Antibodies against the flotillin-1/2 complex in patients with multiple sclerosis

Multiple sclerosis is a tissue-specific autoimmune disease of the central nervous system in which the antigen(s) remains elusive. Antibodies targeting the flotillin-1/2 complex have been described in 1-2% of the patients in a recent study. Other candidate antigens as anoctamin-2 or neurofascin-155 have been previously described in multiple sclerosis patients, although their clinical relevance remains uncertain. Our study aims to analyse the frequency and clinical relevance of antibodies against neurofascin-155, anoctamin-2 and the flotillin-1/2 complex in multiple sclerosis.

Serum (n = 252) and CSF (n = 50) samples from 282 multiple sclerosis patients were included in the study. The control group was composed of 260 serum samples (71 healthy donors and 189 with other neuroinflammatory disorders). Anti-flotillin-1/2, anti-anoctamin-2 and anti-neurofascin-155 antibodies were tested by cell-based assays using transfected cells. We identified 6 multiple sclerosis patients with antibodies against the flotillin-1/2 complex (2.1%) and 1 multiple sclerosis patient with antibodies against anoctamin-2 (0.35%). All multiple sclerosis patients were negative for anti-neurofascin-155 antibodies. Three of the anti-flotillin-1/2 positive patients showed anti-flotillin-1/2 positivity in other serum samples extracted at different moments of their disease. Immunoglobulin G subclasses of anti-flotillin-1/2 antibodies were predominantly 1 and 3.

We confirm that antibodies targeting the flotillin-1/2 complex are present in a subgroup of patients with multiple sclerosis. Further studies are needed to understand the clinical and pathological relevance of anti-flotillin-1/2 autoantibodies in multiple sclerosis.

Post-COVID-19 fatigue: the contribution of cognitive and neuropsychiatric symptoms

Fatigue in its many forms of physical, mental, and psychosocial exhaustion is a common symptom of post-COVID-19 condition, also known as "Long COVID." Persistent fatigue in COVID-19 patients is frequently accompanied by cognitive dysfunction and neuropsychiatric symptoms; however, less is known about the relationships between these components of post-COVID-19 condition and fatigue itself. Consequently, the present study sought to (1) distinguish the types of fatigue experienced by participants, and (2) investigate whether cognitive deficits across various domains and neuropsychiatric conditions predicted these different types of fatigue. The study included 136 COVID-19 patients referred for neuropsychological evaluation due to cognitive complaints 8 months on average after SARS-CoV-2 infection. Measures included self-reported fatigue (physical, cognitive, and psychosocial), neuropsychiatric questionnaires (assessing symptoms of depression, anxiety, apathy, and executive functioning), a comprehensive neuropsychological assessment, and self-reported quality of life and everyday functioning. Results showed that reports of clinical significant fatigue were pervasive in our sample (82.3% of participants), with physical fatigue rated highest on average relative to the subscale maximum. Elevated levels of apathy, anxiety, and executive dysfunction in neuropsychiatric measures along with executive and attentional difficulties on cognitive tests were found to be consistently important predictors among different types of fatigue. This implicates both cognitive and neuropsychiatric symptoms as predictors of fatigue in post-COVID-19 condition, and stresses the importance of a holistic approach in assessing and considering potential treatment for COVID-19 patients experiencing fatigue.

Neuropsychological deficits in patients with cognitive complaints after COVID-19

BACKGROUND

While much of the scientific focus thus far has been on cognitive sequelae in patients with severe COVID-19, subjective cognitive complaints are being reported across the spectrum of disease severity, with recent studies beginning to corroborate patients' perceived deficits. In response to this, the aims of this study were to (1) explore the frequency of impaired performance across cognitive domains in post-COVID patients with subjective complaints and (2) uncover whether impairment existed within a single domain or across multiple.

METHODS

Sixty-three patients with subjective cognitive complaints post-COVID were assessed with a comprehensive protocol consisting of various neuropsychological tests and mood measures. Cognitive test performance was transformed into T scores and classified based on recommended guidelines. After performing a principal component analysis to define cognitive domain factors, distributions of test scores within and across domains were analyzed.

