This document provides an overview of the anatomy and physiology of the neurological system. It describes the central nervous system including the brain and spinal cord. It also describes the peripheral nervous system and autonomic nervous system. Key structures and functions of the brain like the cerebrum, cerebellum, and brainstem are defined. Finally, it outlines various diagnostic tests used to examine the neurological system like MRI, EEG, lumbar puncture, and cerebral angiography.

1. Anatomy and Physiology of the Neurological System

2. Nervous system Coordinates and controls all activities of the body Divisions: Central nervous system: Including the brain, and the Spinal cord. Peripheral nervous system: Made up of the cranial and spinal nerves. Autonomic nervous system: Regulates action of glands and involuntary smooth muscles in the walls of tubes and hollow organs and heart

4. Neurotransmitters Communicate messages from one neuron to another or from a neuron to a specific target tissue. Signaling chemicals released when a nerve impulse reaches a synapse.

5. Central nervous system Brain- largest and most complex part of the nervous system. Weighs about 1400g (adult). Cerebrum -is composed of two hemispheres the thalamus and the hypothalamus. Higherst function of the brain starts here. Cerebral cortex- stores knowledge of impulses received and controls voluntary movement, thought association, discrimination and judgment

6. Frontal lobe- personality, behavior and higher intellectual functions( consciousness, learning, abstract, and creative thinking, problem solving, judgment, memory, volition, and values. Parietal lobe- receives sensory impulses from the opposite side of the body (sight, smell, hearing, taste ) and sensory area for interpretation of pain, touch, temperature, pressure. Temporal lobe- contains auditory center and stores sound memories. Occipital lobe- the posterior lobe of the cerebral hemisphere is responsible for visual interpretation.

7. Brainstem- consist of ascending pathways, reticular formation, cranial nerves and nuclei, descending autonomic and motor pathways. Midbrain- conducts impulses between lower and upper centers . Pons - briges or connects many structures, midbrain and medulla oblongata, cerebellum and rest of nervous system. Center of respiration, swallowing and balance.

8. Cerebellum- aids in coordination of voluntary muscles and balance. Maintenance of muscles tone and posture in space( equilibrium). Medulla oblongata - joins brain and spinal cord ( opening in the base of the skull). Contains nerve fibers ( carrying messages up to and down from brain) group together forming tracts ( bundles ) to function.

10. Peripheral nervous system Cranial nerves- conducts special senses ( smell, visual, auditory). Conducts generalized sense impulses (pain, pressure, touch, vibration, deep muscle sense). Spinal nerves- 31 segments ( 8 cervical, 12 thoracic 5 lumbar, 5 sacral, 1 coccygeal).

11. Autonomic nervous system Control of involuntary bodily functions. Parasympathetic ( cranioscaral )- controls normal body functioning. Sympathetic ( thoracolumbar )- prepares body for “fight” and “flight”.

13. Assessment: The Neurologic Examination Health History An important aspect of the neurologic assessment is the history of the present illness. The nurse may need to rely on yes or no answers to questions. The health history includes details about the onset, character, severity, location, duration, and frequency of symptoms and signs.

14. Physical Examination Neurologic examinationis often limited to a simple screening. The examiner must be able to conduct a thorough neurologic assessment when the patient’s history or other physical findings warrant it. The brain and spinal cord cannot be examined as directly as other systems of the body. The neurologic assessment is divided into five components: cerebral function, cranial nerves, motor system, sensory system, and reflexes.

15. DIAGNOSTIC EXAMINATION Non-invasive tests of structures SPINAL & SKULL X- RAY films examined for the signs of fracture or bony defects, calcification, erosion of the bone, including the size of sella tursica in the skull. Reveals spinal fractures, dislocation, compression, curvature erosion, narrowed spinal cord & degenerative processes Reveals configuration, density vascular markings.

16. Skull X-ray

17. Nursing Care Remove hairpins, hearing aids BRAIN SCANNING [ Radionucleide Imaging Studies] IV injection of radioactive compound & application of scintillation scanner in the patient’s brain an increase uptake of radioactive material at the site of pathology Used to detect intracranial masses, vascular lesions, infarcts, hemorrhage

18. Brain Scanning

19. Nursing Care for Brain Scanning Check for allergy to iodine Keep NPO 4-6 hours before examination MAGNETIC RESONANCE IMAGING [MRI] visualization of the distribution of hydrogen molecules in the body in 3 dimensions superior imaging of body soft tissues & provides more anatomically detailed pictures than that with CT scan does not use harmful ionizing radiation

20. MRI

21. Purposes: Differentiates types of tissues in normal & abnormal states Clinical applications: brain, tumors/ vascular abnormalities, cardiac anomalies, blood vessels, liver dse.,renal abnormalities, gallbladder & tumor Nursing Care Remove all metallic objects andlet patient lie on platform that will be moved into a table cont’ng the magnet

