Similar neurocognitive patterns in patients treated with lenalidomide: chemobrain effect?

ABSTRACT

Purpose: o report and describe cognitive impairments during lenalidomide treatment in three patients. Despite the relevant clinical impact of chemotherapy-related cognitive deficit (known as “chemobrain effect”), very few data are available in the literature.

Methods: We present three subjects who developed cognitive impairment during treatment with lenalidomide. Their neuropsychological assessment was evaluated in order to better define the cognitive areas involved. For each patient medical history, drug therapy, physical examination and other instrumental tests (brain CT scan and/or MRI scan, FDG-PET and electroencephalography) were collected.

Results: In all patients, we observed an homogeneous neuropsychological pattern characterized by long-term verbal and visuospatial memory deficits, and decline in attentional and executive functions.

Conclusions: Lenalidomide treatments can determine severe cognitive impairments especially in elderly patients. Our data suggest the need for a careful evaluation of cognitive decline risk before and after drug administration. However, larger studies are required to confirm our findings.     

Cognitive function in the locked-in syndrome

Objective The lockedin syndrome (LIS) originates from a ventro-pontine lesion resulting in a complete quadraplegia and anarthria. Classically, communication remains possible by means of spared vertical eye movements and/or blinking. To allow assessing cognitive functions in LIS patients, we propose here a neuropsychological testing based on eye-coded communication. Methods Ten chronic LIS survivors were assessed 1 to 6 years after their brain insult.One patient was evaluated subacutely (at 2 months) and retested at 6 and 16 months.Neuropsychological testing encompassed short- and long-term memory, attention, executive functioning, phonological and semantic processing and verbal intelligence. Results None of the patients showed alterations in verbal intelligence. Impairments in one or several tests were found in five patients. In three of these patients, neuropsychological deficits could be related to additional cortical or thalamic structural brain lesions. In the other 2 patients, weakness or signs of fatigue only were observed in one or two cognitive tasks. Repeated measures in a subacute patient with pure brainstem lesion indicate the recovery of good levels of cognition 6 months after injury. Conclusion Results indicate that LIS patients can recover intact cognitive levels in cases of pure brainstem lesions, and that additional brain injuries are most likely responsible for associated cognitive deficits in the LIS. Furthermore, a systematic neuropsychological assessment in LIS patients would allow detecting their cognitive deficits,which will contribute to improve their quality of life and of communication with family and medical caretakers. * The Coma Science Group.     

Cognitive impairments due to focal cerebellar injuries in adults

IntroductionIt has been asserted that damage to the cerebellum produces a specific pattern of cognitive deficits, but clinical studies have had ambiguous results. There remains particular uncertainty about the effects of focal cerebellar injuries on cognition in adults. Clinical reports and anatomical connectivity studies have suggested a possible functional convergence of frontal lobes and cerebellum. This investigation was designed to assess whether focal cerebellar injuries in adults would cause impairment on tasks previously demonstrated to be sensitive to prefrontal lesions.MethodWe investigated this question in 32 adults with either stroke or resection of benign tumours and 36 healthy control subjects. Patients underwent standard and experimental cognitive testing and an assessment of general health and well-being at least 3 months post onset.ResultsThe group with right cerebellar lesions had lower performance on some tests of response control and verbal fluency than the controls and also the patients with left cerebellar lesions. On most tests, including most of the experimental tests sensitive to prefrontal lesions, the patients had no significant difference from the controls. The patient groups reported no health or functional decline.ConclusionsThese results and the bulk of the clinical literature suggest that damage to some cerebellar sites may have specific cognitive consequences, but the cognitive impairment after focal cerebellar injury in adults is mild or transient. After the acute epoch, demonstration of deficits may require more demanding probes of specific domains of cognition.     

Contribution of the cerebellum to neuropsychological functioning: evidence from a case of cerebellar degenerative disorder.

