[Dream content in different sleep disorders: sleep apnoea and hypopnoea syndrome, primary insomnia, idiopathic REM sleep behaviour disorder and narcolepsy type 1]

AIM

The aim of this study is to determine whether there are any differences in the dream content in different sleep disorders and to describe their characteristics.

PATIENTS AND METHODS

We studied four sleep disorders: sleep apnoea and hypopnoea syndrome (SAHS), primary insomnia (PI), idiopathic REM sleep behaviour disorder (IRBD) and narcolepsy type I. Each patient was asked to keep a dream diary for two weeks. The content of the diaries was transcribed and analysed for length, mental content, complexity and threat. The results were compared to establish differences.

RESULTS

Eighty-nine patients were studied: 23 with SAHS without continuous positive airway pressure (CPAP) who had the highest number of dreams involving threats (32.5%); 19 with SAHS treated with CPAP who had the highest number of dreams involving objects (64.8%), descriptive elements (38%) and higher complexity (9.5%); 22 with primary insomnia who had the highest number of dreams with threatening events in the social sphere (57.7%); 12 with IRBD who had the highest number of dreams with failures (14%) and lower complexity (71.7%); and 13 with narcolepsy type I who had the highest number of dreams related to activities (84.3%) and threats to life (41.4%) These differences were statistically significant (p <0.05).

CONCLUSIONS

Different sleep disorders are associated with different dream contents, which would be translating different underlying neurological processes. These findings should be replicated in studies that analyse more patients and add a control group without sleep disorders.

[Sleep-related movement and behavioural disorders in adults]

Sleep-related movement and behaviour disorders may have an impact on sleep quality and lead to daytime symptoms. These groups of conditions include diseases such as restless legs syndrome, periodic leg movements, and REM and NREM parasomnias. The knowledge of their clinical features and management is of utmost importance for the neurologist and sleep specialist. Frequently, these patients are referred to such specialists and it is relevant to know that certain sleep disorders may be associated with other neurological conditions.

Cortical gray matter progression in idiopathic REM sleep behavior disorder and its relation to cognitive decline

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Cortical degeneration over time in IRBD patients is larger than in normal aging.

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IRBD patients have progressive parieto-occipital and orbitofrontal thinning.

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Visuospatial decline in IRBD is associated with degeneration in parietal regions.

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Increasing motor signs in IRBD are related to frontal and parietal degeneration.

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Cortical thinning in posterior regions is associated with late-onset IRBD.

Background

Idiopathic Rapid eye movement sleep behavior disorder (IRBD) is recognized as the prodromal stage of the alpha-Synucleinopathies. Although some studies have addressed the characterization of brain structure in IRBD, little is known about its progression.

Objective

The present work aims at further characterizing gray matter progression throughout IRBD relative to normal aging and investigating how these changes are associated with cognitive decline.

Methods

Fourteen patients with polysomnography-confirmed IRBD and 18 age-matched healthy controls (HC) underwent neuropsychological, olfactory, motor, and T1-weighted MRI evaluation at baseline and follow-up. We compared the evolution of cortical thickness (CTh), subcortical volumes, smell, motor and cognitive performance in IRBD and HC after a mean of 1.6 years. FreeSurfer was used for CTh and volumetry preprocessing and analyses. The symmetrized percent of change (SPC) of the CTh was correlated with the SPC of motor and neuropsychological performance.

Results

IRBD and HC differed significantly in the cortical thinning progression in regions encompassing bilateral superior parietal and precuneus, the right cuneus, the left occipital pole and lateral orbitofrontal gyri (FWE corrected, p < 0.05). The Visual form discrimination test showed worse progression in the IRBD relative to HC, that was associated with gray matter loss in the right superior parietal and the left precuneus. Increasing motor signs in IRBD were related to cortical thinning mainly involving frontal regions, and late-onset IRBD was associated with cortical thinning involving posterior areas (FWE corrected, p < 0.05). Despite finding olfactory identification deficits in IRBD, results did not show decline over the disease course.

Conclusion

Progression in IRBD patients is characterized by parieto-occipital and orbitofrontal thinning and visuospatial loss. The cognitive decline in IRBD is associated with degeneration in parietal regions.

