Neurological Assessment Flashcards
CNS vs PNS
Central Nervous System (CNS): brain and spinal cord
- Meninges: connective tissue covering the brain and spinal cord; three layers: dura mater, arachnoid membrane, and pia mater.
- Cerebrospinal fluid (CSF): clear fluid that circulates in and around the brain and spinal cord. Protects the CNS, supplies nutrients and removes waste
Peripheral Nervous System (PNS): cranial nerve, spinal nerves and branches
- Sensory (afferent) message to CNS (body → brain)
- Motor (efferent) messages from CNS(brain → body)
CNS: Cerebral Cortex:
Centre of highest functions; governs thought, memory reasoning, sensation, and voluntary movement. Divided into 2 hemispheres, left and right. (95% of people are left dominated). Each hemisphere is divided into 4 lobes, frontal, temporal, parietal, and occipital.
Describe each lobe in the cerebral cortex:
- Frontal Lobe: personality, behavior, emotion, intellectual functioning
- Broca’s Area: mediates motor speech. When it is damaged in a person’s dominant hemisphere, expressive aphasia results.
- Expressive aphasia: the person cannot talk. The person can understand language and knows what it means but can produce only a garbled sound
- Temporal Lobe: auditory, taste and smell
- Wernicke’s Area: associated with language comprehension. When it is damaged, a person’s dominant hemisphere, the result is receptive aphasia
- Receptive aphasia: can hear sounds, but it has no meaning. Like hearing a foreign language.
- Parietal Lobe primary sensory area
- Occipital Lobe primary vision reception center
Basal Ganglia
situated deep within the two cerebral hemispheres. They control automatic associated movements of the body, such as the arm swing that alternates with the leg movement during walking
Thalmaus
just above the brain stem, it is the main relay station for the nervous system. Sensory pathways of the spinal cord and brain stem form synapses on their way to the cerebral cortex
Hypthalamus
a major control center with vital functions: temperature, heart rate, blood pressure; regulates sleep and the anterior/posterior pituitary gland; actions happen w/o conscious control
Pituitary gland:
below hypothalamus; master gland of the body; produces many different hormones to direct certain processes
Cerebellum
under occipital lobe, its concerned with motor coordination of voluntary movements (doesn’t initiate movement), equilibrium, muscle tone
Brainstem
relays messages to and from the brain. Plays a role in coordinating vitals
- Midbrain: most anterior part, contains motor neurons and tracts
- Pons: enlarged area containing ascending and descending fiber tracts
- Medulla: continuation of the spinal cord, contains all ascending and descending fiber tracts connecting the brain to the spinal cord. Has a vital role in ANS.
Pathways from CNS (Sensory and Motor)
Sensory Pathways (ascending tract): detects in the periphery and sends to the brain
1. Spinothalamic:
Pain, temperature light (crude) touch (cannot be precisely located)
2. Posterior (dorsal) column
Proprioception, vibration, stereognosis (able to identify a familiar item in hand, eyes closed)
Motor Pathways (descending tract): message from the brain to periphery
1. Corticospinal (Pyramidal) Tract (highest order motor system)
Voluntary movement, purposeful and skilled movements (playing piano)
2. Extrapyramidal Tract (older, more primitive system)
Muscle tone
Gross body movements
3. Cerebellar System (works on a subconscious level)
Coordinates movement
Maintains equilibrium
Posture
Upper vs Lower Motor Neurons
Upper Motor Neurons (UMN):
Located in CNS
Influence LMN
Ex: Corticospinal, extrapyramidal, cerebellar
Lower Motor Neurons (LMN):
Located in PNS
Final pathway
Ex: Spinal cord nerves, cranial nerves
Describe the components of the peripheral nervous system:
Afferent vs Efferent: sensory vs motor
12 Cranial Nerves: exit brain rather than spinal cord; mainly supply head a neck; sensory, motor or both
31 pairs of Spinal Nerves: exits spine; mixed nerves (sensory and motor)
Dermatomes: area on the skin that is supplied by 1 spinal nerve
Reflex Arc: part of normal function of PNS; basic defense system; involuntary. Sensory message causes immediate motor response (hot plate)
Autonomic Nervous System
Sympathetic Nervous System: fight or flight
Parasympathetic Nervous System: feed, breathe, rest, digest
Cranial Nerves:
- OLFACTORY (sensory) smell
- OPTIC (sensory) vision
- OCULOMOTOR (mixed) m-EOM movements, opening eyes; P-pupil constrictions, lens shape
- TROCHLEAR (motor) down and inward eye movement
- TRIGEMINAL (mixed) M- muscle of mastication; S- sensation on face, scalp, cornea, muscous membranes of mouth and nose
- ABUDCEN (motor) lateral movement of eye
- FACIAL (mixed) M- facial muscles, close eys, labial speech, close mouth; S- anterior 2/3 tongue taste; P- saliva and tear secretion
- ACOUSTIC (vestibulocochlear)(sensory) hearing and equlibrium
- GLOSSOPHARYNGEAL (mixed) M- pharynx, S- taste posterior 1/3 tongue; P- parotid gland, carotid reflex
- VAGUS (mixed); M- pharynx and larynx, S- general sensation from carotid body, carotid sinus, pharynx, viscera; P- carotid reflex
- SPINAL ACCESSORY (motor) movement of trapezius and sternomastoid muscle
- HYPOGLOSSAL (motor) movement of tongue
Describe the reflex arc
- Basic, adaptive response to a painful or damaging stimulus; reactions before thinking.
