Is that a mass of burrs in that lovely topknot? In case anyone has to deal with those, the best (and least hair-damaging) way to get them out is to crack them with a pair of flat pliers. It breaks them into a mass of tiny slivers that can be easily finger-combed out without damaging of further tangling the hair.
I learned this the hard way. My heart-horse was a burr-magnet. Any time he went out into the "big field," Billy came back with a solid mane and tail. After trail rides, he often sported a mighty mass in his forelock. Friends would laugh because I carried a pair of mini pliers in my pocket alongside my hoof pick!