CPR APPLICATIONS FOUNDATION · CHAPTER 16 · NORMAL
Normal Foundations of the Neurological System
Organize the chapter before drilling into individual CPR concepts.
Supplemental foundation map: this page orients the detailed CPR Applications for Chapter 16. It is not part of the canonical CPR object inventory.
Move through Chapter 16
Normal Foundations · You are here
Abnormal Foundations
Treatment Foundations
16.1 · SOURCE CPR FOUNDATION
Concept
Neurology is solved by localization first and diagnosis second. The nervous system is organized by anatomic level and function: cortex, brainstem, spinal cord, root, plexus, peripheral nerve, neuromuscular junction, and muscle. Once you know what function is lost and where that function normally lives, the disease list narrows quickly.
Pattern
Step 1 gives motor, sensory, cranial nerve, reflex, autonomic, cognitive, or gait deficits and expects you to triangulate the lesion. Neurology stems feel overwhelming when read as disease lists. They become manageable when read as maps of disrupted pathways.
Rule
- Localize by function first. Ask whether the deficit is cortical, brainstem, spinal cord, root, nerve, NMJ, or muscle.
- Use side and pattern to refine. Crossed findings suggest brainstem; dermatomal or tract findings suggest cord or root.
- Use time course after localization. Sudden, episodic, progressive, infectious, and fluctuating patterns imply different mechanisms.
Applications
- Face-arm weakness with aphasia or neglect → consider an MCA cortical lesion; isolated face-arm weakness can also arise from subcortical lesions
- Crossed facial palsy and contralateral weakness → brainstem lesion
- Acute bilateral leg weakness and urinary retention → urgent evaluation for spinal cord compression or cauda equina pathology; localization depends on reflexes, sensory level, and other findings
- Stocking-glove sensory loss → peripheral neuropathy
- Fluctuating weakness without sensory loss → NMJ or motor-unit problem
- Tip: Name the location before naming the disease
CPR APPLICATIONS · ACTIVE REASONING
Localize the nervous-system lesion
Commit to a mechanism before checking your response. Worked explanations remain available without scripts. No responses are stored or transmitted.
Reveal worked answer and transfer
Best answer: Dominant left MCA cortical territory. Dominant frontotemporal language and lateral motor areas can account for aphasia with contralateral face-arm weakness.
Change one variable: If aphasia is absent, why could the lesion instead be subcortical?
Reveal worked answer and transfer
Best answer: Left pons involving facial fibers and descending corticospinal pathways. Ipsilateral cranial-nerve findings with contralateral body weakness are characteristic of a crossed brainstem syndrome.
Change one variable: Which associated gaze or cranial-nerve findings would refine the brainstem level?
Reveal worked answer and transfer
Best answer: Length-dependent peripheral polyneuropathy. Long peripheral axons are affected first, producing a distal symmetric sensory and reflex pattern.
Change one variable: How would a clear sensory level and bladder dysfunction shift localization toward the spinal cord?
Change the mechanism
Review all model outcomes without scripts
- Aphasia with contralateral face-arm weakness: A dominant-hemisphere cortical lesion becomes more likely.
- Crossed cranial-nerve and body motor findings: A brainstem lesion is an important localization.
- Distal symmetric sensory loss: Length-dependent peripheral neuropathy is favored over a single cortical lesion.
Explain it back: State the localization or treatment mechanism, and identify the clinical finding that would change the priority.
Unscored educational self-checks, not validated assessment items or individualized medical guidance.
How to use this foundation map
- Identify the organizing mechanism.
- Recognize the pattern.
- Restate the rule without looking.
- Test transfer with applications and question practice.
Pair CPR with the 5P Approach™ when solving cases and questions.