The Neurological Examination Robin Meek, M.D. Introduction to the Medical Profession March 22, 2006

Objectives: 1. List and discuss the 3 essential questions to consider when assessing neurological function. 2. Describe the 6 components of the neurological exam.

Three Key Questions Is there evidence of nervous system disease or dysfunction? Where is the problem located? What is the nature of the problem?

1. Is there evidence of nervous system disease or dysfunction ? Focal – stroke Diffuse – multiple sclerosis Systemic –peripheral neuropathy Focal- affects only anatomically related structures in a certain area regardless of their structure or function Diffuse - incomplete involvement in which some nerve cells are affected more than others Systemic - only anatomically and functioally related sytem of cells or fibers are affected

2. Where is the problem? CNS vs. PNS Tracts vs. neurons UMN vs. LMN Cortical vs. subcortical

Peripheral vs. Central Peripheral CNS - Muscle - Neuromuscular junction - Spinal or cranial nerves - Plexus - Nerve roots CNS Spinal cord Brainstem Cerebellum Cerebrum Right vs. left Cortex vs. subcortical

3. What is the nature of the problem? PIT VET 3-D

PIT VET 3 - D PIT - pressure VET 3 - D - demyelinating - infection - toxic or metabolic VET - vascular - epilepsy - trauma 3 - D - demyelinating - degenerative - developmental

Six Components 1. Mental status 2. Cranial nerves 3. Motor 4. Sensory 5. Reflexes 6. Coordination

Six Components 1. Mental status 2. Cranial nerves 3. Motor 4. Sensory 5. Reflexes 6.Coordination

Mental Status Alertness or awareness Orientation

Six Components 2. Cranial nerves 1. Mental status 3. Motor 4. Sensory 5. Reflexes 6.Coordination

The Cranial Nerves I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducens VII Facial VIII Acoustic IX Glossopharyngeal X Vagus XI Spinal accessory XII Hypoglossal

Olfaction (CN I) Almost never tested Smell Coffee, mint, essence of orange Impaired olfaction: Inflammation (allergies or colds) Smoking Aging Anosmia

CN II - Vision Three steps: 1.Visual fields by confrontation 2. Visual acuity testing – patient should wear their usual corrective lenses 3. Funduscopic examination –red reflex, optic disc, retinal vessels Visual fields - 3 ft. from patient, cover one eye of yours and the opposite one of the patient. Ask them to tell you the sum of the fingers you hold out. Nasal Temporal Superior Inferior Draw pictures

II Optic and III Oculomotor Pupillary light reflex Opening the eye Most extraocular movements - CN III innervates 4 extraocular muscles (superior, medial, inferior rectus, and the inferior oblique) and the levator palpebrae

Pupillary Light Reflex (CN II,III) Check pupil symmetry Swinging penlight– pupils should remain equally constricted Anisocoria – one pupil is larger than the other - Normal variant - Sympathetic vs. parasympathetic

Sympathetic – responsible for dilation - asymmetry greatest in the dark Parasympathetic – responsible for constriction - asymmetry greatest in the light

                                                                                                                                             

IV Trochlear Downward and inward movement of the eye Innervates the superior oblique

VI Abducens Lateral deviation of the eye Innervates the lateral rectus

Nystagmus

Experiment on your buddy!

V Trigeminal Mixed nerve – somatic sensory and somatic motor Sensory nucleus – pons and medulla, becoming continuous with the posterior horn of the spinal cord Motor nucleus – confined to the pons

Trigeminal - Sensory Three branches: opthalmic, maxillary, mandibular Sensory input from the face and mucus membranes (ocular, nasal, and oral) excluding the external ear and the posterior head, via the trigeminal ganglion

Trigeminal - Motor Supplies the muscles of mastication (masseter, temporal, internal and external pterygoid) muscles and other minor pharyngeal muscles

Trigeminal Examination Pinprick and fine touch sensation in forehead, cheek, and mandible bilaterally Corneal reflex Jaw movements and jaw reflex Palpation of jaw muscles for tone and strength with teeth clenched

VII Facial Mixed nerve Motor – facial musculature except for levator palpebrae (CN III) Superior salivatory nucleus – submandibular and sublingual glands

VII Facial Sensory Nucleus solitarius – taste from anterior 2/3 of the tongue ( sweet and salty) Sensory nucleus 5 – sensation from the external ear

VII – Three Steps Inspection at rest and with facial expression Wrinkling the forehead – differentiates central from peripheral lesion Identifying sweet and salty tastes on both sides of the tongue

Try it out!

VIII Acoustic Hearing - cochlear division Balance – vestibular division - seldom tested in basic neuro. exam

VIII – Two Steps Assess hearing, covering opposite ear: whispered words rubbing your fingers ticking watch Rinne test – bone and air conduction

IX Glossopharyngeal Mixed nerve Motor – pharynx Sensory – posterior portions of the eardrum and ear canal, the pharynx, and the posterior tongue (salty, sweet, sour, and bitter)

X Vagus Mixed Motor – palate, pharynx, and larynx Sensory – pharynx and larynx

Testing IX and X Listen to the patient’s voice – is it hoarse or does it have a nasal quality? Say “ah” – look at the soft palate and the pharynx. Gag reflex – stimulate both sides of the back of the throat and note the gag response (warn the patient)

XI Spinal accessory Shoulder and neck movements Look for atrophy or fasiculations in the trapezius muscles, compare one side to the other Shrug shoulders Turn head against your hand

XII Hypoglossal Somatic motor – muscles of the tongue Observe the tongue for muscle atrophy or fasiculations Ask patient to protrude tongue and move it from side to side – ? symmetry, deviation from the midline

Your turn!

