Neurophysiological approach to the study of cluster headache.
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Blinking↗
Biomedical subjects
I Milanov
Publications and source records attributed to I Milanov.
Prevalence of multiple sclerosis in Gypsies and Bulgarians.
There are occasional reports about the low prevalence of multiple sclerosis among Gypsies. To verify these reports of low prevalence of multiple sclerosis among Gypsies compared to the white population in Bulgaria, an epidemiological study was conducted in two small regions of Bulgaria. All patients with clinically or laboratory-supported, definite multiple sclerosis according to Poser's criteria were personally interviewed and examined. The study was begun on January 1, 1997 and March 31, 1998 was selected as prevalence day. For the white population, the prevalence ratio of multiple sclerosis per 100,000 population was 44.9 in the first region and 44.4 in the second. The prevalence of multiple sclerosis in Gypsies was found to be 19.1/100,000 in the first region and 18.4 in the second. It is concluded that multiple sclerosis is less common in Gypsies than in whites living in the same areas.
Adolescent↗
Central nervous system impairment in diabetic patients.
The aims of this study were to investigate the function of the central motor control system in interaction with the vestibular and auditory systems (measured by H-reflex changes in response to vestibular and acoustic stimulations) in diabetics without clinical data for CNS impairment, in order to establish whether the disease affects these CNS mechanisms; and to assess this approach in detecting subclinical CNS diabetic pathology. The results show the same mode of change of H-reflex amplitude in response to acoustic and vestibular stimulations in diabetics as in normal subjects. However the degree of facilitation and inhibition was significantly (p < 0.001) higher in diabetics which indicates subclinical CNS dysfunction. Therefore it was concluded that the test is useful in early diagnosis of the diabetic CNS impairment.
Acoustic Stimulation↗
Parkinsonian syndrome as a neurological manifestation of Behçet's disease.
BACKGROUND: The central nervous system is often involved in Behcet's disease. Most common are meningoencephalitic and brain stem syndromes. Although basal ganglia involvement is not an uncommon finding on necropsy, there are only single reports on extrapyramidal syndromes-dyskinesia, chorea and Parkinsonism in patients with Behcet's disease. CASE STUDY: We report a patient fulfilling the criteria of the International Study Group for Behcet's disease. He had recurrent oral ulcerations, bilateral posterior uveitis and retinal vasculitis, skin papules and pustules, and recurrent monoarthritis. Neurologic examination revealed pseudobulbar palsy, slight and asymmetric bilateral pyramidal syndrome, muscle rigidity involving the four limbs, bradykinesia, masked face, and impaired postural reflexes. There was postural tremor in the extremities and myoclonic jerks involving the tongue and face muscles. Magnetic resonance imaging demonstrated small bilateral multifocal hyperintense lesions, with right predilection, involving the periventricular white matter, brain stem and basal ganglia. CONCLUSIONS: The Parkinsonian syndrome found in our patient might be due to involvement of both substantia nigra and basal ganglia. This case further emphasizes the wide spectrum of the neurological manifestations of Behcet's disease.
Adult↗
Prevalence of multiple sclerosis in Bulgaria.
The previously reported prevalence of multiple sclerosis in Bulgaria is considerably lower than that reported for neighbouring countries. The aim of this study was to perform a detailed epidemiological investigation in well-defined populations in this country to obtain an accurate estimate of the frequency of multiple sclerosis. An epidemiological study was conducted in two small areas of the country. All patients with clinically or laboratory-supported, definite multiple sclerosis according to Poser's criteria were personally interviewed. The study was begun in January, 1993 and December 31, 1995 was selected as prevalence day. The prevalence ratio of multiple sclerosis per 100,000 population was 39.3 in the first community and 39.1 in the second. Thus, the prevalence ratio of multiple sclerosis in Bulgaria is not significantly different from that reported in bordering countries.
Adolescent↗
Differential diagnosis of scapuloperoneal syndrome.
