Gabapentin versus Gralise

Hi I'm a C5-C7 walking quad of 15 years. I've dealt with nerve pain for the last 12 years and have had previous success with 25 mg of amitriptyline to more or less keep the nerve pain in check. However the side effects made me feel fatigued and sleepy most of the time so I stopped taking it and started taking gabapentin instead. I have found that 300 mg taken four times a day is the most effective dose without going further up. However I have noticeable short-term and long-term memory loss specifically short-term. Also I find that my cognitive function as far as rapid retrieval of words phrasing or thinking quickly has also suffered at this dose. My neurologist suggested trying Gralise 600 mg twice daily. He said that because it's time released the side effects shouldn't be as bad as there are no spikes in the release of the medicine.

I would greatly appreciate it if Dr. Wise and the forum nurse would be able to chime in as well as anybody else with any experience between the two medications. Would the memory loss and other cognitive impairments be better on the time release Gralise version of the medication albeit at the same dosage? Secondly does Gralise have the same tolerance building effects as regular gabapentin, where over time more is needed to have the same effect? Also is there any risk towards memory loss over long-term use?

Thanks in advance

Gabapentin versus Gralise