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

Structural abnormalities in bipolar euthymia: a multicontrast molecular diffusion imaging study

BACKGROUND

Evidence from decades of magnetic resonance imaging (MRI) research in bipolar disorder has been summarized in meta-analyses of various MRI modalities. Notably, although structural MRI studies suggest gray matter reductions are restricted to specific cortical regions, functional MRI has also shown involvement of subcortical dysfunction. Such disparity in results is open to discussion and requires further exploration with additional MRI modalities.

METHODS

We applied whole-brain high angular resolution molecular diffusion imaging to compare different properties of the water diffusion process in brain tissues, using different contrasts. Specifically, we looked at fractional anisotropy, mean diffusivity, probability of return to the origin, and generalized fractional anisotropy in a sample of 40 euthymic patients with bipolar disorder and 40 well-matched healthy control subjects.

RESULTS

Convergent abnormalities were detected by contrasts in various tissue types. Apart from alterations in white matter (in corpus callosum, cingulum bundle, corona radiata, and superior fronto-occipital fasciculus) and cortical gray matter (in medial frontal cortex, left insula, Heschl's gyrus, and cerebellum), three of the contrasts (fractional anisotropy, mean diffusivity, and generalized fractional anisotropy) revealed abnormalities in subcortical structures, including the hippocampus, the thalamus and the caudate nucleus.

CONCLUSIONS

Our findings point to a wider pattern of axonal pathology in bipolar disorder than previously thought. Although findings related to cortical gray matter are consistent with structural meta-analyses, subcortical abnormalities suggest a cytoarchitectonic basis for previously reported subcortical dysfunction. Diffusion results could be interpreted in terms of loss of tissue volume and/or altered membrane permeability, agreeing with both hypotheses of mitochondrial malfunction and neuroinflammation.

Microparticles and microscopic structures in three fractions of fresh cerebrospinal fluid in schizophrenia: case report of twins

Schizophrenia is a diagnosis with a set of symptoms of aberrant psychological phenomena. Here, we discuss that there may be an imbalance of proteostasis of neurons in the brain leading to increase in membrane shedding and buildup of microparticles (MPs) appearing in the cerebrospinal fluid. The number of MPs can be determined and their phenotypes verified by size and membrane expression with flow cytometry. This is the first report of specified MPs in cerebrospinal fluid (CSF) in schizophrenia. Two 56-year-old Swedish-born female monozygotic twins of Caucasian ethnicity with onset of schizophrenia more than 30years ago were studied. Three fractions of fresh CSF were examined for microparticles by flow cytometry analysis, which measure the specific binding of antibodies to CD42a (platelet-MP; 33 GPIX), CD144 (endothelial-MP; Ve-cadherin), CD45 (leukocyte-MP; pan-leukocyte antigen) and of phosphatidylserine to lactadherin. The patients with schizophrenia displayed more phosphatidylserine-positive MPs in CSF compared with healthy control subjects. The scanning electron microscopic (SEM) structures in CSF studied over a 3-year period in twins with schizophrenia were of similar appearance at both time points. The increased number of MPs in fresh CSF may be a sign of enhanced membrane shedding in the central nervous system. Such MPs can be investigated for both human and non-human DNA, RNA and microRNA that may activate different immune signaling systems in patients with schizophrenia.

Microscopic particles in two fractions of fresh cerebrospinal fluid in twins with schizophrenia or bipolar disorder and in healthy controls

Background

Using scanning electron microscopy, microscopic structures have been identified in fresh cerebrospinal fluid (CSF) in patients with schizophrenia and bipolar disorder, but only rarely in control subjects. However, it has not been determined whether these microscopic particles represent state or trait markers, i.e. if their presence is related to clinical manifestations of the disease or if they also can be found in as yet asymptomatic individuals with a genetic liability. This question can be addressed by studying twins discordant or concordant for schizophrenia or bipolar disorder.

Methodology/Principal Findings

We investigated microscopic structures in CSF in 102 individuals: 21 monozygotic and 16 dizygotic twins affected or not affected with schizophrenia, schizoaffective disorder or bipolar disorder and in 65 healthy singleton controls. A first and a second fraction of CSF was freshly applied on filters and examined by scanning electron microscopy technique. Spherical particles with lipid appearance averaging between 0.1 to 8.0 µm in diameter were detected in the center of the filter as well as located in the margins of larger aggregates binding in a viscous state. Structures were found in 12 of 17 probands, 5 of 12 healthy co-twins and 3 of 73 healthy controls. Thus, a positive microscopic finding significantly increased the likelihood of belonging to the proband group (OR = 48, 95% CL: 8.2–550, p<0.0001) and the co-twin-group (OR = 16, 95% CL: 2.0–218, p = 0.006). Age, sex, history of alcohol abuse or anxiety syndrome, somatic disorder and markers of acute inflammatory activity did not account for group differences; nor did exposure to psychotropic medication.

