[Application of shot-latency cortical somato-sensory evoked potentials for evaluation of swallowing disorders in early period after posterior fossa surgery].

UNLABELLED: Main tasks of early postoperative period in patients after posterior fossa surgery are the timely and safe weaning from mechanical ventilation and extubation. For clinical assessment of the hypopharynx function we use an algorithm developed in the intensive care unit (ICU) of the Burdenko Scientific Research Institute of Neurosurgery. Disadvantages of the clinical test for assessment of patient's readiness for extubation are subjectivity and impossibility to use it in conditions of even superficial sedation. Shot-latency somato-sensory evoked potentials (SSEP) can be applied in conditions of sedation and objectify the brain stem deficit. The goal of the study was to define the changes of cortical SSEP in patients with disorders of swallowing after posterior fossa surgery. To assess the swallowing disorders we used a scale of swallowing disorders in intubated patients with brain stem damage. We compared results of cortical SSEP, test of swallowing disorders in intubated patients and clinical results of extubation. 17 patients with tumors of posterior fossa were included in the study. All patients were divided into two groups depending on duration of mechanical ventilation. Patients of the group-1 were successfully extubated in 4.5 hours. Patients of the group-2 were mechanically ventilated more than 15 hours because of impossibility to pass the test of readiness for extubation. RESULTS: Central conduction time symmetry index after the surgery was lower in the group-1 than in group-2. There was inverse correlation between amplitude of cortical response N20 and time from the patient's admission to the ICU until the moment of extubation. CONCLUSIONS: Asymmetry of central conduction time and decreasing of N20 amplitude can be used as additional predictor of swallowing disorder.

[Prognostic value of D-dimer fibrin level in neurosurgical patients before elective hospitalization].

Deep vein thrombosis and pulmonary embolism in postoperative period are very dangerous complications for patient with any surgical pathology. Frequency of deep vein thrombosis in neurosurgical patient can be up to 25-30%. D-dimer level is considered as one of the most reliable indicator of thrombosis. We measured D-dimer level before hospitalization for elective surgery in 4052 patients with different neurosurgical pathology. It was found clear correlation with elevated D-dimer level and frequency of ultrasound signs of thrombosis. In patients with simultaneous presence of elevated D-dimer level and external signs of varicose veins diagnosis was confirmed by ultrasound in every cases. We consider that D-dimer can be reliable screening method for assessment the risk of thrombosis in neurosurgical patients in preoperative period.

[Specific features of cerebral blood flow changes after surgical removal of chiasmatic-sellar region tumors using data of transcranial duplex sonography].

Aim of the study was to discover specific features of linear blood velocity in early postoperative period in patients with tumors of chiasmatic-sellar region. Measurement of linear blood velocity using transcranial duplex sonography was performed in 294 patients with tumors of hypothalamo-hypophyseal area (149 suprasellar pituitary adenomas, 145 endosuprasellar, hypophyseal and ventricular craniopharyngiomas). It was found that vasospasm of different severity was present in 62% cases after surgical removal of chiasmatic-sellar region tumors. This "primary vasospasm" was associated with intraoperative damage to a vessel. Delayed angiospasm was caused by subarachnoid hemorrhage into basal cisterns due to hyperactivation of neuroendocrine systems of adenohypophysis and aldosterone. Persistent vasospasm with linear blood velocity over 200 cm/s results in irreversible ischemic damage of subcortical and hypothalamic structures.

[Venous thromboses and pulmonary arterial thromboembolism in neurosurgical patients].

The paper gives the results of a study conducted in 3 groups of neurosurgical patients in the analysis of autoptic material over 15 years in order to detect pulmonary arterial thromboembolism (PATE) as a cause of postoperative death in neurosurgical patients. In the latter, the incidence of PATE was ascertained to be 5.4%, as evidenced by autopsy and the distribution of the onset of a fatal outcome was biphasic. The informative value of determination of the blood level of fibrin D-dimer was analyzed in neurosurgical patients as a screening method for diagnosing prethrombosis. The method has shown to be of high informative value (about 90% sensitivity) and may be used in clinical practice. The effectiveness and safety of the combined procedure of preventing venous thromboembolic events (mechanical method with a subsequent switching over to pharmacological methods on days 3) were evaluated. The method has proven to be effective and safe.

[Pulmonary thromboembolism in neurosurgical patients. Part 3. Analysis of the clinical effectiveness and safety of combined prevention of thromboembolic events in neurosurgical patients in the perioperative period].

