hypoxic brain injury/ 12th nerve palsy

Hi, questions about my mum (71yr - in the UK)
After having a community cardiac arrest (she was in VF) on the 12/01/10 my mum has developed a hypoxic brain injury and bilateral 12th nerve palsy. Her MRI shows ischaemia in the pons (not sure exactly where!!). Drs not sure what caused cardiac arrest. Drs not sure what caused ischaemia. Difficult to determine if she had a heart attack due to insult to heart during arrest, not sure if ischaemia is due to stroke. Dr said he is impressed with echo. Mum can moves all limbs independently (walk with zimmer, wash herself). GCS 15. Continent. Had trachea, now out no problems. Memory not bad at all (cant recollect much about earlier weeks when in ICU thank goodness). Problems now, fatigues easily (can understand this) main problem cannot eat/drink due to poor swallow secondary to tongue paralysis. Has nasogastric feed and possible PEG insertion if doesnt get better. Sorry for long winded message. My question is can her swallow improve with speech and language input?? has anyone experience/knowledge on this?? Issue appears so isolated, still has gag reflex sometimes hypersensitive, no facial weakness, eyesight not best to begin with but appears ok, hearing no problems. Concerned for mental health, been commenced on anti-depressants as a cover for post traumatic syndrome.Sorry Many thanks