Disruption of posterior brain functional connectivity and its relation to cognitive impairment in idiopathic REM sleep behavior disorder

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There is a reduced brain posterior functional connectivity in IRBD patients.

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Reduced temporo-parietal connectivity correlates with mental processing slowness.

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Left superior parietal lobule has reduced centrality in IRBD patients.

Background

Resting-state functional MRI has been proposed as a new biomarker of prodromal neurodegenerative disorders, but it has been poorly investigated in the idiopathic form of rapid-eye-movement sleep behavior disorder (IRBD), a clinical harbinger of subsequent synucleinopathy. Particularly, a complex-network approach has not been tested to study brain functional connectivity in IRBD patients.

Objectives

The aim of the current work is to characterize resting-state functional connectivity in IRBD patients using a complex-network approach and to determine its possible relation to cognitive impairment.

Method

Twenty patients with IRBD and 27 matched healthy controls (HC) underwent resting-state functional MRI with a 3T scanner and a comprehensive neuropsychological battery. The functional connectome was studied using threshold-free network-based statistics. Global and local network parameters were calculated based on graph theory and compared between groups. Head motion, age and sex were introduced as covariates in all analyses.

Results

IRBD patients showed reduced cortico-cortical functional connectivity strength in comparison with HC in edges located in posterior regions (p <0.05, FWE corrected). This regional pattern was also shown in an independent analysis comprising posterior areas where a decreased connectivity in 51 edges was found, whereas no significant results were detected when an anterior network was considered (p <0.05, FWE corrected). In the posterior network, the left superior parietal lobule had reduced centrality in IRBD. Functional connectivity strength between left inferior temporal lobe and right superior parietal lobule positively correlated with mental processing speed in IRBD (r = .633; p = .003). No significant correlations were found in the HC group.

Conclusion

: Our findings support the presence of disrupted posterior functional brain connectivity of IRBD patients similar to that found in synucleinopathies. Moreover, connectivity reductions in IRBD were associated with lower performance in mental processing speed domain.

Comparing the accuracy and neuroanatomical correlates of the UPSIT-40 and the Sniffin' Sticks test in REM sleep behavior disorder

BACKGROUND

Olfactory impairment increases the risk of developing neurodegenerative diseases in patients with idiopathic REM sleep behavior disorder (IRBD). Knowing the test properties of distinct olfactory measures could contribute to their selection for clinical or research purposes.

OBJECTIVE

To compare the accuracy in distinguishing IRBD patients from controls with the University of Pennsylvania Smell Identification Test (UPSIT-40) and Sniffin' Sticks Extended test, and to assess the gray-matter volume correlates of these tests.

METHOD

Twenty-one patients with IRBD and 27 healthy controls were assessed using both olfactory tests. Independent logistic regressions were computed with diagnosis as a dependent variable and olfactory measures as predictive variables. Receiver operating characteristic curves were computed for each olfactory subtest. Diagnostic accuracy for IRBD was calculated according to the resulting optimal cut-off score. Structural MRI data, acquired with a 3T scanner, were analyzed with voxel-based morphometry.

RESULTS

Patients differed from controls in all olfactory measures. The Sniffin-Identification correctly classified 89.1% of cases; the UPSIT-40, 85.4%; the Sniffin-Discrimination, 82.6%; the Sniffin-Total, 81.8%; and the Sniffin-Threshold, 77.3%. Respective AUROC, optimal cut-off, sensitivity, and specificity for each test were: 0.902, ≤26, 85.7%, and 85.2% for the UPSIT-40; 0.884, ≤29, 89.5%, and 76.0% for the Sniffin-Total; 0.922, ≤11, 90.5%, and 88.0% for the Sniffin-Identification; 0.739, ≤4, 73.7%, and 76.0% for the Sniffin-Threshold; and 0.838, ≤11, 85.7%, and 76.0% for the Sniffin-Discrimination. UPSIT-40 scores correlated with gray-matter volumes in orbitofrontal regions in anosmic patients.

CONCLUSIONS

UPSIT-40 and Sniffin' Identification showed similar discrimination accuracy, but only the UPSIT-40 showed structural correlates (p ≤ .05 FDR-corrected).

