The document outlines an approach to evaluating neurologic patients based on three key questions: 1) Is the problem neurological? 2) Where is the lesion located? And 3) What is the lesion? It emphasizes using the neurological exam and patient history, particularly the temporal profile of symptoms, to help localize and identify the nature of the lesion. By considering features like acute vs. chronic onset and focal vs. diffuse signs, the differential diagnosis can be narrowed down. This systematic approach aids in evaluating complex neurologic presentations.

1. Approach to the Neurologic Patient
James H. Bower, M.D.
Professor of Neurology
Department of Neurology
Mayo Clinic

2. Three Questions
1. Is there a lesion involving the nervous
system? (Is the problem neurological?)
2. Where is the lesion located?
3. What is the lesion?

3. Is the Problem Neurological?
• Toughest question to answer
• Practice, practice, practice

4. Where is the Lesion?
• Requires understanding of functional
neuroanatomy
• Neurological exam is the prime determinant

5. Where?
A. Supratentorial
B. Posterior fossa
C. Spinal cord
D. Peripheral neuromuscular system
E. More than one level (multifocal vs
diffuse)

6. Levels of the Nervous System
Level:
Supratentorial
Common signs:
Unilateral face/arm/leg
weakness, unilateral
face/arm/leg sensory loss,
increased reflexes on one
side of body, unilateral
extensor plantar response,
homonymous hemianopsia

7. Levels of the Nervous System
Level:
Posterior fossa
Common signs:
Diplopia, facial numbness
on opposite side of
extremity numbness, facial
weakness on opposite side
of extremity weakness,
vertigo, nystagmus,
dysphagia, dysarthria, gait
ataxia, past pointing on
nose-finger-nose test

8. Levels of the Nervous System
Level
Spinal cord
Common signs:
Bilateral weakness in
upper motor neuron
pattern, increased
reflexes, extensor plantar
responses, sensory level,
bladder/bowel
incontinence

9. Levels of the Nervous System
Level: Peripheral neuromuscular
A. Peripheral nerve
B. Neuromuscular junction
C. Muscle
Common signs:
A. Distal weakness of upper and
lower extremities, decreased
reflexes, glove and stocking
distribution sensory loss
B. Dysarthria, diplopia, ptosis,
dysphagia, fatigable weakness, no
sensory loss
C. Proximal muscle weakness,
decreased reflexes in correlation
with muscle weakness, no sensory
loss

10. More than One Level
• Multifocal lesions are often asymmetric, and
involve more than one circumscribed area or
several noncontiguous structures (think MS)
• Diffuse lesions involve large portions of the
nervous system in a symmetric fashion
(think SAH)

11. The Neuraxis
Muscle
N-M
junction
Nerve Plexus Root
Supra-
Tent
Post
Fossa
Cord
Ant
Horn
Cell/DRG

12. Case Study
• 50 y.o. male with 1 year of progressive
numbness and weakness in the feet and
hands

13. The Neuraxis
Muscle
N-M
junction
Nerve Plexus Root
Supra-
Tent
Post
Fossa
Cord
Ant
Horn
Cell

14. 40 yr old man with..
• Moderate weakness of right deltoid, triceps,
wrist extensors, iliopsoas, anterior tibialis
• R Hyperreflexia
• R Babinskis
• (Moderate right spastic hemiparesis)

15. The Neuraxis
Muscle
N-M
junction
Nerve Plexus Root
Supra-
Tent
Post
Fossa
Cord
Ant
Horn
Cell

16. What is the Lesion?
• Different pathological processes at same
level may produce similar symptoms/signs
• Manifestations of disease dependent on
where lesion is rather than on its
pathological nature
• Patient history is the prime mover in
determining what the lesion is
• Temporal profile!!

