Source / episode info
- **Episode:**48
- **Title:**Divine Intervention Episode 48 – Neurology Clerkship Shelf Review Part 5.
- **Published:**2018-09-05
- Source:Episode page
One-liner
This episode reviews high-yield neurology concepts including Myasthenia Gravis vs Lambert-Eaton Syndrome, Guillain-Barré Syndrome pathophysiology (CSF findings), Amyotrophic Lateral Sclerosis buzzwords, the interpretation of Weber and Rinne hearing tests, and CNS infections in immunocompromised patients.
High-yield summary
- Myasthenia Gravis (MG): Autoantibodies target the nicotinic acetylcholine receptor at the neuromuscular junction; treatment involves AChE inhibitors (Pyridostigmine) and addressing underlying thymoma/thymoma mass via surgery.
- Lambert-Eaton Myasthenic Syndrome (LEMS): Antibodies target presynaptic voltage-gated calcium channels, leading to impaired ACh release; weakness improves with repeated muscle use, and the association with Small Cell Lung Cancer is critical.
- Guillain-Barré Syndrome (GBS): Acute peripheral demyelinating polyneuropathy, often triggered by infection (e.g., Campylobacter jejuni) and classically presents with areflexia; CSF shows high protein/normal WBC count (albuminocytologic dissociation).
- Amyotrophic Lateral Sclerosis (ALS): Progressive motor neuron disease affecting both upper (corticospinal tract) and lower (anterior horn cell, cranial nerves) motor neurons; key EMG buzzwords include chronic denervation and fibrillation potentials.
- Weber/Rinne Tests: Normal finding is Air Conduction > Bone Conduction in both ears. If Weber lateralizes to one side, the cause is either a conductive loss in that ear OR a sensory loss in the contralateral ear.
Learning objectives
- Differentiate the pathophysiology and clinical presentation of Myasthenia Gravis versus Lambert-Eaton Syndrome.
- Recognize the classic CSF findings in Guillain-Barré Syndrome (albuminocytologic dissociation).
- Identify the key signs and symptoms associated with Amyotrophic Lateral Sclerosis, including characteristic EMG findings.
- Interpret the results of Weber and Rinne tests to localize hearing loss (conductive vs. sensorineural).
- Understand the differential diagnosis and management of CNS infections in immunocompromised patients (e.g., Cryptococcus vs. Toxoplasma).
Board exam buzzwords