Perception in Neurological Assessment

Perception in Neurological Assessment

• Perception is the brain's ability to receive, interpret, and respond to sensory stimuli.
• Assessment evaluates sensory systems, cranial nerves, spinal cord, and brain function.
• It requires afferent nerves and the cerebral cortex.

Neurological Basis of Sensory Perception

• Sensory perception begins with skin, eyes, and ears, which detect touch, pain, temperature, and sound.
• Signals travel through peripheral nerves and the spinal cord to the brainstem and parietal lobe.
• Higher-level perception involves recognition and spatial awareness in the cortex association areas.

Superficial Sensation

• Light Touch assessment involves using a cotton wisp, the nurse lightly touches the patient's skin (e.g., arms, legs, face) and asks them to identify the location.
• Pain assessment involves applying sharp and dull stimuli alternately, asking for identification of "sharp" or "dull."
• Temperature is assessed with test tubes of hot and cold water are applied to the skin.

Deep Sensation

• Vibration assessment involves placing a tuning fork on bony prominences like wrist or ankle and noting when a patient feels and ceases to feel vibrations, assessing the dorsal column-medial lemniscus pathway.
• Position Sense (Proprioception) tests dorsal columns and the cerebellum by moving a patient’s finger or toe up or down, asking them to identify the position without looking.

Cortical Sensation

• Stereognosis assessment involves the patient identifying a familiar object such as a key or coin, assesses parietal lobe function.
• Graphesthesia assessment involves the nurse tracing a letter/number on the patient’s palm, assesses cortical sensory integration.
• Two-Point Discrimination assessment involves calipers applied to the skin; reported stimuli indicate sensory cortex precision.

Cranial Nerve & Visual Perception

• CN II (Optic) tests visual perception using a Snellen chart and confrontation test.
• CN III, IV, VI (Oculomotor, Trochlear, Abducens) assess eye movement perception by following an "H" pattern.
• CN VIII (Vestibulocochlear) assesses auditory perception via whispered words or a tuning fork with Weber and Rinne tests.

Interpreting Abnormal Perception

• Numbness or inability to distinguish stimuli may indicate diabetes, spinal cord lesions, stroke in parietal lobe etc.
• Normal perception indicates intact peripheral nerves, spinal cord pathways, and intact cerebral processing.

Coordination in Neurological Assessment

• Coordination enables smooth, accurate, purposeful movements by integrating the motor system with the cerebellum, basal ganglia, and sensory feedback.
• It synchronizes muscle activity and maintains posture and balance.

Neurological Basis of Coordination

• Coordination is managed by the cerebellum which fine-tunes motor movements and maintains equilibrium.
• The motor cortex initiates voluntary movements in the frontal lobe whereas the basal ganglia regulates automatic movements and muscle tone.
• Sensory feedback via the dorsal columns and spinocerebellar tracts provides the brain with body position information to ensure appropriate adjustments.

Techniques for Coordination Assessment include:

• Standardized tests evaluating the upper and lower extremities, balance, and gait.

Upper Extremity Coordination Tests

• The Finger-to-Nose Test assesses cerebellar function through rapid and smooth nose and finger alternation.
• Rapid Alternating Movements (RAM) test cerebellar function by rotation of the palms up and down; slow, clumsy movements (dysdiadochokinesia) indicate dysfunction.
• Finger-to-Finger Test assesses accuracy and tremor by touching the nurse's finger with patient's index finger.

Lower Extremity Coordination Test

• The Heel-to-Shin Test identifies cerebellar issues by running the heel down the opposite shin; jerky or irregular movements indicate problems.

Balance Tests

• Romberg Test assesses proprioception (dorsal column), not cerebellar function, by observing sway or fall with eyes closed.
• Tandem Walking assesses cerebellum and vestibular system via heel-to-toe walking.

Gait Assessment

• Examination includes natural walking, turning, and walking back, where signs of ataxia, spasticity, or shuffling can be observed.
• This assesses the cerebellum, motor cortex, and basal ganglia.

