The patients will be offered enrollment by sequential measures with odd numbers placed into the Control Group and even numbers in the Treatment Arm. One hundred patients will be enrolled in each arm. Study medications will be initiated in the outpatient setting following informed consent, enrollment and baseline lab evaluation. Scheduled clinic visits at 3 months and 1 year from date of enrollment will be used to re-assess performance via repeat cognitive testing. Lab evaluation of CBC, CMP, histidine and histamine levels will occur at baseline and the 3 month clinic visit for the treatment arm subjects.
Group I: Control Arm- No intervention. Subjects will receive cognitive and lab testing and continue with current management of their cognitive impairment.
Group II: Treatment Arm- In the outpatient setting, one chewable tablet multivitamin (Zn and folic acid containing) plus a titrated dosing of L-histidine powder or capsules starting at 2g consumed before noon escalating every 2 weeks up to 4, 6, then 8 g per day as tolerated.
