How do you approach the symptomatic management of Lhermitte's phenomenon in a patient with MS?

In my experience, Lhermitte's phenomenon (signifying a cord lesion) generally resolves with time. If the tingling, vibration, or "electric shocks" are persistent and bothersome, I would consider medications that can be helpful for neuropathic pain, such as SNRIs (e.g., duloxetine or venlafaxine) or GABA-ergic medications (e.g., gabapentin or pregabalin).

Lhermittes is almost always transient, maximal during the first week or 2 of transverse myelitis, and generally abates or becomes ephemeral over time. Reassurance is usually all that’s needed. If persistent or bothersome, I agree with Robert. GABA-ergic or even carbamazepine can be helpful. Although, the side effects can outweigh benefit. I really try to avoid medicating this.