated by MUNE and ADM clinical function by the MRC scale was found (P<0.001). An increased value of surface-detected single motor action potential was associated with a decreased MRC score for ADM (P<0.1). No relation was found between MUAP parameters in FDI and MRC scores. Our data support the value of the MUNE method for the detection of motor unit loss in ALS, and it could be postulated that MUNE studies may be considered complementary tests for ALS in a future revision of ALS criteria.

Clinical and Functional Assessment of Dysautonomia and Its Correlation in Alzheimer’s Disease

The aims were to assess dysautonomia in Alzheimer’s Disease (AD), clinically and electrophysiologically, using sympathetic skin response (SSR) test and R-R interval variation (RRIV) test and to analyze the relationship between symptoms of dysautonomia and SSR/RRIV results. A tota of 54 patients with AD and 37 controls were evaluated using Autonomic Symptoms Questionnaire and SSR/RRIV test. Clinical dysautonomia was observed in 66% of patients (eg, orthostatic hypotension in 34.5%, constipation in 17.2%, urinary incontinence in 13.8%). The SSR test was abnormal in 26%, but the RRIV test was abnormal in 97.7% of cases; there was significant difference in RRIV test results between AD and controls (R mean 8.05% and 14.6%, respectively). In AD, clinical dysautonomia occurs at a various degree, and the abnormal SSR and RRIV test results were not always related to the presence of clinical dysautonomia; this observation points that the tests could be used as a useful tool in the assessment of subclinical dysautonomia.

Value of short exercise and short exercise with cooling tests in the diagnosis of myotonic dystrophies (DM1 AND DM2)

Introduction: Standard electromyography (EMG) is useful in the diagnosis of myotonic dystrophy type 1 (DM1) and type 2 (DM2), but it does not differentiate between them. The aim of this study was to estimate the utility of the short exercise test (SET) and short exercise test with cooling (SETC) in differentiating between DM1 and DM2. Methods: SET and SETC were performed in 32 patients with DM1 (mean age 35.8 ± 12.7 years) and 28 patients with DM2 (mean age 44.5 ± 12.5 years). Results: We observed a significant decline in compound motor action potential (CMAP) amplitude in DM1 with both SET and SETC immediately after effort. In DM2, there was no marked change in CMAP amplitude with either SET or SETC. Conclusions: SET and SETC may serve as useful tools for clinical differentiation between DM1 and DM2, and they may be used as a guide for molecular testing. Muscle Nerve 49: 277–283, 2014

Peripheral nerve involvement in myotonic dystrophy type 2 – similar or different than in myotonic dystrophy type 1?

INTRODUCTION Multisystem manifestations of myotonic dystrophies type 1 (DM1) and 2 (DM2) are well known. Peripheral nerve involvement has been reported in DM1 but not in genetically confirmed DM2. The aim of our study was to assess peripheral nerve involvement in DM2 using nerve conduction studies and to compare these results with findings in DM1. METHODS We prospectively studied patients with genetically confirmed DM2 (n=30) and DM1 (n=32). All patients underwent detailed neurological examination and nerve conduction studies. RESULTS Abnormalities in electrophysiological studies were found in 26.67% of patients with DM2 and in 28.13% of patients with DM1 but the criteria of polyneuropathy were fulfilled in only 13.33% of patients with DM2 and 12.5% of patients with DM1. The polyneuropathy was subclinical, and no correlation was found between its presence and patient age or disease duration. CONCLUSIONS Peripheral nerves are quite frequently involved in DM2, but abnormalities meeting the criteria of polyneuropathy are rarely found. The incidence of peripheral nerve involvement is similar in both types of myotonic dystrophy.

Long lasting dysautonomia due to botulinum toxin B poisoning: clinical-laboratory follow up and difficulties in initial diagnosis.

BackgroundBotulism is an acute form of poisoning caused by one of four types (A, B, E, F) toxins produced by Clostridium botulinum, ananaerobic, spore forming bacillus. Usually diagnosis of botulism is considered in patients with predominant motor symptoms: muscle weakness with intact sensation and preserved mental function.Case presentationWe report a case of 56-year-old Caucasian female with a history of arterial hypertension, who presented with acute respiratory failure and bilateral ptosis misdiagnosed as brainstem ischemia. She had severe external and internal ophtalmoplegia, and autonomic dysfunction with neither motor nor sensory symptoms from upper and lower limbs. Diagnosis of botulinum toxin poisoning was made and confirmed by serum antibody testing in the mouse inoculation test.ConclusionsOphtalmoplegia, autonomic dysfunction and respiratory failure can be caused by botulism. Early treatment and intensive care is essential for survival and recovery. The electrophysiological tests are crucial to correct and rapid diagnosis. Botulism (especially type B) should be considered in any case of acute or predominant isolated autonomic dysfunction.

Motor unit potentials with satellites in dystrophinopathies

INTRODUCTION The objective of this study was to analyze the motor unit potentials (MUPs) with satellite components i.e., delayed by at least 2ms baseline from the main component, in the dystrophinopathies. METHODS The parameters of the MUPs recorded from the biceps brachii muscle in the Duchenne and Becker Muscle Dystrophy (DMD, BMD) were analyzed. The origin of the MUP satellite components was studied using a computer simulation. RESULTS As compared with normal potentials, both the main and the satellite MUP components are smaller in size, while the main components are more irregular. The computer simulation allows the range of muscle fiber diameters to be determined, and suggests that the variability characterizing diameters within the motor unit is responsible for generating the delayed, satellite components, via the linear relationship between the fiber diameter and the conduction velocity of the action potential. DISCUSSION The enhanced understanding of the origin of the MUP satellite components augments the knowledge about the relationship between muscle morphology and bioelectrical activity. The indirect evaluation of the range of muscle fiber diameters by means of a computer simulation may provide a new quantitative morphological data available from the EMG.