Weakness Flashcards
(13 cards)
What features in history help localize the cause of weakness?
Onset (sudden vs gradual), symmetry, proximal vs distal distribution, presence of sensory or cranial nerve symptoms, fluctuation, and associated systemic signs.
What is the typical pattern of weakness in upper motor neuron (UMN) lesions?
Spasticity, increased reflexes, upgoing plantar response (Babinski), minimal atrophy, no fasciculations.
What is the typical pattern of lower motor neuron (LMN) lesions?
Flaccid weakness, decreased reflexes, muscle atrophy, fasciculations.
What are common causes of sudden onset focal weakness?
Stroke, TIA, spinal cord compression, demyelination (e.g. MS), Todd’s paralysis (post-seizure).
What is the classic weakness distribution in myopathies?
Symmetrical, proximal muscle weakness (e.g., difficulty climbing stairs or combing hair), no sensory loss.
What conditions are characterized by fluctuating weakness?
Myasthenia gravis (ocular and bulbar involvement), Lambert-Eaton myasthenic syndrome.
What are red flags in a patient presenting with weakness?
Acute onset, respiratory compromise, bulbar symptoms, sphincter dysfunction, progressive worsening.
What blood tests are useful in evaluating generalized weakness?
Creatine kinase (CK), thyroid function, vitamin B12, electrolytes (K+, Ca2+, Mg2+), ESR/CRP, glucose.
What neuroimaging is indicated in new-onset or focal weakness?
MRI brain/spine to assess for stroke, demyelination, tumor, or spinal cord compression.
What test confirms the diagnosis of myasthenia gravis?
Anti-AChR antibodies (or MuSK antibodies), edrophonium test (rarely), and EMG with decremental response.
How is acute stroke managed in a patient with weakness?
If ischemic and within time window: thrombolysis or thrombectomy; supportive care, antiplatelets, and secondary prevention.
How is Guillain-Barré syndrome (GBS) managed?
Supportive care (monitoring respiratory function), IV immunoglobulin or plasma exchange; avoid steroids.
What is the treatment for myasthenia gravis?
Acetylcholinesterase inhibitors (e.g., pyridostigmine), immunosuppressants (steroids, azathioprine), thymectomy if indicated.