[«Apuntes en Neurologia» (Notes in Neurology): a synthesis of the evidence on common paroxysmal neurological disorders and on neurodegenerative disorders]

«Apuntes en Neurologia» is an initiative in which prominent national and international leaders, with broad academic recognition, came together to synthesise the most outstanding clinical aspects within their area of interest and to discuss the latest developments in a more accessible language. Understanding the factors that affect the onset and progression of any neurological disease through a review is important to be able to develop strategies to reduce the burden of these diseases. Moreover, knowledge of the clinical aspects is essential to solve the problems of daily clinical practice. The data collected here reflect the weight of evidence and some of them anticipate a promising future in the treatment of these diseases. This first edition focuses on common paroxysmal neurological disorders such as migraine, epilepsy and sleep disorders, as well as neurodegenerative disorders such as Parkinson's disease and cognitive impairment. These are clearly different pathologies, although some of them such as migraine and epilepsy, may share clinical symptoms. Sleep disorders, however, are important manifestations of neurodegenerative diseases that are sometimes clinically apparent long before the onset of other neurological symptoms. After recalling pathophysiology and diagnosis, the current review focuses on bringing together the main advances in five of the major neurological diseases.

EEG extreme delta brush: An ictal pattern in patients with anti-NMDA receptor encephalitis

INTRODUCTION

The anti-NMDA receptor (NMDAr) encephalitis-associated syndrome includes neuropsychiatric symptoms, impaired consciousness, seizures, autonomic instability, and hypoventilation. The electroencephalographic (EEG) activity throughout the course of the disease has still not been well documented. We reviewed electroclinical data of patients with NMDAr encephalitis to characterize their EEG and its clinical correlation.

MATERIAL AND METHODS

We retrospectively identified 16 patients with NMDAr encephalitis from 8 Spanish medical centers, 15 of whom underwent video-EEG in the acute phase.

RESULTS

In 15 patients (11 females, median age: 37.4, range: 14-87 years), seizures occurred in 9 (60%) and status epilepticus (SE) in 5 (33.3%). Magnetic resonance imaging (MRI) was abnormal in 10 (66.6%), and CSF (cerebrospinal fluid) was normal in 3 and abnormal in 12, with positive PCR (polymerase chain reaction) for Mycoplasma pneumoniae (1/15) and herpes simple virus (1/15). An ovarian teratoma was found in 1 patient and other malignancies (small cell lung carcinoma) in 1 patient. The EEG was abnormal in the acute phase in 14/15 (93.3%). Extreme delta brush (EDB) was observed in 5 (33.3%), and the presence of EDB was associated with SE in all cases. Rhythmic delta activity without EDB was observed in 5 (33.3%), while excessive beta activity was present in 4 (26.6%). Extreme delta brush can follow a pattern of well-characterized electroclinical seizures.

CONCLUSIONS

Almost invariably, patients with NMDAr encephalitis had abnormal EEG. The presence of EDB, which can follow a pattern of well-characterized electroclinical seizures, in our patients was associated with seizures and SE. These findings suggest that EDB could be an evolutive pattern of an SE in NMDAr encephalitis. This article is part of a Special Issue entitled "Status Epilepticus".

123I-MIBG cardiac uptake, smell identification and 123I-FP-CIT SPECT in the differential diagnosis between vascular parkinsonism and Parkinson's disease

Vascular parkinsonism (VP) may occur as a distinct clinicopathological entity but the comorbid presence of vascular damage in Parkinson's disease (PD) is very frequent too. This differential diagnosis has therapeutic and prognostic implications but remains challenging as the usefulness of a number of supporting tools is still controversial.

OBJECTIVE

To ascertain the clinical value of cardiac (123)I-meta-iodobenzylguanidine ((123)I-MIBG) SPECT, olfactory function and (123)I-FP-CIT SPECT as supporting tools in the differential diagnosis between VP and PD.

METHODS

Cross-sectional study of 15 consecutive patients with suspected VP, 15 PD patients and 9 healthy subjects. Cardiac (123)I-MIBG SPECT (heart-to-mediastinum ratio) and olfactory testing (University of Pennsylvania Smell Identification Test-UPSIT) were performed in all of them. (123)I-FP-CIT SPECT was performed in VP-suspected patients.

