11/8/2015 1 Assessment of Neurologic System Anatomy and Physiology • Nervous system controls body functions through voluntary and autonomic responses to external and internal stimuli • Nervous system consists of the central nervous system (brain and spinal cord), peripheral nervous system and the autonomic nervous system Anatomy and Physiology: Central Nervous System • Protective structures • Skull protects the brain • Foramen magnum – spinal cord extends from medulla oblongata in brainstem • Meninges – between the skull and the brain • Dura mater, arachnoid and pia mater • Subarachnoid, between arachnoid and pia mater, where cerebrospinal fluid (CSF) circulates •Cerebral ventricular system – four interconnecting chambers (ventricles) that produce and circulate CSF • One lateral in each hemisphere, 3 rd adjacent to thalamus, 4 th adjacent to brainstem.
Transcript
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Assessment of Neurologic System
Anatomy and Physiology
• Nervous system controls body functions through voluntary and autonomic responses to external and internal stimuli
• Nervous system consists of the central nervous system (brain and spinal cord), peripheral nervous system and the autonomic nervous system
Anatomy and Physiology: Central Nervous System
• Protective structures• Skull protects the brain
• Foramen magnum – spinal cord extends from medulla oblongata in brainstem
• Meninges – between the skull and the brain• Dura mater, arachnoid and pia
mater
• Subarachnoid, between arachnoid and pia mater, where cerebrospinal fluid (CSF) circulates
•Cerebral ventricular system – four interconnecting chambers (ventricles) that produce and circulate CSF•One lateral in each hemisphere, 3rd adjacent to
thalamus, 4th adjacent to brainstem.
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• Cerebrospinal fluid and cerebral ventricular system• CSF –colorless, odorless fluid that contains glucose, electrolytes,
oxygen, water, carbon dioxide, protein and leukocytes
• Produced in choroid plexus of ventricles
• Circulates around brain and spinal cord to provide cushion, maintain normal intracranial pressure, provide nutrition and remove metabolic wastes
• CSF circulation: from lateral ventricle through interventricularforamen to 3rd ventricle through aqueduct of Sylvius to 4th
ventricle into cisterna magna (small reservoir for CSF).
• From cisterna magna, CSF flows up around brain and down around spinal cord.
• CSF absorbed through arachnoid villi and returned to venous system
Anatomy and Physiology: Brain
•Consists of cerebrum, diencephalon, cerebellum and brainstem•Gray matter (cell bodies) and white matter (myelinatednerve fibers)
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Anatomy and Physiology: Brain (cont)
• Cerebrum – Largest part of brain• Composed of two hemispheres divided into four lobes ( frontal
lobe, parietal lobe, temporal lobe, and occipital lobe)• Frontal lobe –primary motor cortex and responsible for voluntary
motor activity functions, controls intellectual function, awareness of self, personality and autonomic responses related to emotion• Left frontal lobe – Broca’s area – formulation of words
• Parietal lobe – contains primary somesthetic (sensory) cortex• Major function to receive sensory input such as position sense, touch,
shape and texture of objects
• Temporal lobe –contains primary auditory cortex and interprets auditory, visual and somatic sensory inputs that are stored in thought and memory• Left temporal lobe – Wernicke’s area – responsible for
comprehension of spoken and written language
• Occipital lobe – contains primary visual cortex and is responsible for receiving and interpreting visual information
Anatomy and Physiology: Brain (cont)
•Diencephalon – comprises thalamus, hypothalamus, epithalamus and subthalamus•Thalamus – relay station •Hypothalamus – maintain homeostasis
• Regulation of body temperature, hunger and thirst, formation of autonomic nervous system responses and storage and secretion of pituitary gland hormones
•Basal ganglia - create smooth, coordinated voluntary movement by balancing production of two neurotransmitters: acetylcholine and dopamine
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Anatomy and Physiology: Brain (cont)
•Brainstem – midbrain, pons and medulla oblongata
•Midbrain – relay stimuli concerning muscle movement to other brain structures,
•Pons – relays impulses to brain centers Medulla oblongata – reflex centers for controlling involuntary functions of breathing, sneezing, swallowing, coughing, vomiting and vasoconstriction.