1. Deep Tendon Reflexes (DTRs) (patellar/knee jerk)
2. Superficial Reflexes: exist within the skin (corneal reflex-blink when something comes towards the eye)
3. Visceral Reflexes (pupil response to light)
4. Pathological Reflexes: unexpected reflex response (newborn reflexes existing for longer than they should)
Neurological considerations: Infants:
- Dramatic growth and development of the neurological system during 1st year of life
- Initially, movement directed primarily by primitive reflexes
- Sensory and motor system develops during process of myelinization
- Cephalocaudal and proximal to distal order: starts with control of head, neck, then trunk and can sit, then outer limbs to crawl and walk
Neurological Considerations: Older Adults
- General atrophy: impaired fine coordination and agility, correction and balance (The brain atrophies 10-15% by age 90)
- Cranial/spinal nerves: velocity of nerve conduction decreases, which slows reaction time and causes sensory changes
- Motor system: slowing down of movement (motor system atrophy). Progressive decline in cerebral blood flow and oxygen consumption. May cause dizziness, loss of balance
- Intellectual capabilities: possible to maintain cognitive functioning till the end, but depends on the person. Due to changes in myelin, reaction time may be slower to respond but not necessarily changes in cognition
Dysarthria
difficult or unclear articulation of speech, that’s otherwise linguistically normal
Systematic approach of neurological physical exam?
Cranial nerves
Motor system
Sensory system
Reflexes
How do you test the motor system in a neurological exam?
- MUSCLES: engage in passive ROM
- Size
- Strength
- Tone
- Involuntary movements - CEREBELLAR FUNCTION
Balance Tests
- Gait: walk 10 feet back and forth, observe involuntary arm swing, smooth and symmetrical
- Tandem walking: walk on a line, heel to toe. Issues with coordination are highlighted when the base of support decreases
- Romberg test: support patient. Stand with feet together, arms at their side and close eyes for 20 secs. A little swaying is expected but should be corrected without falling. Falling = positive sign
Coordination & skilled Movement:
- Rapid alternating movements: ex touch thumb to each finger on the same hand, starting with index finger, then reverse the direction. Or hands on thighs, alternate palm and back of hand. Should be done quickly and accurately with an even pace/rhythm
- Finger-to-finger test: with patients eyes open, ask them to use their index finger to touch your finger, than their own nose. Move your finger around to a few different spots. Movement should be smooth and accurate
- Finger-to-nose test: ask patient to close eyes and stretch out arms. Patient touches tips to their nose with each index finger, alternating hands and increasing speed. Movement should be accurate and smooth
- Heel-to-shin test: patient in supine position, places heel on opposite knee and run it down the shin from knee to ankle. Normally, heel moves in straight line down the shin
How do you test the sensory system in a neurological exam?
Spinothalamic Tract
Pain: break tongue blade in half. Alternate touching the patient with the jagged side and rounded side. Ask the patient to identify if its dull or sharp
Temperature: not routinely tested, you may if abnormal response to pain. Can put cold object like metal against skin
Light touch: use cotton or gauze and touch different points of the body, patient tells you when they feel it
Posterior Column Tract
Vibration: place vibrating tunning fork on bony prominence, ask the patient to indicate when the vibration starts and stops. Start distally, if they feel it they likely feel it proximal too so no need to test. If no vibration is felt, move proximally. Test both sides
Position (kinesthesia): close eyes and move the patient’s limb in different positions (finger). They tell you whether it moved up or down
Fine touch (tactile discrimination): also measures the discrimination ability of the sensory cortex. The patient needs a normal or near-normal sense of touch and position sense
Stereognosis: eyes closed, put something familiar in hand and they identify the object (pen, key).
Graphesthesia: write a letter or number in patients hand, see if they can identify
2-point discrimination: apply two points of an opened paper clip lightly to the skin in ever-closing distances. Note the distance at which the patient no longer feels two separate points. Most sensitive in fingertips, least sensitive un upper arms, thighs, back
Cranial nerve I
- OLFACTORY (sensory) smell
Cranial nerve II
- OPTIC (sensory) vision
Cranial never III
- OCULOMOTOR (mixed)
motor: EOM movements, opening eyes
Parasympathetic: pupil constrictions, lens shape
Cranial nerve IV
- TROCHLEAR (motor)
down and inward eye movement
Cranial nerve V
- TRIGEMINAL (mixed)
Motor: muscle of mastication
Sensation: sensation on face, scalp, cornea, muscous membrane of nose and mouth
Cranial nerve VI
- ABDUCENS (mixed)
Lateral and outward movement of the eye
Cranial nerve VII
- Facial (mixed)
Motor: facial muscles, close eye, labial speech, close mouth
Sensory: taste on anterior ⅔ of tongue,
Parasympathetic: saliva and tear secretion
Cranial nerve VIII
- Acoustic (sensory)
Hearing and equilibrium
Cranial nerve IX
- Glossopharyngeal (mixed)
Motor: pharynx (vocal cords and swallowing)
Sensory: taste on posterior ⅓ of tounge, pharynx (gag reflex),
Parasympathetic: parotid gland, carotid reflex
Cranial nerve X
- Vagus (mixed)
Motor: phraynx and larynx (talking and swallowing)
Sensory- carotid body, carotid sinus, pharynx, viscera
Parasympathetic - carotid reflex
Cranial Nerve XI
- Spinal accessory (motor)
Movement of trapezius and sternomastoid muscle
Cranial Nerve XII
- Hypoglossol (motor) movement of tongue
