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A N Konovalov

Publications and source records attributed to A N Konovalov.

At least 19 recordsLinked to original sources
PubMed2004

[Results and outlooks of using cell technologies in the treatment of neurological diseases].

An attempt was undertaken in the last decade of the 20th century to use a principally new approach to the treatment of neurological diseases--cell therapy. Main efforts were focused on developing a method related with replacement of neurons dying in neurodegenerative pathology, primarily, in Parkinson disease (PD). Outlined below are the key elements of the technology:--ensuring, in experiment, of a prolonged therapeutic effect in transplantation, to the affected part, first of embryonic neurons of the animal of the same species (allografting) and then of homologous embryonic neurons of man (heterografting);--obtaining, standardization and preparation (for transplantation) of embryonic nervous tissue of man; transplantation of embryonic nervous tissue of man to the brain of patient and evaluation, in situ, of the functional activity of its neurons; and evaluation of the therapeutic effect of grafting. Cell suspension of meseencephalon of 6-9 week human fetus containing around 10% of differentiating dopaminergic neurons was used for grafting in PD. Embryonic dopaminergic neurons, administered stereotactically into the striatum of patient, established synaptic links with neurons of the recipient, which was accompanied by the onset of synthesis and reverse uptake of dopamine (DA) as well as by the onset of spontaneous and stimulated release of DA. Neurografting ensured a temporary improvement of the condition in a part of PD patients but did not cure them. Moreover, such positive therapeutic effect was registered only in patients with the akineticorigid but not trembling variation of the disease. Hence, although there was a certain progress in clinical neurografting, the approach cannot be now recommended for introduction in neurology and neurosurgery. The limited therapeutic effect of the treatment method is primarily explained by a low rate of survival of transplanted dopaminergic neurons and, consequently, by the persisting DA deficit in patient's body. Therefore, the outlooks for perfecting the cell technology are related with increasing the survival rate of implanted dopaminergic neurons and with stimulating the innervation of target neurons in patient's striatum as well as with using the neural (glia) and non-neural (fibroblasts, myoblasts) cells with modified gene and stem cells. Finally, despite a certain progress of advancing the cell technology in neurology the approach still needs more research, which would enable further clinical trials.

Brain Tissue Transplantation↗
PubMed2002

Surgical treatment of the thrombosed vein of galen aneurysm.

OBJECTIVE AND IMPORTANCE: Vein of Galen aneurysm is a rare congenital anomaly of cerebral circulation and occurs mainly in newborns and children. The spontaneously thrombosed vein of Galen aneurysm is especially rare and an uncommonly reported event. CLINICAL PRESENTATION: Two patients with a spontaneously thrombosed vein of Galen aneurysm were operated on at our institute. CT and MRI demonstrated space-occupying lesions of the pineal region and two other masses in the posterior fossa in the second case. The first described case should be referred to as the true type of aneurysm. The vascular malformation, revealed in the second case should be referred to as the false type. In this case the vein of Galen was enlarged to a gigantic size due to the blood drainage from the arteriovenous malformation supplying it from the inferior posterior cerebellar artery. TECHNIQUE: Thrombosed aneurysmal sacs were resected totally by subtentorial supracerebellar and median suboccipital approaches. CONCLUSION: The authors report two cases of successful surgical resection of a thrombosed vein of Galen aneurysm in children. Diagnostic features are considered and the informative value of magnetic resonance imaging is stressed. The principles of choosing the right approach and dissection techniques of thrombosed aneurysms of the vein of Galen are described.

Cerebral Veins↗
PubMed2001

Infratentorial supracerebellar approach to the colloid cysts of the third ventricle.

OBJECTIVE: The transcallosal and the frontal transcortical approaches are the most widely used methods in surgery of third ventricle colloid cysts. However, these approaches require traction of the frontal lobe and dissection of the corpus callosum or corticotomy and involve some postoperative consequences. The rationale of the proposed method is to remove the colloid cyst by the infratentorial supracerebellar approach and the posterior wall of the third ventricle without dissection of any neural structures. METHODS: Five patients with a colloid cyst of the third ventricle were operated on by the proposed method. The first patient presented with several months' history of symptoms that included increased intracranial pressure and right-sided cerebellar signs, caused by a metastatic tumor of the right cerebellar hemisphere. The other four patients had symptoms including intracranial hypertension for an extended period of time without any other neurological deficits. In all patients, magnetic resonance imaging revealed a colloid cyst of the third ventricle without hydrocephalus. TECHNIQUE: With the infratentorial supracerebellar approach, the arachnoid of the quadrigeminal cistern is dissected. The pineal body is separated and displaced from the internal vein medially, and the posterior velum interpositum is opened. Perforation of the inferior layer of the tela choroidea just above the suprapineal recess allows opening of the third ventricle cavity. A foraminal region is exposed after a slight lateral displacement of medial surfaces of the thalamus along the third ventricle roof. CONCLUSION: The proposed approach through the infratentorial supracerebellar space and the posterior wall of the third ventricle may be used for removal of colloid cysts, especially in patients in whom the lateral ventricles are not enlarged.

