BUDAPEST, HUNGARY – Autoimmune striatal dysfunction may be the underlying cause of dementia-like presentations, in rare cases.
This was the case for a 48-year-old woman, who presented with a 1-year history of progressive difficulties with attention and memory, said Gabriel C. Léger, M.D., speaking at the 4th International Congress on Autoimmunity.
Her husband complained that there had been a profound change in her personality. In particular, he found her to have become uninhibited and exhaustingly hypersexual. She had progressive difficulties functioning at home and at work–finally losing her job.
Her medical history included an episode of self-limiting, ballistic-like movements of the right side of her body during her early 20s. Exhaustive testing turned up no cause. The condition resolved spontaneously after a few months. She had no history of rheumatic fever or childhood chorea. However, at the age of 17 years her mother had Sydenham's chorea, which lasted about 1 year.
Cognitive testing also revealed attention and memory (acquisition) deficits. In addition, the patient displayed frontal network dysfunction, which psychologic testing confirmed.
Her physical exam was unremarkable, except for some mild psychomotor activity of the right hand and right side of the face. The usual battery of tests was unrevealing, as were infectious and autoimmune serologies, said Dr. Léger, a neurologist at the University of Montreal.
The clinicians initially diagnosed frontotemporal dementia, but “the presence of a very mild focal examination bothered us just a little bit,” said Dr. Léger. An FDG-PET scan revealed a dramatic increase in metabolism in the left striatum–70% more metabolic activity than in the right striatum.
Hypermetabolic lesions have traditionally been associated with diseases of autoimmunity, Dr. Léger noted. They treated her with a 3-day course of pulsed methylprednisolone sodium succinate, followed by a 2-week prednisone taper period.
Within weeks, she noted a resolution of her attention deficits. FDG-PET imaging demonstrated a fairly substantial resolution of the asymmetry of the striatum.
Based on the suspicion that autoimmunity against the basal ganglia was involved, the researchers sent pre- and post-therapy plasma to the laboratory for analysis. High titers of antibodies to the striatum–the antibodies found in Sydenham's chorea–were found in the pretreatment sample and reduced titers were found in the post-treatment sample.
Unlike this case, previous studies involving hypermetabolic lesions have also involved previously diagnosed disorders, such as Sydenham's chorea, Dr. Léger said.