RESULTS

Results revealed pervasive impact on attention abilities, both as the singularly affected domain (19% of single-domain impairment) as well as coupled with decreased performance in executive functions, learning, and long-term memory. These salient attentional and associated executive deficits were largely unrelated to clinical factors such as hospitalization, disease duration, biomarkers, or affective measures.

DISCUSSION

These findings stress the importance of comprehensive evaluation and intervention to address cognitive sequelae in post-COVID patients of varying disease courses, not just those who were hospitalized or experienced severe symptoms. Future studies should investigate to what extent these cognitive abilities are recuperated over time as well as employ neuroimaging techniques to uncover underlying mechanisms of neural damage.

Structural Gray and White Matter Differences in Patients With Type 1 Diabetes and Impaired Awareness of Hypoglycemia

CONTEXT

Type 1 diabetes (T1D) is associated with an increased risk of cognitive decline, where severe hypoglycemia (SH) and impaired awareness of hypoglycemia (IAH) may play a role. While there is evidence of a possible association between IAH and brain damage, the potential brain changes remain poorly characterized by magnetic resonance imaging (MRI).

OBJECTIVE

To investigate whether there are structural brain differences in a group of T1D patients with IAH compared with normal awareness of hypoglycemia (NAH).

DESIGN

General practice, population-based, cross-sectional study (July 2018 to July 2019).

SETTING

Endocrinology Department, Hospital Santa Creu i Sant Pau.

PARTICIPANTS

A total of 40 T1D patients (20 each with IAH and NAH) matched for age, sex, T1D duration, and education level.

MAIN OUTCOME MEASURES

Using different neuroimaging techniques, we compared whole-brain gray matter (GM) and white matter (WM) differences. We used voxel-based morphometry and cortical surface area analysis methods to assess GM differences, and fractional anisotropy (FA) to assess WM differences.

RESULTS

Compared with patients with T1D-NAH, patients with T1D-IAH had reduced GM volumes and cortical surface areas, especially in frontal and parietal regions (P < 0.05 corrected), and also showed reduced FA values in major WM tracts. The observed MRI differences correlated with both SH frequency and IAH severity.

CONCLUSIONS

MRI for patients with T1D show that IAH is associated with brain changes involving both GM and WM. Further research is needed to elucidate whether the observed differences are a consequence of increased SH episode frequency and increased IAH severity.

White matter involvement on DTI-MRI in Cushing's syndrome relates to mood disturbances and processing speed: a case-control study

PURPOSE

Cushing's syndrome (CS) is an endocrine disorder due to prolonged exposure to cortisol. Recently, microstructural white matter (WM) alterations detected by diffusion tensor imaging (DTI) have been reported in CS patients, and related to depression, but other functional significances. remain otherwise unclear. We aimed at investigating in more depth mood symptoms in CS patients, and how these relate to cognition (information processing speed), and to WM alterations on DTI.

METHODS

The sample comprised 35 CS patients and 35 healthy controls. Beck Depression Inventory-II (BDI-II) was used to measure depressive symptoms, State-Trait Anxiety Inventory (STAI) to assess anxiety, and processing speed was measured by the Symbol Digit Modalities Test (SDMT). DTI studies were acquired using a 3-Tesla Philips-Achieva MR-facility. Voxelwise statistical analysis of fractional anisotropy (FA), mean, axial and radial diffusivities (MD, AD, RD) data were performed using FMRIB Software Library. Correlation analysis were obtained between mood and processing speed variables, and FA, MD, AD and RD values, taking both CS patients and healthy controls.

RESULTS

Active, controlled and cured CS patients showed greater depression (F = 12.4, p < 0.001), anxious state (F = 4.8, p = 0.005) and anxious trait (F = 9.6, p < 0.001) scores, than controls. Using the entire sample, depression scores correlated negatively to FA and positively to RD values. Although there were no differences in processing speed between groups, SDMT scores correlated positively to both FA and AD values.

