Metabolic and neurological warning phenotypes during tirzepatide treatment: a clinical pharmacology and pharmacovigilance review

This preprint presents a critical neuroimaging review of the relationship between cerebral energetic reserve, large-scale network organisation, and hierarchical functional vulnerability across anaesthesia, disorders of consciousness, and Alzheimer’s disease. The central question is whether metabolically demanding integrative functions become disproportionately vulnerable when the brain’s capacity to sustain distributed signalling, ionic homeostasis, synaptic activity, and recovery is reduced. Evidence from positron emission tomography, functional magnetic resonance imaging, electroencephalography, perturbational studies, and clinical neurophysiology is examined comparatively across reversible and progressive states of impaired consciousness. The review distinguishes regional metabolic activity from the energetic requirements of maintaining coordinated communication across distributed networks. It does not propose a strictly linear or universal sequence of functional failure. Instead, it evaluates whether reduced energetic reserve may constrain the maintenance of higher-order integration and contribute to context-dependent hierarchical functional vulnerability. Across the reviewed conditions, disturbances of frontoparietal, default-mode, thalamocortical, and other integrative systems frequently accompany impaired responsiveness, metacognition, and conscious access. However, the available evidence remains heterogeneous and does not establish energetic insufficiency as a sufficient or exclusive cause of these changes. The article proposes testable neuroimaging predictions and identifies the need for longitudinal, within-participant studies combining metabolic measurements, functional connectivity, perturbational complexity, vascular assessment, and recovery kinetics. Energetic reserve is presented as a necessary physiological constraint on sustained integration, rather than a complete explanation of consciousness, anaesthetic state transitions, or neurodegeneration.