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Tumors of peripheral nerves.
Among the tumors of the peripheral nerves, neuroma (neurolemmoma), arising from Schwann cells of the nerve shells, and neurofibroma, which develops from endobromous and fibrous fibroblasts, occur most frequently. Neuroma can be localized in the cranial cavity and spinal canal, in the distal regions of the peripheral nerves. When intracranial localization, the tumor is usually located either in the bridge-cerebellar angle and develops from the lemocytes of the eighth pair of nerves, or near the top of the pyramid of the temporal bone and affects the trigeminal nerve in the area of the large semilunar Gasser node. When localized in the vertebral canal, neurinomas are usually located in the region of the posterior roots, sometimes taking the form of an hourglass due to growth beyond the spinal column. If the neuroma is localized in the distal parts of the peripheral nerves, then it can be located in the soft tissues or in the internal organs. Macroscopically, the tumor is an encapsulated node usually 2-3 cm in diameter. Casuistic cases of giant neuromas weighing several kilograms are described. Microscopically, two types of neurino by Antony are distinguished: type A and type B neurinomas. Type A neuromas are constructed from elongated cells that form rhythmic figures in the form of parallel rows that are separated by a homogeneous eosinophilic nuclear-free zone. Such structures are called Taurus Verokai. Type B neurinomas do not form Verocai. They often define myxomatous patches, foci of xanthomatosis, viciously developed vessels, and fibrosis. Malignization with neurinomas is rarely observed, malignant neuromas (neurogenic sarcomas) of the peripheral nerves, characterized by increased mitotic activity and a cystic structure, are more typical. On the basis of histological and biological features, neurofibromas are divided into two types: skin neurofibromas and plexiform neurofibromas. Skin neurofibromas are localized in the dermis or subcutaneous tissue, do not have a capsule, and are constructed from spindle-shaped cells.
The stroma is rich in collagen fibers. Plexiform neurofibromas develop in patients with type 1 neurofibromatosis (Recklinghausen's disease). They are often multiple, appearing, as a rule, on the scalp or on the neck. Microscopically, the tumor has a myxoid structure with a small number of cells of various shapes. Axons may pass through the tumor site. Ultrastructural and immunohistochemical studies have confirmed the mixed structure of this tumor. Neoplasm cells have Schwann, perineural and fibroblastic elements markers. Lecture equipment Macro preparations: hydrocephalus, brain abscess, purulent leptomeningitis, skeletal muscle atrophy, brain hematoma, ischemic cerebral infarction, brain cyst, brain glioblastoma; atherosclerosis of the arteries of the vilisiev circle. Micropreparations: ischemic cerebral infarction, stasis in brain capillaries, perivascular and pericellular cyst edema, purulent leptomeningitis, acute anterior poliomyelitis, Babesh body — Negri, cerebral hemorrhage, brain cyst wall, diffuse sclerosis, I –––––––––––––––––––– glioblastoma multiforme, meningioma, neuroma.
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Tumors of peripheral nerves.
- MESENCHYMAL TUMORS. TUMORS MELANE-FORMING I TISSUE. TUMORS OF THE CENTRAL NERVOUS SYSTEM, BRAIN SHELL AND PERIPHERAL NERVES
MESENCHYMAL TUMORS. TUMORS MELANE-FORMING I TISSUE. TUMOR CENTRAL NERVOUS SYSTEM, BRAIN SHELL AND PERIPHERAL
- Tumors of the central nervous system (CNS), the membranes of the brain, peripheral nerves
General characteristics. • Most of these tumors are brain tumors; spinal tumors are less common. • In adults, most tumors are supratentorial. • In children, most tumors are infra-central. • CNS tumors are significantly more common in children than in adults. • Primary malignant tumors of the central nervous system metastasize rarely, mainly within the central nervous system by current
- INJURIES TO PERIPHERAL NERVES
There are industrial injuries of peripheral nerves, domestic and wartime injuries. The nerves of the upper extremities — the radial, ulnar and median, are more often affected; less commonly, the nerves of the lower extremities are sciatic and peroneal, which is due to the anatomical relationship with the surrounding tissues. There are closed and open damage. Closed peripheral nerve damage
- DAMAGE TO PERIPHERAL NERVES
Definition Damage to peripheral nerves is called a new neurological deficit that appeared after anesthesia, which can be anatomically localized distal to the CNS. Etiology Damage to peripheral nerves and plexuses due to: direct injury, ischemia, compression; banners. Idiopathic lesions. Typical cases After operations in which for
- Peripheral nerve injury
Wayne E. Wingfield, DVM, MS 1. What is the most common cause of animal neuropathy? Trauma is the most common cause of peripheral, cranial and spinal nerve neuropathy in animals. 2. What are the causes of nerve damage? · Gunshot wounds. · Fractures. · Compression. · Stretching (see below: brachial plexus). · Mechanical shocks. · Iatrogenic causes:
- Diseases of the peripheral nerves and paraganglia
Peripheral nerves consist of dorsal and ventral nerve roots, their endings, vegetative ganglia and their nerve fibers. Most nerves have a mixed structure and consist of somatic (torso), motor (motor) and sensory (sensory) visceral and vegetative fibers. Peripheral nerves are constructed of non-myelinous (0.4-3 microns diameter) and
- Peripheral nerve block
The use of regional anesthesia for operations on the limbs is not a new idea. At the end of the XIX century. Amputation of the extremities was performed after surgical exposure of the nerve trunk and cocaine application: for amputation of the arm, for the brachial plexus, for amputation of the leg, for the sciatic and femoral nerves. With the development of general anesthesia in the first half of the XX century. interest in regional methodologies is noticeable
- Peripheral nerve neuropathy
Neuropathy of the radial nerve. Among the nerves of the upper limb, the radial nerve is affected more often than others. Etiology. Often the nerve is affected during sleep, when the patient is asleep, putting his hand under his head or under the body, with very deep sleep, often associated with intoxication or in rare cases with great fatigue (“sleepy” paralysis). Possible compression of the nerve crutch ("crutch" paralysis), for fractures
- Peripheral Nerve Blockade Techniques
During the blockade of the peripheral nerves, anatomical landmarks, infiltration anesthesia, verification of the needle position by paresthesia, sheath perivascular blockade, transarterial access, and electrostimulation of the nerve are used. 1. CORRECT INSTALLATION OF THE NEEDLE Anatomical landmarks Some types of blockades are performed strictly according to anatomical landmarks. An example is intercostal
- Traumatic injuries of peripheral nerves
As a result of nerve injury, its structural changes occur both in axons and in the bodies of neurons. Degenerative changes in cells are characterized by chromatolysis, edema, the movement of Nissl's substance to the periphery of the nerve cell and several others. In axons distal to the site of its damage, Wallerian degeneration begins. Axoplasma and myelin disintegrate and undergo phagocytosis, in
- Peripheral nerve impairment of the extremities