Sleep and brain lesions: a critical review of the literature and additional new cases

Symptomatic, Drug-Resistant Narcolepsy Remission After Fenestration of an Arachnoid Cyst - A Case Report

Objective

The pathogenesis of different narcolepsy phenotypes remains unclear. In rare cases, narcolepsy can be attributable to secondary brain pathologies affecting the midbrain. These cases may elucidate the pathological background and the treatment of narcolepsy, but are often limited by poor objective symptom characterization and effects of therapeutic intervention, especially by modern diagnostic standards.

Methods

A young adult presented with excessive daytime sleepiness (EDS) that was refractory to classic narcolepsy medication. Diagnosis of narcolepsy was made based on the pathologically shortened sleep latencies in polysomnography and Multiple Sleep Latency Test (MSLT), together with confirmed sleep-onset REM-sleep (SOREM). Preserved hypocretin levels in cerebrospinal fluid, together with the absence of cataplectic events confirmed the diagnosis of narcolepsy type II. MRI revealed a large arachnoid cyst with compression of the midbrain.

Results

Six months after fenestration of the cyst, the patient's EDS had vastly improved. No further SOREM was observed, and polysomnographic and MSLT sleep latencies normalized. No further drug treatment was required.

Conclusion

Symptomatic narcolepsy due to space-occupying lesions in the mesencephalon comprises a unique curative treatment option. Here, surgical intervention offers an effective curative therapeutic approach. However, differential diagnosis of symptomatic narcolepsy requires special consideration.

Comparative effectiveness of different treatments for post-stroke insomnia: A network meta-analysis

Background

：Post-stroke insomnia（PSI）is one of the common complications after stroke and it is a chronic problem and hampers the patient's recovery. Some treatments have been shown to be effective in treating post-stroke insomnia. However, it is not clear which treatment is more effective.

Methods

In this study, we searched CNKI, PubMed, and Cochrane Library for appropriate keywords with a deadline of October 2022 to select 23 randomized controlled trials（RCTs）. The mean difference between different treatments was assessed and summarized as mean and 95 % confidence interval (CI), resulting in a Bayesian network meta-analysis.

Results

By meta-analysis of Bayesian networks, we found acupuncture(MD, -2.49; 95 % CI, [-3.63, -1.31]) and herbal (MD, -2.79; 95 % CI, [-4.9, -0.69]) were significantly better than estazolam in terms of PSQI score change, and the difference was statistically significant. Dexzopiclone, electrics stimulation, rTMS and zopiclone were not statistically significant with other treatments.

Conclusion

Herbal, zopiclone, and acupuncture were more effective in improving PSQI scores in patients with post-stroke insomnia, followed by rTMS and dexzopiclone. However, the effectiveness between herbal, zopiclone and acupuncture was not statistically significant. Acupuncture and herbal are promising for the treatment of PSI, and more research remains to be invested.

Acupuncture Reduced the Risk for Insomnia in Stroke Patients: A Propensity-Score Matched Cohort Study

Background: Post-stroke insomnia (PSI) affects the quality of life for stroke patients, reduces the likelihood of successful rehabilitation, and produces additional complications following stroke. Previous reports have provided some information regarding PSI risk factors, but little is known concerning protective factors for PSI. This study analyzed the relationship between acupuncture and insomnia in stroke patients and explored the use of acupuncture as a preventive treatment.

Methods: Patients diagnosed with stroke from 2010 to 2019 were identified in the case database of the First Affiliated Hospital of Guangzhou University of Chinese These patients followed until 2020, and numerous factors were examined, including gender, age, stroke type, stroke location, and baseline comorbidities. A 1:1 propensity score was used to match an equal number of patients receiving acupuncture with stroke patients who did not receive acupuncture (N = 1,680 for each group). The purpose of the study was to compare the incidence of insomnia in these two stroke cohorts. We used the Cox regression model and Kaplan-Meier method to estimate the risk of insomnia as the outcome event.

