Nokea
A previously healthy 68-year-old male presents with progressive muscle weakness in his right hand, swallowing difficulty and difficulty with walking. He believes these symptoms occurred "out of the blue" and have worsened over the last 2-3 months. His temperature is 98.6 deg F (37 deg C), blood pressure 145/86 mmHg, pulse is 80/min, and respirations are 17/min. Neurologic examination is significant for mild dysarthria. He has atrophy of the thenar muscles of the right hand and forearm, and 2/5 strength on wrist extension and flexion, as well as 3/5 power in intrinsic hand muscles on right. He has some fasciculations in his right thigh, and mild (4+/5) weakness of hip flexors bilaterally. Tone is increased in both legs. Sensory examination is intact. 3+ patellar reflexes are noted on the left lower extremity. On gait testing, the patient has poor balance, and spastic gait. Which of the following is the most likely diagnosis?
Correct Answer: B
Rationale: The patient's presentation of progressive muscle weakness, atrophy, fasciculations, and spasticity with hyperreflexia is classic for amyotrophic lateral sclerosis (ALS). ALS involves both upper and lower motor neuron degeneration, leading to a combination of weakness, atrophy, and spasticity. The absence of sensory deficits and the presence of bulbar symptoms (dysarthria, swallowing difficulty) further support this diagnosis. Guillain-Barre syndrome typically presents with ascending paralysis and areflexia, while myasthenia gravis is characterized by fatigable weakness without atrophy or fasciculations. Multiple sclerosis and dermatomyositis do not fit the clinical picture.