neurological examination

What is a neurological exam?

series of tests conducted by a neurologist

• evaluates the integrity of the Nervous System

  • Following a trauma/stroke

  • When there are suspected neurodegenerative changes

  • Following exposure of neurotoxic agent

Localization of neurological exams

• targets the Nervous system

• Cerebral hemisphere (telencephalon)

• Spinal cord

• Cranial nerves

  • Neuromuscular junction

  • Muscles

Common components of exam

• patients history

• Cranial nerve’s function

• Motor function (reflexes)

• Somatosensory function

• Coordination

• Mental status

Patient history - common component

• age - way to narrow down disorders (schizophrenia doesn’t occur in young children)

• Education - better cardiovascular health/lower rates of dementia/cognitive decline

• Handedness - hemispheric dominance → R-handed = left hemisphere (dominant in language)

  • Important after strokes (language production/processing)

• Past medical history

• Use of prescription and/or recreational drugs → positive symptom for schizophrenia is very similar to high doses of psychostimulants (hard to diagnose immediately)

• Disease process

  • Temporal profile: sudden vs gradual or acute vs chronic

  • Changes over time: static, improvement or worsening

  • Identify triggers/relievers of symptoms

  • Gauge severity of symptoms - individual comparison to other patients with similar damages

Cranial nerves

Set of 12 cranial nerves that send electrical signals from brain to other parts of the body

Sensory patterns: give them sensory stimulation assess integrity of both L/R sides

• tinging fork to test asymmetry between sides

• Occlude (cover) one side to test the other side

Motor patterns: give tasks to complete how much control + strength you have in movement, testing both sides physically touch patient to feel asymmetry

• turning head with resistance

Olfactory cranial nerve

Cranial nerve #1

• sensory control

• Controls smell (all sensory info with sent)

• Olfactory nerves travel through holes in the cranium (cribs form plate)

  • Skull can cut through afferent cells in brain injury

Testing Olfractory Nerves

• close eyes and block/occlude one nostril and get patient to smell

  • Switch left and right

• olfractory nerves effected by covid (losses sense of smell)

Cranial nerves (1-12)

1. Olfactory

2. Optic

3. Oculomotor

4. Trochlear

5. Trigeminal

6. Abducens

7. Facial

8. Auditory - vestibular

9. Glossopharyngeal

10. Vagus

11. Spinal accessory

12. Hypoglossal

Optic cranial nerve

• second cranial nerve (II)

• Sensory information - VISION

• Collects info from back of eye and yields all visual info

Visual test

• occluding one eye at a time and testing visual skill

  • Snellen chart

• Intracranial pressure

  • Pushing on fungus/making it stretched and being blurred

  • Thiroid, intracranial pressure can cause eyes to bulge out (mainly an aesthetically problem than a medical issue)

Oculomotor cranial nerve

• cranial nerve 3 (III)

• Motor information

  • Most eye movement/eyelid movement

  • Controls 4/6 muscles in the pupil/eyelid

Testing occuomotor nerve

• using finger we move it corner to corner of the visual field and detect eye movement (if muscles aren’t strong enough eye tracking will be weak)

Ptosis

• eyelids cover part of pupil → blocking the visual field and information

Trochlear cranial nerve

• cranial nerve 4 (IV)

• Purely motor control - smallest cranial nerve

• Only dictates 1 muscle → the Traceal muscle (inferior oblique muscle) which controls eyes looking down

Testing Trochlear cranial nerve

• moving finger from corner to corner in visual field to test eye tracking strength 8

Trigeminal Cranial nerve

Cranial nerve 5 (V)

• has both sensory and motor information processing

• Facial sensation, movement of biting/chewing/swallowing with jaw muscles

• Largest cranial nerve, Trigeminal nerve branches in 3 areas of the face (top, medial and bottom)

  • Top - Ophthalmic division

  • Medial - Maxillary division

  • Bottom - mandibular division

Test the Trigeminal cranial nerve branches

• touching patients face in the 3 areas (testing all levels of the facial sensation)

• Touching parts of jaw and getting patient to shut jaw tight to activate jaw strength

Abducens cranial nerve

• 6th cranial nerve (VI)

• Motor control

  • Controls eye movement with Abducens muscle → regulates rotation of the eyes alway from the midline

Testing Abducens cranial nerve

• moving finger from corner to corner of the visual field to test eyes tracking ability

Nystagmus

“Dancing eyes”

• eyes vibrating/moving without conscious control

Facial cranial nerve

Cranial nerve 7 (VII)

• move sensory and motor information

• Taste from anterior of the tongue, a little facial sensation, all muscles of facial expression

  • Not responsible for facial sensation, only facial movement/taste from front of tongue

Testing facial cranial nerve - we are looking for symmetry of the face

• getting patient to smile

• Looking up to wrinkle forehead

• Close eyes

Roman numerials with cranial nerves

I = 1 (olfactory)

II = 2 (optic)

III = 3 (oculomotor)

IV = 4 (Trochlear)

V = 5 (Trigeminal)

VI = 6 (Abducens)

