Mistress Frankenstein (2000)

Dr. Victor Frankenstein neglects the sexual needs of his frigid and frustrated wife Helena. After Helena gets killed in a horse riding accident, Victor decides to bring her back to life. However, Victor's inept assistant Igor accidentally damages Helena's brain and replaces it with a lesbian's brain, so Helena is now a crazed, aggressive, and predatory vixen with a raging insatiable libido.