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Complexity of facial anatomy and its rich innervation complicate the diagnosis of prosopalgias. An acute syndrome, including trigeminal, myofascial and cervical pains, is described. Authors discuss algesic interrelations, combined therapeuric effect and peculiarities of diagnosis.

The review of literature presents the contemporary neurophysiological methods of study of pain syndromes in the maxillofacial area (MFA). The authors showed that clinical/neurophysiological features of different variants of chronic headache, the functional state of afferents systems and mechanisms of afferent-efferent interactions in different kinds of chronic headache are been intensively explored. The neurophysiological studies of trigeminal system in the pathogenesis of the pain syndromes have been analyzed as well. Current neurophysiological methods and techniques for estimation of the functional MFA innervation may be used for the diagnosis of different kinds of maxillofacial pain, specification of pathogenetic mechanisms, development of treatment tactics and estimation of treatment efficacy.

Bicoronary access is now considered as optimal for performance of operative interventions in the upper part of face. At the same time, this access is associated with the probability of damaging the innervation of the frontal muscles. Thus, the objective of this investigation was to study the individual variability of topography of facial nerve branches in temporal and parotid areas, with specification of projections of temporal branches of a facial nerve to frontal muscle in order to define a safe zone for dissection. The material was obtained from 36 corpses of adult persons, and precision preparation method was used together with the recording and mathematical processing of the results obtained. It was established, that in objects with a size of tragoorbital line less than 8 cm, a single frontal branch of a facial nerve was present, and its safety zone was about 1 cm to the front from tragus auris. In objects with the size of tragoorbital line equal to 8 cm and more, a common trunk of frontal branch of facial nerve was present together with a branch to m. orbicularis oculi, while its safety zone was equal to 1.5 cm and it was located to the front of tragus auris.

A method for stimulation of the central regulation mechanisms has been used in 53 patients during the early period after cheilorhinoplasty. Electrostimulation by the flickering reflex method is a nonspecific method stimulating sanogenesis which can be used for repair of the neuromuscular function after correction of secondary deformation of the upper lip and palate. Transcerebral laser stimulation indirectly affected the reparative processes in the maxillofacial area by improving metabolism in the cerebrocortical projection zones.

Responses of 375 neurons of SI cortex region in the vibrissae projection zone were recorded in unanesthetized cats: responses to electrical stimulation of infraorbital nerve and mechanical stimulation of vibrissae were studied. Nerve and vibrissae stimulation evoked complex synaptic potentials (short EPSPs followed by IPSPs) in most neurons primary IPSPs were found in other units. The corresponding changes of impulse activity could be recorded in many neurons extracellularly. Initial inhibition was evoked by vibrissae stimulation more frequently (in 45% units comparing to 16% when the nerve was stimulated). Difference of minimal EPSP and IPSP latencies during intraorbital nerve stimulation was 0.8 ms, difference of mean values--1.4 ms. Directional sensitivity of cortical neurons (to the changes in direction of vibrissae deflection) is demonstrated. Neurons located in the close proximity may possess different pattern of directional sensitivity. It is supposed that short latency neuronal inhibition in SI cortical zone is mainly afferent (not recurrent). Probable mechanisms of directional sensitivity of the studied neurons are discussed.

Data obtained by recording single neuronal pulse responses in the fourth layer of somatosensory cortex were compared with those on simulation of coding by cortical neurons of the pattern of tactile image. The results of the simulation indicate that some parameters of tactile stimulus are encoded by the pulse pattern, whose form depends upon the actual spatial form of the tactile stimulus. A study of a neuronal network simulating interaction of cortical neurons in the first somatosensory area has shown that a neuronal network can filter "blot" and "band" configuration.

Combined damage to the large and small superficial petrosal nerves is associated with paradoxical phenomena: face hyperemia, profuse salivation from the parotid gland, lacrimation and mucus secretion from the nose. Face hyperemia and salivation develop following atropine administration (an atropine salivatory paradox) while lacrimation and mucus secretion at the impaired side usually develop during eating. The above is explained by the development of ephaptic ("false") relation between the damaged nerves.