22. Nothing will be be felt during scanning, but (+) sound of the magnetic coils Closely monitor pt. w/ potential respiratory or cardiac collapse Non-invasive tests of structures OPHTHALMODYNAMOMETRY DOPPLER ULTRASONOGRAPHY DOPPLER SCANNING QUANTITATIVE SPECIAL PHONOANGIOGRAPHY

23. Invasive test of Structures Lumbar Puncture introduction of hollow needle with stylet into the lumbar subarachnoid space of the spinal between L1-L5 withdrawal of CSF fluid for diagnostic & therapeutic purposes Purposes: Measures CSF pressure [ n opening P60-150mmH2O] Obtain specimen fore laboratory analysis Check color of CSF & presence of blood Inject air, dye, drugs into spinal canal

25. -Nursing Care Pretest Have client empty bladder Position to lateral with head & neck flexed on the chest Explain the need to remain still Post- test Ensure labeling of CSF specimens in proper sequence Keep client flat for 12-24 as ordered Force fluids

26. Check puncture sites for bleeding, leakage of CSF Assess sensation and movement in lower extremities Monitor vital signs Administer analgesics for headache as ordered. MYELOGRAPHY injection of dye or air into lumbar or spinal subarachnoid space followed by x-rays of the spinal column. Used to study the spinal canal & subarachnoid space Potential complicatins are the same as for lumbar puncture; cerebral irritation from dye

28. Nursing Care: Pretest Keep NPO after liquid breakfast Check for iodine allergy Confirm signed informed consent Pos-test Similar with that of lumbar puncture If oil-based dye was used [ Pantopaque], keep pt. flat for 12 hrs. If water-based [ Mtrizamide-Amipaque], elevate head of bed 30-45 degree to prevent upward displacement of dye meningeal irritation & seizures Institute seizure precautions & don’t administer any phenothiazines

29. PNEUMOENCEPHALOGRAPHY introduction of air or O2 subarachnoid space by lumbar or cisternal puncture to outline the ventricular system & intracranial subarachnoid space for special x-ray studies to localize intracranial lesion VENTRICULOGRAPHY Introduction of air or O2 directly into lateral ventricles by ventrular puncture thru opening made in the frontal, post or occipital regions for special x-ray studies

30. Pnuemoencephalography

31. Ventriculography

32. To visualize ventricles; localize tumors Potential complications: HA,N,V, meningitis, increase ICP Nursing Care Post-test Monitor VS Check neurological status Elevate head of bed ( 15-20degree)

33. CISTERNAL PUNCTURE introduction of hollow needle with stylet in the median line below the occipital bone into the cisterna magna remove CSF when possible to obtain at lumbar level potential complication: Respiratory distress Nursing Care Observe for cyanosis, dyspnea & apnea Same as for lumbar puncture

34. Cisternal puncture

35. CEREBRAL ANGIOGRAPHY injection of radiopaque substance into the cerebral circulation [carotid/vertebral arteries on the neck] to visualize by means of x-rays the blood vessels in the head & neck used to localize tumors, abscesses, aneurysms, hematomas & occlusions Potential complications: anaphylactic rxns to dye, local vasospasm, adverse intracranial pressure]

36. Nursing Care Pretest Keep NPO after midnight or clear liquid Check for iodine allergy Take baseline assessment\ Measure neck circumference Explain warm flushed feeling and salty taste in mouth may be felt during the procedure During & Post-test Have emergency equipment available Monitor neurological status & vital signs for shock, LOC, hemiplegia & aphasia

37. Monitor swelling of the neck, difficulty of swallowing & breathing Administer ice collar/cap intermittently Maintain pressure dressing Bed rest until next morning as ordered

38. Cerebral Angiograhy

39. CERBRAL PERFUSION STUDIES injection of 99 mTc to assess cerebral perfusion in suspected brain death

40. ELECTROENCEPHALOGRAM [EEG] Consists of graphic record of the electrical activity of brain by several small electrodes palced on the scalp Purposes: To detect abnormalities indicative of intracranial pathology or pathological physiology To determine the existence & type of epilepsy

41. Nursing Care Pretest Hair shampoo Withhold sedatives, tranquilizers, stimulant [ 2-3 days] Post test Remove electrode paste with acetone & shampoo hair

42. EEG

43. Peripheral Nerve Studies ELECTROMYELOGRAPHY [EMG] measure & records activity of contracting muscles in response to electrical stimulation helps differentiate muscle disease from motor neuron dysfunction Nursing Care Explain procedure; (+) discomfort due to needle insertion

44. EMG

45. NERVE CONDUCTION STUDIES stimulating a peripheral nerve at several points along its course & recording the muscle action potential or the sensory action potential

46. MUSCLE BIOPSY Used to diagnose neuropathies & myopathies

47. CELLULAR ASSESSMENT Chromosome analysis assists diagnosis of some abnormal neurologic conditions Provides basis for genetic counseling in families w/ evidence of congenital neurologic malformations, mental retardation & seizures.

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