Conversion, dissociative amnesia, and Ganser syndrome in a case of "chameleon" syndrome: anatomo-functional findings.

The term "chameleon" was first used in the seventeenth century by Sydenham to describe a patient with a protean semiology. We report a single case of "chameleon" syndrome that challenges the current international criteria for somatoform disorders, dissociative amnesia, and Ganser syndrome. The florid symptoms were as follows: anterograde and retrograde amnesia (including semantic, episodic, and procedural deficits), loss of identity, atypical neuropsychological impairment (approximate answers), left sensitive and motor deficit, and left pseudochoreoathetosis movement disorders. Additional behavioral disorders included the following: anxiety, clouded consciousness, hallucinations, and "belle indifference". A single photon emission computed tomography examination showed bilateral temporal, frontal and a right caudate (in the head of the caudate nucleus) hypoperfusion concordant with a common mechanism of repression in these disorders.

Neuropsychological and neuroimaging phenotype induced by a CAMTA1 mutation.

BACKGROUND/AIMS: CAMTA1 mutations have recently been reported in families with intellectual disability and/or non-progressive congenital ataxias. The objective of this study was to describe the neuropsychological and neuroimaging phenotype of CAMTA1 mutation. METHODS: We performed neuropsychological examinations, MRI and FDG-PET imaging in three patients with autosomal dominant mild intellectual disabilities and ataxia induced by a CAMTA1 intragenic deletion at 1p36.31p36.23. RESULTS: Neuropsychological tests showed similar findings in two patients, with low information processing speed, slow memory consolidation, phonological disorders, working memory deficits, but mainly preserved executive function. Bilateral parietal and medial temporal abnormalities were found on brain MRI. Diffuse parieto-occipital and local left temporo-parietal decrease of FDG uptake was observed on PET images. CONCLUSION: These results suggest that CAMTA1 mutation may induce an unusual neuropsychological profile and parieto-temporal developmental abnormalities. We recommend screening for CAMTA1 mutations in patients with autosomal dominant mild intellectual disability presenting with similar a phenotype.

On the estimation and correction of bias in local atrophy estimations using example atrophy simulations.

Brain atrophy is considered an important marker of disease progression in many chronic neuro-degenerative diseases such as multiple sclerosis (MS). A great deal of attention is being paid toward developing tools that manipulate magnetic resonance (MR) images for obtaining an accurate estimate of atrophy. Nevertheless, artifacts in MR images, inaccuracies of intermediate steps and inadequacies of the mathematical model representing the physical brain volume change, make it rather difficult to obtain a precise and unbiased estimate. This work revolves around the nature and magnitude of bias in atrophy estimations as well as a potential way of correcting them. First, we demonstrate that for different atrophy estimation methods, bias estimates exhibit varying relations to the expected atrophy and these bias estimates are of the order of the expected atrophies for standard algorithms, stressing the need for bias correction procedures. Next, a framework for estimating uncertainty in longitudinal brain atrophy by means of constructing confidence intervals is developed. Errors arising from MRI artifacts and bias in estimations are learned from example atrophy simulations and anatomies. Results are discussed for three popular non-rigid registration approaches with the help of simulated localized brain atrophy in real MR images.

Initial neuropsychological profile of a series of 20 patients with logopenic variant of primary progressive aphasia.

BACKGROUND: Logopenic variant of primary progressive aphasia (LPPA) is classically considered as an isolated language disorder, but verbal short-term memory deficit induces difficulties in neuropsychological tests that are not intended to evaluate language. OBJECTIVE: The aim of this study is to describe the initial symptoms and neuropsychological profiles of LPPA. METHODS: A retrospective study was conducted with a series of 20 consecutive patients diagnosed with LPPA. Clinical, neuroimaging, neuropsychological, and linguistic examinations are reported. The first neuropsychological examinations (mean time between neuropsychological assessment and diagnosis: 11 months) were then compared to 20 patients with mild cognitive impairment (MCI) and 20 patients with Alzheimer's disease (AD) matched by age, gender, and education level. RESULTS: A recent onset or aggravation of anxiety disorders was frequently reported. An unusual neuropsychological profile, different from that of AD or MCI, was observed: dissociation between verbal and visual memory performances, poor encoding performances on verbal memory tests, and preserved orientation to time, difficulties with mental calculation and fluency tasks. Biparetal abnormality and left hippocampal diaschisis was frequently observed. Asymptomatic dopaminergic depletion was observed in four patients. CONCLUSION: Our study identifies that de novo or recently worsening anxiety and specific neuropsychological profiles call for screening for LPPA, including a linguistic examination. Sometimes, there may be a continuum between LPPA and corticobasal syndrome.

