Systematic review and meta-analysis of cognitive impairment in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is commonly associated with cognitive complaints. To bring out the neuropsychological symptomatology inherent to ME/CFS, we conducted a systematic review according to PRISMA and MOOSE guidelines of the literature through the analysis of 764 studies published between 1988 and 2019 by using PubMed Central website and Clarivate analytics platform. We performed a meta-analysis to delineate an idea of the neuropsychological profile inherent in ME/CFS. The clinical picture typically affects visuo-spatial immediate memory (g = - 0.55, p = 0.007), reading speed (g = - 0.82, p = 0.0001) and graphics gesture (g = - 0.59, p = 0.0001). Analysis also revealed difficulties in several processes inherent in episodic verbal memory (storage, retrieval, recognition) and visual memory (recovery) and a low efficiency in attentional abilities. Executive functions seemed to be little or not affected and instrumental functions appeared constantly preserved. With regard to the complexity and heterogeneity of the cognitive phenotype, it turns out that determining a sound clinical picture of ME/CFS cognitive profile must go through a neuropsychological examination allowing a complete evaluation integrating the notion of agreement between the choice and the number of tests and the complexity intrinsic to the pathology.

Cognitive dysfunction associated with aluminum hydroxide-induced macrophagic myofasciitis: A reappraisal of neuropsychological profile.

Patients with macrophagic myofasciitis (MMF) present with diffuse arthromyalgias, chronic fatigue, and cognitive disorder. Representative features of MMF-associated cognitive dysfunction include attentional dysfunction, dysexecutive syndrome, visual memory deficit and left ear extinction. Our study aims to reevaluate the neuropsychological profile of MMF. 105 unselected consecutive MMF patients were subjected to a neuropsychological battery of screen short term and long-term memory, executive functions, attentional abilities, instrumental functions and dichotic listening. From these results, patients were classified in four different groups: Subsymptomatic patients (n=41) with performance above pathological threshold (-1.65 SD) in all tests; Fronto-subcortical patients (n=31) who showed pathological results at executive functions and selective attention tests; Papezian patients (n=24) who showed pathological results in storage, recognition and consolidation functions for episodic verbal memory, in addition to fronto-subcortical dysfunction; and Extinction patients (n=9) who had a left ear extinction at dichotic listening test in association to fronto-subcortical and papezian dysfunction. In addition, inter-test analysis showed that patients with apparently normal cognitive functions (Subsymptomatic group) performed significantly worse to attention tests compared to others. In conclusion, our study shows that (i) most patients have specific cognitive deficits; (ii) all patients with cognitive deficit have impairment of executive functions and selective attention; (iii) patients without measurable cognitive deficits display significant weakness in attention; (iv) episodic memory impairment affects verbal, but not visual, memory; (v) none of the patients show an instrumental dysfunction.

Macrophagic myofasciitis-associated dysfunctioning: An update of neuropsychological and neuroimaging features.

Macrophagic myofasciitis (MMF) syndrome is a subtype of autoimmune/inflammatory syndrome induced by adjuvants (ASIA) or Shoenfeld's syndrome, characterized by the presence of stereotyped inflammatory lesions at muscle biopsy attesting the long-term persistence of aluminum hydroxide particles at the site of previous immunization. Most frequently reported symptoms are chronic arthromyalgias and fatigue and cognitive complaint. MMF-associated cognitive disorder (MACD) is characterized by the dysfunctioning of attention, executive functions, short-term term and long-term memory, and, in some instances, left ear extinction. MACD is expressed in a chronic, nonevolving, well-defined syndromic framework within which the expression in terms of severity differs from one patient to another. While brain MRI is usually noncontributive, functional imaging using SPECT and PET has revealed the existence of a suggestive pathological pattern with involvement of posterior associative areas, temporal lobes, limbic system, and cerebellum. Put together, neuropsychological and functional neuroimaging investigations support the view that MACD relates to organic central nervous system involvement.

Predictive value of brain 18F-FDG PET/CT in macrophagic myofasciitis?: A case report.

RATIONALE: Although several functional studies have demonstrated that positron emission tomography/computed tomography with F-fluorodeoxyglucose (F-FDG PET/CT) appears to be efficient to identify a cerebral substrate in patients with known macrophagic myofasciitis (MMF), the predictive value of this imaging technique for MMF remains unclear. PATIENT CONCERNS: We presented data and images of a 46-year-old woman. DIAGNOSES: The patient was referred to our center for suspected MMF due to diffuse arthromyalgias and cognitive disorder (involving an impairment of visual selective attention and a weakness in executive functions revealed by neuropsychological assessment) which occurred few years after last vaccine injections. INTERVENTIONS: After a first negative deltoid muscle biopsy, a brain F-FDG PET/CT was performed and revealed the known spatial pattern of a cerebral glucose hypometabolism involving occipital cortex, medial temporal areas, and cerebellum. OUTCOMES: Given the clinical suspicion of MMF and brain F-FDG PET/CT findings, a 2nd deltoid muscle biopsy was performed and confirmed the diagnosis of MMF with typical histopathological features. LESSONS: This case highlights the predictive value of brain F-FDG PET/CT as a noninvasive imaging tool for MMF diagnosis, even when muscle biopsy result comes back negative.

