This patient should be treated with a skeletal muscle relaxant, such as oral baclofen. He is experiencing muscle spasms and cramps as a long-term consequence of corticospinal tract injury from multiple sclerosis. Damage to upper motoneuron pathways has resulted in reduced inhibition of reflex arcs in the spinal cord, which allows for tonic activation of the lower motoneuron and resultant spasms and cramps. These symptoms can be reduced with the use of skeletal muscle relaxant medications, including baclofen, tizanidine, and cyclobenzaprine. Some patients may require intrathecal baclofen pumps or botulinum toxin injections for refractory symptoms.

Electroencephalography would be an appropriate test if a high suspicion of seizure was present. This patient's history and clinical evaluation do not suggest seizure, and his symptoms are highly consistent with upper motoneuron spasticity.

Because the physical examination findings are clearly consistent with an upper motoneuron injury, electromyography (EMG) (nerve conduction studies and needle electrode examination) is inappropriate. EMG is most appropriate for disorders of the lower motoneuron, neuromuscular junction, or muscle. The lack of fasciculations makes lower motoneuron injury even less likely, and the normal serum creatine kinase level and lack of pain on muscle palpation make an inflammatory myopathy very unlikely.

Pramipexole would be an appropriate treatment for restless legs syndrome (RLS), but this patient is not experiencing RLS symptoms. RLS does not result in upper motoneuron signs on examination or daytime muscle cramps. Also, patients with RLS experience feelings of discomfort in the legs or periodic limb movements while sleeping, not tonic leg spasms and cramps as with this patient.