Transient improvement in sensorimotor conversion during post-anoxic encephalopathy with bilateral medial temporal ischemia.

We report the case of a patient with sensorimotor conversion that improved transiently during post-anoxic medial temporal ischemia inducing anterograde and retrograde amnesia. Symptoms reappeared in parallel with mnesic recovery. This case raises a hypothesis concerning the role of hippocampi and amygdalae, which are involved in emotionally-associated memory. The amnesia may have modified the patient's "self," giving her a "distant" point of view. Another hypothesis is that cerebral anoxic stress may have "reset" the cerebral network that controls behavior. These findings give clues about the mechanisms of somatoform disorder and highlight the possibility of specific therapeutic strategies to induce cognitive reappraisal of emotionally-associated experiences.

Logopenic syndrome in posterior cortical atrophy.

Few language disorders have been reported in posterior cortical atrophy (PCA). Furthermore, no study has focused on screening for them and described these language deficits. The goal of this work was to describe linguistic examination of PCA patients and the impact of language disorders on neuropsychological performances compared to patients with other neurodegenerative syndromes and control groups. Linguistic examination of 9 PCA patients was carried out. The neuropsychological performance of the PCA group (16 patients) in the RAPID battery tests was compared with performances of patients with a logopenic variant of primary progressive aphasia (LPPA), patients with Alzheimer's disease and patients with amnestic mild cognitive impairment, as well as the control group. A "logopenic syndrome" with anomia, fluency impairment, and length-dependent deficit was found in 8/9 PCA patients. A comparison with other neurodegenerative syndromes showed that not only visual disorders but also language and verbal short-term memory disorders, such as those found in LPPA, can explain neuropsychological performances. A "logopenic syndrome" is frequently found in PCA and may be associated with poor performance on other verbally mediated neuropsychological tasks (e.g., verbal memory). Specific logopedic rehabilitation should be offered to these patients.

Validation of a new quality of life scale related to multiple sclerosis and relapses.

PURPOSE: Multiple sclerosis (MS) has a significant impact on all aspects of patient quality of life (QoL). Furthermore, the fear of relapses and the feelings of patients during relapses must be taken into account in care. The objective of this work was to validate the PERSEPP scale ("PERception de la Sclérose En Plaques et de ses Poussées"), a new QoL evaluation scale for relapsing-remitting forms of MS. METHODS: Relapsing-remitting patients were included in a multicenter study. Various validation criteria of this scale were analyzed: acceptability, construct validity (internal and external validity), and reliability (internal consistency and reproducibility test-retest). Responsiveness will be studied in order to complete the validation process. RESULTS: The responses of 305 MS patients were analyzed. The process of reducing the items led us to retain 66 items of a total of 112 items. The 66-item PERSEPP scale (final version) was well accepted. Five dimensions (33 items) make up the scale: social support (α = 0.81), relationship difficulties (α = 0.71), fatigue (α = 0.74), state of mind and associated sleep disorders (α = 0.78), and time perspective (α = 0.75). Three additional modules (33 items) explore coping (α = 0.60), symptoms (α = 0.89), and treatment (α = 0.92). Test-retest reliability, measured by the intraclass correlation coefficient (ICC), was acceptable (0.72 < ICC < 0.92). CONCLUSIONS: The PERSEPP scale has been validated and could be used in clinical trials and in daily practice. Additional studies will then complete the validation process.

Fractional anisotropy in three variants of primary progressive aphasia.

OBJECTIVE: Our aim was to report diffusion tensor imaging (DTI) patterns in three patients, each with a different primary progressive aphasia (PPA) variant. DESIGN: One agrammatic PPA, one semantic PPA, and one logopenic PPA subject underwent a magnetic resonance imaging examination including DTI sequences. The fractional anisotropy (FA) value was calculated in regions of interest (ROIs) involved in these three variants (perisylvian region, temporal pole, and parietotemporal junction) for each patient. Left-right FA ratios in each ROI were compared between PPA subjects and a group of three amnestic mild cognitive impairment patients with a cerebrospinal fluid biomarker profile of the Alzheimer type. RESULTS: The FA values were lower in the left hemisphere (p=0.03). The lowest FA values were observed in the left perisylvian region for the non-fluent/agrammatic subtype PPA patient, in the left anterior temporal lobe for the semantic subtype PPA patient, and in the left parietotemporal junction for the logopenic patient (p=0.028). The left-right FA ratio in these specific ROIs for each PPA variant was significantly lower than in the amnestic mild cognitive impairment group (p=0.009). CONCLUSION: DTI patterns could be an effective new tool for diagnosing PPA and classifying the three variants.

