You need to give more details to arrive at proper diagnosis However Syndopa is advised for Parkinson disease  & Strocit advised for cognitive enhancement which can be associated with the disease

Hello. Both these medicines are sometimes prescribed together for specific neurological conditions, but whether they should be taken together in your father-in-law’s case depends on his exact diagnosis, examination findings, and other medications he may be on. Persistent dizziness and imbalance at his age need proper clinical evaluation, as they can be due to multiple causes (inner ear issues, blood pressure fluctuations, neurological conditions, medication effects, etc.). I would strongly advise not to start, stop, or combine these medicines on your own. Please consult the treating neurologist/physician who prescribed them (or a nearby neurologist) for a review and medication reconciliation. If symptoms are severe, worsening, or associated with vomiting, weakness, or falls, please seek urgent medical attenti