A detailed neuropsychological evaluation was performed on a patient with an idiopathic cerebellar degenerative disorder. Significant deficits were found in verbal and nonverbal intelligence, verbal associative learning, and visuospatial skills. These deficits were not readily explained by motor control difficulties. In contrast to the patient's moderately impaired language abilities, he was severely impaired on a test of verbal fluency and demonstrated mild naming deficits. Severe cerebellar parenchymal volume loss was demonstrated by magnetic resonance examination. Supratentorial structures showed only minimal posterior parietal and occipital sulcal prominence. On neurological examination, this patient had signs of severe involvement of the cerebellar systems and mild-to-moderate dysfunction of the corticospinal tract. As is characteristic of patients with cerebellar degeneration, there was neurophysiological evidence of subclinical involvement of auditory and somatosensory pathways at the level of the brain stem. Since relatively little cerebral cortical atrophy was noted in this patient, these findings suggest that an intact cerebellum is important for normal cognitive functions.     

Cognitive profiling of Parkinson disease patients with mild cognitive impairment and dementia

BackgroundPrevalence of mild cognitive impairment (MCI) and dementia in Parkinson disease (PD) is variable because different classification criteria are applied and there is lack of consensus about neuropsychological tests and cut-off used for cognitive profiling. Given the important therapeutic consequences for patient management, we aimed at identifying suitable diagnostic cognitive tests and respective screening cut-off values for MCI and dementia in PD (PDD).MethodsWe evaluated 105 PD patients using an extensive neuropsychological battery categorized as PD without cognitive impairment (PD-CNT) (35%), PD-MCI (47%) and PDD (18%) based on established criteria and calculated Receiver Operating Characteristic (ROC) curves.ResultsWe found different sensitivity and specificity among neuropsychological tests in detecting PD-MCI and PDD. In particular performance in attention/set shifting, verbal memory and language abilities, discriminated both PD-MCI and PDD from PD-CNT. Abilities involved mainly in semantic retrieval mechanisms discriminated PD-CNT from PD-MCI but also PD-MCI from PDD. Finally deficits in executive and visual-spatial abilities were only affected in PDD.ConclusionOur data point to an independent and different load of each test in defining different PD cognitive statuses. These findings can help selection of appropriate cognitive batteries in longitudinal studies and definition of stage-specific therapeutic targets.     

The influence of impaired processing speed on cognition in first-episode antipsychotic-naïve schizophrenic patients

BackgroundImpaired cognition is a prominent feature of schizophrenia. To what extent the heterogeneous cognitive impairments can be accounted for by considering only a single underlying impairment or a small number of core impairments remains elusive. This study examined whether cognitive impairments in antipsychotic-naïve, first-episode schizophrenia patients may be determined by a relative slower speed of information processing.MethodForty-eight antipsychotic-naïve patients with first-episode schizophrenia and 48 matched healthy controls were administered a comprehensive battery of neuropsychological tests to assess domains of cognitive impairments in schizophrenia. Composite scores were calculated, grouping tests into cognitive domains.ResultsThere were significant differences between patients and healthy controls on global cognition and all cognitive domains, including verbal intelligence, processing speed, sustained attention, working memory, reasoning and problem solving, verbal learning and memory, visual learning and memory, and reaction time. All these significant differences, except for verbal intelligence and global cognition, disappeared when processing speed was included as a covariate.ConclusionAt the first stage of illness, antipsychotic-naïve patients with schizophrenia display moderate/severe impairments in all the cognitive domains assessed. The results support the contention of a global cognitive dysfunction in schizophrenia that to some extent may be determined by impaired processing speed.     

Cilostazol may improve cognition better than clopidogrel in non-surgical adult patients with ischemic moyamoya disease: subanalysis of a prospective cohort

ABSTRACT

Objective: Adult patients with ischemic moyamoya disease (MMD) who receive treatment with antiplatelet drugs reportedly show improvements in neuropsychological test scores after around 2 years. The purpose of the present study subanalyzing the same patient cohort used in a previous study was to determine which antiplatelet drug, clopidogrel or cilostazol, results in better improvement of cognitive function among non-surgical adult patients showing ischemic MMD without severe hemodynamic compromise.

