[Ototoxicity of cisplatin].

The objective of this publication is to summarize "classical" and modern concepts of pathogenesis, clinical features of cisplatin ototoxicity, its screening, and prophylaxis. It is argued that pathogenesis of a cisplatin-induced injury to the inner ear shares common features with the ototoxic mechanisms of action of other pharmaceuticals even though it is characterized by certain important differences. The authors consider the mechanisms of ototropicity, specific cytochemical aspects of cisplatin cytotoxicity that aggravate risk factors, and genetic predisposition to the development of iatrogenic problems. The data are presented on monitoring and experimental aspects of otoprotection for the prevention of cisplatin-induced damage to the auditory analyzer.

Can chronic irritations of the trigeminal nerve cause musculoskeletal disorders?

In this article, five cases of odontogenous dysfunctions and musculoskeletal complaints are presented. A common finding in all patients of this study was that the presence of joint complaints was related to deficits in the corresponding muscular function. These deficits were determined by manual muscle tests as described by Kendall et al. [Muscles - Testing and Function, ed 4. Baltimore, Williams and Wilkins, 1993] and were eliminated immediately by a neural therapeutic test injection into the disturbed dental region. The therapy provided solely aimed to eliminate the odontogenous dysfunction. No other therapeutic measures were carried out with regard to the patients' respective muscle, tendon, or joint complaints.

Neural correlates of action attribution in schizophrenia.

Patients with first-rank symptoms (FRS) of schizophrenia do not experience all of their actions and personal states as their own. FRS may be associated with an impaired ability to correctly attribute an action to its origin. In the present study, we examined regional cerebral blood flow (rCBF) with positron emission tomography during an action-attribution task in a group of patients with FRS. We used a device previously used with healthy subjects that allows the experimenter to modulate the subject's degree of movement control (and thus action attribution) of a virtual hand presented on a screen. In healthy subjects, the activity of the right angular gyrus and the insula cortex appeared to be modulated by the subject's degree of movement control of the virtual hand. In the present study, the schizophrenic patients did not show this pattern. We found an aberrant relationship between the subject's degree of control of the movements and rCBF in the right angular gyrus and no modulation in the insular cortex. The implications of these results for understanding pathological conditions such as schizophrenia are discussed.

Dystonia: a disorder of motor programming or motor execution?

For some time, dystonia has been seen as purely a motor disorder. Relatively novel concepts published approximately 10 years ago also presumed that in the development of dystonic dyskinesias, only motor behaviour was abnormal. Neurophysiological observations of various types of dystonic disorders, which were performed using sophisticated electromyography, polymyography, H-reflex examination, long-latency reflex, etc., as well as new insights into the behaviour of dystonia, have urged the inclusion of sensory (particularly somatosensory) mechanisms into the pathophysiological background of dystonia. The major role has been considered to be played by abnormal proprioceptive input by means of the Ia proprioceptive afferents, with the source of this abnormality found in the abnormal processing of muscle spindle afferent information. However, neurophysiological investigations have also provided evidence that the abnormality in the central nervous system is located not only at the spinal and subcortical level, but also at the cortical level; specifically, the cortical excitability and intracortical inhibition have been revealed as abnormal. This evidence was revealed by SEP recordings, paired transcranial magnetic stimulation recordings, and BP and CNV recordings. The current concept of dystonic movement connects the abnormal function of somatosensory pathways and somatosensory analysers with the dystonic performance of motor action, which is based on the abnormality of sensorimotor integration.

Upbeat nystagmus: clinicoanatomical correlation.

A patient is reported on with isolated upbeating nystagmus with a linear slow phase in whom a solitary lesion, probably inflammatory, was detected radiologically in the dorsal paramedian caudal medulla, encompassing the most caudal of the perihypoglossal nuclei, the nucleus intercalatus of Staderini. The conjunction of a vestibular pattern of nystagmus with this focal lesion runs contrary to a previous suggestion that the nucleus intercalatus may act as a neural integrator for vertical conjugate eye movements.

Underconstrained perception: a theoretical approach to the nature and function of verbal hallucinations.