Extracellular and intracellular reactions of 57 neurons from the vibrissal projection region in SI cortical zone were studied in cats. Intensity of both excitatory and inhibitory reactions decreased when stimulation of the receptive field was shifted from the centre to the periphery. A relative role of inhibition of vibrissal stimulation in inhibition/excitation interactions increased during such shift. Neurons recorded in the same microelectrode track had a common centre in the receptive field, but the dimensions of the receptive fields could differ substantially. Units with primary inhibition to the vibrissal stimulation were met.

Extracellular and intracellular responses of cortical neurons localized in SI cortex to repetitive mechanical stimulation of vibrissae were studied in unanesthetized immobilized cats. Spike responses of neurons to stimulation of vibrissae could reproduce somewhat higher frequencies than those in response to electrical stimulation of the infraorbital nerve. An increase in frequency of vibrissae stimulation led to a limitation of peripheral receptive fields. Cortical neurons being able to reproduce relatively high frequencies of vibrissae stimulation and having a tendency to bursting activity were found; correlation between the pattern of discharges in such neurons and IPSPs in other cortical neurons makes it possible to regard such bursting neurons as inhibitory ones. Interaction between excitatory and inhibitory processes in cortical neurons during repetitive vibrissae stimulation is discussed.

The paper is concerned with the results of a clinical electrophysiological, biochemical, histochemical, X-ray and morphological study of 289 patients with different vegetovascular and trophical disturbances, mainly of a regional character, in the facial area. Some clinical aspects and questions of the pathogenesis of these disturbances are discussed which are not sufficiently reflected in the literature. It is suggested that the form of the pterygopalatine ganglion is related to the incidence of the pathological process and the traits of vegetative and pain phenomena, accompanying the Sluder syndrome. Vegetovascular changes were revealed in the skin of the face and enzymatic changes in mucous membrane of the nose on the homolateral to the paresis side of the face in lesions of the facial nerve. Specific vegetative trophical changes were also found in a progressive hemiatrophy of the face, Barrakera-Simons disease, in the syndrome of facial hemistrophy due to lesions of the different vegetative and somatic structures of the nervous system.

Localization and morphology of neuronal groups in the ventrobasal thalamic complex that project to the vibrissae area in the somatosensory rat cortex were studied by means of retrograde axonal transport of horseradish peroxidase (HRP). The HRP-labelled cells were located in the ventroposterolateral nucleus of the ventrobasal complex and were grouped in "barreloids" 100-120 microns wide. Staining of several "barreloids" even when the injection was made in a restricted area of the cortex and the growth of labelled cells number in each "barreloid" with an increase in the injection area suggested the existence of divergence as well as convergence of thalamocortical specific connections. Various forms of relay neurons and different extent of HRP-granule inclusion may reflect their different functional value in thalamocortical relationship.

Results of many-year studies and literary data on the clinical course, pathogenesis and pathogenetic therapy of motor, sensor, and vegetotrophic disturbances in the facial region are reviewed. A concept is substantiated, that neuralgia of the trigeminal, glossopharyngeal and vagal nerves, secondary contracture of the mimic muscles, and facial hemiatrophy are diseases with a specific pathogenesis having no analogy with pain, motor, and trophic disturbances in other parts of the body. This is reflected in the special methods of the pathogenetic therapy of the diseases.

On the basis of analyzing 800 observations on patients with neuralgias and prosopalgias, the authors identify special or paroxysmal neuralgias of the tunnel origin that are marked by a pathognomic clinical picture and require specific therapy. Another group of facial pains--prosopalgias proper--includes pains varying in the origin, clinical course and therapeutic approach. Diagnostic terms for describing neuralgias of the trigeminal nerve are reviewed, and the concept of their primarily central or primarily peripheral origin is proved to be untenable.