Results: Compared with the non-acupuncture cohort in general, stroke patients who received acupuncture treatment exhibited a lower risk of insomnia after adjusting for age, gender, stroke type, stroke location, and comorbidities (adjusted hazard ratio HR = 0.27, 95% confidential interval = 0.23 to 0.32). Acupuncture also reduced the risk of PSI for both genders. The respective risks were HR = 0.28 (adjusted) for males and HR = 0.26 (adjusted) for females. Acupuncture also lowered the risk for PSI for different age groups. The risks were HR = 0.22 (adjusted) for individuals 18 to 39 years of age, HR = 0.31 (adjusted) for individuals 40 to 59 years of age, HR = 0.28 (adjusted) for those 60 to 79 years of age, and HR = 0.18 (adjusted) for individuals 80 years of age and older. Concerning the stroke type, regardless of whether the stroke was ischemic, hemorrhagic, or a combination of the two stroke types, patients who received acupuncture exhibited lower risk (adjusted HR = 0.28, 0.17, and 0.49, respectively). Concerning stroke location, except for the cerebral hemispheres (adjusted HR = 1.10, 95% confidential interval = 0.12 to 1.01), the risk of PSI after receiving acupuncture was lower for the frontal lobe (adjusted HR = 0.42), the basal ganglia (adjusted HR = 0.22), the radiation crown (adjusted HR = 0.42), the diencephalon (adjusted HR = 0.20), or multiple partial strokes (adjusted HR = 0.26), the risk of PSI after receiving acupuncture was lower. For all baseline complications, acupuncture reduced the risk of insomnia. The cumulative incidence of insomnia in the acupuncture cohort was significantly lower than the non-acupuncture cohort (log-rank test, P = 0.000).

Limitations: First, our research only included patients from a single center. Second, we did not classify the post-stroke insomnia severity. Second, the information was extracted manually. Overall, the sample size was small, and we needed to increase the sample size to strengthen the conclusions.

Conclusion: Acupuncture treatment reduced the risk of insomnia in stroke patients. Future research be conducted with increased sample sizes and further elaboration on the specific acupuncture protocols that were used.

Amantadine and Modafinil as Neurostimulants During Post-stroke Care: A Systematic Review

Amantadine and modafinil are neurostimulants that may improve cognitive and functional recovery post-stroke, but the existing study results vary, and no comprehensive review has been published. This systematic review describes amantadine and modafinil administration practices post-stroke, evaluates timing and impact on clinical effectiveness measures, and identifies the incidence of potential adverse drug effects. A librarian-assisted search of the MEDLINE (PubMed) and EMBASE databases identified all English-language publications with "amantadine" or "modafinil" in the title or abstract from inception through February 1, 2020. Publications meeting predefined Patient, Intervention, Comparator, Outcome (PICO) criteria were included: Patients (≥ 18 years of age post-stroke); Intervention (amantadine or modafinil administration); Comparison (pretreatment baseline or control group); Outcomes (cognitive or functional outcome). Amantadine and modafinil administration practices, cognitive and functional outcomes, and incidence of potential adverse drug effects were collected following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidance. Quantitative analyses were not performed due to heterogeneity in the clinical effectiveness measures; descriptive data are presented as number (percent) or median (interquartile range). Of 12,620 publications initially identified, 10 amantadine publications (n = 121 patients) and 12 modafinil publications (n = 120 patients) were included. Amantadine was initiated 39 (16, 385) days post-stroke, with most common initial doses of 100 mg once or twice daily (range 100-200 mg/day), and final daily dose of 200 (188, 200) mg/day. Modafinil was initiated 170 (17, 496) days post-stroke, with initial and final daily doses of 100 (100, 350) mg/day and 200 (100, 350) mg/day, respectively. The most common indication was consciousness disorders for amantadine (n = 3/10 publications; 30%) and fatigue for modafinil (n = 5/12; 42%). Forty unique clinical effectiveness measures (1.8 per study) with 141 domains (6.4 per study) were described across all studies. A positive response in at least one clinical effectiveness measure was reported in 70% of amantadine publications and 83% of modafinil publications. Only one publication each for amantadine (10%; n = 5 patients) and modafinil (8%; n = 21 patients) studied acutely hospitalized or ICU patients; both were randomized studies showing improvements in neurocognitive function for amantadine and fatigue for modafinil. Potential adverse drug effects were reported in approximately 50% of publications, most commonly visual hallucinations with amantadine (2% of patients) and dizziness (5% of patients) and dry eyes or mouth (5% of patients). Amantadine and modafinil may improve cognitive and functional recovery post-stroke, but higher-quality data are needed to confirm this conclusion, especially in the acute care setting.

