The Recurrence Study

Patient admitted to the stroke service with acute stroke and TIAs will be eligible for the study. The study will enroll patients at Hamad General Hospital in the setting of the Stroke Ward.

The investigators anticipate approximately 300 patients to be enrolled based on the number of strokes that are admitted to the HGH stroke service every year.

The research primarily involves the evaluation of best medical therapy, and the incidence of biomarkers in the recurrence and progression of the disease in a high-risk cohort of stroke and TIA patients.

After obtaining informed consent the subjects medical information such as medical history will be collected in the case record forms. subjects MRI studies ( performed as standard of care) will be analyzed with a special software to determine the extent and volume of the most recent infarction. The degree of previous white matter damage and any incidental previous strokes will be recorded. MRI brain is a routine imaging technique in the care of stroke patients. Corneal confocal microscopy (CCM) imaging will be ordered for subjects whose standard of care attending physicians havent ordered for them. Some Stroke patients at HGH are ordered CCM if considered necessary by their physician. For the purpose of the study, the investigators would like to order CCM for all the subjects. CCM can be perfomed at anytime within the first month of recruitment into the study so the investigators will have it scheduled as it is convenient to the subjects within the month. The investigators hypothesize that corneal nerve loss may be driven by the same common vascular risk factors which may lead to stroke and thereby provide a surrogate for cerebral neuronal loss and hence pre-stroke 'neuronal reserve'. Hence CCM may allow us to identify the extent of risk factor burden. Furthermore, the quantification of corneal nerves may allow the identification of those with a lower pre-stroke neuronal reserve, and hence may suffer worse neurological outcomes following a stroke.

The subjects will be offered the best medical treatment for stroke, risk factors will be assessed by a team of stroke neurologists and nurse specialists. There will be regular follow-up visits at 1 month+/- 7 days, 3 months ( telephonic follow up only) and 1 year (clinical and repeat MRI brain).

After consent, serum and plasma will be obtained at onset of participation: Sample A (at onset), Sample B: within less than 48 hours, and Sample C:at 30 day +/- 1 week follow up visit. The blood samples will assist the team to study pro-coagulant and inflammatory markers. The team will require 10 mL ( 3 vials, 2 of which will have 4 mL of blood and the 3rd will have 2 mL) of blood on the aforementioned three days.

The blood , plasma and urine samples will undergo testing at the Neuroscience lab at iTRI, HMC, Qatar. A comparison between the different circulating biomarkers, proteins, DNA and metabolites might provide useful information on correlation between diabetes ( and other risk factors) and stroke. A variety of techniques are to be used including the following

1. Metabolites (metabolomics) High performance liquid chromatography (HPLC) and Liquid chromatography mass spectroscopy (LC/MS/MS) for detection of branching amino acids, glycine, aromatic amino acids and neurotransmitters.

Molecular biology techniques for detection of cytokines and interleukins Measurement of microparticles and their content in human serum via flow cytometry ELISA for detection of reactive oxygen species SDS-PAGE for detection of cysteine proteases and inflammatory response proteins vWF testing to be done in Hamad General Hospital laboratory

2. Proteomics In the proposed study, th einvestigators will use a proteomics based approach to perform a global proteomic profiling using the plasma from patients reportedly suffering from ischemic stroke and are at the same time diabetic. The proteomic profiling could lead to the identification of set of novel proteins that can be used as potential markers involved in the ischemic stroke development in patients with diabetic condition. By using a gel-based proteomics approach, the plasma proteins will be subjected to pre-fractionation by SDS-PAGE analysis followed by in-gel tryptic digestion and the purified peptides will be analyzed by Liquid Chromatography coupled to tandem Mass Spectrometry. The sequenced peptides will be searched against the available database to obtain protein identifications.

Samples required: Serum, plasma and urine samples. Plasma can be retrieved from whole blood in EDTA sample bottles after centrifugation. Serum can be retrieved from whole blood in plain sample bottles after centrifugation. Urine can be collected in plain sample bacti bottles.