PubMed Health⌕ Search

Biomedical subjects

D Wochnik-Dyjas

Publications and source records attributed to D Wochnik-Dyjas.

At least 19 recordsLinked to original sources
PubMed2000

Motor evoked potential studies in Creutzfeldt-Jakob disease.

OBJECTIVES: Motor evoked potentials (MEPs) were recorded in 7 cases of Creutzfeldt-Jakob disease (CJD) to asses the involvement of pyramidal motor pathways in these cases. The diagnosis of CJD was confirmed by autopsy in 5 cases and based on clinical data in two cases. METHODS: Transcranial (MEP-cortex), root magnetic (MEP-root) and electrical stimulation of peripheral nerves (F-wave, direct M-response) were performed. The cortical excitability threshold, F-wave frequency, MEP amplitudes, peripheral motor conduction velocity, standardized distal latencies and central, root, and F-wave conduction times were evaluated. RESULTS: The results of MEP testing were markedly abnormal. Cortical excitability thresholds were elevated, MEP amplitudes were reduced while the conduction function was rather preserved. The features of functional disturbances and/or loss of upper and lower motor neurons were revealed. They correlated with the advancement of key clinical CJD symptoms (progressive dementia, extrapyramidal and cerebellar signs, myoclonic jerks, mutism and typical periodic EEG changes), while motor lesion signs might only be slight or absent. CONCLUSIONS: Conduction slowing, if present, seemed to be secondary to axonal lesion.

Adult↗
PubMed1998

Peculiarity of soleus motor potentials evoked by transcranial magnetic stimulation and electrical stimulation of tibial nerve.

OBJECTIVE: To reveal and discuss the peculiarities of soleus muscle in comparison with electrophysiological features of other leg muscles. METHODS: Vastus lateralis (L3), tibialis anterior (L4), extensor digitorum brevis (L5) and soleus (S1) muscles were tested at rest. Transcranial magnetic stimulation (TMS) combined which electrical stimulation of relevant peripheral nerves were applied. Cortically evoked motor potentials (C-MEP), peripheral compound muscle action potential (CMAP) and F-wave were recorded. Estimating F-wave conduction time allowed to calculated the central conduction time (CCT-F) within the cortex-spinal motoneurones segment for each muscle. RESULTS: One could expect that the lower spinal metameric representation of the muscle the longer a corresponding CCT-F. However, a study of 30 healthy subject (60 right and left muscles) reveals a relatively short CCT-F for the soleus muscle. Moreover, the mean amplitude of soleus C-MEP is the lowest, CMAP and F-wave amplitude are the highest and standardised distal motor latency is the longest compared to the analogous parameters for the other muscles. CONCLUSIONS: The reason for these special features can be attributed probably to a different structure and innervation of the soleus (mainly red, slow, tonic muscle) in contrast to the tibialis anterior and extensor digitorum brevis (mainly white, fast, phasic muscle).

Adolescent↗
PubMed1998

Cortical excitability threshold for distal limb muscles in transcranial magnetic stimulation. Method--normative values.

Transcranial magnetic stimulation was carried out in 30 healthy subjects, aged 20 to 55 and 156 to 180 cm tall, in whom cortical excitability threshold was determined for musculus (m.) abductor digiti minimi (ADM) and m. extensor digitorum brevis (EDB). The lowest stimulus intensity causing in the muscle a reproducible potential of an amplitude of 0.1 mV was adopted as the threshold value. The intensity of the stimulus was noted as a percentage of maximum stimulator output, defined as 100% (Magstim 200). In the stimulation of cortical areas for ADM, a circular coil (2.0T-530 V/m) was used while the in case of EBD, a double-cone coil (1.4T-660 V/m) was used. The threshold was noted while the muscle was relaxed and during weak voluntary contraction. The application of the double-cone coil allowed us to obtain for foot muscles similar threshold values as for hand muscles with a circular coil. It was confirmed that the threshold declines with voluntary contraction of the muscles under investigation. Normative values were prepared, with the norm, limits of the norm, outlier values and pathological markers being distinguished.

Adult↗
PubMed1996

The F-wave in the vastus lateralis M. and the segmental motor conduction times for L2/L4 motoneurons.

The study was performed in 30 normal subjects. Electrical stimulation was applied to the femoral nerves and the muscle evoked potential (CMAP) together with their late components were recorded from the vastus lateralis muscle bilaterally (60 nerves). Features of the late component demonstrating its antidromic nature (F-wave) were proved. Additionally, in each subject transcranial cortical (C) magnetic stimulation and root (Rx) magnetic stimulation at the level of the L3-L4 was applied. The measured latencies of respective motor evoked potentials C-MEP (relaxed muscles), CA-MEP (activated), Rx-MEP as well as the latencies of peripheral CMAP and F-wave allowed the calculation of the derived parameters, i.e. segmental times of motor conduction: central, root and peripheral. The normative values were established. The F-wave measurement also allowed for the calculation of the so-called real central conduction time, which proved to be significantly shorter than the corresponding times previously established for the lower situated L4/S1 motoneurons. This finding suggests usefulness of the method in the precise diagnosis of the lumbosacral spinal enlargement.

Adult↗
PubMed1994

[Somatosensory evoked potentials in vascular damage to central sensory pathways].

Somatosensory evoked potentials from median nerve (SEP-M) were examined bilaterally in 43 patients with a well delimited vascular foci in central somatosensory pathways. Scalp, far field, cervical, Erb potentials and conduction times were recorded in each patients. Five subgroups based on localization of foci (parietal cortex, corona radiata, internal capsule, thalamus and extensive subcortical--cortical hemispheric focus) were distinguished. The results from the unimpaired (n-38) and impaired (n-48) sides, focus subgroups and control healthy group were statistically compared. The attempt to establish a specific relationship between the SEP-M picture and site of the lesion gave a negative result. SEP-M changes were more pronounced in cases of very extensive axons run in a compact bundle (internal capsule). The SEP-M examination indicates only the degree of the central sensory system damage. Correlations between intensity SEP-M pathology and clinical sensory disturbances were found. SEP-M parameters on the unimpaired side differed significantly from those of the control group. Therefore the impaired side should not be used as a reference for evaluation of impaired side pathology. The diagnostic validity of far field potentials recordings in such investigations is stressed.

Adult↗
PubMed1978

Porphyric polyneuropathy and its pathogenesis in the light of electrophysiological investigations.

Twenty-four patients with acute intermittent porphyria were examined by means of routine electromyographic (EMG) tests, measurements of motor and sensory conduction in peripheral nerves and stimulation fatigue tests. The EMG results gave evidence of an initial, reversible disorder of function of the peripheral neuron, only sometimes followed by evidence of axonal degeneration of the "dying back" type. In stimulation fatigue tests there was some evidence of potentiation but none of fatigue. Attention is drawn to some analogies between the electrophysiological changes in porphyric polyneuropathy and in botulism. It seems that the pathogenesis of porphyric polyneuropathy may be dependent upon a block of cholinergic endings.

Acute Disease↗