Methods: Sixty-six patients without cerebral misery perfusion on ¹⁵O gas positron emission tomography were treated with pharmacotherapy alone. Patients ≥50 years old and <50 years old initially received clopidogrel and cilostazol, respectively. Any patient suffering side effects of the antiplatelet drug switched to the other antiplatelet drug. Neuropsychological tests were performed at study entry and at the end of the 2-year follow-up, and differences in each neuropsychological test score between the two time points (second test score – first test score) were calculated and defined as Δ scores.

Results: Among the five neuropsychological tests, Δ scores for two tests were significantly greater in patients treated with cilostazol (n = 36) than in those treated with clopidogrel (n = 30), and Δ scores of the remaining three tests did not differ between patient groups. Based on Δ scores, 15 patients (23%) were defined as showing interval cognitive improvement. On multivariate analysis, cilostazol administration (95% confidence interval, 1.19–193.98; P = 0.0361) represented an independent predictor of interval cognitive improvement.

Conclusions: Cilostazol may improve cognition better than clopidogrel in non-surgical adult patients with ischemic MMD.     

A multidimensional assessment of obese patients with obstructive sleep apnoea syndrome (OSAS): a study of psychological, neuropsychological and clinical relationships in a disabling multifaceted disease

BackgroundRare are the studies that focus on OSAS (obstructive sleep apnoea syndrome) obese patient assessing neuropsychological, psychological and clinical aspects simultaneously.MethodsOne hundred and fifty-seven obese patients with OSAS were psychologically and neuropsychologically assessed by a standardized battery of validated tests in a cross-sectional study.ResultsPatients reported with higher frequency, compared to the normal distribution, the presence of an extrovert personality trait and depressive behaviours: 15.9% of the patients minimized symptoms and denied distress, whereas 28.0% presented psychological disorders. Compared to the normative group, patients’ results were characterized as impaired with a higher percentage in short-term verbal memory (30.6%) and in short-term visual spatial memory (20.5%). Moreover 30.6% of patients were impaired in one cognitive function, 11.5% in two, 8.9% in three, and 8.2% in four or more cognitive functions. No significant relations between psychological–neuropsychological data and clinical variables emerged.ConclusionsThe results of our obese patients with OSAS were significantly different from the normative data as for psychological and neuropsychological variables (extroversion, depression, short-term verbal and visual spatial memory, logical ability). Further studies are needed in order to investigate the eventual dose effect on psychological and neuropsychological variables of OSAS and obesity severity and treatment efficacy.     

Neuropsychological evaluation and follow-up of children with cerebellar cortical dysplasia

Aim To describe neuropsychological disturbances and the developmental course associated with cerebellar cortical dysplasia (CCD). Method The neuroimaging findings from 10 children (five males, five females; aged 3–10y) with CCD were reviewed and classified. These children all underwent clinical neurological examination and neuropsychological assessment (NPA) on admission, then were followed for an average of 6 years using the cognitive Wechsler Scale, Vineland Adaptive Behavior Scales, and Rey–Osterrieth Complex Figure/McCarthy Drawing subtests. Results Based on magnetic resonance imaging, CCD was categorized as minor (n=4), moderate (n=1), and severe (n=5). The first NPA disclosed mental retardation * 1 UK usage: learning disability.
in six (profound, three; moderate, one; mild, two) and normal intelligence in four (low, two; average, one; high, one), but with verbal/performance dissociation in three cases. Socio‐adaptive functions were altered in all children except one. Visuospatial abilities were delayed in eight children. In the follow‐up, no progression was observed in the three cases with profound mental retardation, whereas the remainder showed homogeneous or disharmonic progression, including improvement or deterioration of verbal/performance function. Cognitive impairment and evolution was not associated with the degree of cerebellar involvement. Interpretation The neuropsychological profile and evolution associated with CCD do not appear to be predictable, and some features might improve over time.     

