Clinical examination of the Nervous System

DrPuneet Kaur

Schemata

Examination OfHigher FunctionsCranial nervesMotor system(incl reflexes)Sensory systemAutonomic nervous system

Examination of Higher Functions

Mental stateMemory Speech

Two cerebral Hemisphere:1.Dominant or Cerebral Hemisphere-categorization and symbolization2.Representational Hemisphere-spatiotemporal relations

Hemisphere specialisation related to handedness

Mental state

Appearance and BehaviorEmotional stateDelusions and HallucinationOrientation in Place and TimeLevel Of ConsciousnessIntelligence

Appearance and Behaviour

DressPersonal HygieneGeneral GroomingFacial ticsVerbal or physical aggression

Emotional state

Mood : facial expression (reflective of depression, mania, anxiety, schizophrenia)

Sleep and dreams : insomnia , sleep disturbing dreams

Delusions and Hallucinations

Delusion : false and unshakeable beliefs which continue to be held despite evidence to contrary.Hallucination : False impressions referring to organs of special sense(hearing , smell , vision etc) for which no cause can be found.

Orientation In Place and Time

Disorientation : Organic Brain DiseaseSchizophrenicsHysterical states

Level of Consciousness

Stupor-Patient shows some response, example to painful stimuli

Coma-makes no psychologically meaningful response to external stimulus or to internal need

Intelligence

Approximate from occupation and educational qualifications

Formal testing: calculating ability , serial subtraction, copying a complex figure etc

Memory

Recent or short term memoryRemote or long term memory

Retrograde amnesia for events immediately before brain concussion

Language or Speech

Aphasias

Dysarthria

Aphasia

Sensory or Fluent aphasiaLesion in Wernicke area-area 22,sensory speech centre(Posterior end of the superior temporal gyrus in the dominant hemisphere)Symptoms:-speech not disturbed but the person talks excessively that makes little sense-Pure word blindness or anomic aphasia

Motor or non fluent aphasiaLesion in the Broca’s area-area 44,motor speech centre(inferior frontal gyrus of dominant hemisphere)Symptoms:-Loss of articulate speech or inability to write or both-person is dumb and speech is slow-words are hard to come by limited to 2-3 words

Global aphasia:result of loss of both Wernicke’s and Broca’s area

Dysarthria

There is difficulty in spoken speech.

Cranial Nerves

12 pairs of cranial nervesSome are afferent(sensory)Some are efferent(motor)Some are mixed nerves

First nerve : Olfactory nerve

Origin : From the olfactory epithelium

Function: Pure sensory nerve concerned with olfaction (smell)

Paralysis:-AnosmiaTest:-Clove oil presented to each nostril separately

Anosmia : complete absence of smell

Parosmia : is alteration in the character of smell

Hypoosmia :reduction in the sense of smell

Second Nerve : Optic Nerve

Origin :From the Retina

Function: Pure sensory nerve-transmission of visual sensations to brain

Test-Visual acuity -Field of vision -Color vision -Examination of fundus(Opthalmoscopy)

Visual acuity

Near vision: Jaeger’s chartDistant vision: Snellen’s chart

Factors affecting visual acuity

Optical: state of image forming mechanism of eye

Retinal factors: acuity maximal at the fovea centralis

Stimulus factors : size of object and distance from eye,color of object

Field of vision

Confrontation testsPerimetryRed pin test

Color vision

Yarn (spun thread) matching test or Holmgreins skeins of colored wool test

Ishihara chartsEdridge green lantern

Third(Oculomotor)Fourth(trochlear)Sixth(Abducent)nerves

Origin: from a series of nuclei which begins in the floor of the sylvian aqueduct extending upto the fourth ventricle

Function: Mixed nerves-innervate the eye muscles and bring sensation from proprioceptors in eye muscles

Test1.Look for ptosis ,squint,nystagmus2.Test for ocular movement3.Examination of Pupil

Fifth nerve: Trigeminal nerve

Origin : From the lateral surface of Pons at about its middle

Function: It is a mixed nerve with sensory, motor and secreto-motor components

3divisions-Opthalmic -Maxillary - Mandibular

Effect of Paralysis of 5th nerve

Opthalmic division-loss of cut. sensation

-loss of corneal reflex Maxillary division-loss of palatal

reflex -loss of cut.sensation Mandibular division-loss of sensation -weakness of muscles of mastication

Test for sensory function

Touch, pain,pressure,temperature over the face

Corneal reflex-Touch the cornea with a wisp of cotton-subject blinks

Test for motor function : Muscles of mastication

Clench teeth-masseter and temporalis stand out with equal prominence on each side

Open mouth : jaw will deviate to paralysed side-pushed by healthy external pterygoid

Seventh Nerve-Facial

Origin: From the Pons , lateral to that of the sixth nerve nucleus

Function:Mixed nerveMotor fibre-all the muscle of face and scalp except levator palpebrae superiorisStylohyoidBuccinatorStapedius muscle

Sensory fibres-taste sensation from ant. 2/3 of tongueSecreto-motor fibres-supplies lacrimal gland , sublingual and submandibular salivary gland(all salivary gland except the parotid gland)

Effect of paralysis of 7th nerve

Loss of facial expression Furrows over forehead smoothen out Hyperacusis Loss of taste-ant 2/3 of tongue Xeropthalmia,decreased salivation

Tests for 7th nerve

Smile or show upper teeth Close his eyes against resistance Whistle Inflation of cheeks Loudness of sound Taste :ant 2/3 Schirmer’s test for lacrimation

8th nerve: Auditory or vestibulocochlear

Origin : From the groove in between the junction of Pons and Medulla.

Function:Pure sensory nerve supplying the

Vestibular and cochlear portion of ear

Effect of Paralysis of 8th nerve

VertigoNystagmusLossof hearing

Tests for vestibular function

Romberg’s signStand with feet together and close his eyesBarany’s caloric testWater at 7 degree celsius above and below normal body temperature

Cochlear function : Hearing tests

Watch test Tuning fork test : Rinne’s , Weber’s , Schwabach Audiometry

9th nerve:Glossopharyngeal Origin:5-6 rootlets to upper part of

medulla oblongata Function : Mixed nerveMotor fibres supply stylopharyngeus msSensory fibre to posterior 1/3 portion of tongueAnd mucus membrane of pharynxSecretomotor fibres supply the parotid gland

9th nerve paralysis

Loss of taste from post. 1/3 of tongue

Decreased salivary secretion

Test of 9th nerve

Taste sensation in Post. 1/3 of tongue

Palatal reflex

10th nerve: Vagus

Origin:Attached by 8-10 rootlets to the lateral aspect of medulla oblongata below the origin of 9th nerve

Function: mixed nerveMotor to involuntary ms of respiration,heart and part of GIT & voluntary ms of pharynx, larynx and soft palateSensory to GIT upto right 2/3 of colon &mucus memb. of pharynx, larynx and soft palate.

Paralysis of 10th nerve

Regurgitation of fluids through nose

Nasal tone in voiceHoarse and deep voice

Test for 10th nerve

Soft palate movement Laryngoscopy

11th nerve:accessory

Origin :Cranial part and spinal part

Function: Pure motor nerveSupplies Sternocleidomastoid and Trapezius

Test Of 11th nerve

Move the headShrug shoulder

12th nerve: Hypoglossal

Origin: From lowermost part of medulla oblongata

Function :Pure motor nerveSupplies all Ms of tongue.

Paralysis of 12th nerve

Defective articulation Deviation of tongue

Test of 12th nerve

Tongue protrusion-deviation