The Defensive Activation Theory: REM Sleep as a Mechanism to Prevent Takeover of the Visual Cortex

Regions of the brain maintain their territory with continuous activity: if activity slows or stops (e.g., because of blindness), the territory tends to be taken over by its neighbors. A surprise in recent years has been the speed of takeover, which is measurable within an hour. These findings lead us to a new hypothesis on the origin of REM sleep. We hypothesize that the circuitry underlying REM sleep serves to amplify the visual system's activity periodically throughout the night, allowing it to defend its territory against takeover from other senses. We find that measures of plasticity across 25 species of primates correlate positively with the proportion of rapid eye movement (REM) sleep. We further find that plasticity and REM sleep increase in lockstep with evolutionary recency to humans. Finally, our hypothesis is consistent with the decrease in REM sleep and parallel decrease in neuroplasticity with aging.

Excessive daytime sleepiness in cancer patients

PURPOSE

Excessive daytime sleepiness (EDS) is commonly reported in patients with cancer, and it is also a cardinal feature of central disorders of hypersomnolence. Multiple sleep latency testing (MSLT) is used for objective assessment.

METHODS

A retrospective review of patients with cancer history who underwent formal sleep evaluation and MSLT from 2006 to 2019 was performed. Clinical characteristics, sleep-related history, and polysomnographic data were reviewed.

RESULTS

Of 16 patients with cancer history, 9 were women (56%) and median age was 49. Cancer diagnoses included 4 central nervous system, 3 breast, 1 lymphoma, and 9 other solid malignancies, and 31% were undergoing active treatment. Comorbid conditions included depression, obstructive sleep apnea, and cancer-related fatigue. Daytime fatigue (94%), daily naps (81%), and EDS (69%) were the most common symptoms. Hypnopompic and hypnogogic hallucinations, sleep paralysis, sleep attacks, and cataplexy were present in a few. Epworth Sleepiness Scale scores were consistent with EDS in 88%, and mean sleep latency was less than 8 min in 69%. Only 31% had more than 2 sleep-onset REM periods. MSLT supported diagnoses of central disorders of hypersomnolence in 5 patients (4 narcolepsy, 1 idiopathic hypersomnia); 5 hypersomnia due to a medical disorder, psychiatric condition, or medication; and 6 with normal results. Pharmacotherapy was prescribed in 5 patients.

CONCLUSIONS

EDS in patients with cancer may be multifactorial, but persistent symptoms may indicate an underlying disorder of hypersomnolence. Sleep referral and polysomnography to exclude other sleep disorders may be indicated. MSLT can help confirm the diagnosis. In those with normal MSLT, further evaluation for mood disorder should be considered.

Use of Methylphenidate in Excessive Daytime Sleepiness in Alzheimer's Patients Treated with Donepezil: Case Series

Sleep disorders, inversion of sleep rhythm, excessive daytime sleepiness, and sleeplessness at night are common in Alzheimer's disease (AD). Sleep disorders in AD have a diverse pathogenesis and their incidence increases as the disease progresses. Some publications indicate possible beneficial effects of methylphenidate on sleep. We presented two cases of patients with diagnosed AD accompanied by sleep disorders which had a significant impact on their functioning. The pathogenesis of sleep disorders was different in those two cases. In both case studies, the use of methylphenidate brought an immediate clinical effect, improving sleep at night and functioning during the day.

