Danish Study Group of Infections of the Brain: A Nationwide Prospective Observational Cohort Study of All Central Nervous System Infections in Adults at Departments of Infectious Diseases in Denmark

The investigators include data on diagnosis at admission, symptoms and signs on admission, character and timing of diagnostic work-up and treatment and outcome assessed by the Glasgow Outcome Score (GOS).

Diagnostic work-up and treatment is left at the discretion of the local physician and therefore not standardised

In general any symptoms/deficits should only be listed if they are 'new' to the patient, e.g. a known palsy of the facial nerve should not be listed as a new relevant finding at admission. On the other hand, worsening of a known neurological deficit should be listed under signs in the given instrument (bacterial meningitis, encephalitis, neuroborreliosis etc). Likewise, for outcome only changes in pre-morbid conditions should be listed including place of residence, functional status, neurological deficits etc.

Time of admission is obtained in prioritized order from the ambulance charts or notifications of arrival by secretaries or nurses in the emergency departments. Timing of lumbar puncture and cranial imaging is extracted from the electronic records at the departments of biochemistry or radiology while timing of antibiotic therapy for meningitis is identified in electronic medication systems. Time to lumbar puncture, cranial imaging and antibiotic therapy is calculated as time from arrival at hospital to each of the above events.

Quality control of case enrollment is ensured by ad hoc case-to-case discussions and at study group meetings 2-3 times a year