Transcript Part I: Neurological Exam Part II: Coma

Part I: Neurological
Exam
Part II: Coma
Connie Chen
Neurology Consultants of Dallas
Part I
Neurological Exam
Neurological Exam:
Some Basics
Purpose of exam: differential diagnosis
 The mantra:

– History comes first!
– Exam is next best option.
– “Pan-scanning” is a poor substitute for exam.
– “Pan-scanning” results in “missing the boat”.
Neurological Exam:
More Basics

Lecture goal:
– Moving past medical school --see the forests,
not the trees.
– Tailor your exam to meet your needs.
– Full neurological exams will waste your time?
Case example
65 yo with low back pain.
 Pain radiates down right leg.
 He notes new acute weakness in right leg.

Differential?
 How can the exam support/aid in
diagnosis?

Exam Purpose

Identify the part of the “neuro-axis” involved:
– link EXAM with FUNCTION

Neuro-axis:
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–
–
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–
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–
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Cortex
Subcortex
Brain stem
Spinal cord
Nerve root
Peripheral nerve
Neuromuscular junction
Muscle.
The Exam Itself

Components:
– Mental status
– CN
– Motor (tone, bulk, strength)
– Sensation (soft touch/temp/pinprick vs
vib/proprio)
– Reflexes
– Coordination
– Gait (stressed gaits, base, arm swing, turn)
Exam
–
–
–
–
–
–
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Mental status
CN
Motor
Sensation
Reflexes
Coordination
Gait
Matching
to
Location
–
–
–
–
–
–
–
Cortex
Subcortex
Brain stem
Spinal cord
Nerve root
Peripheral nerve
Neuromuscular
junction
– Muscle
Exam

Mental status
– Level of alertness
– Orientation
– Language (naming,
fluency, repetition,
comprehension, reading)
– Calculations
– Memory
– Judgement/insight
– Executive
function/Abstract thought
– Visualspacial ability
Cortex (Frontal,
parietal,
temporal,
occipital)
 Subcortex (white
matter, thalamus)

Exam

Cranial Nerves
– III/IV
– IV-VIII
– V, IX-XII

Brainstem
– midbrain
– pons
– medulla
Motor Exam
0= no movement, 1= f licker, 2= gravity removed,
3= against gravity, 4-/4/4+ = grades of resistance, 5= full
PATTERNS:
 Corticospinal tract: strength “stroke pattern”
– tone and bulk change later
– spinal cord: spinal shock
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Anterior horn: weakness at level, fasciculation
Root: weakness in all muscles involving root
Nerve: weakness in all muscles involving nerve
Muscle: proximal > distal weakness
Sensation Exam
Notoriously painful for all involved.
 Patterns: Central, cord, peripheral
 Main pointers:

– Dorsal columns: late cross, vib/proprio
– Spinal thalamic tract: early cross, ST/temp/PP
Reflexes
0:
 1:
 2:
 3:
 4:

absent
present with distraction
present without distraction
spreads across more than one joint
Clonus- sustained and non-sustained.
PATTERNS:
 “UMN”: Brain, spine (before anterior horn)
 “LMN”:Spine (after anterior horn), root,nerve
Coordination=Cerebellum

Rapid alternating movements
(dysdiadokinesia)
Past pointing
 Dysmetria: finger nose/heel to shin
 ??romberg-- not really
 Wide based stance
 (nystagmus at primary gaze)


***Pre-existing weakness can fool you
Gait
The best part of exam
 Evaluates strength, coordination,
sensation
 look at arm swing, base of stance, steps,
turn,
 stressed gaits will bring out subtleties.


What are matching anatomical locations?
Case Revisited
60 something yo with bilateral UE pain.
 Weakness bilateral UE.

Differential?
 Exam expectations?

Case Series

67 yo fell off of a horse and has developed
bilateral LE weakness over the course of
days.
Differential?
 Exam findings?
 What other pertinent HPI questions would
have helped?

Case series

25 yo notes water feels “funny” on right
hand, and then his right leg felt strange.
Differential?
 Exam findings?
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Case Series

40 yo notes left face and arm feels funny
since last night and notes left arm and leg
weakness.
Differential?
 Exam findings?

Case Series

78yo fell and couldn’t get up. “I knew I
was going to get stuck [on the floor] for
weeks now.” Why is he weak?
Differential?
 Exam findings?

Case Series

26 yo notes stumbling when walking and
an inability to make his jump shots with
basketball over the course of 2 days. His
toes tingle.
Differential?
 Exam findings?

Case series

74 yo wm notes left face and arm weakness that
lasts only 30 minutes. Later that day she
develops vertigo, slurred speech, and diplopia.
She can’t walk because she feels “like I’m
drunk.” She has right carotid stenosis.
Differential?
 Exam findings?
 Right carotid stenosis relevance?

Part II: Coma
Coma Definition
State of sustained unconsciousness
 Ascertained by exam
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How Coma Happens

Structural causes:
– Bilateral supratentorial disruption
– Disruption of the RAS of the brainstem

Practical thoughts (linking history, exam, and
structure):
– “metabolic”causes affect brain globally
– “Vascular” causes are not equal: unilateral carotid
artery vs. vertebral artery vs. basilar artery.
Coma Prognostication

Gauging coma:
– History
– Exam
– Ancillary studies

History cannot accurately predict outcome
of coma.
Coma Prognostication

Ancillary studies/imaging cannot
accurately ascertain coma emergence

Exception:
– SSEP’s performed days 1-3 after coma.
– Absence of cortical response shows poor
prognosis.
Coma Prognosis

Exam
– Glascow coma score (eye opening, motor
response, verbal response)
rather useless in prognositication
Better:
– Motor:
Command>purposeful>flexor>extensor>flaccid
– Cranial nerves: present>absent
– Roving eye movements > no spontaneous
Coma Prognosis: Take Home
(it’s bad when…)

First 24hr post circulatory arrest:
myoclonus status epilepticus

Lack of SSEP’s day 1-3

Or by day 3:
– no corneals, or
– absent pupillary reaction, or
– motor response is extensor or worse