hi - my dad is 65 year old, retired, diabetic, low blood pressure, sustains physical activity by walking 2-3 kms everyday, weak digestive system as suffers from flatulence & loosies quite often. For last 10 - 12 days a new thing has come up, thumb on his right hand starts shaking/shivering without his control, not able to grip a pen also when this happens, not accompanied by any other pain or loss of sensation. What should we do?