Adolescent↗
PubMed1999

Pineal epidermoid cysts: diagnosis and management.

OBJECT: The results of surgical treatment of epidermoid cysts of the pineal region in six cases are presented. METHODS: Six patients with pineal epidermoid cysts underwent surgery at the Institute of Neurosurgery "N. N. Burdenko," in Moscow, during the period 1976 to 1995. The duration of the patients' preadmission clinical history varied from 6 months to 2 years (average 1.4 years). Headache, diplopia, and vertigo were the most frequently occurring symptoms. Neurological examination demonstrated papilledema, impaired pupillary reaction, ataxia, and long-pathways deficit; Parinaud's syndrome was found in only one case. Computerized tomography and magnetic resonance imaging constituted the primary diagnostic tools. Surgery was performed using either an infratentorial-supracerebellar approach (two cases) or an occipital-transtentorial approach (four cases). CONCLUSIONS: Surgical results can be excellent if a removal, as extensive as possible, is performed using either the supracerebellar or occipital-transtentorial approach.

Adult↗
PubMed1997

The Burdenko Neurosurgery Institute: past, present, future.

The Moscow Institute of Neurosurgery was established in 1932. The institute's founders were Nikolai Nilovich Burdenko, the surgeon (his name was later conferred on the institute), and Vasily Vasilyevich Kramer, the neurologist. This article presents the institute's history and its activities in different periods, including scientific and practical achievements in neuro-oncology, cerebrovascular surgery, and neurotraumatology. The institute gave birth to such widely recognized trends as neuropsychology, endovasal neurosurgery, neuroreanimatology (intensive care), and quantitative neuroanatomy. The institute's current problems and prospects for the future are described.

Academies and Institutes↗
PubMed1996

Trigeminal neurinomas. A series of 111 surgical cases from a single institution.

Neurinomas arising from the trigeminal nerve are rare (0.1-0.4% of intracranial tumours: 1-8% of all intracranial neurinomas). A series of 111 trigeminal neurinomas operated on at the Institute of Neurosurgery "N. N. Burdenko" of Moscow, Russia, during the period 1961-1994 is presented. Clinical features, diagnostic radiology, surgery and results of treatment are discussed. We distinguished four groups of trigeminal neurinomas: a) Posterior fossa tumours; b) Tumours of the Gasserian ganglion; c) "Dumb-bell" supra-subtentorial tumours; d) Neurinomas of the peripheral branches. The complex clinical symptomatology is related to the actual location of the lesion. Surgery of trigeminal neurinomas may be very difficult, particularly in cases of dump-bell supra-subtentorial lesions. In this series, 3 cases died postoperatively. Out of the 108 patients surviving surgery, long-term follow-up (min. 13 months, max. 33 years, average 13.5 years) was available in 98 cases. 84 patients (86.7%) showed good-to excellent results, with partial trigeminal deficit as the only surgical sequela. 13 patients (11.7%) had a symptomatic recurrence following incomplete tumour removal. Second surgery, ranging from 1.4 to 9 years (average 3.8 years) following the first operation, was judged radical in 9 cases (69.2), however, the rate of complications of repeated surgery was higher than that occurring after the first operation. The advent of microsurgery, together with the introduction of the techniques of skull base surgery and of modern diagnostic imaging tools, have improved surgical results in terms of increased radicality and reduced complications.

Adolescent↗
PubMed1996

Fronto-orbito zygomatic approach: a technical modification.

The fronto-orbito zygomatic approach is part of the surgical armamentarium of modern skull base surgery. As described in the literature, it requires costly technological tools such as powerful drills and saws, to be performed. In the present communication we describe a technical modification that allows the zygoma to be elevated "en bloc" together with the fronto-orbital bone flap by means of appropriate use of the Gigli's saw. Using this technique, adequate replacement of the craniotomy flap requires only two silk sutures. This technical modification, which was already successfully used in over 20 cases, would also allow this useful approach to be performed in those neurosurgical environments where modern costly technology for cranial base surgery is not available.

Journal Article↗
PubMed1996

Meningioma of the pineal region: a surgical series of 10 cases.

