Of all the character-oriented episodes on TNG, those focusing on Troi were among the weakest. The writers rarely put her in interesting situations, instead relying on typically "feminine" stories.
In this case – a sort of hybrid between "Loud as a Whisper" and "The Child" – Troi loses her empathic abilities. The plot is not especially interesting (nor is the sci fi device underlying it). However, Marina Sirtis shines at points – particularly when stoic and not over-emoting. There are some good sequences interacting with the other characters. The conversation with Guinan is particularly strong.
I would emphatically recommend this above "Loud as a Whisper" as a less preachy commentary about disability. But it's only a decent episode, not a great or even good one.