The Neurological Impact of Metabolic and Bariatric Surgery: A Systematic Review of Post-Operative Neuropathic and Non-Neuropathic Complications.

Metabolic and bariatric surgery achieves durable weight loss and meaningful improvement in obesity-related comorbidities yet carries a risk of neurological complications that remains under-recognised in routine clinical practice. This systematic review, registered with PROSPERO (CRD42024591611) and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, searched MEDLINE, Embase, Emcare, CINAHL and Cochrane databases through September 2023 to evaluate the incidence, spectrum, timing, pathophysiology and management of post-operative neurological complications. Twelve studies comprising over 5000 patients were included. Reported incidence ranged from 1.4% to 16%, with peripheral neuropathy the most frequent manifestation. Mononeuropathies, particularly carpal tunnel syndrome, were prominent in several cohorts, while central complications including Wernicke encephalopathy occurred less commonly but with considerably greater severity. Thiamine deficiency was the predominant aetiological factor. Onset varied from days to several years postoperatively, with early presentations typically compression-related and later ones nutritionally mediated. Outcomes were generally favourable with early intervention, though severe or delayed cases were associated with persistent neurological deficits and occasional mortality. Neurological complications after bariatric surgery are heterogeneous and largely preventable, and structured post-operative follow-up with consistent adherence to nutritional supplementation remains central to reducing long-term harm.