CONCLUSIONS

There were greater depressive and anxious symptoms in CS patients than in healthy controls, but no difference in processing speed. However, DTI is related to depression and information processing speed in CS.

Cerebral amyloid angiopathy-related atraumatic convexal subarachnoid hemorrhage: an ARIA before the tsunami

Atraumatic convexal subarachnoid hemorrhage (cSAH) in elderly patients is a rare entity that has been associated with cerebral amyloid angiopathy (CAA) and intracerebral hematomas (ICH). To characterize this entity and to study these associations, 22 patients over 60 with cSAH were included in a multicenter ambispective cohort study. Clinical data, magnetic resonance imaging (MRI) studies, APOE genotyping, and cerebrospinal fluid (CSF) biomarkers were evaluated. Results were compared with data from healthy controls (HC), non-cSAH CAA patients (CAAo), and Alzheimer disease patients. Convexal subarachnoid hemorrhage presented with transient sensory or motor symptoms. At follow-up (median 30.7 months), 5 patients had died, 6 survivors showed functional disability (modified Rankins Scale (mRS)>2), and 12 cognitive impairment. Four patients had prior ICH and six had an ICH during follow-up. CSF-Aß40 and Aß42 levels were lower in cSAH and CAAo compared with HC. Convexal subarachnoid hemorrhage presented an APOE-ɛ2 overrepresentation and CAAo had an APOE-ɛ4 overrepresentation. On MRI, all patients fulfilled CAA-modified Boston criteria and 9 showed cortical ischemia in the surrounding cortex or the vicinity of superficial siderosis. The neuropathologic study, available in one patient, showed severe CAA and advanced Alzheimer-type pathology. Convexal subarachnoid hemorrhage in the elderly is associated with cognitive impairment and lobar ICH occurrence. Our findings support the existence of an underlying CAA pathology.

White matter alterations in the brains of patients with active, remitted, and cured cushing syndrome: a DTI study

BACKGROUND AND PURPOSE

Cushing syndrome appears after chronic exposure to elevated glucocorticoid levels. Cortisol excess may alter white matter microstructure. Our purpose was to study WM changes in patients with Cushing syndrome compared with controls by using DTI and the influence of hypercortisolism.

MATERIALS AND METHODS

Thirty-five patients with Cushing syndrome and 35 healthy controls, matched for age, education, and sex, were analyzed through DTI (tract-based spatial statistics) for fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity (general linear model, family-wise error, and threshold-free cluster enhancement corrections, P < .05). Furthermore, the influence of hypercortisolism on WM DTI changes was studied by comparing 4 subgroups: 8 patients with Cushing syndrome with active hypercortisolism, 7 with Cushing syndrome with medication-remitted cortisol, 20 surgically cured, and 35 controls. Cardiovascular risk factors were used as covariates. In addition, correlations were analyzed among DTI values, concomitant 24-hour urinary free cortisol levels, and disease duration.

RESULTS

There were widespread alterations (reduced fractional anisotropy, and increased mean diffusivity, axial diffusivity, and radial diffusivity values; P < .05) in patients with Cushing syndrome compared with controls, independent of the cardiovascular risk factors present. Both active and cured Cushing syndrome subgroups showed similar changes compared with controls. Patients with medically remitted Cushing syndrome also had reduced fractional anisotropy and increased mean diffusivity and radial diffusivity values, compared with controls. No correlations were found between DTI maps and 24-hour urinary free cortisol levels or with disease duration.

CONCLUSIONS

Diffuse WM alterations in patients with Cushing syndrome suggest underlying loss of WM integrity and demyelination. Once present, they seem to be independent of concomitant hypercortisolism, persisting after remission/cure.

Small cerebellar cortex volume in patients with active Cushing's syndrome

OBJECTIVE

Cushing's syndrome (CS) is associated with neuropsychological deficits. As the cerebellum plays a key role in neuropsychological functions it may be affected in CS. The aim of this study was to investigate whether patients with CS have a smaller cerebellar volume than healthy controls, and to analyse whether cerebellar volume is associated with neuropsychological performance and clinical parameters.

