A 55-year-old male patient presents to the clinic with a 6-month history of muscle weakness and difficulty speaking. He reports that he initially noticed difficulty gripping objects with his right hand and that his speech has become progressively more slurred over the past few months. He also experiences muscle cramps and occasional fasciculations (muscle twitching) in his arms and legs. His medical history is unremarkable, with no family history of neurological disorders. On physical examination, the patient demonstrates weakness in both upper limbs, with hyperreflexia and atrophy of the right hand muscles. There are no signs of sensory deficits, and his cognitive function remains intact. The neurologist suspects that the patient may have amyotrophic lateral sclerosis (ALS). What is the most common initial symptom of amyotrophic lateral sclerosis (ALS)?