Hyperbaric Oxygen Therapy for Prodromal Alzheimer´s Disease With Cerebrovascular Disease

Overview

Alzheimer´s disease is a devastating illness that effects the patients as well as their family members. Its prevalence increases exponentially and the burden on the healthcare system is enormous. AD neuropathology begins 15-20 years before the occurrence of cognitive symptoms, which ranges from preclinical stage to mild cognitive impairment (MCI) to dementia. Prodromal AD is an early stage of the disease which is characterized by positive biomarkers and MCI. To this day, there is no medication that can cure or halt the progression of the disease and most studies focus on finding reversible risk factors and changing their influence. Several aetiologies have been proposed, like the deposition of amyloid and tau proteins, neuroinflammation and cerebral ischemia due to cerebrovascular factors. The Amyloid deposition, which serves as the biological marker of AD, was originally thought to be the main cause of the disease, however, recent data suggests that it is not the cause and that it might actually has a protective role. On the other hand, it is known today that vascular changes with related tissue ischemia and neuroinflammation have a crucial role in the development of AD in many patients. These pathologies, ischemia \& neuroinflammation, can be improved by the use of hyperbaric oxygen therapy (HBOT). The goal of this study is to explore the potential beneficial effect of HBOT on prodromal AD.

Alzheimer disease is characterised by cognitive, mental and functional disability that is expected to progress until the patient is fully dependent on others for activities of daily living. The pathology begins many years until the cognitive symptoms appear. Prodromal Alzheimer's disease is a state where a person has mild cognitive impairment and Amyloid deposition, which is seen on brain Amyloid PET or in lumbar puncture. To date, there has been neither a cure nor a therapy that can significantly halt or relieve symptoms for most patients. This study offers a new biological therapeutic approach aimed to induce neuroplasticity and improve neurological and cognitive functions. Pre -clinical as well as clinical data indicate that HBOT can be beneficial for those patients who suffer from MCI due to Alzheimer's disease and also to patients with cerebral vascular disease. HBOT is a well-known treatment used in clinical practice for other indications and is considered to be safe with relative rare mild and reversible side effect .The study is designed as a prospective, randomized, sham controlled double blinded study. Subjects will be enrolled up to a total of 100 subjects, age 60-85, diagnosed with MCI and positive Amyloid PET and vascular changes on brain MRI. Eligible patients will be randomized to the two study groups at a ratio of 6:6 (in clusters of 6 patients). The HBOT/sham treatment includes 60 daily sessions of 90 minutes each, five days per week. After the treatment period, there will be a maintenance period of HBOT/sham sessions twice a week for 6 months. All assessments with be done on baseline, after the treatment period and after the maintenance period. The primary endpoint includes improvement in cognitive scores in neurocognitive evaluations (Neurotrax). Secondary and tertiary endpoints include changes in cognitive, physiological, physical, imaging, lab tests and self report questionaires.