The paper presents the results of clinical evaluation of combined prevention of leg deep vein thrombosis and pulmonary thromboembolism in 130 neurosurgical patients undergoing intracranial interventions for brain tumors. Combined prevention comprises mechanical (compression knitted wear + periodic pneumatic leg compression by a special device) and pharmacological (subcutaneous injection of low molecular-weight heparins on postoperative day 2, followed by the daily administration of acetylsalicylic acid from the moment of a patient's activation) treatments. The study has indicated that this preventive procedure is effective and at the same time safe against the development of intracranial hemorrhagic complications.

[Pulmonary thromboembolism in neurosurgical patients. Part 2. Estimation of the informative value of determination of fibrinogen D-dimer levels in the preoperative period].

The paper presents the results of clinical evaluation of the informative value of determination of blood fibrinogen D-dimer in 177 neurosurgical patients undergoing intracranial interventions for brain tumors. Screening detection of patients at high risk for thromboembolic complications is based on the determination of the blood levels of D-dimer on the first day after admission. To verify the diagnostic informative value of D-dimer determination, the patients with higher values (0.5+/-0.03 ng/l) underwent ultrasound scanning of lower extremity veins within the following 1-2 days. Despite its preliminary nature, the study showed the predictive value of determination of blood D-dimer levels in neurosurgical patients in the preoperative period and in the screening of prethrombotic events.

[The adaptive-compensatory reactions of the systemic circulation in the acute period of severe craniocerebral trauma]. / Adaptatsionno-kompensatornye reaktsii sistemnogo krovoobrashcheniia v ostrom periode tiazheloi cherepno-mozgovoi travmy.

The paper deals with the most important problem of performance of central hemodynamics in the acute period of craniocerebral injury. The author recorded an informative set of central hemodynamic parameters, which allowed him to assess not only central hemodynamics, but its reserve and compensatory potentialities. He investigated variations of the parameter set in various brain injuries, by using it as a functional test for some pharmacological agents, which is essential in evaluating their efficacy in these abnormalities. The findings define the role of disorders of blood circulation regulation and cardiac performance. The mode of assessing the hemodynamic parameters is promising in obtaining new data on this point.

[Effect of nootropic agents on the brain bioelectrical activity and on the indices of neuromediator metabolism in the acute period of severe craniocerebral trauma]. / Vliianie nootropov na bioélektricheskuiu aktivnost' mozga i pokazateli neiromediatornogo obmena v ostrom periode tiazheloi cherepno-mozgovoi travmy.

Clinico-biochemical examination and EEG were conducted in 39 patients with severe craniocerebral trauma who were given nootropic agents in a complex of intensive therapy measures. Four types of changes of monoamine metabolism in treatment with piracetam were revealed which were combined with two types of EEG changes. The authors recommend the time for beginning piracetam therapy depending on the level of traumatic injury to the brain.

[Disorders of systemic hemodynamics in the acute period of severe craniocerebral trauma]. / Narusheniia sistemnoi gemodinamiki v ostrom periode tiazheloi cherepno-mozgovoi travme.

Disorders of systemic hemodynamics were studied in 68 patients in the acute period of severe cerebrocranial trauma. Three types of systemic hemodynamics were revealed: normodynamic--in corticohemispheric level of brain injury, hypodynamic--in injury to the stem, and hyperdynamic--in hemispheric-subcortical damage. The authors consider the hyperdynamic and hypodynamic types of the responses of systemic hemodynamics as a prognostically unfavourable sign.

[Disorders of viscero-autonomic and neurohumoral regulation in tumors of sellar-diencephalic localization]. / Narusheniia vistserovegetativnoi i neirogumoral'noi reguliatsii pri opukholiakh selliarno-diéntsefal'noi lokalizatsii.

Twenty-nine patients with varying degrees of hypothalamic lesion were studied for disorders of viscero-vegetative and neurohumoral regulation. Three types of impairments were identified: intact under-compensated, reduced, and perverted. The type of disorders was found to correlate with the degree of the impact of the pathologic process on the hypothalamic structures. It is emphasized that preoperative examination of the central hemodynamics and biogenic amines allows the prediction of their impairment in the postoperative period.

[Experimental study of emotional reactions in patients with destruction of the mediobasal structures of the temporal lobe of the brain]. / Eksperimental'noe izuchenie émotsional'nykh reaktsii u bol'nykh s destruktsiei mediobazal'nykh struktur visochnoi doli mozga.

In 15 patients with destruction of the amygdala complex and the hippocampus, changes in EEG and skin-galvanic reflex were recorded when they were imagining events inducing emotions and when they were anticipating nociceptive stimulation. It was shown that lesion of mediobasal structures in the right temporal lobe results in a more pronounced impairment of emotional reactions than their ablation on the left. Bilateral lesion of the amygdala complex and the hippocampus brings about a decrease of the heart rate under the action of emotiogenic stimuli instead of its increase, and diminishes the difference between objective manifestations of positive and negative emotional states.