362.4 📋 章末速蚘 Summary

362.4.1 🔑 䞀句話瞜結

Neurologic diagnosis = two-step approach — (1) anatomic localization (where is the lesion?) by tracing along neuroaxis (cortex → subcortical white matter → basal ganglia → brainstem → cerebellum → spinal cord → root → plexus → peripheral nerve → NMJ → muscle) + (2) etiologic diagnosis (what is the cause?) by time course pattern (vascular sudden, infectious days, neoplastic weeks, degenerative months-years, fluctuating NMJ, relapsing-remitting MS); history most important (onset + duration + course + distribution + associated + medications + family); neurological examination components — mental status + cranial nerves I-XII + motor (strength 0-5 MRC + tone + bulk + fasciculations) + reflexes (DTR + plantar Babinski) + sensation (primary + cortical) + coordination + gait/station; UMN vs LMN distinction critical — UMN ↑ tone + ↑ reflexes + Babinski + late atrophy vs LMN ↓ tone + ↓ reflexes + early atrophy + fasciculations; Glasgow Coma Scale E (1-4) + V (1-5) + M (1-6) = 3-15; neuroimaging — CT for acute hemorrhage/trauma/bone (fast widely available); MRI definitive for most pathology — T1 anatomy + T2 pathology + FLAIR for MS/edema + DWI for acute stroke (bright within minutes-hours) + T2*/SWI for hemosiderin/microbleeds + gadolinium for BBB disruption (tumor, infection, inflammation); MR/CT angiography for vessels; amyloid/tau/dopamine transporter PET emerging; electrophysiology — EEG for seizures/encephalopathy/brain death + EMG/NCS for neuropathy (axonal vs demyelinating)/NMJ (decremental MG, incremental LEMS)/myopathy; CSF analysis (LP) — opening pressure 10-20 cm H2O, normal < 5 WBC/no RBCs/protein 15-45/glucose 2/3 serum; classic patterns: bacterial meningitis ↑↑ PMN + ↑↑ protein + ↓ glucose, viral lymphs + mild ↑ protein + normal glucose, TB/fungal lymphs + ↑↑ protein + ↓ glucose, MS oligoclonal bands, SAH many RBCs + ↑ protein, GBS albuminocytologic dissociation (↑↑ protein + normal cells); brainstem crossed signs — Wallenberg (lateral medullary), Weber (midbrain CN III + contralateral hemiparesis), Millard-Gubler (pons CN VI/VII + contralateral hemiparesis); spinal cord syndromes — anterior cord, central cord (syringomyelia cape distribution dissociated), Brown-Séquard hemisection (ipsilateral UMN + position + contralateral pain/temp), posterior column, cauda equina (saddle anesthesia + bowel/bladder), conus medullaris; genetic testing for hereditary disease (HD, ataxias, CMT, dystonia, ALS, AD genetics)。

362.4.2 💊 治療粟芁

  • Approach principles (not therapeutic): localize first (anatomic location along neuroaxis) then etiology (cause by time course pattern)
  • CT urgent: trauma, suspected acute hemorrhage, stroke initial screening
  • MRI definitive: most neurological pathology — choose sequence per question
  • LP indications: meningitis, encephalitis, suspected SAH (CT-negative), MS workup, autoimmune, malignancy, IIH/NPH
  • LP contraindications: ↑ ICP with mass effect (herniation risk — image first if focal signs + papilledema), coagulopathy, infection at puncture site
  • EEG: seizure activity, encephalopathy, brain death determination
  • EMG/NCS: timing — wait 2-3 weeks after onset for full picture (denervation changes)
  • genetic testing: pre-test counseling + post-test counseling essential

362.4.3 🎯 盧醫垫的考前提醒

  1. Two-step neuro diagnosis (memorize): (1) localize (where along neuroaxis) (2) etiology (what kind by time course) — this is the framework for every neuro question
  2. Time course to etiology mapping: sudden seconds-minutes = vascular/seizure, hours-days = infection/inflammation, weeks-months = tumor/autoimmune, months-years = degenerative/hereditary, fluctuating = NMJ (MG), relapsing-remitting = MS, stepwise = multi-infarct
  3. UMN vs LMN distinction (always test): UMN ↑ tone + hyperreflexia + Babinski + late atrophy + clonus; LMN flaccid + hyporeflexia + early atrophy + fasciculations + downgoing plantar
  4. MRI sequences purpose: **T1 anatomy, T2 pathology, FLAIR for MS/edema, DWI for acute stroke (bright within minutes), T2*/SWI for microbleeds, gadolinium for BBB disruption**
  5. CT vs MRI choice: CT urgent for hemorrhage/trauma/bone; MRI definitive for most else; DWI MRI changes within minutes of stroke vs CT often normal in first hours
  6. CSF patterns (memorize all 5): bacterial = ↑↑ PMN + ↑↑ protein + ↓ glucose; viral = lymphs + mild protein + normal glucose; TB/fungal = lymphs + ↑↑ protein + ↓ glucose; MS = oligoclonal bands + IgG index; GBS = albuminocytologic dissociation (↑↑ protein + normal cells)
  7. LP precautions: do not perform if ↑ ICP with mass effect (focal signs + papilledema) — get imaging first; correct coagulopathy
  8. GCS 3-15: E (1-4) + V (1-5) + M (1-6); GCS ≀ 8 → intubate consideration
  9. Brainstem crossed signs: ipsilateral CN + contralateral hemisphere/body — Wallenberg (lateral medullary), Weber (midbrain), Millard-Gubler (pons)
  10. Spinal cord syndromes: Brown-Séquard hemisection (ipsilateral UMN + posterior column + contralateral pain/temp); central cord (syringomyelia) cape distribution dissociated sensory; cauda equina (saddle anesthesia + bowel/bladder); always test for sensory level