DESIGN

A cross-sectional study was performed.

METHODS

Thirty-six CS patients (15 with active CS and 21 with CS in remission) and 36 controls matched for age, sex, and education underwent neuropsychological testing, quality of life assessment, clinical evaluation, and magnetic resonance imaging brain scan. Cerebellar volumes (white matter and cortex, bilateral) were calculated using FreeSurfer Software.

RESULTS

Patients with active CS showed smaller bilateral cerebellar cortex volumes than controls (left, P=0.035 and right, P=0.034), as well as a trend toward smaller right cerebellar cortex volumes than patients in remission CS (P=0.051). No differences were observed in the volume of cerebellar white matter between the three groups. Both right and left cerebellar cortex volumes correlated negatively with triglyceride levels (right: r=-0.358, P=0.002 and left: r=-0.317, P=0.005) and age at diagnosis (right: r=-0.433, P=0.008 and left: r=-0.457, P=0.005). Left cerebellar cortex volume also correlated positively with visual memory performance (r=0.245, P=0.038). Right cerebellar cortex volume positively correlated with quality-of-life scores (r=0.468, P=0.004).

CONCLUSIONS

The cerebellar cortex volume is smaller in active CS patients than in controls. This finding is associated with poor visual memory and quality of life and is mostly pronounced in patients with higher triglyceride levels and older age at diagnosis.

Hippocampal dysfunction in cured Cushing's syndrome patients, detected by (1) H-MR-spectroscopy

BACKGROUND

Proton magnetic resonance spectroscopy ((1) H-MRS) is a sensitive, noninvasive imaging technique capable of measuring brain metabolites in vivo. Chronic exposure to endogenous hypercortisolism in Cushing's syndrome (CS) is associated with negative effects on memory and hippocampal volumes, even after biochemical cure.

OBJECTIVE

To investigate metabolites in the hippocampi of CS patients and controls, using (1) H-MRS.

PATIENTS AND METHODS

Eighteen right-handed cured CS patients (age 44·8 ± 12·5 years, 12·6 ± 3·8 years of education) and 18 right-handed healthy controls, matched for age (40·0 ± 11·9) and years of education (14·4 ± 3·8), underwent 3-Tesla magnetic resonance imaging (3T MRI) and (1) H-MRS including the head of each hippocampus. Concentrations of Glu (Glutamate), Glx (Glutamate + Glutamine), NAA (N-Acetyl-aspartate), total NAA (N-Acetyl-aspartate + N-Acetyl-aspartyl-Glutamate), Cho (Glycerophosphocholine and Phosphocholine compounds), Cr (Creatine) and MI (mionositol) were measured (mmol/l). Hippocampal volumes (mm(3) ) were additionally calculated using an automated procedure (FreeSurfer).

RESULTS

CS patients had lower NAA than controls in the left and right hippocampus (5·2 ± 1·0 vs 6·1 ± 0·7, P < 0·05; 4·9 ± 0·8 vs 6·1 ± 0·6, P < 0·001, respectively), and lower total NAA on the right side (5·7 ± 0·9 vs 6·3 ± 0·9, P < 0·05), suggesting neuronal dysfunction/loss. CS patients had higher Glx than controls in both hippocampi (10·4 ± 1·9 vs 8·6 ± 1·4, P < 0·01; 9·9 ± 1·6 vs 8·9 ± 1·3, P < 0·05, respectively), suggesting glial proliferation, as a repair mechanism after neuronal dysfunction. No differences were found in the other brain metabolites, and there were no differences in left (3815·78 ± 502·96) and right (3980·75 ± 369·44) total hippocampal volumes between CS patients and controls (3945·08 ± 408·90 and 4108·39 ± 365·11, respectively).

CONCLUSION

Persistently abnormal metabolites are evidenced in the hippocampi of CS patients despite endocrine cure. These functional alterations could be early markers of glucocorticoid neurotoxicity, preceding hippocampal volume reduction.

