Neurology as science Neuropathology (from Greek neuro – nerve, pathos – disease, logos – science) – is a part of clinical medicine, which is involved in nervous diseases and its role in pathology of other organs and systems of human body
Functions of nervous system The main function of nervous system is unification and regulation of different physiological processes. That means that nervous system unites, integrates and subordinates all the parts of human body and provides its connection with environment.
Functions of nervous system The base of nervous system activity is reflex principle Reflex – is a reaction of our organism to various outside and inside effects. It is provided by nervous system.
Reflex consists of: afferent part (which accepts information) central part (that keeps information) efferent part (that creates response). As a result we have a circle – like structure - receptor (primary information centre) – programme centre – executive apparatus. As a result we have a circle – like structure - receptor (primary information centre) – programme centre – executive apparatus.
Reflexes are divided into: simple and complex inborn and trained conditioned and unconditioned
Unconditioned reflexes: They are inborn ones They are phylogenetically old, that means they were formed in course of phylogenesis They are based on certain anatomic structures (segments of spinal cord or brain stem) They exist even without brain cortex influence They are inherited They can be regulated by brain cortex They are basis for the conditioned reflexes
Conditioned reflexes: They are the result of the individual experience and are formed during ontogenesis They are unstable, that means they need constant support They arent based on certain anatomic structures They are fixed in brain cortex There are such conditioned reflexes as speaking, writing, reading, calculation, practice
Unconditioned reflexes are divided into: Superficial and deep Simple and complex Proprioceptive (stretch, periosteal, joint) Exteroceptive (dermal, from mucose membrane) Interoceptive (from mucose membrane of internal organs – for example urination in case of internal sphincter irritation)
Motor system Provides conduction of nervous impulse from brain cortex to muscles. The way of this impulse is known as motorway or tractus corticomuscularis. It consists of two neurons: centralperipheral
Paralysis is divided into: Central (spastic) Peripheral (flaccid) Central or spastic paralysis is caused by the lesion of central neuron and its fibers (tr. corticospinalis or tr. corticonuclearis). Peripheral or flaccid paralysis is caused by the lesion of peripheral neuron (tractus spinomuscularis or tractus nucleomuscularis).
Features of central (spastic) paralysis are: 1. It is a diffuse paralysis 2. There is spastic hypertonus of muscles 3. Hyperreflexion of stretch and periostal reflexes 4. There are pathologic reflexes. They are considered to be reliable signs of central paralysis 5. Protective reflexes (the reflexes of spinal automatism) 6. Pathologic synkinesis is involuntary movements in paralysed extremity
Spastic hypertonus features: Tonus is increased in the group of flexors in upper extremities and in the group of extensors in lower extremities clasp – knife symptom in course of evaluation tonus decreases
Flexing pathological reflexes Bechterevs sign Jukovski sign Rossolimo (Venderovych) reflex
Extension pathological reflexes
Synkinesis are divided into: GlobalCoordinatoryImitating
Pathologic reflexes on upper extremities: Bechterevs sign. This is simply a muscle-stretch reflex of bending of fingers obtained by tapping the back of hand with a reflex hammer. Jukovski sign. This is caused by hammer impact on a palm under fingers; response is reflex flexing of II-V fingers. Rossolimo (Venderovych) reflex: This is simply a muscle-stretch reflex obtained by tapping the palmar surfaces of the fingers with a reflex hammer; the response is reflex flexing of II-V fingers. Tremner reflex. This is simply a muscle-stretch reflex obtained by tapping the palmar surfaces of the nail-phalax of II – V fingers. The response is fingers flexing. Jakobson – Laske reflex. This is caused by hammer impact on processus styloideus; the response is reflex flexing of II-V fingers. Klipel – Veil reflex. This is caused by passive bending of II – V fingers. The response is thumb flexing.
Central paralysis
Features of peripheral paralysis 1. Areflexion or hyporeflexion 2. Atonia or hypotonia 3. Muscular atrophy 4. Fasciculation of muscles 5. It is limited paralysis 6. There is reaction of degeneration.
Types of gate:
Symptoms of motor way lesion 1. The lesion of anterior central gyrus monoplegia (or monoparesis) on the opposite side. If the focus is situated in upper part of anterior central gyrus, paralysis of lower extremity occurs. If it is in middle part of anterior central gyrus, we can observe paralysis of upper extremity. If it is in lower one, face suffers. If it is in lower one, face suffers. In case of anterior central gyrus irritation Motor Jackson takes place. Motor Jackson is a set of local seizures that can cause generalized seizures. 2. The lesion of radiate crown central hemiplegia on the opposite side (that means that arm, leg, lower mimic muscles and tongue muscles are involved). Paralysis can dominates in lower extremity,in upper extremity or in face muscles Besides hemianesthesia can join hemiplegia.
Symptoms of motor way lesion The lesion of internal capsule part of motor way hemiplegia on the opposite side, central paresis of tongue muscles and lower mimic muscles Hemihypesthesia often joins all the other symptoms. Vernike – Mann posture is typical for this lesion. Hemianopsia 4. The lesion of brain stem alternating syndrome- central paralysis on the opposite side and peripheral paralysis of face muscles on the side of lesion. The last are divided into peduncle, pontine and bulbar ones. 5. The lesion of pyramidal decussation part of motor way central paralysis of upper extremity on the side of lesion and paralysis of lower extremity on the opposite side. Sometimes tetraplegia or triplegia is observed.
Symptoms of motor way lesion 6. The lesion of motor way in lateral funiculus of spinal cord central paralysis below the level C1-C4, C5-Th1, Th1- Th12, L1-S2 7. The lesion of anterior horns or motor nucleus of CNs peripheral paralysis of certain muscles with fasciculation of muscles. Also there are early atrophy and degenerative reaction. 8. Anterior roots lesion peripheral paralysis. In most of cases it is observed only when several roots are damaged. 9. The lesion of nerve plexus peripheral paralysis, pain, sensory and autonomic disturbances 10. The lesion of peripheral nerve peripheral paralysis of the muscle, innervated by this nerve, pain, sensory and autonomic disturbances.