RESULTS

Heart-to-mediatinum ratio was significant lower in suspected VP (mean 1.45) and PD (mean 1.16) compared to control group (mean 1.69) (p = 0.017 and p < 0.0001). VP patients presented a higher ratio than PD patients (p = 0.001). Control group presented a significant higher UPSIT score (mean 30.71) when compared to both VP (mean 18.33) and PD (mean 15.29) (p = 0.001 for both groups). Those VP with a cardiac (123)I-MIBG non suggestive of PD were more likely to have a higher UPSIT score (p = 0.006). (123)I-FP-CIT SPECT imaging was heterogeneous (7/15 VP normal, 3/15 abnormal suggestive of PD and 5/15 abnormal but atypical for PD).

CONCLUSIONS

The use of cardiac (123)I-MIBG SPECT and to a lesser extent UPSIT could assist the differential diagnosis between VP and PD in subjects in which the diagnosis remains uncertain despite (123)I-FP-CIT SPECT imaging.

Sexsomnia: parasomnia associated with sexual behaviour during sleep

INTRODUCTION

The purpose of our study is to describe 4 cases of sexsomnia, a form of parasomnia characterised by sexual behaviour during sleep.

METHODS

Clinical history and video-polysomnography recordings from patients diagnosed with sexsomnia in the Multidisciplinary Sleep Unit at Hospital Clínic in Barcelona.

RESULTS

Three men and one woman between 28 and 43 years of age reported sexual behaviours during sleep with progression times ranging from 9 months to 7 years. Episodes consisted of masturbation without seeking the participation of a sleeping partner (2 cases) and attempts at sexual intercourse with inappropriate and uncharacteristic vocalizations and behaviours (3 cases). The frequency of the episodes ranged from 4 isolated episodes to 2-3 per week. Patients were amnestic of these events and surprised by their partners' accounts of their behaviour. Medical histories revealed that 1 patient was a somnambulist, 2 had confusional arousals, and 1 experienced somniloquy. Video-polysomnography did not disclose sexual behaviours during sleep but revealed sleep apnoea in 2 cases and periodic leg movements in sleep in another. The only patient treated with clonazepam reported decreased frequency of both confusional arousals and sexsomnia episodes.

CONCLUSIONS

Sexsomnia occurs in young adults and is characterised by masturbation and inappropriate attempts at achieving sexual intercourse followed by total amnesia of the events. It can be associated with other parasomnias such as sleepwalking and confusional arousals. Other sleep disorders, including sleep apnoea and periodic leg movement disorder, may trigger episodes of sexsomnia.

Socio-demographic and clinical factors influencing the adherence to treatment in Parkinson's disease: the ADHESON study

BACKGROUND

Symptoms of Parkinson's disease (PD) are usually controlled by a continuous titration of medication and addition of multiple therapies over the course of the disease. Therapeutic complex schemes, polymedication, comorbidities and the number of medications required contribute to non-adherence.

METHODS

This cross-sectional survey was performed in 418 patients with PD on treatment with any antiparkinsonian medication. Patient adherence was assessed through physicians' subjective perception and the Morisky-Green test (MGT). Several social, demographic and clinical features were correlated through bivariate and multivariate analyses.

RESULTS

According to the physician's opinion 93.7%, and according to the MGT 60.4% of patients were adherent to parkinsonian therapy. The bivariate analysis showed greater adherence in patients with a high level of knowledge about the disease (62.8%), good clinical control (63.6%), a spouse or life partner (63%) and higher incomes (66%). Negative correlation with psychiatric symptoms was found. In relation to the MGT, the logistic regression model showed a negative correlation between cognitive deterioration and psychiatric pathology and adherence to therapy.

CONCLUSIONS

The physician's impression overestimated the compliance of patients when compared with an objective evaluation such as the MGT. Cognitive impairment and psychiatric symptoms are the clinical variables associated with a lower level of adherence.