The nosology of scapuloperoneal syndrome remains controversial. It may be only a stage in the development of facioscapulohumeral dystrophy. The aim of this investigation was to re-establish the clues for distinguishing between scapuloperoneal syndrome and facioscapulohumeral muscular dystrophy. Twelve patients with a scapuloperoneal syndrome were investigated and compared with seventeen patients with facioscapulohumeral dystrophy. The distribution of weakness for both groups of patients was quite different. The electromyographic examination of patients with scapuloperoneal syndrome revealed typical mixed myogenic and neurogenic features and peroneal nerves involvement. The electromyographic findings in patients with facioscapulohumeral muscular dystrophy were typical for myogenic involvement. In conclusion we can suppose that the scapuloperoneal muscular atrophy is not a stage in the development of facioscapulohumeral dystrophy. It is a separate nosological entity with typical clinical and electromyographic findings.
Adolescent↗
Differential diagnosis of limb girdle syndromes.
The term limb girdle syndrome includes a variety of neuromuscular disorders like the scapulohumeral and pelvifemoral types of muscular dystrophy, quadriceps myopathy and Wohlfart-Kugelberg-Welander syndrome. There may be considerable difficulty in distinguishing between different types of limb girdle syndrome, even with the aid of electromyographic and muscle biopsy examinations. The aim of this investigation was to reestablish the clues for distinguishing between different types of limb girdle syndrome. Fifty-four patients with limb girdle syndromes took part in this investigation. They were subdivided into two groups according to EMG and muscle biopsy data. The first group consisted of 39 patients with limb-girdle type of muscular dystrophy and the second group consisted of 15 patients with juvenile type of spinal muscular atrophy. Our results revealed that neurological examination was not enough to distinguish the different types of limb girdle syndrome. The most important electromyographic findings in patients with muscular atrophy are the neurogenic action potentials and fasciculations. Fibrillations, positive sharp waves and bizzare discharges may be found also in some patients with muscular dystrophy. Myogenic action potentials are found in some patients with muscular atrophy and so may cause confusion. Muscle biopsy may also reveal some myogenic features in patients with muscular atrophy. In conclusion electromyography and muscle biopsy are useful in the differentiation of different types of limb girdle syndrome, as well as, in determining the exact pattern of muscle involvement.
Action Potentials↗
Vestibular and auditory influences on segmental motoneuron excitability--a comparative study.
This study aimed to investigate the vestibular and acoustic influences on segmental motoneuron excitability in the same normals in order to compare the effects of both sensory systems. The results show that both systems exert similar influences on H-reflex in the same subjects. These indicate similarities in the function of motor control and suggest common final pathways of the vestibular and auditory activity to the segmental motoneuron. The alternative effect, facilitation or inhibition, of acoustic and vestibular stimuli on H-reflex is devoted to processing of the labyrinthine activation in the brainstem reticular formation, or to the state of the spinal interneurons.
Acoustic Stimulation↗
Writer's cramp and tremor due to brain tumor.
Writer's cramp is frequently associated with hand tremor and with other focal dystonias. Sometimes brain infarction, haemorrhage, arterio-venous malformations or tumors are found to cause symptomatic focal dystonias. A 44-year-old man came to our attention due to writer's cramp of his right hand and postural 6-8 Hz tremor. About three months after the onset of the disease the tremor and dystonia disappeared, while a right hemiparesis gradually appeared. Cranial computed tomography showed a hypodense nonhomogeneous lesion in the left cerebral hemisphere parietally, that was assumed to represent a cystic tumor. The patient underwent craniotomy and the histological diagnosis revealed an astrocytoma (Grade II-III). In conclusion our findings confirm the common anatomical basis of symptomatic focal dystonia and tremor. Both can appear after disruption of the pathways within and adjacent to the basal ganglia.
Adult↗
Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome.
