Nervous system- its anatomy and physiology, and detailed neurological examination

2. SEMINAR ON NERVOUS
SYSTEM
Ms Alisha Talwar

3. ANATOMY AND
PHYSIOLOGY OF NERVOUS
SYSTEM

4. NERVOUS SYSTEM
Nervous system consists of the brain, spinal cord, sensory organs and Nerves
These organs are responsible for the control of the body and communication among its parts.
The brain and spinal cord form the control centre known as the central nervous system (CNS), where
information is evaluated and decisions made.
The sensory nerves and sense organs of the peripheral nervous system (PNS) monitor conditions inside
and outside of the body and send this information to the CNS. Efferent nerves in the PNS carry signals
from the control center to the muscles, glands, and organs to regulate their functions.

5. FUNCTIONS OF NERVOUS SYSTEM
Sensory input – gathering information
To monitor changes occurring inside and outside the body
Integration - To process and interpret sensory input and decide if action is needed
Motor output
A response to stimuli
Activates muscles or glands

6. Classification of Nervous System

7. CENTRAL NERVOUS SYSTEM

8. REGIONS OF THE BRAIN
Cerebral Hemisphere
Diencephalon
Cerebellum
Brain Stem

9. • Paired (left and right)
superior parts of the
brain
• Include more than
half of the brain mass
• The surface is made
of ridges (gyri) and
grooves (sulci)
CEREBRAL HEMISPHERE

10. The cerebral hemisphere involved in logical resoning, moral
conduct, emotional responses, sensory intepretation and the
initiation of voluntary muscle activity.
“Pathways of nerve impulses are crossed pathways- means that
Left side of brain controls RIGHT SIDE OF BODY and Right side of
brain controls LEFT SIDE OF BODY”

11. Figure 7.13c
SPECIALISED AREA OF BRAIN

13. YELLOW BLUE ORANGE BLACK RED GREEN PURPLE YELLOW
RED ORANGE GREEN BLACK MAGENTA CYAN BROWN PINK
Left-Right Conflict
Your right brain tries to say the colour but your left brain insists
on reading the word.
LOOK AT THE CHART AND SAY THE COLOUR NOT THE WORD

14. Sits on top of the brain stem
Enclosed by the
cerebral hemispheres
Three parts:
Thalamus
Hypothalamus
Epithalamus
DIENCEPHALON

15. Attaches to the spinal cord
Parts of the brain stem:
• Midbrain
• Pons
• Medulla oblongata
BRAIN STEM

16. • Two hemispheres with
convoluted surfaces
• Provides involuntary
coordination of body
movements
• “Arbor vitae” design of
white & grey matter
CEREBELLUM

17. FUNCTIONS OF LOBES

18. Extends from the
medulla oblongata to
the region of T12
Below T12 is the cauda
equina (a collection of
spinal nerves)
Carries sensory and
motor information
SPINAL CORD

19. PERIPHERAL NERVOUS SYSTEM

20. Sensory (afferent) division - Nerve fibers that carry information to
the central nervous system
Motor (efferent) division - Nerve fibers that carry impulses away
from the central nervous system.
Somatic system:
voluntary
Autonomic system:
involuntary
PERIPHERAL NERVOUS SYSTEM

21. AUTONOMIC NERVOUS SYSTEM

22. The involuntary branch of the nervous system
Consists of only motor nerves
Divided into two divisions
Sympathetic division(stimulates) – “fight or flight” response. Its activation
results in increased heart rate and blood pressure.
Parasympathetic division(inhibits) – “housekeeping system” It maintains
homeostasis by seeing that normal digestion and elimination occur and
that energy is conserved.
AUTONOMIC NERVOUS SYSTEM

23. NEURON

24. • Dendrites – conduct impulses toward
the cell body
• Cell body (soma): contains organelles
& Nissl substance (specialized rough
ER)
• Axons – conduct impulses away from the
cell body
• Schwann cells – produce myelin
sheaths in jelly-roll like fashion
• Nodes of Ranvier – gaps in myelin
sheath along the axon
NEURON

25. CLASSIFICATION OF NEURON
On the Basis of Function
• Sensory (afferent) neurons-Carry impulses from the sensory receptors
• Interneurons (association): “connector”
• Motor (efferent) neurons-Carry impulses from the central nervous system

27. CLASSIFICATION OF NEURON
On the Basis of Structure

29. Reflex – rapid, predictable, and involuntary responses
to stimuli
Reflex arc – direct route from a sensory neuron, to
an interneuron, to an effector
REFLEX ARC