Verbal and visual memory performance and hippocampal volumes, measured by 3-Tesla magnetic resonance imaging, in patients with Cushing's syndrome

CONTEXT

Cushing's syndrome (CS) affects cognition and memory.

OBJECTIVE

Our objective was to evaluate memory and hippocampal volumes (HV) on 3-tesla magnetic resonance imaging (3T MRI) in CS patients and controls.

PATIENTS AND METHODS

Thirty-three CS patients (11 active, 22 cured) and 34 controls matched for age, sex, and education underwent Rey Auditory Verbal Learning Test and Rey-Osterrieth Complex Figure memory tests. Gray matter and HV were calculated on 3T MRI, using FreeSurfer image analyses software.

RESULTS

No differences in HV were observed between active and cured CS or controls. Memory performance was worse in CS patients than controls (P < 0.04 in active; P < 0.03 in cured CS) but did not differ among CS groups, which were therefore analyzed together; they performed worse for verbal (P = 0.02) and visual memory (P = 0.04) than controls. In 12 CS patients, memory was below normative cutoff values for verbal (n = 6, cured), visual memory (n = 10, six cured) or both (n = 4); these patients with severe memory impairments showed smaller HV compared with their matched controls (P = 0.02 with verbal impairment; P = 0.03 with visual impairment). They were older (P = 0.04), had shorter education (P = 0.02), and showed a trend toward longer duration of hypercortisolism (P = 0.07) than the remaining CS patients. Total (P = 0.004) and cortical (P = 0.03) brain gray matter volumes were decreased in CS compared with controls, indicating brain atrophy, whereas subcortical gray matter (which includes HV) was reduced only in the 12 patients with severe memory impairment.

CONCLUSION

Verbal and visual memory is worse in CS patients than controls, even after biochemical cure. HV was decreased only in those whose memory scores were below normative cutoff values.

Motor and mental dysfunction in mother-daughter transmitted FXTAS

OBJECTIVES

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neuropsychiatric degenerative disorder that occurs predominantly in male FMR1 premutation carriers. Recently, a broader FXTAS spectrum that, besides the core features of tremor and gait ataxia, also includes neuropsychiatric symptoms and neuropathy as further clinically relevant symptoms has been described among females. Herein 2 fragile X syndrome families with a mother-daughter FXTAS transmission are described in detail in order to shed more light on the female FXTAS phenotype.

METHODS

Molecular characterization included CGG repeat length, X-chromosome inactivation pattern determination, as well as FMR1 mRNA and FMRP levels quantification. Neuroradiologic examination was performed by 3-T MRI. Neuropsychological assessment included global cognitive, attention, and executive prefrontal functions, verbal fluencies, verbal memory, and visuospatial perception.

RESULTS

Molecular, neurologic, neuropsychiatric, psychological, cognitive, and neuroradiologic features description of 2 fragile X syndrome families with a mother-daughter FXTAS transmission in which dementia is present in both mothers.

CONCLUSIONS

Although it is not yet clear to what extent FXTAS shortens lifespan, our findings show that FXTAS progresses from mild tremor and/or ataxia to disabling motor and cognitive impairment, compromising the patients' quality of life. Furthermore, our results show that FXTAS in women can also develop as a multisystem neurodegenerative disorder with central and peripheral nervous system involvement, and both motor and mental disturbances.

Neuropsychological profile of prodromal Alzheimer's disease (Prd-AD) and their radiological correlates