Cognitive functions in patients with MR-defined chronic focal cerebellar lesions

Abstract The aim of the present study was to examine cognitive functions in a group of chronic patients with focal cerebellar lesions. Both effects of localization (anterior vs. posterior lobe) and side (left vs. right cerebellar hemisphere) were of interest. Fourteen patients with infarctions within the territory of the posterior inferior cerebellar artery (PICA) and seven patients with infarctions within the territory of the superior cerebellar artery (SCA) participated. The affected lobules and nuclei were assessed based on 3D MR imaging. The right cerebellar hemisphere was affected in eight PICA and two SCA patients, the left hemisphere in six PICA and four SCA patients. One SCA patient revealed a bilateral lesion. In order to study possible lateralization of functions, subjects performed a language task as well as standard neglect and extinction tests. Moreover, two tests of executive functions were applied. There were no significant group differences apart from a verbal fluency task, in which all cerebellar patients – but especially those with right-sided lesions – were impaired. Voxel-based lesionsymptom mapping (VLSM) revealed that a lesion of the right hemispheric lobule Crus II was associated with impaired performance in the verbal fluency task. In sum, the results showed preserved cognitive abilities in chronic cerebellar patients apart from impairments of verbal fluency in patients with right-cerebellar lesions. The latter findings are in line with the assumption that the right posterolateral cerebellar hemisphere supports functions associated with verbal fluency.     

Multiple system atrophy with early cognitive deficits: A case report

We present the case of a patient with multiple system atrophy with predominant cerebellar ataxia (MSA-C) in the early stage of the disease, who was assessed using a comprehensive neuropsychological test battery. Many studies have found cognitive deficits in MSA patients assessed after 2–3 years, but not in the first stages of the disease. The aim of this paper is to stress the importance of a complete neuropsychological assessment, even at the initial stage of the disease, when instrumental examinations are not able to show cortical involvement and daily life activities have not been affected. The neuropsychological tests examined general cognition, verbal and visual memory, visuospatial and constructional ability, language, executive function, depression and functional autonomy. Results showed cognitive deficits in executive functions, above all in the control and inhibition of automatic response, planning and reasoning abilities, memory and visuoconstructional functions. However, these problems did not affect the patient’s autonomy in everyday life. MRI scan showed the involvement of the cerebellum and the fibers of the pons and raphe, with normal cerebral ventricles and sulci. The cognitive deficits in our patient could be explained by a disruption in cerebrocerebellum connections between the frontal areas and the cerebellar structures. These results show that a more comprehensive cognitive evaluation is necessary to detect early the onset of neuropsychological deficits, also in order to begin in time adequate rehabilitation programs.     

Cerebellar Transcranial Direct Current Stimulation Modulates Verbal Working Memory

BackgroundNeuroimaging studies show cerebellar activations in a wide range of cognitive tasks and patients with cerebellar lesions often present cognitive deficits suggesting a cerebellar role in higher-order cognition.ObjectiveWe used cathodal transcranial direct current stimulation (tDCS), known to inhibit neuronal excitability, over the cerebellum to investigate if cathodal tDCS impairs verbal working memory, an important higher-order cognitive faculty.MethodWe tested verbal working memory as measured by forward and backward digit spans in 40 healthy young participants before and after applying cathodal tDCS (2 mA, stimulation duration 25 min) to the right cerebellum using a randomized, sham-controlled, double-blind, cross-over design. In addition, we tested the effect of cerebellar tDCS on word reading, finger tapping and a visually cued sensorimotor task.ResultsIn line with lower digit spans in patients with cerebellar lesions, cerebellar tDCS reduced forward digit spans and blocked the practice dependent increase in backward digit spans. No effects of tDCS on word reading, finger tapping or the visually cued sensorimotor task were found.ConclusionOur results support the view that the cerebellum contributes to verbal working memory as measured by forward and backward digit spans. Moreover, the induction of reversible “virtual cerebellar lesions” in healthy individuals by means of tDCS may improve our understanding of the mechanistic basis of verbal working memory deficits in patients with cerebellar lesions.     