Motor Coordination Assessment

• Assessments include cranial nerves III, IV, VI for coordinated eye movements reflecting brainstem and cerebellar function.
• Additionally, cranial nerve VII is evaluated based on symmetry in facial movements indicating intact motor coordination.
• Normal coordination indicates smooth, precise movements and balance, reflecting healthy motor, sensory, and cerebellar integration.

Abnormal Movement

• Staggering/irregular movements (ataxia) indicates cerebellar lesion or toxicity.
• Intention tremor worsens near the target, suggesting cerebellar damage.
• Resting tremor indicates basal ganglia issues.
• Spasticity or rigidity may indicate upper motor neuron lesions or extrapyramidal dysfuntion.

Perception and coordination

• Proprioception provides sensory feedback to the cerebellum.
• The dorsal columns carry data supporting both.
• The cerebellum pairs sensory input with refined motor output by using sensory input to refine motor output.
• The frontal lobe executes coordinated responses and parietal lobe interprets data.

Mental Status in Neurological Assessment

• Mental status examination assesses a patient's cognitive, emotional, and behavioral functioning.
• Key components include cerebral cortex, limbic system, and subcortical structures.
• Mental status reflects how the brain processes information, awareness, and responses to the environment; it provides insight into brain dysfunction.

Neurological Basis of Mental Status

• The cerebral cortex, including the frontal, parietal, temporal, and occipital lobes, handles various other cognitive functions.
• The prefrontal cortex regulates executive function, attention, judgment, and behavior.
• Limbic system modulates memory, emotion, and motivation.
• Reticular Activating System (RAS) maintains arousal and consciousness..
• Thalamus and Basal Ganglia: Relay sensory and motor information, supporting attention and coordination of thought processes.
• Mental status abnormalities: Abnormalities often point to structural damage, tumors, metabolic disturbances, and degenerative problems.

Major Brain Divisions

• Forebrain (prosencephalon) is responsible for higher cognitive processes, sensory integration, voluntary movement, and autonomic regulation.
• Midbrain (mesencephalon) is a conduit between the forebrain and hindbrain, and plays a role in motor movement, auditory and visual processing, and alertness.
• Hindbrain (rhombencephalon) controls fundamental life functions, such as breathing, heart rate, and balance.

The Forebrain structures include

• Cerebrum.
• Diencephalon (thalamus and hypothalamus).
• Limbic system.

Forebrain: The Cerebrum

• Executive functions reside here along with the capability for voluntary motor control, language production, problem-solving, and emotional regulation.
• The prefrontal cortex is responsible for decision-making, personality, and social behavior.
• The primary motor cortex controls voluntary muscle movements.
• Broca’s Area plays an essential role in speech production and language articulation.

Forebrain: The Parietal Lobe

• Somatosensory processing, spatial orientation, and sensory integration are the main functions.
• Key structures include primary Somatosensory Cortex (Postcentral Gyrus) and the Superior Parietal Lobule.

Forebrain: The Temporal Lobe

• Auditory processing, memory encoding, language comprehension, and emotional association are the primary functions.
• Key structures include the primary auditory cortex, Wernicke's area, and hippocampus.

Forebrain: The Occipital Lobe

• The primary function is Visual processing and interpretation
• The key structure is the primary visual cortex processes stimuli and motions.

Forebrain: The Diencephalon

• Its located deep within the forebrain
• The thalamus acts as a sensory and motor relay station and plays a role in consciousness, alertness, and sleep regulation.
• The hypothalamus regulates autonomic functions and hormone secretion.
• The limbic system modulates emotions and is essential for memory encoding and spatial movements.

Midbrain details

• The tectum processes visual and auditory and controls reflexes and movements.
• The tegmentum is involved in motor coordination, produces dopamine, and regulates movements.