•Cerebellum –separated from cerebral cortex by tentorium cerebelli•Coordinate movement,
equilibrium, muscle tone and proprioception. Controls movement for same side of body (ipsilateral)
Anatomy and Physiology: Brain (cont)
•Blood flow•Carotid arteries supply 80% to brain and two
vertebral arteries supply 20%•Blood to cerebrum by posterior, middle and
anterior cerebral arteries•Posterior and anterior communicating
arteries to circle of Willis•Blood leaves brain through venous sinuses
into jugular veins
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Anatomy and Physiology: Spinal Cord
•Spinal cord – continuation of medulla oblongata• Begins at foramen magnum and ends at L1/2 vertebrae
• At L1/2 branches into lumbar and sacral nerve roots ( cauda equina)
• Nerve fibers transmit sensory, motor and autonomic impulses between brain and body
• Descending (motor) tracts carry impulses from frontal lobe to muscles for voluntary movement and play role in muscle tone and posture
• Ascending (sensory) tracts carry sensory information from body through thalamus to parietal lobe
5 pairs sacral and 1 pair coccygeal • First seven cervical nerves exit above corresponding
vertebrae• Rest exit below corresponding vertebrae• Motor fibers carry impulses from brain (frontal lobe)
through spinal cord to muscles and glands• Sensory fibers carry impulses from sensory receptors of
body through spinal cord to brain (parietal lobe)
Anatomy and Physiology: Peripheral Nervous System (cont)
•Reflex Arc • Response to sensory stimuli
• Deep tendon reflexes – responses to stimulation of a tendon that stretches neuromuscular spindles of a muscle group• Strike a deep tendon reflex – stimulates sensory neuron that
travels to spinal cord – stimulates interneuron – stimulates motor neuron to create movement
• Superficial reflexes tested in same manner
• Each reflex corresponds to specific spinal segment
Anatomy and Physiology: Autonomic Nervous System
•Regulates body’s internal environment with endocrine system• Sympathetic nervous system
• Activated during stress (flight or fight response)
• Increase blood pressure and heart rate, vasoconstricting peripheral blood vessels, inhibits gastrointestinal peristalsis and dilates bronchi
• Parasympathetic nervous system• Controls vegetative functions (breed and feed)
• Conserving energy: decrease heart rate and force of myocardial contraction, decrease blood pressure and respiration and stimulate gastrointestinal peristalsis
Anatomy and Physiology: Gerontological Considerations
• Dilation of ventricles
• Cortical atrophy (greater in frontal and temporal lobes)
• Decrease in brain weight (decrease in neuron size)
• Change in release of neurotransmitter
• Changes in motor function –stooped, forward-flexed posture and slow gait
• Loss of muscle strength
• Changes in sensory and motor function, memory, cognition and proprioception
• Decline in sensorimotor function
• Changes in eye-lens thicken, smaller pupil size
• Hearing loss (50% over 75)
• Decrease in short term memory
• Decline in fluid intelligence
• Slow reaction time
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Health History: Present Health Status
•Changes in ability to move around or participate in usual activities
•Medications – anticonvulsant, antitremor, antivertigo or pain medications
•Alcohol consumption, legal or recreational mood-altering drugs
Health History: Past History
• Injury to head or spinal cord. Residual changes from experience
• Surgery to brain, spinal cord or any nerves. Outcome of surgery
• Stroke. Residual changes
• Seizure disorder, type, frequency, prevention
Health History: Family History
•Stroke, seizures or tumor of brain or spinal cord
Risk Factors for Brain Attack
• Non-modifiable• Age• Gender• Family history• Race• Previous brain attack or heart attack
• Modifiable• Smoking• Control of Diabetes • Coronary artery disease• Transient ischemia attacks• Atrial fibrillation• High serum cholesterol • Obesity• Excessive alcohol intake• Cocaine use
Problem-Based History• Using symptom analysis or “OLD CARTS” for each of the following
symptoms
• Headache, recent surgeries or medical procedures (spinal anesthesia or lumbar puncture)
• Dizziness or light headedness, difficulty keeping balance, feel like may fall, associated with positional change or activity, sensation of room spinning
• Seizures, become unconscious, warning signs of impending seizure, if unconscious – progress through body, change in color of face or lips, loss of bowel or bladder control, length of time before back to normal self, feelings afterwards, confused, headache or aching muscles, sleep, factors that start seizure (stress, fatigue, activity or stopping medication), methods initiated to prevent injury during seizure, affect on your lifestyle, wear alert ID, occupation
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Problem-Based History (cont)
• Loss of Consciousness, blackout or faint –occurs suddenly, history of diabetes, liver failure or kidney failure
• Changes in movement – length of time had mobility change, continuous or intermittent, tremors or shaking of hands or face, affect of tremors or shaking on performance of ADL’s, history of thyroid disease, twitches or sudden jerks, sense of weakness in or difficulty moving parts of body, associated with an activity, problems with coordination or keeping balance, lean to one side, legs give way
• Change in sensation – numbness or tingling, description of feeling, associated with any activity
• Dysphagia –length of time, involve liquids or solids or both, excessive saliva or drooling, cough or choke when trying to swallow
• Dysphasia/Aphasia – length of time, difficulty forming your words or finding right words, understanding things said to you, change in handwriting
Physical Examination
•Many of the cranial nerves will be examined later under the specific system, eg eyes etc. For this reason, we will omit them here but they are considered indicative of Neurological assessment.