Cerebral 18F-FDG PET in macrophagic myofasciitis: An individual SVM-based approach.

INTRODUCTION: Macrophagic myofasciitis (MMF) is an emerging condition with highly specific myopathological alterations. A peculiar spatial pattern of a cerebral glucose hypometabolism involving occipito-temporal cortex and cerebellum have been reported in patients with MMF; however, the full pattern is not systematically present in routine interpretation of scans, and with varying degrees of severity depending on the cognitive profile of patients. Aim was to generate and evaluate a support vector machine (SVM) procedure to classify patients between healthy or MMF 18F-FDG brain profiles. METHODS: 18F-FDG PET brain images of 119 patients with MMF and 64 healthy subjects were retrospectively analyzed. The whole-population was divided into two groups; a training set (100 MMF, 44 healthy subjects) and a testing set (19 MMF, 20 healthy subjects). Dimensionality reduction was performed using a t-map from statistical parametric mapping (SPM) and a SVM with a linear kernel was trained on the training set. To evaluate the performance of the SVM classifier, values of sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Acc) were calculated. RESULTS: The SPM12 analysis on the training set exhibited the already reported hypometabolism pattern involving occipito-temporal and fronto-parietal cortices, limbic system and cerebellum. The SVM procedure, based on the t-test mask generated from the training set, correctly classified MMF patients of the testing set with following Se, Sp, PPV, NPV and Acc: 89%, 85%, 85%, 89%, and 87%. CONCLUSION: We developed an original and individual approach including a SVM to classify patients between healthy or MMF metabolic brain profiles using 18F-FDG-PET. Machine learning algorithms are promising for computer-aided diagnosis but will need further validation in prospective cohorts.

Brain 18F-FDG PET Metabolic Abnormalities in Patients with Long-Lasting Macrophagic Myofascitis.

The aim of this study was to characterize brain metabolic abnormalities in patients with macrophagic myofascitis (MMF) and the relationship with cognitive dysfunction through the use of PET with 18F-FDG. Methods:18F-FDG PET brain imaging and a comprehensive battery of neuropsychological tests were performed in 100 consecutive MMF patients (age [mean ± SD], 45.9 ± 12 y; 74% women). Images were analyzed with statistical parametric mapping (SPM12). Through the use of analysis of covariance, all 18F-FDG PET brain images of MMF patients were compared with those of a reference population of 44 healthy subjects similar in age (45.4 ± 16 y; P = 0.87) and sex (73% women; P = 0.88). The neuropsychological assessment identified 4 categories of patients: those with no significant cognitive impairment (n = 42), those with frontal subcortical (FSC) dysfunction (n = 29), those with Papez circuit dysfunction (n = 22), and those with callosal disconnection (n = 7). Results: In comparison with healthy subjects, the whole population of patients with MMF exhibited a spatial pattern of cerebral glucose hypometabolism (P < 0.001) involving the occipital lobes, temporal lobes, limbic system, cerebellum, and frontoparietal cortices, as shown by analysis of covariance. The subgroup of patients with FSC dysfunction exhibited a larger extent of involved areas (35,223 voxels vs. 13,680 voxels in the subgroup with Papez circuit dysfunction and 5,453 voxels in patients without cognitive impairment). Nonsignificant results were obtained for the last subgroup because of its small population size. Conclusion: Our study identified a peculiar spatial pattern of cerebral glucose hypometabolism that was most marked in MMF patients with FSC dysfunction. Further studies are needed to determine whether this pattern could represent a diagnostic biomarker of MMF in patients with chronic fatigue syndrome and cognitive dysfunction.

FDG-PET/CT Brain Findings in a Patient With Macrophagic Myofasciitis.