VII = 7 (Facial)

VIII = 8 (Vestibulocochlear)

IX = 9 (Glossopharyngeal)

X = 10 (Vagus)

XI = 11 (Accessory)

XII = 12 (Hypoglossal)

Bell’s palsy

Related to cranial nerve 7 (VII) - facial cranial nerve

• short lasting in many cases

• Causes droopy eyes/facial paralysis/drooping of corner of mouth/dry mouth/impaired taste

Vestibulocochlear Cranial nerve

• cranial nerve 8 (VIII)

• Only sensory information

  • Sound/sense of balance, labriynth

  • Auditory perspection

Testing cranial nerve

• occlude one ear and whisper something

• Ask patient what they heard

• Repeat on other side

Glossopharyngeal cranial nerve

Cranial nerve 9 (IX)

• taste and sensation from posterior of the tongue, muscles of the pharynx (speech and swallowing)

Testing cranial nerve

• patient to cough, open mouth, observe uvula position → should have a central position within the mouth

Vagus cranial nerve

Cranial nerve 10 (X)

Motor and sensory control

• Swallowing and voice/cough, outer ear canal sensation, sensory input and motor control of heart, lungs, viscera, larynx (speech/gag reflex)

• Wondering nerve (nerve moves into organs → a part of the parasympathetic nervous system!)

Testing patient for cranial 10 (X)

• asking patient to cough, open mouth wide

Accessory cranial nerve

Cranial nerve 11 (XI)

• motor information

• Movement of muscles of head and shoulder shrug

Testing cranial nerve

• getting patient to turn head in all directions + with restraint (holding head)

• Getting patient to shrug shoulders + with restraint (pushing shoulders down)

Hypoglossal cranial nerve

Cranial nerve 12 (XII)

• motor control

• Movement of tongue muscles (speech/swallowing)

Testing cranial nerve 12 (XII)

• asking patient to press tongue to sides of the mouth and palpate and assess for strength of tongue

• Ask patient to stick out tongue → examine for asymmetry

Cranial nerves III, IV and VI

All motor cranial nerves controlling the eyes

• Oculomotor (III) - most of eye movement (4/6 muscles controlled + pupils/eyelids)

• Trochlear (IV) - inferior oblique eye muscle (Trochlear muscle) → controls looking down

• Abducens (VI) - controls Abducens muscle in eye → controls eyes looking away from the midline

Cranial nerves V, and VII

Cranial nerves determining both sensory and motor information

• Trigeminal (V) - largest cranial nerve, receives sensory information from facial touch (3 layers of touch) and movement of the face/jaw (chewing)

• Facial (VII) - controls motor information on facial expressions and taste from front (anterior) of the tongue

Sensory cranial nerves

I. Olfactory

II. Optic

V. Trigeminal (both)

VII. Facial (both)

VIII. Vestibulococholear

IX. Glossopharyngeal (both)

X. Vagus (both)

Motor cranial nerves

III. Oculomotor

IV. Trochlear

V. Trigeminal (both)

VI. Abducens

VII. Facial (both)

IX. Glossopharyngeal (both)

X. Vagus (both)

XI. Accessory

XII. Hypoglossal

Cranial nerves that are both motor and sensory

V. Trigeminal

VII. facial

IX. Glossopharyngeal

X. Vagus

Mnemonic to remember the cranial nerves sensory vs motor

Some say marry money, but my brother says big brains matter more

Mnumonic for remembering cranial nerves

Only odd octipi teach troubled tigers and freaky Vultures good voice and habits

Upper vs lower motor neurons

Motor function → testing reflexes/quality of movement form left to right

Motor neurons going down to muscles from the spinal cord = lower motor neurons (sending axons down to muscles)

Upper Motor neurons - motor neurons within the cranium that signal to lower motor neurons to fire

Damage to Lower motor neurons

• lesions/damage to the area causes muscles to contract → reflexes are decreased

  • Hyporeflexia (reduced reflexes)

Damage to upper motor neurons

• weakness in control

• Differentiating with reflexes

• Brain inhibits some reflexes all the time (like Knee-jerk reflexes)

• Lesion to upper motor neurons = less descending inhibition (lower motor neurons)

  • Hyper reflexes (exaggerated reflexes)

  • Spacisity/hyper reflexia

Somatosensory Function

Testing pain

• light touch and proprioception

  • Understanding of body within the space/knowledge of body position

• Testing for Astereognosis (in central Nervous system)

  • Damage in ability to identify objects with touch (eyes closed, holding object, must determine what it is)

• Testing for Agraphesthesia

  • Damage organizing info from body (drawing a number on someone’s hand/back and interpreting what it is)

Coordination

• quick, alternating movements

  • Rapidly moving form 1 pattern to another (testing upper motor leisons)

• Heel-to-shin test - rapidly moving foot up and down shin while laying on the side

  • Cerebellum reflective action

• standing/sitting

  • Testing how easily we can move from sitting to standing (issues with point to point actions) → sign for Parkinson’s

• Romberg test

  • Balance comes from cerebellum, vision, and vestibular organ (in the ear)

