Neuropathic pain is a pathological response of the nervous system to a great variety of damages, secondary to diabetes, shingles, amputation, post-surgery or trauma, stroke or spinal cord injury, trigeminal neuralgia and HIV infection. As its aetiology can vary, so can its pathophysiology and clinical presentation. This Cochrane Systematic Review is an update of the review published in 2009 with the aim to assess the analgesic efficacy and adverse effects of pregabalin for chronic neuropathic pain in adults. It included 45 studies, with 11,906 participants with chronic neuropathic pain mostly due to postherpetic neuralgia, painful diabetic neuropathy and mixed neuropathic pain.
Evidence showed pregabalin is effective in postherpetic neuralgia, painful diabetic neuralgia, and mixed or unclassified post-traumatic neuropathic pain, but its analgesic efficacy in other causes was shown to be inadequate. These results are similar to the findings in the 2009 review. 
The most commonly reported side effects were dizziness and sleepiness which were more common in the pregabalin group than in the placebo group. 
The main issues with the examined studies were the small sample and inadequate reporting of important methodological information. 

Comment by María Soriano Micò