30. 12 pairs of nerves
that mostly serve the
head and neck
Numbered in order,
front to back
Most are mixed
nerves, but three
are sensory only
CRANIAL NERVES

32. FACTS ABOUT NERVOUS SYSTEM
There are more nerve cells in the human brain than there are stars in the Milky Way
If we lined up all the neurons in our body it would be around 965 km long
There are 100 billion neurons in your brain alone
A newborn baby's brain grows almost 3 times during the course of its first year
The left side of human brain controls the right side of the body and the right side of the brain
controls the left side of the body
A new born baby loses about half of their nerve cells before they are born

33. There are about 13, 500,00 neurons in the human spinal cord
The nervous system can transmit nerve impulses as fast as 100 meters per second, and in some cases,
the speed of transmission is around 180 miles per hour
A man's brain has 6.5 times more gray matter compared to women, but a woman's brain has 10 times
more white matter compared to men
Your nervous system cannot function properly in the absence of potassium and sodium ions. Vitamin B is
equally essential for your nervous system.

38. NEUROLOGICAL
EXAMINATION

39. NURSING HISTORY
• Current Health History
– Headaches, memory and concentration, visual disturbances, hearing,
balance, dizzy spells, speech, muscle strength, abnormal sensations
• Past Health History
– Head injury, spinal cord injury, surgery, seizures
• Family History
– Neurological diseases, headaches, HTN, stroke, DM
• Social History and Habits
– Diet, vitamin deficiencies, ability to read or concentrate,
exposure to toxins or chemicals, alcohol or drug use, sexual
difficulties, sleep problems
• Medication History-neuro as well as all others

40. WHAT ARE THE COMPONENTS AND HOW DO I DOCUMENT
THEM?
Neuro:
Mental Status
Language, Speech
Cranial Nerves
Motor
Reflexes
Sensory
Cerebellar
Gait

41. COMPLETE NEUROLOGICAL ASSESSMENT HAS 5 COMPONENTS
• Cerebral Function
• Cranial Nerve Function: I-XII
• Cerebellar and Motor Function
• Sensory System
• Reflexes

42. NEURO CHECK
• Level of consciousness (LOC)
• Pupil response and size
• Verbal responsiveness
• Extremity strength and movement
• Vital signs
Establishing BASELINE and regularly re- evaluating key indictors
reveals trends and detects changes  warning signs of problems

43. CEREBRAL FUNCTION
• Level of consciousness:
– Level of arousal: Subcortical RAS
• Alert  lethargic  unresponsive
• Auditorytactile painful stimuli to elicit response
– Level of orientation: Cortex activity
• Person, place, time
• Speech
– Quality: Clear, slurred
– Verbal responses appropriate or nonsensical
– Ability to understand and follow commands
– Awareness of and difficulties with communication

44. 44
ASSESSING LOC:
GLASGOW COMA SCALE
Eye opening
Verbal responsiveness
Motor responsiveness

45. 45
PHYSICAL EXAMINATION
Levels of Consciousness
Alert- awake or easily aroused
Lethargic- not fully alert, drifts off when not
stimulated
Obtunded- sleeps most times, difficult to arouse (loud
noise, vigorous shaking or pain)
Stupor- need persistent loud noise or pain for
arousal; responds to stimuli
Coma- no response
(Jarvis CH 2)

47. PUPIL REACTION SCALE
•Assess Pupillary Status and Eye movement
Size of pupils should be equal
Reaction of pupils
Accommodation: pupillary constriction to accommodate near vision
Direct light reflex: constriction of pupil when light is shone directly into the
eye
Consensual reflex: constriction of the pupil in the opposite eye when the
direct light reflex is tested.
•Evaluate ability to move eye
Note nystagmus
Ability of eyes to move together
Resting position of iris should be at mid-position of the eye socket
•PERRLA

49. CEREBRAL FUNCTION:
Verbal Responsiveness and Speech
• Dysarthria: difficulty with mechanics of speech
• Aphasia:
– TEMPORAL-receptive
• Inability to understand or process speech Wernicke’s
• Auditory: spoken word
• Visual: written word
– FRONTAL-expressive
• Inability to form or use language Broca’s Area
• Spoken OR written or BOTH

50. MINI-MENTAL STATE
• Widely used tool
• Assesses only cognitive abilities
– LOC, abstract reasoning, arithmetic calculations, writing
ability, memory and judgment
• Objective score based on results

