My cousin was first diagnosed with Selective Mutism, then suspected of Aspergers, and was put on a gluten free diet. It helped with the tantrums. However not completely. She was put on a diet free from all allergens and sweeteners/refined sugar, even some meats. This helped, once more. Lead poisoning was next suspected - the lead, however it may have initially been ingested, would have possibly damaged her gut, making her first intolerant to foods, then provoking aggressive mood swings as a reaction to these foods.
The latest is, at the age of around 9, she has been tried with Prozac for OCD. After many alternative and psychiatric consultations, the traditional medical approach has so far worked, seemingly the best, by easing her anxiety (solar plexus-heart relationship has balanced - the solar plexus will have been very overactive, perhaps, with a blocked heart chakra - I'm hazarding..).. I hope that it aids her in the long term as I've heard that similar medicines can not treat the long term issue adequately.
Did you try taking the[url] Asperger Test[/url] , its basically a free online diagnosis tool?