  • We only require 2/3 parts to be working to have correct balance

  • Close eye/hold out hands → shifting the centre of gravity = problems can be from cerebellum or vestibular organs

Mental status exam

Test that examines

• attention and orientation - “do you know where you are/what day is it”

• Language perception

• Memory - remembering 3 things over the course of the examination

• Visuospatial function - recognizing objects

• Executive functions - cognitive flexibility

Attention - MSE

We test attention first - if alertness is damaged, the entire test will fail anyways

• observe patients alertness

• Spelling words backwards, counting backwards from 20, current whereabouts

Regions involved

• large widespread damage to the NS functioning → especially the forebrain

• Can be cortical, subcortical

• Can be caused by diffuse agents (toxins, medication withdrawals)

Attention problems (disorders)

1. Controlatreal Neglect: failure to attend to the left side of the world

   1. Hemisphere-neglect/left neglect (ego-centric left)

   2. Nothing wrong with the perseption/motor signals

2. Anosognosia: failure of individual to self-reflect that they have a disorder

   1. Can’t comprehend their issue

Regions involved

• right hemispheres attention network

• Commonly right parietal lobe (causes left neglect)

Language (MSE)

We test the…

• fluency - production of language (smoothness/volume)

• Naming - identifying objects

• Repetition

• Prosody - how rhythm changes the content of the sentences

• Comprehension

• Reading/writing

• Praxis - carrying out motor activity from language commands

Language problems in MSE - disorders

Aphasia - disorder regarding language

Fluent - ability to produce language but unable to comprehend it

• Receptive aphasia (Wernicke’s area)

Non Fluent - can’t produce language, but can comprehend language

• Expressive (broncas area)

• Global aphasia (can’t comprehend or produce language)

Alexia - unable to read

A graphic - inability to write

Regions involved:

• focal or diffuse damage to the left hemisphere of the brain (language network)

Memory (MSE)

• Digit span - remembering series of numbers (5-9 is sweet spot)

• Pointing span - same idea, but with linguistics (remembering/repeating series of actions eg. Pointing to sides of the wall)

• Verbal, visual object learning

• Past public/personal events - naming things people should generally know (semantic information) - targets temporal lobe (hippocampus/amygdala)

• Factual knowledge

Regions involved

• medial temporal structures (eg hippocampus), thalamus , basal forebrain

MSE: visuospatial function/problems

Tests

• line cancellation - controlateral neglect → crossing lines of both sides of the picture

• Copy of geometric designs

• Judgement of line orientation

• Object/face/colour recognition

Prosopagnosia: failure to recognize faces

• can recognize components (eyes/mouth) but not comprehending them to be a face

Regions involved

• ventral side of temporal lobe (Fusiform Gyri = processes facial info)

MSE: Executive Function

Cognitive/behavioural flexibility

• ability to receive info and change behaviour based on the feedback

Testing

• judgement - giving ambiguously assigned tasks/judgement questions to see how people react

• Verbal fluency - measuring juggling ideas in a fast way

• *Luria 3-step (fist-edge-palm test)

  • Tests perseverative behaviour

Regions involved

• prefrontal cortex and/or associated projections

Headaches/migrains

Poorly researched (bc it isn’t fetal)

• no actual sensation to the brain, the sensation comes from the meninges, blood vessels, scalp and skull

• Pain pathways are from Cranial Nerve V (Trigeminal nerve)

• Headaches are characterized in 3

1. Vascular (migraine, cluster headache)

2. Tension-type (common head aches)

3. Other (rare - due to head trauma, stroke, tumour or hydrocephalus)

Migraines

• most common form of Vascular headache

• Relatively high heritability estimate

• Preceded by Aura: temporary neurological or sensory set backs (visual disturbances/sensory changes)

• Often but not always related to triggers (amount of sleep/stress/msg/wine)

Main symptoms

• head pain

• Sensory sensitivity

• Nausea and vomiting

Treatment

• abortive treatment - getting rid of it as it is occurring

  • NSAIDS (Advil/ibeprophen) and Triptans (serotonin agonists)

• Previous prophylactic treatment - preventative drugs

  • Beta blockers, anticonvulsants, tricyclics

  • All these drugs were developed for other disorders

Mechanisms of migraines

• migraines (esp. aura) related to cortical spreading depression

  • Bursts of activity in areas of the brain, then turning off → domino effect surrounding the brain

• Vasodilation - how blood flows around the skull (blood vessels dialate/press onto surrounding meninges)

  • Recently suggests that its an effect, not the cause

Calcitonin gene-related peptide (CGRP)

• CGRP is a neuropeptide

• Released by pain neurons from meninges (Crainial nerve V)

• Release is elevated at beginning and all throughout the migraine

• Has strong vasodilation

• Covered in serotonin receptors → blocking the receptors help to stop migraines

How we stop migraines

Blocking the serotonin receptors on the CGPRs

3 varieties of CGPRS

1. CGPR antibodies

2. CGPR receptor antibodies

3. CGPR receptor antagonists

Drugs that block these are very strong (transformative)