17. Onset
• Acute--within minutes to hours
• Subacute--within days
• Chronic--within months

18. What?
1. What is the temporal profile?
Onset: acute, subacute, or chronic

19. The neurologic differential
is very manageable.

20. Mnemonic
• The Trauma
• Neurologic Neoplastic/Paraneoplastic
• Differential Degenerative/Demyelinating/Developmental
• Is Infectious/Inflammatory
• Very Vascular
• Manageable Metabolic/Toxic
• Don’t forget seizures and migraines

21. Important Temporal and Spatial
Features
ACUTE SUBACUTE CHRONIC
FOCAL Vascular Inflammatory/
Infectious
Neoplasm
DIFFUSE Vascular
Toxic/Metab
Inflammatory/
Infectious
Toxic/Metab
Degenerative
Toxic/Metab

22. Case Study
• 50 y.o. male with 1 year of progressive
numbness and weakness in the feet and
hands

23. Important Temporal and Spatial
Features
ACUTE SUBACUTE CHRONIC
FOCAL Vascular Inflammatory/
Infectious
Neoplasm
DIFFUSE Vascular
Toxic/Metab
Inflammatory/
Infectious
Toxic/Metab
Degenerative
Toxic/Metab

24. 40 yr.old man with right spastic
hemiparesis
• Acute- Stroke
• Subacute- Multiple Sclerosis, Abscess
• Chronic- Tumor

25. Case 1
A 26-year-old RH woman began having
infrequent, brief episodes of twitching of her
left hand 10 months ago. These stopped 4
months ago, but she then noted clumsiness
when using her left hand. This progressed to
moderate weakness. In the past month, she
began having headaches. On exam, she
was lethargic but otherwise mentally intact.
There was mild papilledema bilaterally. She
had a mild droop of the lower part of her face
on the left, moderate weakness and slowing
of AMRs of left hand, and a circumduction
gait on the left. Reflexes were hyperactive in
the left arm and leg. Left plantar response
was extensor. Tone increased on the left.
Sensation normal except for inability to
recognize some objects in her left hand.
• Q1: Is problem neurological?
• Q2: Where is the lesion?
1. Level (supratent, post fossa,
spinal, peripheral, more than one
level)
2. Side
• Q3: What is the lesion?
1. Temporal profile
Onset: acute, subacute, chronic
2. Etiology

27. Case 2
An 18-year-old RH male is
brought in comatose from the
weight room at the school gym.
He collapsed while doing bench
presses after complaining of the
worst headache of his life.
When you see him, he is
unresponsive to deep pain, his
neck is rigid, and his pupils are 2
mm and fixed to light. His eyes
remain in the midline during the
doll’s eye maneuver.
• Q1: Is problem neurological?
• Q2: Where is the lesion?
1. Level (supratent, post fossa,
spinal, peripheral, more than
one level)
2. Side
Q3: What is the lesion?
1. Temporal profile
Onset: acute, subacute, chronic
2. Etiology

29. Case 3
A 55-year-old RH woman
developed proximal symmetric
weakness during a 2-week
period, with mild muscle
soreness. She thinks this is
slowly getting worse. On exam,
reflexes, sensation, and
mentation were normal. All
proximal muscles were
moderately weak, distal muscles
mildly so. There was no fatigue
with exercise.
• Q1: Is problem neurological?
• Q2: Where is the lesion?
1. Level (supratent, post fossa,
spinal, peripheral, more than
one level)
2. Side
Q3: What is the lesion?
1. Temporal profile
Onset: acute, subacute, chronic
2. Etiology

30. Case 4
A 21-year-old RH man sustained a knife
wound in his spinal column two years ago.
He tells you that his left leg weakness and
his right leg sensory loss are unchanged
for the last several months. On exam, you
note that he has weakness of the left lower
extremity. In addition, he has loss of pain
and temp perception on the right side from
about the level of his navel downward.
Vibration and joint position sense are
reduced in the left leg. Touch is normal.
• Q1: Is problem neurological?
• Q2: Where is the lesion?
1. Level (supratent, post fossa,
spinal, peripheral, more than one
level)
2. Side
• Q3: What is the lesion?
1. Temporal profile
Onset: acute, subacute, chronic
2. Etiology

32. Conclusions
• 1. Is problem neurological?
• 2. Where is the lesion?
Use exam to help localize
• 3. What is the lesion
Use history for temporal profile
Temporal profile with exam helps to
narrow down diagnostic category.