Cerebellar mutism syndrome

Cerebellar mutism most commonly, but not exclusively, develops in children after surgery for midline cerebellar or intraventricular tumors in the posterior fossa, typically medulloblastoma. Cerebellar mutism syndrome (CMS) comprises a complex set of neurologic and neurocognitive signs and symptoms, the cardinal and central component of which is an initially profound but usually reversible speech disorder. As such, CMS is currently recognized as an extreme form of the so-called cerebellar cognitive affective syndrome (Schmahmann syndrome). The putative cause of CMS is a substantial surgical injury to the proximal components of the bilateral efferent cerebellar pathways, disrupting cerebellar input to the supratentorial brain. The resultant cerebellocerebral diaschisis may lead to supratentorial cortical perfusion depression with frontal predominance. The speech disorder is, therefore, likely an apraxia. As our understanding of the mechanism and the clinical spectrum of CMS evolves, clinically useful preoperative risk stratification schemes, adjustments to surgical strategies and techniques, and possible early therapeutic-rehabilitative measures are being sought and developed to reduce the burden of this severe and particularly handicapping chronic morbidity on affected individuals and their families.

A Classification method for eye movements direction during REM sleep trained on wake electro-oculographic recordings

Rapid eye movements (REMs) are a peculiar and intriguing aspect of REM sleep, even if their physiological function still remains unclear. During this work, a new automatic tool was developed, aimed at a complete description of REMs activity during the night, both in terms of their timing of occurrence that in term of their directional properties. A classification stage of each singular movement detected during the night according to its main direction, was in fact added to our procedure of REMs detection and ocular artifact removal. A supervised classifier was constructed, using as training and validation set EOG data recorded during voluntary saccades of five healthy volunteers. Different classification methods were tested and compared. The further information about REMs directional characteristic provided by the procedure would represent a valuable tool for a deeper investigation into REMs physiological origin and functional meaning.

Insomnia among brain tumor patients: a population-based prospective study of tumor patients in northern Finland

Patients with neurological diseases often suffer from sleep disturbances. Insomnia among adult brain tumor patients has usually been studied as part of quality-of-life studies, or some case reports on insomnia in these patients have been described. The authors aimed to study insomnia in a prospective study setting among patients with primary brain tumors and evaluate whether insomnia is related to tumor laterality. Entire study population consisted of 70 patients with a solitary primary supratentorial brain tumor treated surgically at the Clinic for Neurosurgery, Oulu University Hospital. The overall functional state of the patients was assessed by the Karnofsky Performance Scale, depression was measured by Beck Depression Inventory, and insomnia by Nottingham Health Profile. Repeated measurements were assessed before tumor operation as well as 3 months and one year after surgery. Prevalence of insomnia among patients with a primary brain tumor waiting for surgery was higher compared to general population, but level of insomnia significantly decreased as soon as 3 months after tumor operation. Patients with a bilateral primary brain tumor had significantly more often insomnia without comorbid depression compared to patients with a left or right tumor for up to one year after operation. The authors suggest that insomnia among patients with a bilateral brain tumor may not be associated with depression but have other biological background.

Fatigue and its association with sleep disorders, depressive symptoms and anxiety in patients with multiple sclerosis

BACKGROUND AND PURPOSE

The aetiopathogenesis of fatigue in multiple sclerosis (MS) is not clear. It could be associated with structural changes of the central nervous system, but also with mood and sleep disorders. The purpose of the study was to evaluate frequency of fatigue and its association with sleep and mood disorders in MS patients.

MATERIAL AND METHODS

The examined group consisted of 122 MS patients (mean age 37.7 ± 10.8 years). The following questionnaires were used: Fatigue Severity Scale (FSS), Epworth Sleepiness Scale (ESS), Athens Insomnia Scale (AIS), Montgomery-Asberg Depression Rating Scale (MADRS), and Hospital Anxiety and Depression Scale (HADS).

