Background and Goal of Study:Temperature alterations in neurocritical care setting are common and have striking effect on brain metabolism leading or exacerbating neuronal injury.  Fever has also a negative impact on acute brain injury (ABI) patients outcome. However conclusive evidence linking control of temperature to improved outcome is still lacking.  Aim of this review article is to evaluate the relationship between changes in body temperature in various form ofABI and outcome.
Materials and methods:A literature search of 2 medical data base was ac-complished: PubMed Medline. Only complete studies (no abstracts), pub-lished in English in peer-reviewed journals were included. Two authors (M.P. and  P.S) independently screened and assessed titles, abstracts, and the full-text papers, using inclusion and exclusion criteria. A total of 32401 papers were screened and 32354 were excluded. We present 47 articles into 5 subchapters: mixed acute brain injury (7), brain trauma (6), intracranial hemorrhage (5), subarachnoid hemorrhage (12); ischemic stroke (17).
Results and discussion: 
ABI: fever correlates withincreased inhospital mortality and functional outcome. Fever increases brain metabolism and reduces blood flow. Brain trauma: fever in the first 48 hours after trauma was not a predictor of mortality. Both the degree and duration of early post-trauma hyperthermia
were strongly related with outcome. Intracranial hemorrhage: the presence of fever determines prognosis. Also subacute fever in association with large volume hematoma is a driver of neurological deterioration. 
Subarachnoid hemorrhage: the impact of fever on poor outcome is related to cerebral inflammatory response initiated at the time of aneurysm rupture, increased rate of vasospasm and DIND, increased ICP related to metabolic distress. Ischemic stroke: delayed hyperthermia has a greater adverse association with long-term outcomes and mortality compared with that seen in the early period after an ischemic stroke. In patients treated with recanalization the role of hyperthermia on outcome is still controversial.
Conclusion(s): Fever, regardless whether infectious of central, is strongly correlated with poor neurological and functional outcome. Optimal patient temperature management and optimal method to recognise and treat infections in absence of fever remain still to define.

Relationship between body temperature and neurological outcome in patients with acute brain injury: systematic review of clinical evidence