Fronto-striatal dysfunction in type 3 familial cortical myoclonic tremor epilepsy occurring during aging.

The aim of this work is to study the cognition, progressive gait impairment, and neuroimaging findings in two patients over 65 years old of the previously described type 3 familial cortical myoclonic tremor with epilepsy (FCMTE3). We report investigations in two of these five FCMTE3 subjects over 65 and showing progressive gait disorders. They both had a pseudo-Parkinson's way of walking and visual intolerance to bright light and brightness contrast without EEG abnormalities exacerbating cortical myoclonus or triggering seizure. Case 1 had moderate gait impairment and a severe frontal syndrome. Case 2 had severe gait impairment and diffuse cognitive disorders. Both cases had cortical hypoperfusion (predominantly in the left frontal lobe) and no cerebellar abnormality on cerebral perfusion SPECT. DAT-SPECT showed dopaminergic depletion. These data indicate fronto-striatal dysfunction associated with gait impairment and cognitive disorders appearing after several decades of disease progression. This gives clues to understanding the pathogenesis and evolution of FCMTE3. Permanent myoclonic discharges or long-term valproate treatment may cause significant toxic effects on neurons (dopaminergic and frontal neurons). Further functional and molecular analyses are required in order to better understand this pathology and the consequences of chronic cortical myoclonus.

Longitudinal change detection in diffusion MRI using multivariate statistical testing on tensors.

This paper presents a longitudinal change detection framework for detecting relevant modifications in diffusion MRI, with application to neuromyelitis optica (NMO) and multiple sclerosis (MS). The core problem is to identify image regions that are significantly different between two scans. The proposed method is based on multivariate statistical testing which was initially introduced for tensor population comparison. We use this method in the context of longitudinal change detection by considering several strategies to build sets of tensors characterizing the variability of each voxel. These strategies make use of the variability existing in the diffusion weighted images (thanks to a bootstrap procedure), or in the spatial neighborhood of the considered voxel, or a combination of both. Results on synthetic evolutions and on real data are presented. Interestingly, experiments on NMO patients highlight the ability of the proposed approach to detect changes in the normal-appearing white matter (according to conventional MRI) that are related with physical status outcome. Experiments on MS patients highlight the ability of the proposed approach to detect changes in evolving and non-evolving lesions (according to conventional MRI). These findings might open promising prospects for the follow-up of NMO and MS pathologies.

Generalized likelihood ratio tests for change detection in diffusion tensor images: application to multiple sclerosis.

The automatic analysis of subtle changes between MRI scans is an important tool for monitoring disease evolution. Several methods have been proposed to detect changes in serial conventional MRI but few works have considered Diffusion Tensor Imaging (DTI), which is a promising modality for monitoring neurodegenerative disease and particularly Multiple Sclerosis (MS). In this paper, we introduce a comprehensive framework for detecting changes between two DTI acquisitions by considering different levels of representation of diffusion imaging, namely the Apparent Diffusion Coefficient (ADC) images, the diffusion tensor fields, and scalar images characterizing diffusion properties such as the fractional anisotropy and the mean diffusivity. The proposed statistical method for change detection is based on the Generalized Likelihood Ratio Test (GLRT) that has been derived for the different diffusion imaging representations, based on the core assumption of a Gaussian diffusion model and of an additive Gaussian noise on the ADCs. Results on synthetic and real images demonstrate the ability of the different tests to bring useful and complementary information in the context of the follow-up of MS patients.

Social cognition impairments in relapsing-remitting multiple sclerosis.

Theory of Mind (ToM) is the ability to attribute independent mental states to self and others to explain and predict behavior. Impairment of ToM is well established in developmental pathologies. In neurological populations, investigation of ToM is still rare but data suggest that ToM impairment could contribute to behavioral and social disturbances. In addition to neurological signs, multiple sclerosis (MS) presents with disorders of cognition and behavior directly related to brain damage. The aim of this study was to assess ToM abilities and recognition of facial emotional expression in adults with MS. We compared 64 patients with relapsing MS and 30 matched healthy controls on three levels of ToM tasks, a facial emotion recognition task, and a neuropsychological assessment. MS patients performed significantly worse than controls in emotion recognition and all ToM tasks (p < .02). These deficits were not correlated with demographic variables or neuropsychological test performance. These findings underscore the importance of assessing ToM and facial recognition in MS, as dysfunction in these areas may impact upon social interaction and, thus, impair quality of life for both patients with MS and their families.