Dr. Kevin J. Pacheco Weakness

Introduction Weak = decrease in muscle strength or power Dizzy = lightheadedness, disequilibrium, disorientation, vertigo, or even confusion Weakness First, divide into focal or generalized Then, separate sudden vs. gradual onset

History Hints Focal + Sudden Ischemic CVA/TIA/ICH until proven otherwise Generalized + Sudden Occult infections, anemia, and metabolic disorders (hypoxia, sodium, potassium and glucose)   Focal + Gradual Tumor, peripheral nerve compression, other spinal cord pathology, or autoimmune (MS)

Physical Exam Hints Ptosis – myasthenia gravis Persistent tachycardia – myocarditis (troponin will be positive) Back pain + weakness – MRI (with contrast if fever) for epidural hematoma/abscess, cauda equina, metastatic cancer, transverse myelitis Young female and focal neuro – MRI with contrast for multiple sclerosis

Can’t Miss Differential Stroke – hemiplegia, aphasia, visual Spinal cord compression/ischemia/infection – back pain and true weakness Electrolytes – sodium, potassium, magnesium, glucose CNS infection – fever, meningismus, altered mental status Seizure – post-ictal, tongue laceration, incontinence Toxic

Weakness – Work-Up Orders Start with CBC, BMP, EKG, VS +/- accucheck if DM and UA if elderly or symptoms suggestive Consider troponin if presentation or clinical history suggests Add CT head w/o contrast if sudden or focal and no other explanation Add TSH if gradual Then look at MRI of spinal cord or brain

Weakness Zebras What are you going to miss with above? Myasthenia Gravis – blurred vision, diplopia, and ptosis (anti-acetylcholine R Ab) Guillaine-Barre – ascending paralysis, decreased reflexes, variable sensory deficits (LP + history) Drug Induced Myopathies – meth in particular - total CK or myoglobin ALS – mixed picture of weakness and hyperreflexia (rule out others + EMG) Certain infections – mono (sore throat, monospot), hepatitis (hx +/- jaundice, CMP) Adrenal insufficiency – chronic steroid use, refractory hypotension (cortisol and ACTH stimulation test – give 100mg hydrocortisone)

Often Overlooked Check reflexes This can increase or decrease suspicion of difficult to diagnosis conditions (example: if reflexes present unlikely Guillain Barre)