52. CRANIAL NERVES (CNS)
• CN I- Olfactory
• CN II- Ophthalmic
• CN III-
Occulomotor*
• CN IV- Trochlear*
• CN V- Trigeminal
• CN VI- Abducens*
• CN VII- Facial
• CN VIII-
Vestibulocochlear
• CN IX-
Glossopharyngeal
• CN X- Vagus
• CN XI- Spinal
Accessory
• CN XII- Hypoglossal

53. CRANIAL NERVE I
• Olfactory nerve (sensory)
– Vulnerable to damage in frontal head, basilar, and
facial injuries
– Performed one nostril at a time
– Able to correctly identify smells

55. CRANIAL NERVE II
• Optic nerve (sensory)
– Visual acuity, visual fields, ophthalmic exam of retinal
structures
– Area and extent of visual field loss depends on
location of problem
Use the snellen chart to check/test:
- distant vision
- color
Client should be 20 feet distant from the chart
Use an object to occlude one eye
Evaluate the vision one eye at a time

56. VISUAL FIELD DEFECTS

57. CRANIAL NERVE III
• Oculomotor nerve (motor)
– Elevation of eyelid
– Muscles of eye (with IV and VI)
– Assess pupil size, shape, response to light and accommodation
parasympathetic inervation
– Assesses midbrain
– Normal response: PERRLA-> pupils equal round reactive to light and
accommodation
• How do you test for accommodation?
• If PERRL, usually no need to test

58. CN III, CN IV, CN VI
• Oculomotor, trochlear, abducens nerves (motor)
– Assess EOM’s
– Assesses midbrain and pons

60. CN V: TRIGEMINAL NERVE (SENSORY
AND MOTOR)
• Sensory: three branches:
– Opthalmic, Maxillary, Mandibular
• Motor:
– Muscles of mastication
• Palpate temporal and masseter muscles
• Open mouth symmetry
– Corneal reflex
• ? Contact wearers

62. CN VII: FACIAL NERVE (SENSORY AND MOTOR)
• Sensory: taste to anterior 2/3
of tongue
• Motor: Facialexpression and
secretion of saliva
– Wrinkle forehead, raise and
lower eyebrows, smile and show
teeth, puff cheeks, close eyes
– Observe for symmetry
• UMN problems vs. facial

64. CN VIII: ACOUSTIC NERVE (SENSORY)
• Vestibulocochlear nerve:
– Hearing (cochlear) and balance (vestibular)
• Testing: Tuning Fork: Weber and Rinne tests
– Weber: tuning fork to center of forehead:
• NORMAL: hear equally in both ears
– RINNE: tuning fork to mastoid process then
auditory canal
• NORMAL: hear air conduction 2X as long as
bone (Rinne positive)

66. CN IX AND CN X
• Glossopharyngeal and Vagus
• Sensory and motor
• Assess together
– Taste posterior 1/3 of tongue
– Swallowing, gag reflex
– Movement of pharynx
(ahhhhh)
• Assesses medulla

68. CN XI: SPINAL ACCESSORY NERVE
• Motor
• Shrug shoulders trapezius
• Turn head sternocleidomastoid

70. CN XII: HYPOGLOSSAL NERVE
• Motor
• Tongue movements, strength
• Speech sounds: d, l, n, t

72. MOTOR ASSESSMENT
• Assess muscle strength, tone, size
– Observe for decreased fine motor movements
– Finger grasp, arm strength
– Compare side to side
• Can indicate UMN problems:
– Degenerative cerebral disease, trauma or ischemia
• Can indicate LMN disease:
– Problems within spinal cord: cord compression or injury

74. CEREBELLAR FUNCTION
• Balance:
– Tandem, heel-toe walking
– Romberg test (feet together, eyes closed)
• Coordination:
– Rapid alternating movements
– Finger to nose to finger test
– Heel down shin

75. CEREBELLARFUNCTION: ABNORMAL FINDINGS
• Ataxia: incoordination of voluntary muscle action
• Dysdiadochokinesia: inability to do rapid alternating movement
• Dysmetria: past pointing
• Positive Romberg’s sign
– Pt sways badly or loses balance positive Romberg sign
• If cerebellar, pt sways with eyes open or closed
• If proprioceptive ( posterior columns) patient OK with eyes
open

76. GAIT DISTURBANCES
A. Spastic Hemiparesis
B. Spastic Paresis (Scissors
Gait)
D. Foot Drop
E. Sensory Ataxia
(+ Romberg’s eyes closed)
G. Cerebellar Ataxia
(+ Romberg’s eyes open or
closed)
F. Parkinsonian

