AANP Family Nurse Practitioner (FNP) Certification ExamDiagnosisHard
A 55-year-old male presents with a 3-month history of progressive muscle weakness, particularly in his hands and feet, accompanied by fasciculations. He reports difficulty with fine motor tasks and occasional muscle cramps. His neurological examination reveals atrophy and hyperreflexia in the affected limbs, with no sensory deficits. What is the most likely diagnosis?
- AMultiple Sclerosis (MS)
- BMyasthenia Gravis (MG)
- CAmyotrophic Lateral Sclerosis (ALS)
- DGuillain-Barré Syndrome (GBS)
Show answer & explanationAnswer & explanation
Correct answer: C. Amyotrophic Lateral Sclerosis (ALS)
The combination of progressive muscle weakness, fasciculations, atrophy (lower motor neuron signs), and hyperreflexia (upper motor neuron signs) in the absence of sensory deficits is pathognomonic for Amyotrophic Lateral Sclerosis (ALS).
Why the other options are wrong
- A. MS typically presents with a relapsing-remitting course, sensory deficits, optic neuritis, and ataxia, not primarily with combined upper and lower motor neuron signs without sensory involvement.
- B. MG is a fluctuating muscle weakness that worsens with activity and improves with rest, often affecting ocular and bulbar muscles, and does not typically present with fasciculations or hyperreflexia.
- D. GBS is an acute, ascending paralysis often preceded by an infection, characterized by hyporeflexia/areflexia and sometimes sensory changes, not chronic progression with hyperreflexia and fasciculations.
Amyotrophic Lateral Sclerosis (ALS)
A progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord, leading to muscle weakness, atrophy, and eventually paralysis.
- Characterized by combined upper and lower motor neuron signs.
- Patients experience progressive muscle weakness and fasciculations.
- Sensory function is typically preserved.
Memory trick: ALS: Atrophy, Loss of Strength, Sensory Sparing.