RESULTS

Fatigue was present in 75 MS patients (61.5%). Excessive daytime sleepiness was observed in 25 (20.5%), insomnia in 73 patients (59.8%). According to MADRS, depressive symptoms were present in 33 (27%), according to HADS in 15 people (12.3%). Anxiety was present in 32 patients (26.2%). We observed an association between fatigue (FSS) and sleep disorders (ESS, AIS) and also between fatigue and either depression (MADRS, HADS-D) or anxiety (HADS-A). The FSS score was not associated with age, sex, disease course and duration, Expanded Disability Status Stage (EDSS), treatment or level of education in MS patients. In inactive professionally people we noted significantly higher FSS scores (44.8 ± 13.8) in comparison with active individuals (37.2 ± 14.9; p = 0.0053).

CONCLUSIONS

Fatigue is a very common symptom in MS, sometimes associated with sleep disorders, depressive symptoms or anxiety. The treatable causes of fatigue in MS such as sleep and mood disturbances should be identified and treated.

Clinical and radiologic correlates of insomnia symptoms in ischemic stroke patients

OBJECTIVES

Insomnia is a common complaint in stroke survivors. The purpose of this study was to investigate the clinical and magnetic resonance imaging (MRI) correlates of insomnia symptoms in Chinese ischemic stroke survivors.

METHODS

A comprehensive psychiatric assessment was performed involving 508 ischemic stroke patients 3 months after their first-ever or recurrent acute stroke. Insomnia symptoms were evaluated with a standard insomnia questionnaire. Depressive symptoms were assessed using the Geriatric Depression Scale (GDS).The evaluation of the MRI scans focused on infarctions, white matter lesions, and microbleeds.

RESULTS

One hundred and eight-six patients (36.6% of the sample) had insomnia symptoms. Sixty-four patients (12.6%) had insomnia symptoms with daytime consequences. In the multivariate logistic regression analysis, GDS score (OR = 1.157, p < 0.001) and acute frontal lobe infarction (OR = 1.933, p = 0.039) were significant predictors of insomnia symptoms, while the GDS score (OR = 1.251, p < 0.001) and diabetes mellitus (OR = 1.959, p = 0.017) were significant predictors of insomnia symptoms with daytime consequences.

CONCLUSIONS

Insomnia symptoms have a multi-factorial origin in stroke. Besides depressive symptoms, frontal lobe infarction and diabetes mellitus predict insomnia symptoms.

Neurological complications of acute ischaemic stroke

Complications after ischaemic stroke, including both neurological and medical complications, are a major cause of morbidity and mortality. Neurological complications, such as brain oedema or haemorrhagic transformation, occur earlier than do medical complications and can affect outcomes with potential serious short-term and long-term consequences. Some of these complications could be prevented or, when this is not possible, early detection and proper management could be effective in reducing the adverse effects. However, there is little evidence-based data to guide the management of these neurological complications. There is a clear need for improved surveillance and specific interventions for the prevention, early diagnosis, and proper management of neurological complications during the acute phase of stroke to reduce stroke morbidity and mortality.

Impact of psychotherapy on insomnia symptoms in patients with depression and multiple sclerosis

The purpose of the study was to evaluate the prevalence of insomnia in multiple sclerosis patients with comorbid depression, associations between psychological symptoms, multiple sclerosis symptoms and insomnia, and to test effects of a 16-week protocol-based psychotherapy intervention for depression on insomnia symptoms. Participants with multiple sclerosis and depression (n = 127) were randomized to telephone administered cognitive behavioral therapy and telephone administered supportive emotion-focused therapy. Multiple sclerosis functional limitation was measured at baseline. Depression, insomnia, anxiety and quality of life were evaluated at pre treatment, mid treatment (8 weeks), and post treatment (16 weeks). Prevalence of insomnia ≥3 times per week was 78% at pre treatment and 43% at post treatment. Insomnia at baseline was associated with depression, multiple sclerosis related mood symptoms and anxiety. Middle of the night awakenings were associated with swallowing and speech problems. Improvements in insomnia were associated with improvement in depression and anxiety. Participants with residual insomnia were more likely to have major depressive disorder, greater multiple sclerosis severity, elevated anxiety and lower mental components of quality of life. Results demonstrate rates of insomnia in patients with comorbid multiple sclerosis and depression are higher than those reported in the general multiple sclerosis population and additional insomnia treatment is indicated beyond the treatment of comorbid psychological disorders.

