Hypoglycemic coma resulting in brain damage

Anybody have experience with this?

My Mum's glucose levels went low in her sleep and as a result she slipped into a diabetic coma. Her glucose levels were so low for so long she now has severe brain damage.

All of the medical staff who have dealt with her so far have said that they have never known a patient to survive a case so severe. 7 months later though Mum is still with us but her brain damage means she has no control over her body, is bedridden/wheelchair bound, can't feed herself, her speech is very very limited, she says the odd word and if she tries to speak in sentences she speaks in what they refer to as "lettuce talk" which is basically a load of jumbled up sounds which mean nothing. Mum's sight is also impaired as a result. She is only 45.

Because it is so rare for someone to pull through we as a family do not really know what to expect so anyone with any information or advice based on experiences they have had either froma medical point of view or a personal one, would be appreciated.