Conclusion

Presence of microscopic particles in CSF may possibly reflect trait dependent genetic or environmental vulnerability in patients with schizophrenia, schizoaffective disorder or bipolar disorder.

Leukocyte-derived microparticles and scanning electron microscopic structures in two fractions of fresh cerebrospinal fluid in amyotrophic lateral sclerosis: a case report

Introduction

Amyotrophic lateral sclerosis is a progressive neurodegenerative disorder characterized by degeneration of motoneuron cells in anterior spinal horns. There is a need for early and accurate diagnosis with this condition. In this case report we used two complementary methods: scanning electron microscopy and fluorescence-activated cell sorting. This is the first report to our knowledge of microparticles in the cerebrospinal fluid of a patient with amyotrophic lateral sclerosis.

Case presentation

An 80-year-old Swedish man of Caucasian ethnicity presented to our facility with symptoms of amyotrophic lateral sclerosis starting a year before his first hospital examination, such as muscle weakness and twitching in his right hand progressing to arms, body and leg muscles. Electromyography showed classical neurophysiological findings of amyotrophic lateral sclerosis. Routine blood sample results were normal. A lumbar puncture was performed as a routine investigation and his cerebrospinal fluid was normal with regard to cell count and protein levels, and there were no signs of inflammation. However, scanning electron microscopy and fluorescence-activated cell sorting showed pronounced abnormalities compared to healthy controls. Flow cytometry analysis of two fractions of cerebrospinal fluid from our patient with amyotrophic lateral sclerosis was used to measure the specific binding of antibodies to CD42a, CD144 and CD45, and of phosphatidylserine to lactadherin. Our patient displayed over 100 times more phosphatidylserine-positive microparticles and over 400 times more cell-derived microparticles of leukocyte origin in his cerebrospinal fluid compared to healthy control subjects. The first cerebrospinal fluid fraction contained about 50% more microparticles than the second fraction. The scanning electron microscopy filters used with cerebrospinal fluid from our patient were filled with compact aggregates of spherical particles of lipid appearance, sticking together in a viscous batter. The quantitative increase in scanning electron microscopy findings corresponded to the flow cytometry result of an increase in leukocyte-derived microparticles.

Conclusions

Microparticles represent subcellular arrangements that can influence the pathogenesis of amyotrophic lateral sclerosis and may serve as biomarkers for underlying cellular disturbances. The increased number of leukocyte-derived microparticles with normal cell counts in cerebrospinal fluid may contribute to the amyotrophic lateral sclerosis inflammatory process by formation of immune complexes of prion-like propagation, possibly due to misfolded proteins. The two complementary methods used in this report may be additional tools for revealing the etiology of amyotrophic lateral sclerosis, for early diagnostic purposes and for evaluation of clinical trials, long-term follow-up studies and elucidating the pathophysiology in amyotrophic lateral sclerosis.

Frontal lobe bioenergetic metabolism in depressed adolescents with bipolar disorder: a phosphorus-31 magnetic resonance spectroscopy study

OBJECTIVES

To compare the concentrations of high-energy phosphorus metabolites associated with mitochondrial function in the frontal lobe of depressed adolescents with bipolar disorder (BD) and healthy controls (HC).

METHODS

We used in vivo phosphorus-31 magnetic resonance spectroscopy ((31) P-MRS) at 3 Tesla to measure phosphocreatine (PCr), beta-nucleoside triphosphate (β-NTP), inorganic phosphate (Pi), and other neurometabolites in the frontal lobe of eight unmedicated and six medicated adolescents with bipolar depression and 24 adolescent HCs.

RESULTS

Analysis of covariance, including age as a covariate, revealed differences in PCr (p=0.037), Pi (p=0.017), and PCr/Pi (p=0.002) between participant groups. Percentage neurochemical differences were calculated with respect to mean metabolite concentrations in the HC group. Post-hoc Tukey-Kramer analysis showed that unmedicated BD participants had decreased Pi compared with both HC (17%; p=0.038) and medicated BD (24%; p=0.022). The unmedicated BD group had increased PCr compared with medicated BD (11%; p=0.032). The PCr/Pi ratio was increased in unmedicated BD compared with HC (24%; p=0.013) and with medicated BD (39%; p=0.002). No differences in β-NTP or pH were observed.

CONCLUSIONS

Our results support the view that frontal lobe mitochondrial function is altered in adolescent BD and may have implications for the use of Pi as a biomarker. These findings join volumetric studies of the amygdala, and proton MRS studies of n-acetyl aspartate in pointing to potential differences in neurobiology between pediatric and adult BD.