The Hindbrain

• The cerebellum coordinates movements, balance, posture, and motor skills.
• The pons connects the cerebrum to the cerebellum and plays a role in breathing regulation and motor control.
• The medulla oblongata controls vital autonomic function such as heart rate, blood pressure, and reflexes.

Other important structures

• The corpus callosum connects the two hemispheres and allows communication.
• The basal ganglia regulates movement, habit formation, and reward processing.
• The reticular formation plays a role in consciousness, arousal, and sleep-wake cycle.

Cranial Nerve Assessment

• Test cranial nerve I, olfactory nerve.
• Ask the patient to close their eyes, occlude one nare, present an odorous sample 6" from the open nare, and ask them to identify the odor.
• Clients should be able to correctly identify the oder; those that cannot identify might have partial anosmia or loss of smell.

Test the Optic Nerve (II).

• Position client 20 feet (6 meters) from the Snellen chart. Ask client to cover one eye, and read each line of the letters.
• Numerator indicates the distance from the chart; the denominator indicates the distance a "normal eye" can read that line on the chart.
• For example 20/40 is vision that can read at 20 feet where a normal client can read at 40 feet.

Additional cranial nerve II testing

• If the denominator increases, then vision decreases.
• Corrected-vision that doesn't make it better than 20/200 means the client is legally blind.

Cranial Nerve III, the oculomotor nerve

• It's responsible for papillary constriction, dilation, and lid of the eyelid.
• Turn down low lights and allow pupils to dilate.
• Shine a penlight on one eye and observe pupil constriction with consensual response.
• Examine each eye in this manner.

Additional cranial nerve III testing

• You can check for accomodation by focusing on something distantly (pupil will dilate).
• Move an object ~8-10 cm and test with focus on the finger (cross eyes slightly).
• With age, accomodation and adjustments decrease, called presbyopia.

And more cranial nerve III testing

• Notice your client's eyelids; their presence can show ptosis.
  • Ptosis is when the upper eyelid droops and is covering a portion of its eye.
  • This happens from conditions such as myasthenia gravis as well as neurological damage as a cranial nerve III damage.

Extraocular movements (EOMs)

• Are responsible for the checking of cranial nerves such as the oculomotor (III), trochlear (IV), and the abducens (VI).
• Move your finger about 12"-16", and check with head kept still to move the eyes (6 cardinal and gaze tests).
• Stop for 1" - 2" in each extreme gaze movement when testing for nystagmus (repetitive jerky eye movements).

Cranial Nerve V, the Trigeminal Nerve

• Tests three branches; ophthalmic, maxilllary, and the mandibular.
• Apply the innervation for motor face movements and then apply sensory face functions.
• Use cotton and have the clients close their eyes.
• Lightly brush over the anterior scalp (ophthalmic), check, and jaw to test.
• Weak or face atrophy / face asymmetry is an unexpected finding and will be reported as an indication for trigeminal neuralgia.

Cranial Nerve VII, the facial nerve

• The sensory fibers are involved with taste while the motor controls face functions.
• Instruct your client to have a series of facial expression to check, such as smile to show you their teeth, frown, raise thier eyebrows, pout with their lips, and puff their cheek.
• Also test to see if the patient makes an even sound with words such as "B," "M," and "P."*
• Findings to indicate face nerve damage can show a face that has no movement, an asymmetrical movement, with eyelids drooping down (Ptosis)

Additional Cranial Nerve VII tests

• A flat nasolabial can also be another condition if the eyes are unable to shut.*
• A forehead that does not wrinkle will make the client unable to raise their eyebrows. This could show to present various neurological disorders such as Bell Palsy or Lyme disease.
• Apply sweet and sour samples to the area, the tongue's interior side to test bilaterally.
  • The client should be able to identify each taste when tested, but the causes can change that such as any injury, chemotherapy, or prescription medications.

Cranial Nerve VIII, the acoustic nerve

• Has two divisions; the vestibular (balance) and cochlear (hearing).
• The whisper test checks as you block one end and check from one side to whisper a word or number, this may mean they lost the ability to hear any high frequency sounds if an obstruction takes place or is age related/presbycusis.

