The Neurologic Examination and Localization
Why the Exam Comes First
Clinical reasoning
The neurologic exam translates symptoms into objective signs, helping you localize disease before ordering tests.
Core principle
Think in patterns: weakness, reflex changes, sensory level, eye movement abnormalities, speech disturbance, gait, and mental status each narrow the lesion site.
A practical exam sequence
-
1
Step 1: Assess mental status and language.
-
2
Step 2: Inspect cranial nerves, eye movements, pupils, and facial symmetry.
-
3
Step 3: Test strength, tone, coordination, and reflexes.
-
4
Step 4: Map sensation and look for a sensory level.
-
5
Step 5: Observe gait and posture.
Localization clues
| Finding | Possible localization |
|---|---|
| Aphasia | Dominant cortical hemisphere |
| CN deficits plus long-tract signs | Brainstem |
| Sensory level | Spinal cord |
| Distal symmetric numbness | Peripheral neuropathy |
| Incoordination with normal strength | Cerebellum |
A patient has facial weakness, dysarthria, and contralateral weakness of the arm and leg. The lesion most likely localizes to the:
A combination of cranial nerve findings and long-tract signs strongly suggests a brainstem lesion.
Correct answer: Brainstem
What does a sensory level suggest?
A clear sensory level is a classic clue to spinal cord pathology.
Correct answer: spinal cord involvement
Motor and Sensory Patterns
Upper motor neuron vs lower motor neuron signs
Upper motor neuron
- Weakness with spasticity
- Hyperreflexia and pathologic reflexes
Lower motor neuron
- Weakness with atrophy and fasciculations
- Hyporeflexia or areflexia
Hyperreflexia and spasticity suggest injury to the:
Upper motor neuron lesions disinhibit reflexes, producing hyperreflexia and spasticity.
Correct answer: Upper motor neuron pathway
Name one bedside sign that can support corticospinal tract dysfunction.
An extensor plantar response suggests upper motor neuron involvement.
Correct answer: Babinski sign
Problem-solving tip
If weakness is present without sensory loss and reflexes are reduced, consider lower motor neuron, peripheral nerve, root, or neuromuscular junction disease before assuming a brain lesion.