Is the PANSS cognitive scale measuring cognition?

Abstract

Objective: To investigate the association between the Positive and Negative Syndrome Scale (PANSS) cognitive factors and cognition assessed by neuropsychological tests. Method: Ninety patients with a psychotic illness, the majority having a schizophrenia diagnosis, were assessed with PANSS ratings and tested by a comprehensive computerized neuropsychological test battery, EuCog. Results: Test performance was in the normal range for some of the cognitive indices, but substantially reduced for others, compared with norms, particularly speed-based indices. PANSS ratings were non-specifically associated with cognitive indices representing performance (speed and accuracy) and problem solving strategies (executive functions). There was no discriminant validity for the cognitive factor. A regression analysis suggested that the PANSS cognitive factors reflected verbal IQ but no other cognitive domain like memory, attention or speed. Conclusion: Cognitive test performance is associated with psychopathology as assessed by PANSS items but in a non-specific way. The PANSS cognitive subscale seems to reflect over-learned verbal skills rather than the cognitive domains, which are known to be specifically affected in schizophrenia and relevant for the prognosis. Consequently, PANSS ratings cannot replace the information inherent in neuropsychological test data. The extensive speed problem of patients with schizophrenia should be studied in more detail using test batteries that focus on that problem.     

Comparing executive function,evoked hemodynamic response,and gait as predictors of variations in mobility for older adults

Objective: Falls represent a major concern for older adults and may serve as clinically salient index events for those presenting in the prodromal stages of mild cognitive impairment. Declines in executive function performance and in gait consistency have shown promise in predicting fall risk; however, associated neurophysiological underpinnings have received less attention. In this study, we used a multimodal approach to assess fall risk in a group of older adults with and without a previous fall history.

Method: Processing speed, inductive reasoning, verbal fluency, crystallized ability, episodic memory, and executive functioning were assessed using standardized neuropsychological tests. Cognitive interference was assessed using the Multi-Source Interference Task. Spatiotemporal gait parameters were assessed with and without cognitive load using a 6.4-m instrumented walkway. Hemodynamic responses were measured using functional near-infrared spectroscopy.

Results: Whereas no group differences were observed in cognitive behavioral performance, during a cognitive interference task fallers displayed more oxygenated hemoglobin across the prefrontal cortex than nonfallers, suggesting that engaging in the cognitive task was more effortful for them overall, therefore eliciting greater cortical activation. Between-group differences in spatial as well as temporal gait parameters were also observed.

Conclusions: These results are in keeping with assertions that diminished executive control is related to fall risk. Notably, the group differences observed in prefrontal cortical activation and in gait parameters may ultimately precede those observed in cognitive behavioral performance, with implications for measurement sensitivity and early identification.     

Neuropsychological assessment of patients with severe neuromotor and verbal disabilities

In people with cerebral palsy, severe neuromotor disability and communication problems make standard neuropsychological tests impossible. Therefore, alternative methods and specific aids must be developed to allow patients to autonomously respond to the examiner's questions. In the present individuals and study, a neuropsychological evaluation was made of a group of eight individuals with cerebral palsy, and severe neuromotor and verbal disabilities, and a group of 19 normal subjects matched for mental age. The tests were administered using an autonomous selection method in which the patient selects the various responses through specific aids without the examiner's interference. Patients' group performances in visuo‐spatial and memory tests were on average lower than the mean of the control group. In the verbal domain, patients' scores were comparable to those of normal children in all tests but one assessing the comprehension of syntactically complex sentences. An analysis of the patients' individual performances also revealed heterogeneous cognitive profiles: some patients presented a homogeneously distributed cognitive impairment and others a more selective one. This finding is particularly important for planning differentiated learning programmes, and identifying suitable communicative instruments in rehabilitative and educational settings.     