Brain Positron Emission Tomography/Computed Tomography with (18)F-fluorodeoxyglucose (FDG PET/CT) was performed in a 44-year-old woman with marked cognitive impairment, diffuse myalgias, sensory, memory and visual disorders, and chronic fatigue, presenting with histopathological features of macrophagic myofasciitis (MMF) at deltoid muscle biopsy. Cerebromedullary Magnetic Resonance Imaging (MRI), electromyography, ophthalmic examination, and cerebrospinal fluid analysis were normal. Visual analysis of FDG PET/CT images showed an atypical pattern of hypometabolism, involving symmetrically the occipital cortex, temporal lobes, and limbic system (including in particular amygdalo-hippocampal complexes), and the cerebellum. Posterior cingulate cortex and parietal areas were preserved. This pattern was confirmed by a voxel-based procedure using Statistical Parametric Mapping (SPM12) that compared a patient's images to normal reference samples from six healthy subjects with adjustment to age obtained using the same PET/CT camera. These results provide a glucose metabolism substrate for cognitive complaints in patients with long-lasting aluminium hydroxide-induced MMF.

Neuropsychological Correlates of Brain Perfusion SPECT in Patients with Macrophagic Myofasciitis.

BACKGROUND: Patients with aluminum hydroxide adjuvant-induced macrophagic myofasciitis (MMF) complain of arthromyalgias, chronic fatigue and cognitive deficits. This study aimed to characterize brain perfusion in these patients. METHODS: Brain perfusion SPECT was performed in 76 consecutive patients (aged 49±10 y) followed in the Garches-Necker-Mondor-Hendaye reference center for rare neuromuscular diseases. Images were acquired 30 min after intravenous injection of 925 MBq 99mTc-ethylcysteinate dimer (ECD) at rest. All patients also underwent a comprehensive battery of neuropsychological tests, within 1.3±5.5 mo from SPECT. Statistical parametric maps (SPM12) were obtained for each test using linear regressions between each performance score and brain perfusion, with adjustment for age, sex, socio-cultural level and time delay between brain SPECT and neuropsychological testing. RESULTS: SPM analysis revealed positive correlation between neuropsychological scores (mostly exploring executive functions) and brain perfusion in the posterior associative cortex, including cuneus/precuneus/occipital lingual areas, the periventricular white matter/corpus callosum, and the cerebellum, while negative correlation was found with amygdalo-hippocampal/entorhinal complexes. A positive correlation was also observed between brain perfusion and the posterior associative cortex when the time elapsed since last vaccine injection was investigated. CONCLUSIONS: Brain perfusion SPECT showed a pattern of cortical and subcortical changes in accordance with the MMF-associated cognitive disorder previously described. These results provide a neurobiological substrate for brain dysfunction in aluminum hydroxide adjuvant-induced MMF patients.

Clinical features in patients with long-lasting macrophagic myofasciitis.

Macrophagic myofasciitis (MMF) is an emerging condition characterized by specific muscle lesions assessing abnormal long-term persistence of aluminum hydroxide within macrophages at the site of previous immunization. Affected patients usually are middle-aged adults, mainly presenting with diffuse arthromyalgias, chronic fatigue, and marked cognitive deficits, not related to pain, fatigue, or depression. Clinical features usually correspond to that observed in chronic fatigue syndrome/myalgic encephalomyelitis. Representative features of MMF-associated cognitive dysfunction include dysexecutive syndrome, visual memory impairment, and left ear extinction at dichotic listening test. Most patients fulfill criteria for non-amnestic/dysexecutive mild cognitive impairment, even if some cognitive deficits appear unusually severe. Cognitive dysfunction seems stable over time despite marked fluctuations. Evoked potentials may show abnormalities in keeping with central nervous system involvement, with a neurophysiological pattern suggestive of demyelination. Brain perfusion SPECT shows a pattern of diffuse cortical and subcortical abnormalities, with hypoperfusions correlating with cognitive deficiencies. The combination of musculoskeletal pain, chronic fatigue, and cognitive disturbance generates chronic disability with possible social exclusion. Classical therapeutic approaches are usually unsatisfactory making patient care difficult.

Stroke rehabilitation using noninvasive cortical stimulation: hemispatial neglect.

The rehabilitation of neuropsychological sequels of cerebral stroke such as hemispatial neglect by noninvasive cortical stimulation (NICS) attracts increasing attention from the scientific community. The NICS techniques include primarily repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). They are based on the concept of either reactivating a hypoactive cortical region affected by the stroke (the right hemisphere in case of neglect) or reducing cortical hyperactivity of the corresponding cortical region in the contralateral hemisphere (the left hemisphere). In the studies published to date on the topic of neglect rehabilitation, rTMS was used to inhibit the left parietal cortex and tDCS to either activate the right or inhibit the left parietal cortex. Sham-controlled NICS studies assessed short-term effects, whereas long-term effects were only assessed in noncontrolled rTMS studies. Further controlled studies of large series of patients are necessary to determine the best parameters of stimulation (including the optimal cortical target location) according to each subtype of neglect presentation and to the time course of stroke recovery. To date, even if there are serious therapeutic perspectives based on imaging data and experimental studies, the evidence is not compelling enough to recommend any particular NICS protocol to treat this disabling condition in clinical practice.