This study describes the cognitive profile of Prd-AD, the neuropsychological tests that may predict progression to dementia, and to study their brain structural correlates. We enrolled 24 stable amnesics who did not develop dementia after two years follow-up; 27 patients were considered as Prd-AD, in the initial visit, since they fulfilled NINCDS-ADRDA criteria after two years; 31 Alzheimer's disease (AD) patients and 27 controls (CTR). Structural magnetic resonance imaging (MRI), as well as a neuropsychological battery was performed at the initial visit. The key findings were: Prd-AD patients were characterized by prominent episodic memory dysfunction and minimal semantic memory and executive dysfunction. Semantic fluency test (Sem-Flu), delayed text memory test (Del-text-mem) and memory alteration test (M@T) (including both episodic and semantic memory), together with trail making test A (TMT-A), resulted significant predictors for dementia development in this group of amnesic patients. This optimal predictive model obtained an estimated accuracy of 53% after two years follow-up. M@T and semantic Sem-Flu test performance presented high correlation with decreased gray matter density in the left lateral temporal lobe. We conclude that Prd-AD is characterized by prominent episodic memory dysfunction and minimal semantic memory and executive dysfunction which are related with left medial, inferior and lateral temporal density loss, predominantly in the left side.

Voxel based morphometry features and follow-up of amnestic patients at high risk for Alzheimer's disease conversion

OBJECTIVE

Neuroimaging techniques are able to mark distinct structural and metabolic changes in patients at risk for Alzheimer's disease (AD). The objectives of the study were to compare regional grey matter density in prodromal Alzheimer's disease (Prd-AD), amnestic mild cognitive impairment (aMCI), mild AD patients and healthy aged controls, to study prospectively their clinical and neuropsychological evolution and to evaluate the accuracy of proposed Prd-AD criteria to detect AD conversion.

METHODS

Twenty-seven controls, 16 aMCI, 32 Prd-AD and 34 probable mild AD were included. Evaluations were performed at baseline and annually during a 2-year prospective follow-up period. Focal grey matter density loss was calculated through voxel based morphometry analysis at baseline. Sensitivity, specificity, positive and negative predictive values of Prd-AD criteria were calculated.

RESULTS

Pr-AD, compared to aMCI, had decreased grey matter density mainly in both hippocampi and inferior temporal cortex (p < 0.001). AD patients compared with Prd-AD, presented grey matter loss in the right posterior and lateral temporal, inferior frontal and parietal cortex and left posterior temporal (p < 0.001). After 2-year follow-up, Prd-AD patients presented higher cognitive decline and conversion rate to AD (83.3%) than aMCI (21.4%; p < 0.0001). The sensitivity of Prd-AD criteria to predict AD conversion in the group of amnestic patients was 89.3; specificity 68.7; positive predictive value 83.3 and negative predictive value 78.6.

CONCLUSION

Magnetic resonance imaging provides evidence of more severe temporal grey matter loss in Prd-AD group than in a-MCI. The proposed criteria present good accuracy to predict AD conversion among amnestic patients.

Longitudinal study of amnesic patients at high risk for Alzheimer's disease: clinical, neuropsychological and magnetic resonance spectroscopy features

BACKGROUND/AIMS

To prospectively follow up a group of amnesic patients at risk for Alzheimer's disease (AD), to characterize a group of patients whose features were intermediate between amnesic mild cognitive impairment (aMCI) and probable AD, prodromal AD (Prd-AD), and to investigate if these patients were at higher risk for AD conversion.

METHODS

A total of 109 subjects were assessed by neuropsychological evaluation and by 1H magnetic resonance spectroscopy (1H-MRS): 27 controls, and 16 aMCI, 34 probable AD and 32 Prd-AD patients.

RESULTS

Episodic memory and frontal test scores resulted lower in Prd-AD compared to aMCI patients. Prd-AD patients obtained significantly higher scores than AD ones in language, perception, praxis and frontal functions. Although Prd-AD and AD patients had distinct 1H-MRS features from aMCI ones, there were no 1H-MRS differences between Prd-AD and AD patients. The AD annual conversion rate after 1 year of follow-up for Prd-AD (57.1%) was higher than in aMCI patients (20%; p<0.01). A logistic regression, in which all amnesic patients were treated as a single group, showed that the Visual Memory Test was a significant neuropsychological predictor for AD conversion.

CONCLUSIONS

Prd-AD patients are a clinically distinguishable group, with distinct neuropsychological and 1H-MRS features and a higher conversion rate to probable AD than aMCI patients.