The document provides information on examining the nervous system. It discusses the components of the nervous system and how to examine different aspects including consciousness, cranial nerves, motor and sensory systems, coordination, and involuntary movements. The examination involves testing various functions like strength, reflexes, sensations, and gait to localize neurological deficits. Key signs help to differentiate upper and lower motor neuron lesions.

1. Nervous system
History & Examination

2. Cardinal symptoms
 Altered sensorium
 Seizures
 Weakness
 Paresthesias
 Loss of function
 Abnormal movements
 Headache
 Abnormal behaviour

3. Nervous system
 Brain
 Cerebrum
 Midbrain
 Pons/medulla
 Cerebellum
 Cranial nerves- I-XII
 Spinal cord
 Peripheral nerves

4. Nervous system examination
 Consciousness
 Higher mental function
 Cranial nerves
 Motor system
 Sensory system
 Coordination
 Gait
 Meningial irritation, Skull, Spine

5. Consciousness
 Includes level (wakefulness) & content (awareness)
 Controlled by cerebral hemispheres & RAS in
brainstem
 Levels-
 Drowsy- arousable with verbal stimuli
 Stupor- arousable with painful stimuli
 Coma- not arousable
 Content-
 Confusion- a state of inattention & lack of clarity in thinking
(incoherent)
 Glasgow Coma Scale (GCS)- Eye.Motor.Vocal

6. Released reflexes
 In demented & confused patient
 Grasping- stroking of radial surface of palm, asso.
with C/L frontal lobe lesion
 Avoiding- stroking of ulnar surface of palm, asso. with
C/L parietal lobe lesion
 Glabellar tap
 Snout
 Sucking

7. Higher mental functions
 Orientation- time, place, person
 Memory- immediate, recent, remote
 Attention
 Calculation
 Language

8. Language
 Components-
 Articulation- Dysarthria
 Fluency
 Naming
 Repetition }Dysphasia
 Comprehension
 Reading
 Writing

9. Apraxia, Agnosia, Aphasia
 Apraxia- loss of ability to carry out learned
purposeful movements
 Agnosia- loss of ability to recognise, with
intact sensations & memory
 Aphasia- impairment of structure &
organization of language
 Receptive (fluent)- Wernicke’s
 Expressive (nonfluent)- Broca’s
 Dysarthria- defect in articulation &
enunciation of speech

10. Cranial nerves
 I- olfactory- sensory, smell
 II- optic- visual acuity/field, color vision
 III- oculomotor- MR,SR,IR,IO muscles,
sphincter pupillae (accomodation), levator
palpebrae superioris
 IV- trochlear- motor, superior oblique (SO4)
 VI- abducent- motor, lateral rectus (LR6)
AbR.OAd- abducted recti, obliques adducted

11. III, IV, VI nerve defect
 Squint/strabismus (paralytic)- secondary
(normal eye) > primary (affected eye)
deviation
 Diplopia- double image- true distinct &
false indistinct/blurred
 Head tilt- in the direction of affected muscle
 Past pointing- to same side on looking with
the affected eye
 Loss of accomodation
 Ptosis

12. Cranial nerves
 V- trigeminal- sensory to face
(cornea), motor to muscles of
mastication, controls oral secretion
 VII- facial- motor to all scalp & facial
muscles of expression except LPS,
taste sensation in ant. 2/3rd
of tongue

13. Facial palsy
 Supranuclear
 Lower face affected
 Emotional response
may be affected
 Taste intact
 Facial reflexes
increased
 No atrophy
 Infranuclear
 Whole face affected
 Emotional response
& reflexes affected
 Taste affected
 Hyperacusis
 Corneal reflex -nt
 Atrophy

14. Cranial nerves
 VIII- vestibulocochlear- balance & hearing-
vertigo, nystagmus, tinnitus, impaired
hearing, caloric tests, Rinne/Weber test
 IX- glossopharyngeal- sensory to post. 1/3rd
of tongue & pharynx
 X- vagus- motor to palate & pharynx
 XI- accessory- motor to sternomastoid &
trapezius
 XII- hypoglossal- motor to tongue

15. Motor system
 Upper motor neurons-
Corticospinal fibers from Frontal motor cortex 
Internal capsule  Pyramids in medulla 
crossover  Lateral corticospinal tract
(UM,LL)  terminates in anterior horn
 Lower motor neurons-
Anterior horn cells  Anterior spinal nerve root
 Peripheral nerve

16. Lesion
 Upper motor neuron
 Weakness
 Disuse atrophy
 Spasticity
 Reflexes
 Extensor plantar
 NCV- normal
 No denervation
potentials in EMG
 Lower motor neuron
 Pronounced weakness
 Wasting
 Flaccidity
 Loss of reflexes
 Fasciculations
 NCV- abnormal
 Denervation potentials
in EMG

