Material collection

Cerebrospinal fluid

Serology:

Indication: Differential diagnostics of infectious central nervous system illnesses using antibody evidence method, diagnosis of multiple sclerosis.

Collection of blood sample as well as cerebrospinal fluid on the same day is required, as antibody findings in the spinal fluid can only be evaluated by quantitative comparison to serum findings.

On request of IgG antibody testing in the spinal fluid total IgG as well as albumin in serum and spinal fluid are evaluated in addition to the quantitative antibody evaluation, as these parameters are definitely necessary for the evaluation of findings.

Spinal fluid samples for serological testing can be kept at 4°C or even frozen, if speedy transport to the laboratory is not possible.

PCR-analysis:

Indication: Evidence of pathogens by means of PCR-testing, in case of suspicion of CNS-infection.

Spinal fluid for PCR-evaluation should always be sent in a separate tube and independent of other test requests. The sample material amount should be at least 500-1000 µl. Whether it is recommendable to test further material, such as a pharyngeal swab, stools or blood for pathogens to receive quickest possible confirmation of a suspected diagnosis, is to be decided for each individual case.

Spinal samples for PCR diagnostics should be sent to the laboratory as quickly as possible. If transport is delayed then sample material should be kept at 4-8°C.

Culture:

Indication: Cultural evidence of pathogens in case of suspicion of meningitis, meningoencephalitis or encephalitis.

On request of “pathogens and resistance”, the following investigations are carried out:

Microscopy, aerobe and anaerobe cultures, identification of pathogens including antibiogram, evidence of inhibitors, latex agglutination test for meningococcus (serological groups A, B, C, Y and W 135), haemophilus influenza, pneumococcus, group B streptococcus.

Investigations for mycobacteria, fungus, Cryptococcus, HSV, VZV, CMV have to be specifically requested.

Liquor puncture:

Thorough extensive skin disinfection with PVP-iodine or 70% alcohol. Let it work in for a minimum of 1 min. Following this, perform a second outward disinfection, by concentric wiping of a new sterile alcohol swab from the centre to the periphery. Leave to dry. Do not contaminate the puncture area again, if required also disinfect the palpating finger.

After evaporation of the alcohol, perform lumbar puncture with sterile gloves. The spinal fluid is collected in 2 plastic tubes: One for clinical-chemical testing (amount of cells, protein, glucose, lactate etc.) and a second one for bacteriological evaluation (if necessary a third tube for virological or PCR-testing)

Spinal fluid needs to be taken to the laboratory without delay. Under no circumstances should spinal fluid be stored at 4°C.

Recommendation:

Squirt one part of the spinal fluid into a preheated aerobic blood culture bottle and take to the laboratory as quickly as possible. For mycobacteria diagnostics send 10ml spinal fluid (but not in a blood culture bottle).