Examination: Equipment
•Aromatic material
•Penlight
•Tuning Fork
•Cotton-tipped applicator
•Tongue blade
•Disposable gloves
•Paper clip
•Cotton ball
•Percussion hammer
• Snellen’s chart
Glascow Coma Scale
• Best eye opening response
Spontaneously 4
To verbal command 3
To pain 2
No response 1
Glascow Coma Scale cont
• Best verbal response
Oriented, converses 5
Disoriented, converses 4
Inappropriate words 3
Incomprehensible sounds 2
No response 1
Glascow Coma Scale cont
•Best motor response – to voice or painObeys 6Localizes pain 5
•Test cerebellar function for balance and coordination• General observation – gait of client walking across room
and turning around and walking back• Upper extremity
• Tap thighs with hands using rapid pronation and supination movements
• Have client close eyes and stretch arms outward. Use index fingers to alternately touch the nose rapidly.
• Examine finger coordination by alternating movement of fingers by having client touch each finger to thumb in rapid sequence.
• Have client rapidly move index finger back and forth between his/her nose and your finger 18 inches apart
Coordination with Rapid Alternating Movements
Coordination with Rapid Alternating Movements
Examination of Finger Coordination Fine Motor Function
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Physical Examination (cont)
Test cerebellar function for balance and coordination (cont)• Lower extremity
• With client in supine position, have them place heel of one foot to the knee of other leg, sliding it all the way down the shin.
• For all of the following, stand in front of client to prevent falling:• Romberg test
• Heel-toe walking a straight line
• Hop in place on one foot
• Walk on toes, then heels
Balance
• Heel to Toe
Balance
• Hopping on one
• foot
Physical Examination (cont)
•Evaluate extremities for muscle strength and sensation
•Evaluate extremities for deep tendon reflexes. There are five deep tendon reflexes (triceps, biceps, brachioradial, patellar and Achilles). Refer to pg 630 in your textbook for the correct method for position of the extremity and placement of the reflex hammer. Scoring of deep tendon reflexes are recorded from 0 = no response to 4+ = brisk, hyperactive with intermittent clonus. See Box 25-3 page 630 in textbook.
Triceps Reflex Biceps Reflex
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Brachioradial Reflex Patellar Reflex
Achilles Reflex Plantar Reflex – Babinski sign
Verbalization of Findings
•Client is a 55 yo white male who denies any changes in ability to move or participate in usual ADL’s. Denies any chronic diseases, only takes multivitamin and low dose ASA. Denies alcohol intake, tobacco or recreational or other mood-altering drugs. Has never had injury or surgery to brain or spinal cord, stroke or seizure disorder. No family history of stroke, seizures or tumor of brain or spinal cord. Denies history of headache, dizziness, seizures, loss of consciousness, changes in movement or sensation, dyspagia or dysphasia/aphasia.
Verbalization of Findings (cont)
• Client speaks clearly with appropriate inflection and sufficient volume to be heard. CN I – XII intact. (When you are demonstrating each of these, you will identify the name and number of the cranial nerve as well as what you are examining.). Upright posture, gait smooth, rhythmic and balanced as uses opposing arm swing. Negative Romberg sign. Able to maintain balance when walks heel to toe and hops on one foot. Maintains upper extremity coordination with rapid alternating hand movementand with finger to thumb sequence. Has fine motor function. Maintains lower extremity coordination with point to point testing. Differentiates sharp, dull and light touch on arms and legs. Deep Tendon Reflexes (DTR’s) bilaterally 2+. (When you perform the DTR’s, you will identify each one and give the score for each one as you compete it). Negative Babinski.