Relevance of functional neuroimaging in the progression of mild cognitive impairment

Abstract

Aim: To assess whether combining neuropsychological tests and cerebral blood flow markers improves progression accuracy from mild cognitive impairment (MCI) to Alzheimer's disease (AD) than each of them on its own.

Methods: Forty-two patients were investigated prospectively, undergoing baseline and 3-year follow-up neuropsychological tests and neuroimaging with Tc-ECD–SPECT. Twenty-one patients had developed AD while 21 retained their initial diagnosis. The relative blood flow and cognitive differences were studied. Validity parameters, multivariant analysis and logistic regression model were calculated.

Results: Patients who deteriorated showed lower scoring than stable subjects in some neuropsychological tests (p = 0.03–0.001) and in relative blood flow in selected regions (8–10%). Low cognitive test scoring and low relative blood flow in some regions showed sensibilities and specificities from 70% to 86% for the diagnosis of early Alzheimer's disease. The relative risk of progression to AD was up to 4.7 times higher for these patients (p = 0.0001). The left frontal relative blood flow, the CAMCOG and orientation scoring were the best data to predict the risk of progression to AD.

Conclusions: The combination of functional imaging and neuropsychological tests can diagnose with high sensitivity and specificity if a patient is suffering cognitive impairment in its early stages, and may aid in predicting the risk of developing dementia.     

Gastrointestinal symptoms are predictive of trajectories of cognitive functioning in de novo Parkinson's disease

IntroductionNon-motor symptoms such as cognitive and gastrointestinal (GI) symptoms are common in Parkinson's disease (PD). In PD, GI-symptoms often present prior to motor symptoms. It is hypothesized that GI-symptoms reflect disruptions of the microbiome-gut-brain axis, which leads to altered immune functioning, chronic neuroinflammation, and subsequent neurodegeneration. Initial evidence links gut-dysbiosis to PD pathology and motor symptom severity. The present study examines the longitudinal relationship between severity of GI-symptoms and cognitive impairment in newly diagnosed PD patients.MethodsA secondary data analysis of the Parkinson's Progression Markers Initiative (PPMI) included 423 newly diagnosed PD patients who were followed for up to 5 years. Participants underwent neuropsychological tests of processing speed, attention, visuospatial functioning, verbal learning and verbal delayed recall. Participant were classified as cognitive intact, mild cognitive impairment or Parkinson's disease dementia. Frequency of GI-symptoms were assessed with the Scales for Outcomes in Parkinson's Disease Autonomic (SCOPA-AUT). Multi-level models (MLM) examined the longitudinal relationship between GI symptoms and cognitive impairment.ResultsAll cognitive outcomes were predicted by the main effect of GI symptoms, or the GI-symptom X Occasion interaction term. Specifically, more severe GI-symptoms were predictive of a less favorable trajectory of performance on tests of letter fluency, visuospatial, learning and memory. Cognitive performance was uniquely associated with GI-symptoms and unrelated to non-GI autonomic symptoms.ConclusionsThe presence of GI symptoms may serve as an early marker of cognitive impairment in PD. Future studies should examine specific mechanisms underlying the relationship between gut-dysbiosis and cognitive impairment.     

