Micrometer-sized thread-like and/or spherical particles in the first fraction of cerebrospinal fluid in patients with...

Scanning electron microscopy (SEM) is a powerful tool to identify pathogenic factors for which sensitive tests are lacking. The technique has been used to recognize structures in the cerebrospinal fluid (CSF) of patients with schizophrenia. The aim of this study was to use SEM to screen for potential particles in CSF in bipolar disorder.

Fresh CSF samples from 56 euthymic bipolar patients, 31 bipolar I disorder and 25 bipolar II disorder, were compared to CSF samples from 20 controls. SEM of two portions of 200 microL filtered CSF was performed; the first 0.6 mL of CSF and the following 12 mL. The microscopic structures were identified and the quantity and patterns were rated by two independent researchers.

Quantitative SEM examinations showed that of the 56 patients, 11 were free of any SEM structures in CSF, while 45 patients displayed morphological structures in the first 0.6 mL of CSF. By contrast, only 2 patients showed structures in the second CSF fraction drawn from the following mixed 12 mL of CSF. In total, 45 of the 56 patients had either thread-like, spherical, or both structures in the CSF, compared to none of the 20 controls.

The identified particles in the first fraction of CSF have previously not been described in patients with bipolar disorder. Hypothetically, the amount of SEM structures in CSF, from none to many, might correlate to the degree of the alleged underlying disease processes in the central nervous system in patients with bipolar disease.