Pathological description of a non-motor variant of multiple system atrophy

Multiple system atrophy (MSA) is a neurodegenerative disorder that usually presents clinically as a combination of parkinsonism, cerebellar syndrome and autonomic failure. Patients with MSA can present other clinical features, such as inspiratory stridor and rapid eye movement (REM) sleep behaviour disorder (RBD). We report a patient with pathologically confirmed MSA who presented with a longstanding history of stridor, RBD and autonomic disturbances but did not develop overt parkinsonism or cerebellar signs. This case illustrates that MSA may present clinically without its cardinal motor symptoms, and that stridor and RBD may be clues to recognise the disease in a patient with autonomic failure.

Lrrk2 R1441C parkinsonism is clinically similar to sporadic Parkinson disease

OBJECTIVE

Leucine-rich repeat kinase 2 (LRRK2) mutations are the most common cause of Parkinson disease (PD). Several dominantly inherited pathogenic substitutions have been identified in different domains of the Lrrk2 protein. Herein, we characterize the clinical and genetic features associated with Lrrk2 p.R1441C.

METHODS

We identified 33 affected and 15 unaffected LRRK2 c.4321C>T (p.R1441C) mutation carriers through an international consortium originating from three continents. The age-specific cumulative incidence of PD was calculated by Kaplan-Meier analysis.

RESULTS

The clinical presentation of Lrrk2 p.R1441C carriers was similar to sporadic PD and Lrrk2 p.G2019S parkinsonism. The mean age at onset for parkinsonism was 60 years, range 30-79 years; fewer than 20% of the patients had symptoms before the age 50 years, while by 75 years >90% of them had developed symptoms. Haplotype analysis suggests four independent founders for the p.R1441C mutation.

CONCLUSIONS

The distribution in age at onset and clinical features in Lrrk2 p.R1441C patients are similar to idiopathic and Lrrk2 p.G2019S parkinsonism. Several independent founders of the p.R1441C substitution suggest this site is prone to recurrent mutagenesis.

The premotor phase of Parkinson's disease

There is growing evidence that a variety of symptoms can precede the classical motor features of Parkinson's disease (PD). The period when these symptoms arise can be referred to as the premotor phase of the disease. Well-documented premotor symptoms in PD include constipation, loss of smell, sleep disturbances such as REM sleep behavior disorder (RBD), and mood disturbances like depression. Diagnostic and therapeutic implications linked to improved identification of these premotor features are discussed.

Increased cerebral activity in Parkinson?s disease patients carrying the DRD2 TaqIA A1 allele during a demanding motor task: a compensatory mechanism?

Previous studies suggest that neuroimaging techniques are useful for detecting the effects of functional genetic polymorphisms on brain function in healthy subjects or in patients presenting with psychiatric or neurodegenerative conditions. Former evidence showed that individuals carrying risk alleles displayed broader patterns of brain activity during behavioural and cognitive tasks, despite being clinically comparable to non-carriers. This suggests the presence of compensatory brain mechanisms. In the present study, we investigated this effect in Parkinson's disease (PD) patients carrying the DRD2 TaqIA A1 allelic variant. This variant may confer an increased risk of developing the disease and/or influence the clinical presentation. During a complex sequential motor task, we evidenced by functional magnetic resonance imaging that A1 allele carriers activated a larger network of bilateral cerebral areas than non-carriers, including cerebellar and premotor regions. Both groups had similar clinical and demographic measures. In addition, their motor performance during the functional magnetic resonance experiment was comparable. Therefore, our conclusions, pending replication in a larger sample, seem to reflect the recruitment of compensatory cerebral resources during motor processing in PD patients carrying the A1 allele.

Brain tau expression and correlation with the H1/H1 tau genotype in frontotemporal lobar degeneration patients

Alterations in tau mRNA splicing and association with H1/H1 tau genotype have been described in some sporadic tauopathies. We evaluated the 4R/3R tau mRNA ratio in 18 patients with frontotemporal lobar degeneration (FTLD), and the effect of the H1/H1 genotype on this ratio. The 4R/3R mRNA ratio in frontal cortex was similar in FTLD patients and controls. The H1/H1 genotype carriers showed a significant increase in 4R/3R mRNA ratio, suggesting that this genotype could modulate the tau mRNA splicing.