Brain Diseases, Metabolic

The goal of this observational study is to learn about the relationship between sulfate ion levels in the blood and brain function in people with diabetic encephalopathy, a diabetes-related brain condition that can affect thinking and memory. The main questions it aims to answer are: 1. Are blood sulfate ion levels related to memory and thinking test scores? 2. Are blood sulfate ion levels related to the severity of brain shrinkage (brain atrophy) seen on MRI? 3. Do sulfate ion levels and their relationship with thinking and memory differ among people with different levels of long-term blood sugar control? Researchers will compare participants grouped by long-term blood sugar control (based on HbA1c, a blood test that reflects average blood sugar over the past 2-3 months) to see whether sulfate ion levels and their associations with brain function differ. Participants will: 1. Give a blood sample to measure sulfate ion levels, HbA1c, and neurofilament light chain (NfL), a marker of nerve damage. 2. Complete the Montreal Cognitive Assessment (MoCA), a test of memory and thinking, and questionnaires about daily living skills. 3. Have a brain MRI scan to assess brain shrinkage, unless a recent scan within the past 6 months can be used. 4. Provide information about their diabetes and medical history. This is a cross-sectional study, so participants will be assessed once at enrollment. No treatment or intervention is given. About 220 adults aged 45-75 years with type 2 diabetes and diabetic encephalopathy will take part.

The overall aim of this study is to evaluate LNAA treatment as a potential alternative to conventional dietary treatment for PKU. This study investigates the effects of LNAA treatment compared to the classic dietary treatment on cerebral dopamine synthesis in patients with classic PKU. We will assess LNAAs effectiveness on neurotransmitter synthesis, cognitive function, mental health, and safety, compared to the standard diet.