Neuro-critically ill patients face unique challenges in nutritional support due to varying metabolic and energy demands arising from clinical situations such as elevated intracranial pressure, trauma, stroke, epilepsy, targeted temperature management (TTM), and pharmacological interventions. Despite these challenges, there is a lack of systematic reviews addressing their specific needs. This study conducts a systematic review and narrative synthesis of the existing literature on nutritional support for neuro-critical patients, focusing on amino acids that act as neurotransmitters or their precursors. We examined nutritional requirements and timing in patients with stroke and traumatic brain injury, as well as energy and metabolic demands during TTM, a common therapeutic intervention in neuro-critical care. Our review aims to clarify uncertainties surrounding amino acid provision in neuro-critical patients and provide up-to-date recommendations on nutritional support for those with elevated intracranial pressure and undergoing TTM, serving as a foundation for future research and evidence-based guideline development. Key findings include the potential benefits of branched-chain amino acids (BCAAs) in neuro-critical care, the roles of methionine and serine, the significance of arginine in vascular constriction, the controversial role of glutamate in nutrition, and the potential benefits of selenium supplementation. We also discussed special considerations in nutritional support for neuro-critical patients, such as changes in energy demand, the influence of sedation on energy demand, and metabolism changes during TTM. Our review highlights the need for a better understanding of the unique metabolic requirements of neuro-critical patients and the development of evidence-based guidelines for optimal nutritional support in this population.