Yes, this can be an injury. Whether or not this injury is a side effect of the treatment, or a case of malpractice (a condition caused by the providers acting below their standard of care) is something that you would need to speak with a medical malpractice attorney about to discuss this matter in more detail.
Medical malpractice claims are based on expert testimony, this means you, or your attorney, will need to find a medical expert in the same, or similar field, to testify as to the standard of care in the industry, whether your physician or facility's conduct fell below that standard, and whether that negligence was the cause of your injury. The same (or a different) expert can then testify as to your projected future damages and cost of medical care.
Due to the complexity of these claims, I highly recommend that you retain a medical malpractice plaintiff's lawyer (also called trial attorneys). Fortunately the majority of these attorneys will provide you with a free consultation, and many will represent you on a contingency basis (they will advance the costs of litigation and legal services in exchange for a portion of your successful settlement or judgment).
You can find local attorneys using the State and Local Bar Association directories, or private directories such as www.AVVO.com; www.FindLaw.com; or www.Martindale.com (I personally find www.AVVO.com to be the most user friendly).
Regardless as to whether or not the cause of your wife's condition is malpractice or is a side effect of the treatment, she is likely going to qualify for disability benefits. You can apply for these yourself (without an attorney), but I do recommend retaining a lawyer to help you (the reason for this is that a lawyer will help you navigate the process and ensure that your application is processed quickly and deal with any premature denials, etc. (many claims are denied in error and must be appealed which are later approved - having a lawyer prepare your application can help you get benefits faster).