thank you for your query. Given your condition, it appears that the 'lost sense' and the 'almost unconsciousness' can be due to
seizure activity in the brain. Check for responsiveness during the episode. If she doesn't respond to calling her name or to touch during the episode, and is fine and responding afterwards, it may be due to Seizures (
fits). On the other hand, if she is talking irrelevantly, appears confused and disoriented, clueless about time, place, person, with altered sleep wake cycle, she may be having a condition called 'delirium', which requires urgent medical attention, preferably in a tertiary care hospital.
any of these two can be caused by the
tumor itself (worsening), or by the chemotherapeutic medications or by the
steroids.
A thorough neurological examination, fundoscopy, and preferably an
MRI brain is likely to yield the true cause.
Please contact your Neurologist/ Hospital for the same as soon as possible.
hope I've been able to answer your query. Please feel free to contact me for any further clarifications.