A patient with a three year history of POEMS syndrome-polyneuropathy, hepatosplenomegaly M-protein, skin changes, optic disc edema, peripheral oedema, pleuritis, lymphadenopathy, and osteosclerotic myeloma is described. The patient had a twenty year history of psoriasis and impotence was the first sign of the disease. The pathophysiology of this multisystem disorder is unknown, although the M-protein is essential. No improvement was found after radiation, chemotherapy and steroid treatment.
Adult↗
Mechanisms of tizanidine action on spasticity.
This investigation estimated the mechanisms of tizanidine action on spasticity using a battery of neurophysiological methods. Thirty patients with old post-stroke spastic hemiparesis took part in the investigation. They were treated with tizanidine-mean daily dose 15.8 +/- 5.6 mg for a mean of 23.3 +/- 4.8 days. A questionnaire for assessment of subjective improvement after treatment used a 5-point scale. For standardization of the neurological examination 5-point scales were used to assess muscle tone, muscle force and tendon reflexes. A battery of neurophysiological methods was used to analyze different mechanisms of spasticity: for alpha motoneuron excitability--the F wave parameters; for presynaptic inhibition--the ratio of H reflex amplitudes before and after vibration of the achilles tendon (Hvibr/Hmax); for common interneuron activity--the flexor reflex parameters. Our results revealed that tizanidine reduces spastically increased muscle tone, but has no influence on muscle force, tendon reflexes, Babinski sign and ankle clonus. Tizanidine is supposed to act by increasing the presynaptic inhibition and decreasing of alpha motoneuron excitability. When spasticity has decreased presynaptic inhibition and increased motoneuron excitability, it is better to treat with tizanidine.
Adult↗
Examination of the segmental pathophysiological mechanisms of spasticity.
The purpose of this investigation was to ascertain a complex of electromyographic methods suitable for evaluation of the basic segmental pathophysiological mechanisms of spasticity. Clinical and electromyographic examinations were performed on 120 patients with spastic hemiparesis after stroke. Patients muscle tone, muscle force and tendon reflexes were assessed by the well known clinical five point scales. A battery of electromyographic methods was used to analyze different segmental mechanisms of spasticity: for alpha motoneurone activity--the F-wave parameters; for gamma motoneurone activity--the TA/H amplitude ratio; for common interneurone activity--the flexor reflex parameters; for presynaptic inhibition--the Hvibrated/Hmaximal amplitude ratio. Our results revealed that nearly all of the patients have increased alpha motoneurone activity on the spastic side. In most of the patients at least two of the segmental mechanisms are altered. Different mechanisms participate with different frequency in development of spasticity. We suppose that alpha-motoneurone hyperactivity usually develops secondary after alteration of some other segmental mechanism. In conclusion the applied complex of electromyographic methods gives the possibility for evaluation of the individual pathophysiological profile of patients with spasticity. This is a background for appropriate treatment.
Aged↗
A comparative study of methods for estimation of presynaptic inhibition.
The influence of vibration on the H-reflex and on the tendon reflex amplitudes was compared and the efficacy of both methods for the assessment of the presynaptic inhibition was studied. One hundred and twenty patients with post-stroke spastic hemiparesis were investigated. Muscle tone, muscle force and tendon reflexes were assessed. The H-reflex and the Achilles tendon reflex (TA) were recorded under identical experimental conditions. Vibration at a frequency of 100 Hz and an amplitude of 2 mm was applied to the TA. Just after vibration the maximal amplitudes of both reflexes were measured. The ratios of reflex amplitudes after vibration to normal maximal reflex amplitudes (Hvibr/Hmax and TAvibr/TAmax) were evaluated. In all patients with hemiparesis the healthy side was used as a control. Our results revealed significantly increased amplitude ratios on the spastic side. Hence it is concluded that presynaptic inhibition is decreased in spasticity. The amplitude ratios on the healthy and the spastic side were consistent. There was good positive correlation between Hvibr/Hmax and TAvibr/TAmax ratios, suggesting that they provide similar and reliable estimates of presynaptic inhibition.