77. DEEP TENDON REFLEXES ASSESSING SPINAL
CORD LEVEL
• Biceps
C5C6
• Brachioradialis C5C6
• Triceps
C7C8
• Abdominal
T8T9T10
• Patellar (knee-jerk) L2L3L4
• Achilles

78. GRADING REFLEXES
• Grade 0-4+
– 0  reflex absent
– 2+  “normal”
– 4+  CLONUS  UMN
disease
• Compare side to side
• Many variations
• Patient must be relaxed

79. SUPERFICIAL REFLEXES
• Graded as PRESENT or ABSENT
• Corneal Reflex (CN V)
– Present  Brisk blink
– Loss in stroke, coma, CONTACT WEARERS
– EYE PROTECTION
• Gag Reflex (CN X)
– Present  Elevation of uvula bilaterally
– Loss in stroke
– ASPIRATION PRECAUTIONS

80. PLANTAR REFLEX: BABINSKI RESPONSE
• Stroke lateral aspect of sole of foot
• NORMAL response  plantar FLEXION
• BABINSKI response  pathological in adult
– POSITIVE BABINSKI: Dorsiflexion of great toe with fanning of other
toes
– Indicates upper motor neuron disease

81. GRASP REFLEX: SIGNIFICANCE
• COMA: Stimulation of palm of hand
– POSITIVE: Pt will grasp firmly
– Will not let go to command
– Indicates frontal lobe damage, thalamic
degeneration, cerebral atrophy

82. SENSORY FUNCTION
• Assessing dorsal columns or parietal lobe
– Light touch, position sense, vibration
– Stereognosis: able to identify object placed in hand
– Graphesthesia
– Extinction: touch one or both sides of body
– Two point discrimination
• Spinothalamic tracts and parietal lobe
– Pain and temperature
• Sharp or dull

83. NEUROLOGICAL DIAGNOSTICS

84. ANATOMICAL PLANES

85. SKULL AND SPINAL X-RAYS
• C-spine films routinely ordered in
multiple trauma to rule out cervical
fracture
• X-rays used to evaluate skull, spinal
abnormalities, pituitary tumor
• Frequently ordered to evaluate low back
pain

86. COMPUTERIZED TOMOGRAPHY
• Cross sectional images brain and spine
using radiation and computer
• More specific views of bone and
tissue than X-rays
• Useful in detecting tumors,
hemorrhages, hematomas, ventricular
enlargement
• May be used with IV contrast

87. CT: PATIENT PREPARATION
• Pt must be as motionless as possible
– Confused combative client/ pediatric considerations
• If contrast used:
– ?? allergies to shellfish
– NPO for 4 hours prior to test
– IV started in radiology (if not already in place)
• Should remove wigs, hairpins, clips and jewelry interfere with image
seen
• Test should take 30-60 minutes
• Post-test: resume diet and encourage fluids if IV

88. PET SCAN
• Images of actual organ
functioning
• Inhaled or injected
radioactive substance
• Shows metabolic
changes
– Alzheimer’s
– Brain tumors
– O2 uptake after stroke

89. MRI: NURSING CONSIDERATIONS
• Use of electromagnet and radio waves
• Check patient history!!
– PATIENTS WHO CANNOT HAVE MRI:
• Pacemakers
• Metal implants, plates, screws, or clips (old aneurysm surgeries!)
• IUD’s, metal heart valves
• SAFETY:
– IV pumps, portable oxygen tanks cannot be in scan area
• Patient Preparations and teaching:
– No metals: jewelry, credit cards, eyemakeup
– Process takes 45 minutes to 1 hour  pt. must lie still
– MRI machine makes loud beating noise
– Closed MRI: tight space: problems with claustophobia?
• May need Valium pre-test/ some cannot tolerate

90. CEREBRAL ANGIOGRAPHY
• Injection of contrast medium into
cerebral circulation
• Useful in detecting cause of stroke,
headaches, seizures
• Femoral access most commonly used
vessel
• Risk: stroke

91. CEREBRAL ANGIOGRAPHY:
Procedure & Patient Preparation
• Injection of contrast medium into cerebral circulation
– Useful in detecting cause of stroke, headaches, seizures
• NPO solids 6-10 hours
– Clear liquids/ water encouraged 24 hours prior
• Assess PT/ PTT
– Stop anticoagulants prior to test (usually)
• Contrast dye precautions/ informed consent
• Patient AWAKE; slight sedation
• Femoral puncture  mark peripheral pulses
• Burning or flushing with contrast injection expected
• Procedure will take 1-2 hours