We do not see the world as it is. Perception forms a subjective image of the world in a language that has proven to be adaptive to our interaction with the external world. Perception is mainly determined by current needs of the organism and goals of behavior. Sensory processing itself does not culminate in perception and is not essential for perception, since perception derives from representations of internal symbols and their features. The current stimulation of sensory organs does, however, constrain our perception. Perception might be less constrained by the external world in cases of (1) increased attention, (2) decreased sensory stimulation, or (3) facilitated formation of cortical associations between representations of expectations and internal symbols. Hallucinations are perceptions that are underconstrained by external sensory stimulation. Verbal hallucinations that allow the patient to infer about his self-image might constitute the core psychopathology in a subset of schizophrenia. Commenting and discussing voices might be perceived under the pressure of increased attention to environmental factors that relate to the patient's social fears and wishes. Secondarily, delusions about the possession of thoughts and disorders of self-experience may develop.

[Microwaves and the visual analyzer]. / Mikrovolny i zritel'nyi analizator.

The results of studying an effect of microwaves on the different regions of visual analyzer are investigated. The morphofunctional changes at the light-optic and electron-microscopic levels are revealed. The changes involve not only peripheric area of visual analyzer but also its central regions. Some epidemiologic observations are indicative of: altered sizes of blind spot; decreased magnitudes of optic rheobase and chronaxy; color vision disorder; increased diastolic pressure in central artery of the retina. Study of bioelectrical activity of the retina enabled some investigators to make a conclusion about a reaction disorders occurring in the subcortical visual centers. It is noted that the animal studies not always explain unequivocally the microwave effects on the visual analyzer.

[Characteristics of prolactin secretion in response to different degrees of lesions of the vestibular analyzer]. / Osobennosti sekretsii prolaktina pri razlichnykh urovniakh porazheniia vestibuliarnogo analizatora.

The prolactin concentration in blood of 58 patients was measured during vestibular crisis and compensation of vestibular disorders. The results were compared with the clinical development of the disease and localization of vestibular problems. Patients with acute vestibular lesions at the central level of vestibular disorders showed a significant increase of prolactin concentrations that was higher than the concentrations in patients with the peripheral vestibular syndrome at the decompensation stage. Hyperprolactinemia during central vestibular dysfunction is viewed as a manifestation of dopamine deficiency of the tuberoinfundibular area. It is suggested that inadequacy of dopaminergic structures is one of the factors reducing adaptive and compensatory capabilities of the vestibular apparatus when its central compartments are injured.

[Changes in the functional state of the visual analyzer in operators working with video display terminals]. / O sdvigakh v funktsional'nom sostoianii zritel'nogo analizatora operatorov pri rabote s videoterminalom.

Research in laboratory and on-site conditions was performed to establish correlations between the visual analyzer's functional shifts in display operators, and the duration of work, the type of the screen used (coloured or non-coloured), the duration of the eyes, fixation on the screen, as well as sex related differences.

[Effects of acute psychogenic stress on the state of several functions of the visual analyzer]. / Vliianie ostrogo psikhogennogo stressa na sostaianie nekotorykh funktsii zritel'nogo analizatora.

Accommodation and binocular functions were examined after the earthquake of 1988 in 762 residents of Armenia who had not complained of their organ of vision before. Pseudo-myopia was detected in 30 percent of the examinees, concomitant strabismus in 4, and near-sight heterophoria in 4 percent. This permits a conclusion on the direct effect of an acute psychogenic stress during calamities on accommodation and binocular functions, particularly so in children.

[Sensory sphere function in children with enuresis]. / Funktsional'noe sostoianie sensornoi sfery u detei, bol'nykh énurezom.

The kinesthetic and acoustic analyzers were investigated in 62 enuretic and 50 healthy children. In patients, the sensitivity thresholds of the analyzers were substantially increased. The fall in function of the sensory sphere is a major pathogenetic factor of the disease.

[The function of the taste analyzer in patients with disseminated sclerosis]. / Sostoianie funktsii vkusovogo analizatora u bol'nykh rasseiannym sklerozom.

