Cognitive Function and Fatigue After Brain Abscess

Study Overview
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Brief Summary
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Brain abscess is a focal bacterial or fungal infection of the brain. Treatment is neurosurgical drainage of pus followed by long-term antibiotic treatment. In spite of successful treatment of the infection, long-term cognitive problems or mental fatigue may ensue. The reason for this dysfunction may be a continuing inflammatory state or damage to brain tissue caused by the abscess. The investigators will evaluate these possibilities with the use of [18F]deoxyglucose-positron emission tomography (FDG-PET) in patients who have been treated for brain abscess and who experience cognitive problems and/or fatigue. FDG-PET may identify both inflammation and altered neuronal activity (the latter indicating damage to brain tissue).

Detailed Description
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Brain abscess is a focal bacterial or fungal infection of the brain, which results in a pus-filled cavity within the brain parenchyma. The incidence is approximately 1/100 000 per year, and all age groups are affected. Treatment is neurosurgical drainage of pus followed by long-term antibiotic treatment. Previously, the capsule that surrounds the pus was removed surgically; this is not usually done anymore. In spite of successful treatment of the infection, patients may experience long-lasting cognitive problems or mental fatigue. The reason for this brain dysfunction is not known. The investigators formulated two hypotheses to explain why some patients experience long-lasting cognitive problems and/or fatigue: 1) The brain abscess caused damage to brain tissue, interrupting neuronal networks underlying cognition or 2) The abscess or the remaining capsule causes a long-lasting inflammatory state of the brain, affecting neurotransmission and cerebral function. In this prospective study, the investigators evaluate brain abscess patients by cognitive examination by a neuropsychologist at 2 and 12 months after treatment. Participants then undergo [18F]deoxyglucose-positron emission tomography (FDG-PET). An inflammatory state in the abscess area would be identified by the FDG-PET signal. Likewise, a change in neuronal (neocortical) function would be detectable from a change in the FDG-PET signal. Importantly, brain damage caused by the abscess may be irreversible and functional improvement of the patient would probably have to rely on compensatory strategies, whereas an inflammatory state could probably be modified by anti-inflammatory treatment. Further, the prognosis for the patients' cognitive problems and fatigue is probably different if the underlying cause is inflammation rather than tissue damage.

Official Title
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Cognitive Function and Fatigue After Brain Abscess

Conditions
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Brain Abscess, Fatigue, Cognitive Dysfunction

Intervention / Treatment
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* Other: FDG-PET


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: • Patients who have completed treatment for brain abscess and who agree to participate. Exclusion criteria: Patients who cannot undergo neuropsychological investigation due to unconsciousness Patients who cannot undergo neuropsychological investigation, being mentally too ill Patients who suffer from dementia Patients who cannot undergo FDG-PET due to claustrophobia Age under 16.

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Brain abscess patients with cognitive dysfunction and/or fatigue<br>This group of patients experience cognitive dysfunction and/or fatigue after brain abscess. | Other: FDG-PET<br>* [18F]Deoxyglucose-positron emission tomography at 0-10 years after brain abscess<br>|
| Brain abscess patients without cognitive dysfunction and/or fatigue<br>This group of patients does not experience cognitive dysfunction and/or fatigue after brain abscess. | Other: FDG-PET<br>* [18F]Deoxyglucose-positron emission tomography at 0-10 years after brain abscess<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| A change in FDG-PET signal indicating inflammation | The FDG-PET signal indicates inflammation of brain tissue or the brain abscess capsule. | When all patients have been followed up for at least 1 year. | 
| A change in FDG-PET signal indicating a change in neuronal activity | A change neocortical FDG-PET signal indicates a change in neuronal activity caused by brain tissue damage by the brain abscess. | When all patients have been followed up for at least 1 year. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fatigue after brain abscess | Neuropsychological investigation with the use of Chalder's fatigue questionnaire. Degree of fatigue is determined from the answers to 11 questions. The answer Better than before gives a score of 0, Same as before gives a score of 1, Worse than before gives a score of 2, and Much worse than before gives a score of 3. Thus, a maximum fatigue score is 33, meaning a very high degree of fatigue. | When all patients have been followed up for at least 1 year. | 
| No fatigue after brain abscess | Neuropsychological investigation with the use of Chalder's fatigue questionnaire. Degree of fatigue is determined from the answers to 11 questions. The answer Better than before gives a score of 0, Same as before gives a score of 1, Worse than before gives a score of 2, and Much worse than before gives a score of 3. Thus, a maximum fatigue score is 33, meaning a very high degree of fatigue. | When all patients have been followed up for at least 1 year. |