Six Components 3. Motor 1. Mental status 2. Cranial nerves 4. Sensory 5. Reflexes 6.Coordination

Motor Exam Body position – abnormal positions alert you to deficits such as paralysis Involuntary movements – tremors, tics, or fasiculations Muscle bulk – atrophic, symmetric or asymmetric? Especially shoulders, hands, thighs Tone and strength

Muscle Strength Grade 5 - full strength Grade 4 - weak against resistance Grade 3 - movement against gravity Grade 2 – movement with gravity eliminated Grade 1 – minimal contraction Grade 0 – no contraction

Muscle Tone flaccid – a decrease in tone normal – slight resistance to passive movement spastic – increased tone that varies, often worse at the extremes of the range rigid – resistance that persists throughout the range of motion and in both directions

Lower Motor Neurons Corticospinal tract or pyramidal system – - mediates voluntary movements - crosses over at the junction of the brainstem and the spinal cord Reticulospinal or rubrospinal tracts – - extrapyramidal system - connects basal ganglia with the LMN - integrate motor activity and posture

UMN vs. LMN UMN LMN Paralysis spastic flaccid Muscle atrophy no yes Fasiculations Reflexes Hyper-reflexic Hypo-reflexic Babinski sign May be present Not present

Upper extremity nerve roots                                                                                                 

Lower extremity nerve roots                                                                                                  

Demonstration

Flexion – C5 & C6 (biceps)

Extension – C6, C7, C8 (triceps)

Extension – C6, C&, C8, radial nerve

Grip – C7, C8, T1

Finger abduction – C8, T1, ulnar nerve

Thumb Opposition – C8, T1, median nerve

Screening of Motor Function of the Upper extremity 1. Radial nerve – thumb abduction 2. Ulnar nerve – little finger abduction 3. Median nerve – strong pinch

Flexion at the hip – L2, L3, L4 - iliopsoas

Adduction of the Hip L2, L3, L4 - adductors Place hands between the patient’s knees and ask them to bring them together

Abduction of the Hip L4, L5, S1 gluteus medius and minimus Place hands on the outside of patient’s knees and ask them to spread both legs against your hands

Extension of the Hips S1 – gluteus maximus Have patient push the posterior thigh down against your hand

Flexion at the Knee L2, L3, L4 - quadriceps

Flexion of the Knee L4, L5, S1, S2 - hamstrings

Symmetric weakness of the proximal muscles – myopathy or a muscle disorder Symmetric weakness of the distal muscles suggests a polyneuropathy or a disorder of the peripheral nerves

Dorsiflexion of the foot L4 & L5

Plantar flexion – S1

Six Components 4. Sensory 1. Mental status 2. Cranial nerves 3. Motor 5. Reflexes 6.Coordination

Sensory Examination Superficial pain and touch Temperature Deep pain or pressure Vibration Position Discriminative functions

Ascending Tracts Lateral spinothalamic – superficial pain and temperature Posterior columns – vibration, deep pressure, position sense, point location, stereognosis, and two-point discrimination Spinocerebellar – proprioception Ventral spinothalamic – superficial touch and deep pressure

Superficial pain – pinprick , “sharp or dull” Light touch – fingertips or wisp of cotton (Temperature – ice and warm water in test tubes)

Deep pain – squeezing the calf or biceps muscle Vibration sense – vibrating tuning fork against bony prominences with patient’s eyes closed, “When does it stop?” Position sense – holding a distal joint of the fingers and toes and moving up or down

Discriminative Function Reflects the ability of the sensory cortex to correlate, analyze, and interpret sensations Sterognosis – identify an object (coin) Two-point discrimination - find the distance where the patient no longer perceives two stimuli

Graphesthesia – recognize numbers or letters drawn on skin Extinction – touch both sides of the body simultaneously with closed eyes Point location – with the patient’s eyes closed, touch an area on the body, withdraw the stimulus, and then ask the patient to point to the area touched

Six Components 5. Reflexes 1. Mental status 2. Cranial nerves 3. Motor 4. Sensory 5. Reflexes 6.Coordination

Reflexes Superficial reflexes: - abdominal reflex – contraction toward the stimulus - cremasteric reflex – elevation of the ipsilateral scrotum and testicle by touching the thigh

Deep Tendon Reflexes 0 Absent 1+ Hyporeflexic 2+ Normal 3+ Hyperreflexic 4+ Clonus

Eliciting Reflexes Biceps (C5, C6) Brachioradialis (C5, C6) Triceps (C6, C7) Patellar (L2, L3, L4) Achilles (ankle – S1) Plantar (L5, S1) Clonus – indicates CNS disease

Demonstration

Babinski sign

Six Components 6.Coordination 1. Mental status 2. Cranial nerves 3. Motor 4. Sensory 5. Reflexes 6.Coordination

Coordination Four areas that need to work together: 1. Motor system 2. Cerebellum – for rhythmic movement and steady posture 3. Vestibular system – for balance & for coordinating eye, head, and body movements 4.Sensory system – for position sense

Coordination Rapid alternating movements Point to point movements Gait – walk down the hall, heel to toe, walk on toes, and then on heels Standing – Romberg test

Pronator Drift

Changes With Aging Motor system – move and react with less speed and agility, muscle mass decreases Benign essential tremor Vibration sense decreased or lost in feet or ankles Reflexes – gag, ankle reflexes decreased “Benign forgetfulness”

Demo

Six Components 1. Mental status 2. Cranial nerves 3. Motor 4. Sensory 5. Reflexes 6.Coordination