Hi ICU PT,
Good question. The field of Neuro has always been controversial, especially stroke. I have to admit being a little out of practise in this area, but used to work with closed head injury patients in the past.
Neuroplasticity is the key to recovery for any brain damage, therefore checking into this knowledge base could provide the answers. It is my belief that the damaged brain requires constant reminders of the stored movement patterns,
without which recovery is slowed. Initial phases of stroke causes some anoxic damage due to compromised blood supply flow (bleed or clot), then brain swelling causes further compression. If a clot, thrombus dissolving medication should be given within three hours, although recent evidence states that it is worthwhile within six hours post stroke. Recovery can be very much hastened with these drugs. Obviously thrombus thinners are contraindicated in bleeds.

As swelling reduces it will be more possible to differentiate areas left undamaged, those that have shut down due to compression but no permanent damage, those areas that are damaged but partially operative and those areas of brain that have died. The remodelling around the dead or damaged areas requires stimulation for the brain to have a reason to institute neural repair. The old days of believing that the brain cannot form new interconnections are over.

The unconcious brain will still accept some inputs if the person is eventually going to recover ie brain death is unlikely. If the patient is unconcious, taking the limb through passive movements will likely maintain inputs. This is way before any discussion of muscle tone increases, contractures, hemiplegic limbs etc are considered. The glenohumeral joint should be supported on the affected side to avoid dislocation if the arm is flaccid / no tone, otherwise axillary nerve damage could occur exacerbating problems.

If the patient is conscious, explain the situation and use the unaffected side to assist movement pattern reminders. Teach the patient to use the unaffected side to move the affected side. Ensure that the patient is thinking about what they are trying to achieve. Increase all input cues, visual, kinaesthetic, sound (verbal encouragement), use mirrors and feedback from relatives. The richer the recovery environment the better. As strange as it may sound, allowing the conscious patient to see videos of their pre stroke movement can be utilised as another input. Mirror boxes are becoming more popular to fool the brain into working.

If the movement patterns are kept up front in the patients mind then less retraining may be required later. The movement also helps the joint retain synovial fluid movement in joints improving lubrication and feeding joint cartilage. If the joints are permitted to become stiff and tight then it is far harder for the patient to overcome this resistance as muscle control returns. Prolonged delay in active muscle control means muscle atrophy from disuse and difficulty to use the limb against gravity let alone stiff joints.

I have probably gone on a bit too long here, so will finish.
If you have any further questions please feel free to ask.
Cheers,
MrPhysio+