In patients with Down's syndrome, late onset seizures may have a relationship with the clinical onset of dementia.

to explore the profile of patients in Memory Clinic (MC) in Barnet Learning Disability Service.

Retrospective study of case notes of 41 patients with Learning Disability (LD) who were registered in MC from 2004 to 2007.

Among the patients with different level of LD attending MC the gender distribution was as follows 27 (65.9%) were women and 14 (34.1%) were men. Most of the patients 25 (60.9%) were middle aged (35-49 years old). Patients with Down's syndrome consisted of 31(75.6%). 17 (41.5%) patients were diagnosed with dementia. 24(58.5%) showed borderline results. All patients with diagnosis of dementia had Down's syndrome whereas among those without definitive diagnose of dementia predominated people with mild to moderate LD.

Neuropsychological testing included Dementia Questionnaire for Mentally Retarded Persons (DMR), Psychiatric Assessment Schedule for Adults with Developmental Disabilities (PAS-AD).

12 (26.3%) had epilepsy. The seizure started during childhood and at middle age. Those with childhood epilepsy had the better seizure control. In individuals with late onset epilepsy the beginning of the seizures preceded cognitive decline.

The analysis of patients registered in MC showed the prevalence of middle aged persons with Down's syndrome. The dementia was established in 41.5% of patients with Down's syndrome.

A bimodal distribution for seizure onset in childhood and middle age was described. Late onset of epilepsy was associated with clinical onset of dementia.