Biomedical subjects

R N Konovalov

Publications and source records attributed to R N Konovalov.

5 recordsLinked to original sources

PubMed2006

[The role of neurovisualization methods in diagnosis and verification of vertigo etiology].

Roentgen computed tomography (RCT) and MR-imaging (MRI) were used in investigation of vertigo etiology and affection of the cochleovestibular analyzer in 130 patients aged 28 to 74 years with recurrent systemic rotatory vertigo or its other symptoms. All the patients have undergone comprehensive otoneurological examination, RCT and MRI which showed that peripheral cochleovestibular syndromes (PCVS) caused by arterial hypertension (AH), atherosclerosis (AS), vascular dystonia (VD) are rarely characterized by focal alterations in the brain. PCVS comparison with blood flow in the vertebral arteries (VA) detected most frequently anomalies and asymmetries of the diameters. MR-angiography plays an important role in verification of pathology of intracranial VA. In central cochleovestibular syndrome (CCVS) with AH, AS, VD, principal pathological changes were registered in the brain trunk and cerebellum by MRI. Vestibulometry and otoneurological method detect not only vascular cochleovestibular peripheral and central syndromes but also to make differential diagnosis. RCT and MRI verify cochleovestibular syndromes in patients with multiple encephalomyelitis, VIII nerve neurinoma and tumors of the posterior cranial fossa.

Adult↗

PubMed2006

[Structural and functional analysis of the cortico-spinal tract in multiple sclerosis].

The study aimed at comparison of transcranial magnetic stimulation (TMS) parameters to MRI data in multiple sclerosis (MS), taking into account clinical course of the disease. TMS was conducted in 56 patients and in 10 age- and sex-matched healthy controls. According to stage of activity and variant of the course, the patients were divided into 2 groups: one at the stage of exacerbation and another--at the stage of remission with secondary progressive MS. Latency of segmental evoked motor response was similar in patients and controls. Statistically significant between-group difference or trend toward changing of some TMS parameters were found that indicates a slow-down of the impulse conducting along the cortico-spinal tract, which is characteristic of demyelinization process. The changes were more pronounced in secondary-progressive MS. According to MRI data, a square of the spinal cord on the level of the intervertebral disk center C2/C3 was significantly smaller in the group of patients with secondary progressive MS than in that with exacerbation of the disease. The TMS parameters correlated both with the level of the focal demyelinization process and with the square of the spinal cord on a level selected. It allows to estimate expression of atrophic changes caused, in its turn, not only by myelin loss but also by axon loss.

Adult↗

PubMed2006

[Vestibular cochlear disturbances in multiple sclerosis].

To specify the character of vestibular cochlear disturbances in multiple sclerosis (MS) and mechanisms of their formation, the objective quantitative evaluation of experimental caloric nystagmus using the computer electronystagmographic method and a comparison of hearing impairment with asymmetry of vestibular reactions were conducted in 48 patients with MS. The peculiarities of vestibular disturbance found in the study suggest a predominance of central vestibular syndrome with both subtentorial and supratentorial traits. The influence of the heat stimulus of vestibular analyzer (hot water caloric test) in multiple sclerosis revealed during computer electronystagmography may have diagnostic value.

Adult↗

PubMed2005

[Vertigo and a role of neurovisual methods in it etiology and diagnosis].

Investigation of vestibular system using a standard method of electro-nystagmography in complex otoneurologic examination does not provide enough information on the etiology of vestibular analyzer lesion, location and diffusion of the pathological process. Neurovisual methods, in particular MRI and CT, have demonstrated high diagnostic validity in such pathological states as tumors of pons cerebellum and posterior focca; infarctions in the stem and cerebellum regions. The study revealed a role of MRI and CT in etiology of vertigo and lesions of cochleovestibular analyzer. One hundred thirty patients aged 28-74 years with recurrent attacks of systemic rotary vertigo and other its appearances have been examined. In 14 (11%) patients such an attack was accompanied by loss of consciousness, falls, double-vision and other neurological symptoms. All the patients underwent otoneurological examination, computer electronystagmography, auditory evoked potentials registration, CT and MRI. It is shown that peripheral cochleovestibular syndromes caused by arterial hypertension, atherosclerosis and autonomic vascular dystonia are rarely characterized by focal cerebral changes (11 patients by CT data and 17 by MRI).

Adult↗

PubMed2004

[Lacunar stroke and subcortical arteriosclerotic encephalopathy].

Clinical and neurovisual features were compared in 2 groups of patients who have survived the first lacunar stroke (LS). Group 1 included 35 patients (mean age 59.6 +/- 7.1 years), in stable state for 5.7 +/- 2.5 years; group 2 consisted of 39 patients (mean age 58.1 +/- 8.1 years) with LS as a debut of subcortical arteriosclerotic encephalopathy (SAE), illness duration after LS development--3.9 +/- 2.9 years. Several parameters revealed statistically significant between-group differences: "classical" lacunar syndromes, most frequently motor hemiparesis, were detected in 94% of group 1 patients and in 42% of group 2 patients. Pareses of the extremities were marked or moderate in 57% and 3% of the patients, respectively. Foci characteristic of LS were determined by MRI/CT in all the patients of group 1 and in 69% of the patients of group 2. Foci mean size (MRI, regime T1) was larger in group 1 (0.24 +/- 0.18 cm3), comparing to group 2 (0.11 +/- 0.06 cm3); foci shape was round or oval in 77% of patients in group 1 and irregular--in 51% of patients in group 2. In group 1, concomitant asymptomatic leucoareosis and lacunes were detected in 37% and 20%; in group 2--in 77% and 62%, respectively. The differences revealed may be used in prognosis of LS further course. These differences may be underlied by the lesions of intracerebral arteries of different size and differend of change occurrence that, to a certain extent, relate to different hemodynamic variants of arterial hypertension.

Brain Infarction↗