Relative Brain Perfusion Differences in a Patient With Persistent Fatigue and Subjective Cognitive Symptoms: A Case Report

Persistent fatigue may be accompanied by subjective cognitive symptoms when the available evaluation does not identify a single explanatory disorder. We report the case of a 57-year-old woman with persistent fatigue, reduced mental clarity, and subjective memory difficulties without a loss of independence in daily functioning. Cognitive, mood, attention, and laboratory assessments were performed, although important diagnostic domains remained unassessed or incompletely characterized. Brain perfusion single-photon emission computed tomography (SPECT) was subsequently obtained as an adjunctive functional imaging study. Brain perfusion SPECT depicts relative regional tracer distribution rather than providing an absolute measurement of cerebral blood flow, and the study demonstrated a nonspecific mixed pattern of relative cortical and subcortical tracer distribution. An individualized management plan was subsequently implemented that included a nonstandardized oxygen-enriched hyperbaric intervention using concentrator-supplied chamber air rather than conventional hyperbaric oxygen therapy (HBOT). At approximately 60 days of follow-up, the patient reported improvement in fatigue and exercise tolerance, including the resumption of hiking. However, the improvement was based on patient self-report, standardized pre- and post-treatment outcome measures were not obtained, and additional interventions were recommended concurrently; therefore, the independent contribution of the hyperbaric intervention cannot be determined. This case illustrates the potential descriptive value of adjunctive functional imaging and longitudinal clinical observation in a complex presentation of persistent fatigue and subjective cognitive symptoms while emphasizing that imaging findings and short-term clinical changes should be interpreted within the broader clinical context.