Accuracy of clinical diagnosis of dementia with Lewy bodies: a systematic review and meta-analysis.

BACKGROUND: The diagnosis of dementia with Lewy bodies (DLB) is based on diagnostic clinical criteria, which were updated over the years. OBJECTIVE: To evaluate, through a systematic review, accuracy of the diagnostic criteria, testing a possible improvement over time. METHODS: We searched on MEDLINE and SCOPUS databases for studies reporting diagnostic parameters regarding the clinical diagnosis of DLB until October 2016. We performed meta-analysis, using a Bayesian approach, on those using pathological examination as gold standard, subclassified based on the different diagnostic criteria used. RESULTS: We selected 22 studies on 1585 patients. Pooled sensitivity, specificity and accuracy were 60.2%, 93.8%, 79.7%, respectively, for criteria antecedents to McKeith 1996. For McKeith 1996-possible, pooled sensitivity, specificity and accuracy were 65.6%, 80.6%, 77.9% in early stages and 72.3%, 64.3%, 66% in late stages, respectively. For McKeith 1996-probable, pooled sensitivity, specificity and accuracy were 19.4%, 95.1%, 77.7% in early stages and 48.6%, 88%, 79.2% in late stages, respectively. McKeith criteria 2005 were evaluated only in late stages: pooled sensitivity, specificity and accuracy were 91.3%, 66.7% and 81.6%, respectively, for possible diagnosis (only one study) and 88.3%, 80.8%, 90.7% for probable diagnosis, decreasing to 85.6%, 77.1% and 81.7% if only considering clinical settings focused on dementia diagnosis and care. CONCLUSIONS AND RELEVANCE: Diagnostic criteria have become more sensitive and less specific over time, without substantial change in the accuracy. Based on current data, about 20% of DLB diagnosis are incorrect. Future studies are needed to evaluate if the recently released revised consensus criteria will improve the diagnostic accuracy of DLB.

Cognitive and sleep features of multiple system atrophy: review and prospective study.

BACKGROUND: The profile and degree of cognitive impairment in Multiple System Atrophy (MSA) and the impact of sleep disorders, REM sleep behavior disorder (RBD) in particular, in parkinsonism-related cognitive deficits are currently being debated. SUMMARY: We reviewed the cognitive, affective and sleep findings in MSA and also carried out a longitudinal investigation of 10 MSA patients. At the first evaluation, 3 patients showed isolated cognitive deficits. After a mean of 16 months, these patients remained unchanged, while 1 patient worsened from a normal condition. No significant differences emerged when the cognitive, affective and video-polysomnographic findings of MSA-P and MSA-C were compared. Depression was present in half of the patients, although it did not influence their cognitive performance. Comparisons between the first and second evaluation data showed significant worsening in visual attention and in ADL/IADL and UMSARS. KEY MESSAGES: Isolated cognitive deficits are evidenced in a minority of MSA patients with the absence of a clear-cut diagnosis of dementia in the early stages of the disease. Attention and executive functions are often impaired. This study with a short follow-up period showed that RBD, although present in almost all patients affected by MSA, does not appear a clear early marker of cognitive impairment. Future longer-term studies with a larger patient sample are thus encouraged.

Periodic Limb Movements during Sleep: A New Sleep-Related Cardiovascular Risk Factor?

In recent years, a growing body of evidence suggests that periodic limb movements during sleep (PLMS) are associated with hypertension, cardiovascular, and cerebrovascular risk. However, several non-mutually exclusive mechanisms may determine a higher cardiovascular risk in patients with PLMS and the link between the two remains controversial. Prospective data are scant and the temporal relationship between PLMS and acute vascular events is difficult to ascertain because although PLMS may lead to acute vascular events such as stroke, stroke may also give rise to PLMS. This article describes the clinical and polygraphic features of PLMS and examines the literature evidence linking PLMS with an increased risk for the development and progression of cardiovascular diseases, discussing the possible pathways of this association.

Normal body scheme and absent phantom limb experience in amputees while dreaming.

While dreaming amputees often experience a normal body image and the phantom limb may not be present. However, dreaming experiences in amputees have mainly been collected by questionnaires. We analysed the dream reports of amputated patients with phantom limb collected after awakening from REM sleep during overnight videopolysomnography (VPSG). Six amputated patients underwent overnight VPSG study. Patients were awakened during REM sleep and asked to report their dreams. Three patients were able to deliver an account of a dream. In all dreaming recalls, patients reported that the amputated limbs were intact and completely functional and they no longer experienced phantom limb sensations. Phantom limb experiences, that during wake result from a conflict between a pre-existing body scheme and the sensory information on the missing limb, were suppressed during sleep in our patients in favour of the image of an intact body accessed during dream.

Peduncular hallucinosis: a polysomnographic and spect study of a patient and efficacy of serotonergic therapy.

Peduncular hallucinosis (PH) consists of formed and coloured visual images, which the patient knows are unreal; it is often associated with lesions of the pons, midbrain and diencephalon. A 72-year-old man had noted the sudden onset of visual hallucinations one year before, specifying the time and body position in a 4-week, 24-h diary. Thereafter, he underwent video-polysomnography (VPSG), brain magnetic resonance imaging (MRI), angiography (MRA), proton spectroscopy ((1)H MRS), and single photon emission tomography (SPECT). Patient's diaries and VPSG showed a strong clustering of hallucinatory experiences during the evening/night time while lying in supine position, similar to hypnagogic hallucination and sleep paralysis in supine position. Repeated episodes of REM sleep behaviour disorder (RBD) occurred during the night. MRI and MRA showed an elongated and dilated left internal carotid artery displacing the left subthalamus upwards, and (1)H MRS relatively decreased N-acetyl-aspartate in the left subthalamus. Brain SPECT during PH revealed hypoperfusion in the right temporal region and hyperperfusion in the left occipital and right opercular regions (the latter possibly related to the patient's awareness of unreality). PH resolved with serotonergic (citalopram) therapy.

Status dissociatus evolving from REM sleep behaviour disorder in multiple system atrophy.

OBJECTIVE: We present two patients, a 52-year-old man and a 56-year-old woman, with rapid eye movement sleep behaviour disorder (RBD) since the age of 50. METHOD: In both the patients RBD was videopolysomnographically documented. RESULTS: Both patients developed, with time, autonomic and motor symptoms consistent with the diagnosis of multiple system atrophy. During the course of the disease RBD episodes diminished in frequency but the patients' sleep became even more abnormal, with nearly continuous motor and verbal abnormal behaviours and ambiguous and rapid oscillations of state-determining polysomnographic variables, now consistent with status dissociatus (SD). CONCLUSION: If SD represents the evolution and most extreme form of RBD it should be investigated longitudinally in neurodegenerative diseases.

Axial myoclonus in paraproteinemic polyneuropathy.

We describe a patient with a paraproteinemic anti-myelin-associated glycoprotein (anti-MAG) antibody polyneuropathy and concomitant axial myoclonic jerks. Neurophysiological investigation revealed that axial jerks were asymmetrical and exaggerated by lying in bed. They disappeared during mental arousal and sleep. Analysis of axial myoclonus showed that the first activated muscle was the left rectus abdominis with subsequent rostral and caudal propagation of a propriospinal type. Plasmapheresis substantially reduced the frequency and intensity of axial myoclonic jerks. In our patient, propriospinal myoclonus was associated with anti-MAG polyneuropathy, but the causal relationship remains unclear.