Open-label histological study of scalp biopsies from patients undergoing treatment with Cerebrolysin as therapy for cerebrovascular disease. The aim is to assess by histological techniques the causes of follicular repigmentation that occurs during the Cerebrolysin treatment.

Patients who fulfill the study requirements will receive the standard Cerebrolysin protocol as follows: Intravenous (iv) infusions of 5 vials per week, 2 vials on Mondays and 3 vials on Thursdays for 4 weeks, followed by an 8-week resting period prior to the next cycle of treatment. Each patient will receive 3 cycles giving a total of 9 months of follow-up. For intravenous infusions, each 10 ml vial containing 215.2mg / ml of Cerebrolysin (Ever Pharma) is diluted with physiological saline solution (NaCI 0.9%) to a final volume of 100 mL.

A pre- and post-treatment biopsies will be collected from the achromotrichia area of each patient. Antisepsis of the area will be performed prior to each biopsy with chlorhexidine, followed by local anesthesia with lidocaine 2% and epinephrine. The biopsy will be collected using a 4mm punch and the wound will be sutured with non-absorbable stitches with Prolene 4-0.

Inclusion Criteria:

• Known neurologist prescription for Cerebrolysin treatment due ischemic or hemorrhagic stroke, traumatic brain injury or dementia.
• Age-related white or gray hair.
• Above 40 years old
• Voluntarily consents in written informed consent by the principal or legal representative

Exclusion Criteria:

• Patients with a diagnosis of Chronic Kidney Disease (CKD).
• Known history of seizures, epilepsy, or hypersensitivity to one or any drug components.
• Pregnant patients.
• Patients with a history of recent treatment of hair coloring products.