Adult↗
Mechanisms of tetrazepam action on spasticity.
This investigation assessed the mechanisms of Tetrazepam action on spasticity using a battery of electromyographic methods. Thirty patients with post-stroke spastic hemiparesis treated with Tetrazepam took part in the investigation. A questionnaire for assessment of subjective improvement after treatment used a 5-point scale. The 5-point scales were used to assess muscle tone, muscle strength and tendon reflexes. A battery of electromyographic methods was used to analyse different mechanisms of spasticity: for alpha-motoneuron activity--the F-wave parameters; for gamma-motoneuron activity--the TA/H amplitude ratio; for presynaptic inhibition--the ratio of H-reflex maximal amplitudes before and after vibration on the Achilles tendon (Hvibr/Hmax); for common interneuron activity--the flexor reflex parameters. Our results revealed that Tetrazepam reduces tone in spastic muscles and has a slight effect on tendon hyperreflexia. It has no influence on muscle strength, Babinski sign and ankle clonus. Tetrazepam acts by decreasing motoneurone activity and increasing presynaptic inhibition.
Aged↗
The diagnostic significance of the blink reflex in diseases of the central and peripheral nervous systems.
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Blinking↗
Prevalence of Parkinson's disease in Bulgarian Gypsies.
We studied the prevalence of Parkinson's disease (PD) in Gypsies and Caucasians in Bulgaria. Cases were ascertained by examination in a clinic, a screening questionnaire and a door-to-door survey in a region of Sofia, Bulgaria. The prevalence of PD in the Gypsies was found to be 16/100,000 based on 1 case compared to 137/100,000 for Caucasians with 119 cases. It is concluded that PD is rare in Bulgarian Gypsies.
Adolescent↗
Comparative analysis between Duchenne and Becker types muscular dystrophy.
Duchenne and Becker types of muscular dystrophy are usually differentiated according to age of onset and rate of progression criteria which are not sufficient. The aim of this paper was to re-establish the clues for distinguishing Duchenne from Becker types of muscular dystrophy. According to the onset and progression of the disease, one hundred and eleven patients were subdivided into two groups. First group--Becker muscular dystrophy--consisted of 40 patients and second one of 71 patients with Duchenne type of muscular dystrophy. Clinical data confirm some well known differences between Duchenne and Becker muscular dystrophy concerning the age of onset, severity of disease and rate of progression. Electromyographic signs of myopathic changes and spontaneous activity were found in both diseases. Spontaneous activity--bizarre and fibrillation potentials, as well as sharp waves are more common for Duchenne type. The differences between the Becker from Duchenne type of muscular dystrophy can be described on the basis of complex investigations (clinical, electromyographical, histological and biochemical).
Action Potentials↗
Clinical and neurophysiological correlations of spasticity.
The aim of this investigation was to explore the correlations between some neurophysiological methods and spasticity. An examination of 120 patients with spastic hemiparesis was performed. The muscle tone, force and tendon reflexes were assessed using well-known five-point scales. The F wave, T, H and flexor reflex parameters and the Hvibrated/Hmaximal ratio were obtained. Our results revealed moderate correlations (0.3 < r < 0.5) between the amplitudes of F wave, T and H reflexes and muscle tone. The correlations between the amplitude ratios (Fmaximal/M, Fmean/M, T/M, H/M) and muscle tone were poor, as were the correlations between H reflex thresholds and muscle tone. Moderate correlations existed between Hvibration/Hmaximal ratio and muscle tone. Only the second flexor reflex response showed moderate correlations with muscle tone. In conclusion correlations between the neurophysiological methods employed and muscle tone are moderate. Evaluation of all the F wave, T, H reflex and flexor reflex parameters is not necessary, as only some of these parameters show good correlations with spasticity.
Aged↗