Balance - Cranial Nerve VII Testing

Check with either standing or using the "Romberg test." Balance has steady feet with sides of the arm for balance without sway will show.

• For 30", check with the eyes closed and check with ability and their upright-ness while testing close.
  • A loss of their balance or sway for movements or feet is an example of "Romberg test" failure.

Cranial Nerve IX

• Test for the “Glossopharyngeal nerve", that will sense for the motor/tongue and motor/pharynx
• The sensory will function by identifying bits of various flavors that can taste from one side or on the posterior side

Vagus Nerve

Functions from the test of nerves (Cranial IX), with gag (nerve X gag test) and swallowing functions together

Gag and Swallowing Functions

Start to show the patient and have them be conscious that they will test for the gag reflex Then

• Instruct the client to open their area of mouth, and apply any compression that will allow the tongue to be gently compressed when saying "AH" The soft palate and top tip will move and react when stimulated The then give the mouth in a little amount to try or test with no water, which allow smooth, easy water with no issues involving nostrils Any issues with testing will cause a lot of different reasons to test, such as CVA or an injury

Cranial nerves, Spinal Nerve XI & the Accessory Nerve

To tests nerve movement, start to tests the strength in upper back

• Placing their hands so that the shoulders can start to be squeezed from gentle resistance as they shrug shoulders Apply a good amount of resistance that can apply head to be side to side and check their muscle strength

Cranial Nerve XII

• Note whether the tongue starts there before the test starts. Side/Side the direction can starts with problems if clear articulation can occur with cranial (V, VII, X, XI, XII), that means there have been dysarthria.

Glasgow Coma Scale

• Is used to be tool for knowing a patient's LOC (level of consciousness) as a response for the patient's neurologic insults (seizures and TI).
• Use a standard score that knows the clarity, consistency, and influence is acute for help.

To know with Glasgow is Important For:

• With having the STRUCTURED method to do check and measure 3 key responses with :eyes, motors, and verbals
• This causes high reliable, in state for any assessment with patient

Glasgow Cont.

• Urgent care by the range of points such as less 8 can impact or has great actions for actions Such with giving them to the high or normal scale is key.

Standard Procedure

It can impact a lot of emergency trauma or different needs

• Have a verbal command that are needed or open eye then to continue forward to their needs

• Try not to apply more force, record everything with a strong hand

The Spinal Nerves

• Spinal nerves are in BOTH PNS functions , including every 31 pairs that starts are merge with intervertebral-nerve, these are functions for various :Afferent and Afferent fibers. All these are located at dorsal nerve.
• They are also created * union of two areas *, that can show function for any outside *nerve to spinal cord *.

Spinal Cords

• Spinal cords are in groups by the region 8/C1;12/T1;5/L1; 5 S1s
  • Function with such areas; thorax, head, etc

Summary of Function in spinal

• Main cervical area; Head (motor side), upper trunk (diaphragmatic, the sensation sides)
• Lumbar Lower side + all hips in need

For C-cervical Plexus

It can test with; test for areas or controls where areas such, breathing (movement), + nerve supply with muscles ( sternocleidomastoid)

• It can affect to test area with the c nerves + diaphragmatic reaction*

For Spinal Nerves with Plexuses ; Brachial

There are test in shoulder area that functions such as; shoulder (deltoid), anterior arm (biceps) with sensation functions.

Spinal Nerve Assessment

• They come all various back areas and can do some test

• They test with area for a major nerve function And to test function in lower nerve function It will also help with those to supplies such function *Anterior trunk or some medial nerve *

These nerves with function will start also has sciatica or also pressure if the nerves are cause of the test

Testing injuries

• If a certain damage is felt when compress the joint to a root for the nerves* This can impact the back at certain point for various. For injuries for: “waiting tips"; and some other factors may result. Damage can result for also to help; upper limb function for injuries too in a lot of function-areas such as; with the elbows, etc.