The said case may have two reasons.
One there is reduction in
intervertebral disc spaces and emanating nerves from affected area get compressed. Similarly blood vessels also get constricted esp. in cervical area due to vertebral column bending due to age or other factors, thus hampers blood supply to brain. Also other vessels supplying to other parts get compressed in a similar way. To meet blood supply to brain or
limbs etc heart tries to pump in. This is natural mechanism.
Dementia may also be caused affecting memory. I do not know the age of patient. Relation to age is also important.
If intervertebral spaces are maintained by learning Yoga postures and deep breathing and
meditation, a lot of improvement will be seen in few months.
In allopathic med only surgery can help it but no surety. Yes complications are sure. Yoga and Ayurveda is sure to be safe but sure to be slow but gives benefit in long run.
Be sure to switch to Yoga, Ayurveda for
stress free life ahead. May get the help of Ayurveda doctor near you. Make 21 June a day to learn Yoga in 35 minutes on International Yoga Day.
Hope it helps you. Best wishes.