Normal cognition in Parkinson's disease may involve hippocampal cholinergic compensation: An exploratory PET imaging study with [18F]-FEOBV

BackgroundSevere cholinergic degeneration is known to occur in Parkinson's disease (PD) and is thought to play a primary role in the cognitive decline associated with this disease. Although cholinergic losses occur in all patients with PD, cognitive performance remains normal for many of them, suggesting compensatory mechanisms in those.ObjectivesThis exploratory study aimed at verifying if normal cognition in PD may involve distinctive features of the brain cholinergic systems.MethodsFollowing extensive neuropsychological screening in 25 patients with PD, 12 were selected and evenly distributed between a cognitively normal (PD-CN) group, and a mild cognitive impairment (PD-MCI) group. Each group was compared with matched healthy volunteers (HV) on standardized cognitive scales (MoCA, PDCRS), and PET imaging with [¹⁸F]-FEOBV, a sensitive measurement of brain cholinergic innervation density.Results[¹⁸F]-FEOBV uptake reductions were observed in PD-CN as well as in PD-MCI, with the lowest values located in the posterior cortical areas. However, in PD-CN but not in PD-MCI, there was a significant and bilateral increase of [¹⁸F]-FEOBV uptake, exclusively located in the hippocampus. Significant correlations were observed between cognitive performance and hippocampal [¹⁸F]-FEOBV uptake.ConclusionThese findings suggest a compensatory upregulation of the hippocampal cholinergic innervation in PD-CN, which might underly normal cognitive performances in spite of cortical cholinergic denervation in other regions.     

Cognitive impairment in progressive supranuclear palsy-Richardson’s syndrome is related to white matter damage

IntroductionBeside motor symptoms, patients with progressive supranuclear palsy syndrome (PSPs) commonly present cognitive and behavioral disorders. In this study we aimed to assess the structural brain correlates of cognitive impairment in PSPs.MethodsWe enrolled 23 patients with probable PSP Richardson's syndrome and 15 matched healthy controls. Patients underwent an extensive clinical and neuropsychological evaluation. Cortical thickness measures and diffusion tensor metrics of white matter tracts were obtained. Random forest analysis was used to identify the strongest MRI predictors of cognitive impairment in PSPs at an individual patient level.ResultsPSPs patients were in a moderate stage of the disease showing mild cognitive deficits with prominent executive dysfunction. Relative to controls, PSPs patients had a focal, bilateral cortical thinning mainly located in the prefrontal/precentral cortex and temporal pole. PSPs patients also showed a distributed white matter damage involving the main tracts including the superior cerebellar peduncle, corpus callosum, corticospinal tract, and extramotor tracts, such as the inferior fronto-occipital, superior longitudinal and uncinate fasciculi, and cingulum, bilaterally. Regional cortical thinning measures did not relate with cognitive features, while white matter damage showed a significant impact on cognitive impairment (r values ranging from −0.80 to 0.74).ConclusionsPSPs patients show both focal cortical thinning in dorsolateral anterior regions and a distributed white matter damage involving the main motor and extramotor tracts. White matter measures are highly associated with cognitive deficits. Diffusion tensor MRI metrics are likely to be the most sensitive markers of extramotor deficits in PSPs.     

Effects of NREM sleep instability on cognitive processing

ObjectiveCyclic alternating pattern (CAP) A1 subtypes, characterized by high-voltage slow waves, are generated by the frontal cortex and are suspected to have a role in cognitive processing during NREM sleep. Conversely, CAP A2 and A3 subtypes are characterized by variable amounts of rapid EEG potentials arising from the parietal–occipital areas and often coincide with arousals. We tested the hypothesis that CAP subtypes differentially correlate with cognitive functions.Subjects and methodsEight healthy participants were recruited. Two nocturnal polysomnography studies and a series of neuropsychological tests were obtained in the subjects during the morning and afternoon of the first day and on the morning of the second day.ResultsIn agreement with our original hypothesis, we found that CAP A1 subtypes were correlated with better neuropsychological functioning the day after, for verbal fluency, working memory, and both delayed recall and recognition of words. These same neuropsychological test results were found to be negatively correlated with CAP A2 subtypes. CAP A3 subtypes were negatively correlated with the Trial Making test Parts A and B.ConclusionsThe results suggest that CAP A1 might be related to better cognitive functioning, whereas CAP A2 and A3 correlated with worse cognitive functioning. Further studies are needed to better understand how CAP influences cognitive performance, especially frontally-dependent functions and memory.