In a large skillet, melt the butter over medium heat. Add the mushrooms, onions, and garlic. Cook until the mushrooms are tender, stirring frequently, about 5 minutes. Stir in the cream, wine, lemon juice, Italian seasoning, cayenne pepper, salt and pepper and simmer until slightly thickened, about 8 minutes. Mix in the shrimp, stirring frequently, until the shrimp are pink and firm, about 3 minutes. Add the spinach and cook for 1 minute.
In a large serving bowl, combine the shrimp mixture and hot cooked pasta, tossing gently to coat. Sprinkle with the cheese.