92. MR ANGIOGRAPHY (MRA)
• Utilization of MR technology to view
vasculature
• Same restrictions as MRI
• May use contrast material (gadolinium)
but is not iodine based

93. MYELOGRAM
• Injection of contrast medium into subarachnoid
space x-ray visualization
• Useful for visualizing obstructions within spinal
canal
– Dye bathes nerve roots any compressin of nerve roots
visualized
– Helpful in diagnoses of herniated discs and spinal cord
tumor

94. PATIENT PREPARATION
• Inpatient procedure/ 23 HR
• Consent form
• NPO 4-8 hours prior
• Probably mild sedation given; IV started
• Lumbar puncture in radiology CSF aspirated
• Either water based (Amipaque) or oil based (Pantopaque) dye used
– Hold phenothiazines (Phenergan), TCA’s, SSRI’s 48 hours
• Lower seizure threshhold
– X-ray table tilted
• CT performed at end

95. POST-PROCEDURE CARE
• Amipaque: not aspirated absorbed by body
– HOB 30-60 degrees for 24 hours
• Pantopaque: aspirated at end of visualization
– Patient flat for 24 hours (rarely used)
• Quiet activity, little stimulation
• Push fluids, monitor I and O, BUN, Creatinine
• BP, RR, pulse temperature monitored
• May experience nausea, headache should diminish  no
Phenergan or Compazine!
• No neck stiffness or confusion should occur

96. EEG
• Amplifies and
records electrical
activity in brain
• Uses:
– Detecting areas of abnormal or absent brain
activity
• Brain tumors, hematomas, seizure activity
• Determination of brain death in comatose
patient

97. EEG PREPARATION USE OF
EVOKED POTENTIALS
• Preparation:
– Avoidance of caffeine prior to exam
– No gels, sprays in hair
– Must be quiet and still as possible
• Evoked Potentials:
– Auditory, sensory, visual: record brain activity
in response to stimuli
– Diagnostic for various disorders

98. ELECTROMYOGRAPHY (EMG) AND NERVE CONDUCTION VELOCITIES (NCV)
• EMG: Needle electrodes inserted into skeletal muscles patient
relaxes and contracts various muscles and action potential
recorded
• NCV: Nerve stimulated with electrical impulse
• Useful in studying patients with cervical or lumbar disc
disease, myasthenia gravis, muscular dystrophy (LMN
diseases)
• Patient should be taught to expect some mild discomfort

99. LUMBAR PUNCTURE
• Insertion of needle into
subarachnoid space
between L2 and S1
• Withdrawal of small
amount CSF for
diagnostic evaluation
• Measurement of CSF
pressure
– Should not be
performed if evidence
of greatly increased
CSF pressure

100. LUMBAR PUNCTURE
•Patient preparation:
No diet or fluid restrictions
Empty bowel and bladder before
Careful instructions regarding cooperation during test
Signed consent require
•Positioning
d

101. LUMBAR PUNCTURE
• CSF in three labeled tubes
– Protein and glucose
– Culture
– Blood cell counts
• Post-procedure care:
– Prone with pillow under abdomen for 1 hr
– Flat in bed 6-24 hours (30 degrees)
– Increased fluid intake
– Observe site for swelling, leakage
– Observe for post spinal headache

102. POST-LUMBAR PUNCTURE HEADACHE
• Most common complication
• CSF leaks from needle track  depleted
• Increases when patient upright
• AVOID: use small gauge needle/ keep prone after
• Treatment: bedrest, analgesics, hydration
– Persistent: Blood patch

103. CSF FLUID ANALYSIS
• Pressure: Normal: 70-180 mmH2O (5-15mmHg)
– Increased: SAH, brain tumor, viral meningitis
• Appearance: clear and colorless
– Bloody: SAH or traumatic tap (will clear)
– Cloudy: infection
– Orange or yellow: RBC breakdown, elevated protein

104. CSF FLUID ANALYSIS
• Cell Count: 0-5 monos and no RBC’s
– Elevated monos infection, abcess, tumor, infarction, chronic illness
(MS)
– RBC’s SAH or traumatic tap
• Protein: 15-45 mg/dl
– Lower than plasma because of BBB
– Elevated: infection, tumor, MS, degenerative brain disease
• Glucose: 50-75 mg/dl
– Elevated: DM or diabetic coma
– Decreased: acute bacterial meningitis, tumor

105. THANK YOU