Study on patients with CNS infections.

Aims and objectives:

The present proposal aims to improve the outcome from central nervous system infections (CNS) by improving the understanding of when and why patients develop hearing loss and other neurological sequelae. The investigators will elucidate the temporal development and restitution of a sensorineural hearing loss and will clarify if any therapeutic window exists, where sequelae can be limited.

Also the investigators will investigate if communication between cochlea and cerebrospinal fluid is a window to the intracranial pressure.

Background:

CNS infections remain diseases with high mortality and morbidity. Among survivors from bacterial meningitis, 30 % suffer hearing loss or deafness arising from injury to the inner ear - the cochlea. From previous work it is known that brain inflammation, brain edema and subsequent pressure changes can be transduced to the inner ear due to communication between the cochlea and cerebrospinal fluid (CSF).

The viability of cochlear hair cells can evaluated by non-invasive measurement of otoacoustic (OAE) emissions which are low-intensity sounds from the cochlea (OAE).

Methods and materials:

The investigators will perform repeated measurements of OAE and Wide Band tympanometry (WBT) in all patients admitted with suspicion of a CNS infection. OAE and WBT will be compared to intracranial pressure (ICP) measured during lumbar puncture as well as clinical-, biochemical- and imaging data. An age-matched control group will be included. At discharge and at follow-up patients will receive a neurological, vestibulare examination, cognitive test and a regular hearing test.

Expected outcome and perspectives:

From repeated measures during a course of disease, the investigators will elucidate the development of a hearing loss and clarify if any therapeutic window exists, where sequelae can be limited. This is also an opportunity to assess OAE as a non-invasive measure of intracranial pressure which is believed to be among the clinical complications responsible for a poor outcome.

Inclusion Criteria:

• Patients with a CNS infection admitted to the hospital.

Exclusion Criteria:

• Patients with known hearing loss

Patients admitted to the hospital with a CNS infection.