The absolute threshold of gustatory sensibility was studied in 100 patients with multiple sclerosis by means of applying gustatory irritants by the drop method. The patients showed an elevation of the threshold of gustatory sensation as compared with the healthy concerning sweet, salty, bitter. In 5 patients unstable loss loss of taste was the first symptom of the disease.

[Evaluation of time parameters of visual perception in the diagnosis of retrobulbar neuritis]. / Otsenka vremennykh parametrov zritel'nogo vospriiatiia v diagnostike retrobul'barnogo nevrita.

The suggested complex of the perimetric and electrophysiologic methods for the assessment of the function of the visual analyzer has helped detect diffuse involvement of the ocular system in clinically unilateral retrobulbar neuritis and define the incidence rate of involvement of the contralateral normal optic nerve. Prolongation of the latency of visual perception appears to be characteristic of retrobulbar neuritis and indicates the demyelinization of the nerve visual fibers.

[Specific anosmia to isovaleric acid in the peripheral portion of the olfactory analyzer of the laboratory mouse]. / Spetsificheskaia anosmiia k izovalerianovoi kislote v perifericheskom otdele oboniatel'nogo analizatora laboratornoi myshi.

The olfactory mucosa of laboratory male mice of lines C57BL/6 and AKR was stimulated by vapours of isovaleric acid and isoamylacetate of various concentrations. Study of electro-olfactography has demonstrated that mice of line C57BL/6 were insensitive to isovaleric acid of concentrations from 10(-5) to 10(-3) mol/l and remained normally sensitive to isoamylacetate. The mice of line AKR were sensitive to isovaleric acid of the same concentrations. The authors suggest using mice of these line as a model for investigations of the olfactory reception mechanisms.

[Status of the sensory sphere in schizophrenic patients with a cenestopathic-hypochondriacal syndrome]. / Sostoianie sensornoi sfery u bol'nykh shizofreniei s senestopaticheski-ipokhondricheskim sindromom.

The state of and interrelations between the kinesthetic and visual sensitivity were studied in 70 patients and 24 normal subjects by using the technique of parallel-sequential sensometry suggested by A. V. Zavyalov. At 30 sec intervals at the constant baseline irritation, 16 thresholds of weight differentiation and 16 thresholds of brightness differentiation were registered. The results were subjected to the correlational and informational analysis. It was established that hyposensitivity of the sensory systems studied was accompanied with the weakening of direct and strengthening of the inverse optical-kinesthetic correlation, the absence of the functional predominance of the kinesthetic analyzer over the visual one, low orderliness of the parameters of the interanalyzer relationship and a sharp liability of the intersensory correlation to the effect of the heterosensory irritant. Changes in the systemic organization of the sensory sphere seem to be responsible for various cenesthopathies.

GABA-related phenomena, models of nervous system function, and seizures.

Models of nervous system function are presented that place particular emphasis on the roles in nervous system function of inhibitory neurons that liberate gamma-aminobutyric acid (GABA) as neurotransmitter. The nervous system is considered to be highly restrained, with inhibitory neurons acting like reins that serve to keep the neuronal "horses" from running away. In behavioral sequences, whether innate or learned, preprogrammed circuits are released to function at varying rates and in various combinations. This release is accomplished largely by the disinhibition of pacemaker neurons whose activities are under the control of tonically active inhibitory command neurons, many of which may use GABA as a transmitter. In addition to their restraining function, local circuit GABAergic neurons participate in feed-forward, feedback, surround, and presynaptic inhibition and in presynaptic facilitation. Information arriving from several sources is integrated in specialized analyzing regions, such as the cerebellar cortex, basal ganglia, and reticular nucleus of the thalamus. Monosynaptic inhibitory GABAergic outputs reflecting this analysis then play upon neural elements in the direct channels, making their activity optimally compatible temporally and spatially with that of neural elements elsewhere in the central nervous system. Seizures are prototypical of incoordination between inhibition and excitation. Major causes of seizures may be the loss of inhibitory GABAergic terminals at the site of focal cortical epilepsy or a disturbance in various aspects of GABAergic function.