PANDAS versus Hashimoto`s encephalopathy: a diagnostic dilemma in a Saudi girl.

Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) is a rare recently recognised clinical syndrome with common presentations that include tics, Tourette's-like syndrome or obsessive-compulsive disorder. It is associated with various behavioural and psychiatric manifestations in children, such as separation anxiety disorder, body dysmorphic disorder, and attention deficit hyperactivity disorder. Steroid responsive encephalopathy with autoimmune thyroiditis (SREAT) is a rare disorder in children associated also with various movement disorders and neuropsychiatric manifestations. The present report describes a previously healthy 10-year-old girl who presented with motor tics, visual hallucination, separation anxiety, and emotional liability. Her workup showed an evidence of Hashimoto's thyroiditis on laboratory results, in addition to the elevation of antistreptolysin O titre (ASO). Based on this, a diagnosis of SREAT was made, and she was given courses of methylprednisolone with inadequate response. Then, the possibility of PANDAS was considered, and she responded to multiple courses of antibiotics with abate of symptoms after a course of intravenous immunoglobulin combined with monthly benzathine penicillin injections. To the best of our knowledge, this is the first reported case of PANDAS associated with autoimmune thyroiditis causing such diagnostic dilemma.