Ten cases of meningioma of the pineal region were histologically verified at a single institution during an 8-year period. These represented 0.3% of 3061 intracranial meningiomas, as well as 6.2% of 164 pineal tumors. Patients were predominantly women. Symptoms and signs of increased intracranial pressure were most common, whereas Parinaud's syndrome was observed in only one case. Computerized tomography (CT) was the main diagnostic test used in the present series. It usually revealed a hyperdense mass with high-intensity contrast enhancement and a calcified mass eccentrically located at the periphery, which returned to its central location postsurgically and was likely to represent a calcified pineal gland. Magnetic resonance imaging was performed in the more recent cases and confirmed the suspicion raised by CT of a meningioma with a calcified mass at its periphery. Surgery was performed using an occipital transtentorial microsurgical approach with the patient placed in the semisitting position. Gross-total tumor removal was achieved in all cases, although this required sacrifice of the vein of Galen in six patients. Venous occlusion was performed only after adequate intraoperative verification of functional occlusion and blood flow diversion from the galenic system and had no consequences in any case but one. This latter patient had an infiltrative meningioma that was removed at the expense of intraoperative sacrifice of the two internal cerebral veins, as well as unavoidable trauma to the region of the quadrigeminal plate. All the remaining patients improved postsurgery, and only one had a permanent visual field deficit as a result of the surgical approach. Pineal meningiomas represent a rare subgroup of pineal tumors that can be treated surgically with reasonably good results. Sacrifice of major basal veins may be required to achieve radical tumor removal and can be tolerated by the patient provided that functional occlusion of the galenic system, as indicated by preoperative angiography, is verified during surgery.

Adult↗
PubMed1992

Surgical treatment of anterior third ventricle tumours.

A review is given on the operative management of anterior third ventricle tumours, with special emphasis on the selection of the approach, the postoperative results and complications. The review is based on our own experiences with 337 cases and 340 operations, among them 198 craniopharyngiomas, 80 gliomas, 23 colloid cysts, 11 ependymomas, and 25 others. The tumours can be approached through the lamina terminals or transcallosally or using a combination of both of these approaches. The approach through the lamina terminalis is useful only in rather small tumours, because it does not allow a sufficient revision of the upper and posterior third ventricle compartments. For larger tumours the transcallosal approach is preferable. We have abandoned the approach through the anterior horn of the lateral ventricle, because it does not allow an equally good vision of both sides of the third ventricle. In some of the craniopharyngioma cases it was necessary to combine the transcallosal and subfrontal approaches in order to achieve total or subtotal tumour resection. In craniopharyngiomas total or subtotal tumour removal was possible in 66% of the children and 59% of the adult patients, with a mortality higher in adults (30%) than in children (18.5%). The main causes of complications in craniopharyngiomas were acute disturbances of hypothalamic circulation and function, with water-electrolyte imbalance and other signs of diencephalic insufficiency. In glioma cases an additional important cause of complications has been haemorrhage into the remaining tumour parts. Colloid cysts could be exstirpated without mortality, using the transcallosal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Endo-suprasellar teratoma with teeth formation. Case report.

A highly ossified teratoma was diagnosed and surgically treated in a 2-year old girl. More than 150 teeth were macroscopically identified during the operation. Pathological study established the diagnosis of mature teratoma with teeth formation. Only six analogous cases have been reported previously and only two patients survived the operation.

Brain Neoplasms↗
PubMed1990

Surgical management of hematomas of the brain stem.

Nine patients with brain-stem hematoma were admitted to the authors' institute during the period from 1985 to 1988. Clinical symptoms and signs pointed to pontine involvement in most cases. Progressive clinical deterioration was quite common and usually led to a clinical diagnosis of brain-stem intra-axial tumor. Angiography was noncontributory; computerized tomography (CT) was the main diagnostic test. This gave evidence of different pathological characteristics, including masses showing highly increased density, nonhomogeneous hyperdense lesions, and isodense lesions with peripheral contrast enhancement. No clear correlation was found, however, between the presumed duration of the clinical picture and the CT characteristics of the lesion. In the last four cases, magnetic resonance imaging was performed using a 0.015-tesla resistive system. This examination usually confirmed the presence of a brain-stem mass already shown by previous CT scans. There were, however, no cases in which direct evidence of an intra-axial vascular malformation could be obtained. The patients were all treated surgically with an attempt at total removal of the lesion and thorough inspection of the hematoma cavity and biopsy. Evidence of "cryptic" arteriovenous malformation was obtained in six of the nine cases. There were minor transitory complications in three cases. All of the patients were able to resume their previous activity, and none suffered recurrence of the symptoms following the operation. It may be concluded that surgery is the treatment of choice for brain-stem hematoma.

Adult↗
PubMed1988

[The unified interdisciplinary classification of closed cranio-cerebral trauma].

The article gives an account of the classification of cranio-cerebral traumas recommended by the IIIrd All-Union Congress of Neurosurgeons. Main clinical forms of cranio-cerebral traumas are described: concussion of the brain, contusion of the brain of light, mild and critical degree, compression of the brain against the background of its contusion and without it. A uniform gradation of disturbed consciousness and criteria for the assessment of the patient's state are presented.

Brain Concussion↗