ASSESSMENT OF NERVOUS SYSTEM

1. ASSESSMENT OF NERVOUS SYSTEM

2. 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.

3. 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.

6. Reflexes are divided into: • simple and complex • inborn and trained • conditioned and unconditioned

7. 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

8. 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 aren’t based on certain anatomic structures • They are fixed in brain cortex There are such conditioned reflexes as speaking, writing, reading, calculation, practice

9. Unconditioned reflexes are divided into: • Superficial and deep • Simple and complex

10. Unconditioned reflexes are divided into: • 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)

11. In clinical practice we evaluate the following reflexes:

12. 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: • central • peripheral

15. Face, tongue and pharynx muscles innervation This way is called tractus corticomuscularis. • The first central neuron is called tractus corticonuclearis. • The second peripheral one is called tractus nucleomuscularis.

17. We can make the following conclusions: • 1. The face muscles have bilateral cortex innervations except the mimic muscles and tongue muscles that have unilateral innervations from the opposite hemisphere. • 2. The muscles of upper and lower extremities, lower mimic muscles and tongue muscles have unilateral cortical innervations. • 3. All the other muscles (the muscles of neck, trunk, perineum, m. oculomotorial, m. masseter, pharyngeal and palatal muscles) have bilateral cortical innervation.

18. Paralysis • Paralysis (plegia) - means the absence of active movements. It occurs in case of complete lesion of motor way (tractus corticomuscularis) . • Paresis occurs in case of incomplete lesion of motor way. That means disorders of active movements • Clinically can be – hemi-, tetra-, mono-, tri- and paraparesis.

19. 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).

20. 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 synkinesisis involuntary movements in paralysed extremity

22. Central paralysis

23. 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.

27. Gait disorders

28. Sensation is an ability of an organism to accept stimuli from external and internal environment

29. Reception is a set of all afferent systems, which accept stimuli from external and internal environment and carry them out to the center • Reception is wider concept, than sensation. One doesn’t not feel everything he accepts. • Sensation is a part of reception, which one feels and can analyze by certain structures of his brain. It means that sensation is closely connected with activity of analyzers.

30. Analyzer is a sole functional system that consists of three parts: 1. Receiving apparatus (receptors) - receptor part (peripheral) 2. Sensory explorers - conductive part 3. Part of cortex, which receives information, analyzes and synthesizes it

31. The main function of Analyzer is to accept and analyze stimuli. We distinguish the following analyzers: • Visual • Acoustical • Sensual • Testate • Tactile

32. Receptors are sensitive structures that have ability to accept different changes of external and internal environment and transmit them as impulse. Receptors are divided into: • Exteroreceptors (in skin and external mucose membrane) • Proprioreceptors (in muscles, tendons, joints) • Interoreceptors (in inner organs, in vessels)

33. Exteroreceptors accept superficial sensitiveness - light touch (tactile), pain and temperature sense. mechanoreceptors (touch, pressure) thermoreceptors (cold, hot) nociceptors (accept pain)

34. The tactile sense is perceived by: tactile Меrkеl’s bodies on fingers tips Меysnеr’s bodies on palms, soles, lips, on the end of the tongue are very sensitive to any touch Fater-Pachini’s bodies in deep layers of skin perceive sense of pressure. Cold receptors are situated in Krause’s flasks. Thermal receptors are located in Ruffin’s bodies. More fibers react to cold stimuli than to thermal ones. Pain is accepted by free nervous endings between epidermal cells.

35. Proprioreceptors are situated in deep tissues (muscles, joints, tendons). The muscular receptors are variable. The most important of them are: • nervous - muscular cords. They react to tension of muscles. They are covered by a connective tissue case and are situated intra- and extrafusally between the fibers of striated muscles. • The Goldie’s and Matson’s bodies accept joint feeling. They are situated between muscles and tendons. • Osmoreceptors • Chemoreceptors • Baroreceptors

36. The impulse is transmitted from the receptor apparatus to the brain by means of nerve fibers. • The last are axons of unipolar cells of dorsal root ganglia.

37. Classification of sensation І.Classification, which is based on the place of originating of stimuli: • Exteroceptive • Interoceptive • Proprioceptive

38. Classification of sensation ІІ.Classification, which is based on biological principle of originating of sensation: • Protopatical (vital, nociceptive, thalamic). This ancient sensation is typical for the primitive nervous system of our ancestors. • Epicritical sensation is connected with cortex and it is based on the differentiation of stimuli according to their modality, intensity, localization etc.

39. Classification of sensation In clinical practice usually we use classification, which is based on the kind of stimuli: • Superficial • Deep • Complicated

40. Superficial sensation This term includes the modalities of light touch, pain and temperature. • Light touch (tactile) sensation – is feeling of touch, which may be examined by touch of cotton, end of hammer, paintbrush • Superficial pain – is a feeling of pain, which can be tested with a corsage pin or pinwheel (acutely or bluntly, pricks or does not prick) • Temperature sensation – is feeling of cold or hot, which may be tested by application of glass tubes filled with iced (10 C) and hot (43 C) water to the skin

41. Superficial sensation • Trihoesthesia– is a sensation of touch of hair • Hydroesthesia– is a sensation of humidity • Sensation of electrical current • Feeling of tickling

44. Deep sensation This includes joint and vibratory sense and pain from the deep-lying somatic structures, namely, muscle, ligaments, fascia, bone, and so on. • Joint sense(bathyesthesia) - is the ability to distinguish position and passive movements in joints. • Vibration sense (pallesthesia)– is the ability to distinguish different vibration • Feeling of mass (baroesthesia) – is the ability to distinguish different weights • Feeling of pressure - is the ability to distinguish pressure from touch. • Kinesthesia - is a sensation of movement of dermal fold.

48. Complicated sensation • Stereognosis (Three-point distinction) is the ability to identify familiar object placed in the palm of the patient by palpation when the eyes are closed. • Graphism – is the ability to determine figures and numbers traced on the skin with the closed eyes. Graphesthesia – impaired graphism is very sensitive indicator of parietal lobe damage.

50. Complicated sensation • Localization sense- is the ability to point an exact place of the stimuli. • Discrimination sense(two-point discrimination) - tests the ability of the patient to differentiate one stimulus from two. It may be examined by Weber’s circus. • Baragnosis – is the impaired ability to distinguish different weights.