17. Motor system examination
 Bulk
 Tone
 Power
 Reflexes
 Coordination
 Gait
 Involuntary movement

18. Power- grading
 0- complete paralysis
 1- flicker (any slightest movement)
 2- movement with gravity excluded
 3- movement against gravity but
not against resistance
 4- mild weakness
 5- normal power

19. Deep tendon reflexes (DTR)
 Jaw jerk- lesion
above trigeminal
motor nucleus-pons
 Supinator- C 5/6
 Biceps- C 5/6
 Triceps- C 6/7
 Knee- L 2-4
 Ankle- S 1/2
 Grading
 0- absent
 1- present
 2- brisk
 3- very brisk
 4- clonus

20. Superficial reflexes
 Corneal- trigeminal or facial nerve
 Palatal- IX-X cranial nerves
 Scapular- C5-T1
 Abdominal- T7-12
 Cremasteric- L1/2
 Plantar- L5/S1- extensor always abnormal
except age <1 year & postictal
 Bulbocavernosus- S3/4
 Anal- S3/4

21. Plantar reflex
 L5/S1
 Normally flexion of toes
 Extensor plantar reflex- components
 Extension of big toe, fanning of other toes, dorsiflexion of ankle,
flexion of knee, flexion of hip
 How to elicit?
 Babinski- stroke plantar surface of foot laterally from heel to toe
 Chaddock- stroke dorsal surface of foot laterally
 Oppenheim- stroke shin downwards
 Gordon- pinch/squeeze calf muscles
 Shaeffer- pinch Achilles tendon
 Extensor response denotes UMN lesion

22. Spinal segment & vertebra
 Vertebral column is longer than spinal cord
 Vertebra & corresponding spinal cord
segment
 Cervical vertebrae- +1
 Thoracic 1-6- +2
 Thoracic 7-9- +3
 T10- L1 & L2
 T11- L3 & L4
 T12- L5
 L1- sacral segments

23. Coordination
 Needs sensory input (joint/position),
cerebellum (lobes) & muscle tone
 Tests-
 Finger-nose test
 Rapid finger movements (touching the thumb)
 Dysdiadochokinesia
 Heel-shin test
 Walking in straight line  Tandem walking
 Romberg’s sign

24. Gait
 Legs exposed, feet bare
 Abnormal gait-
 Spastic- narrow base, knees extended, feet drag, circumduction
 Sensory ataxic- stamping with heel first
 Cerebellar ataxic- broad base, ‘drunken’
 Festinant (parkinsonian)- rapid, short shuffling steps
 Waddling (myopathic)- body tilted backwards, feet wide apart,
body sways sideways with each step
 High-stepping (peripheral neuropathic)- high step, toes landing
first

25. Involuntary movements
 Mostly due to disease of basal ganglia &
extrapyramidal system
 Types-
 Myoclonus- rapid irregular jerks of a group of muscles
 Tremor- distal, oscillatory, resting (P)/intentional (C)
 Athetosis- distal writhing purposeless movement
 Chorea- arrythmic forcible, jerky, rapid, restless movements
 Dystonia- abnormally maintained posture, plastic rigidity
 Hemiballismus- involuntary rapid violent flailing of arm
 Tics- repetitive abnormal movements, embarassing

26. Sensory system
 Receptors in skin  Peripheral nerves 
Posterior roots  Spinal cord (post. horn)
 Pain/temp./crude touch fibers crossover & ascend
in anterolateral spinothalamic tracts (UM,LL)
 Fine touch/position/vibration fibers ascend
ipsilaterally in posterior columns (LM,UL) that
crossover in medulla & travel in medial lemniscus
 Both join in thalamus, from where sensory
fibers travel via internal capsule to Parietal
cortex

27. Testing sensations
 From abnormal to normal areas
 Mark boundaries/dermatomes
 Touch & 2-point discrimination
 Vibration- tested at bony prominences
 Position- <10 degree movement can be appreciated
at all joints
 Pain- superficial (pin prick) & deep (muscle squeeze)
 Temperature
 Recognition of size/shape/weight/form

28. Other tests
 Meningeal irritation- neck rigidity,
Kernig’s sign (extend knee with hip
flexed)
 Straight leg raising test
 Deformity of skull or spine

29. Abbreviated neuro. exam.
 Pupils & ocular movements & fundus
 Facial movements
 Speech
 Power in arms & legs
 DTR & plantar reflex
 Pain & vibration in hands & feet
 Gait

30. Supported by
LP, X-ray, EMG/NCV, CT & MRI