Sleep-wake changes and cognition in neurodegenerative disease

With the increasing aging population, neurodegenerative disorders will become more common in clinical practice. These disorders involve multiple pathophysiological mechanisms that differentially affect cognition, mood, and physical functions. Possibly due to the involvement of common underlying neurobiological circuits, sleep and/or circadian (sleep-wake) changes are also common in this disease group. Of significance, sleep-wake changes are often a prodromal feature and are predictive of cognitive decline, psychiatric symptoms, quality of life, need for institutional care, and caregiver burden. Unfortunately, in neurodegenerative disease, few studies have included detailed polysomnography or neuropsychological assessments although some data indicate that sleep and neurocognitive features are related. Further studies are also required to address the effects of pharmacological and nonpharmacological treatments on cognitive functioning. Such research will hopefully lead to targeted early intervention approaches for cognitive decline in older people.

Strokes and their relationship with sleep and sleep disorders

INTRODUCTION

In the current population, strokes are one of the most important causes of morbidity and mortality, to which new risk factors are increasingly being attributed. Of late, there is increased interest in the relationship between sleep disorders and strokes as regards risk and prognosis.

DEVELOPMENT

This article presents the changes in sleep architecture and brain activity in stroke patients, as well as the interaction between stroke and sleep disorders, including those which may also influence the outcome and recovery from strokes. The different treatments discussed in the literature are also reviewed, as correct treatment of such sleep disorders may not only improve quality of life and reduce after-effects, but can also increase life expectancy.

CONCLUSIONS

Sleep disorders are becoming increasingly associated with stroke. In addition to being a risk factor, they can also interfere in the outcome and recovery of stroke patients. This article aims to present an exhaustive and current review on strokes and their relationship with sleep alterations and sleep disorders.

The relationship between sleep disorders and stroke

Although sleep appears to be a quiescent, passive state externally, there are a multitude of physiological changes occurring during sleep that can affect cerebral homeostasis and predispose individuals to cerebrovascular disorders. Therefore, it is not surprising that sleep-disordered breathing causes significant nocturnal perturbations, such as obstructive sleep apnea (OSA), that can lead to cerebrovascular disorders. There is evidence to suggest that OSA is a risk factor for stroke, although studies have not been able to clearly discern the absence or presence of OSA before the stroke event. Sleep-disordered breathing, such as OSA and central sleep apnea, can occur as a consequence of stroke. Fortunately, treating OSA appears to decrease morbidity and possibly mortality. Unfortunately, continuous positive airway pressure compliance in this population group is low, and significant efforts and resources may be needed to improve compliance and adherence. Various other sleep disorders, such as insomnia, fatigue, hypersomnia, and parasomnia, can occur following a stroke, and physicians treating patients following a stroke need to be aware of these disorders in order to effectively treat such patients.

Spontaneous arm movement activity assessed by accelerometry is a marker for early recovery after stroke

The factors determining recovery from hemiparetic stroke are manifold. We studied spontaneous arm movement activity in the acute phase after stroke as a predictor of recovery. Included in this prospective study were 25 patients (63 ± 10 years; 9 women, 16 men) with acute middle cerebral artery stroke and 7 control patients without neurological disease (61 ± 14 years; 3 women, 4 men). Movement activity was measured continuously for 4 days in both arms using Actiwatches and analysed off-line. Movement activity of the nonaffected arm ranged from <10 to >16 h per day in the stroke patients. Nine stroke patients with an initial decline in arm movement activity showed no increase in movement activity in either arm over 4 days after stroke, and the other 16 patients improved steadily after admission (p < 0.003). C-reactive protein was elevated in the non-recovering patients (4.4 ± 4.9 mg/dl) related to a low number of waking hours (r = -0.512, p < 0.01). Stroke severity, location and treatment, as well as arterial blood pressure (162 ± 21 mmHg) and body temperature (36.9 ± 06 °C) were not different among the groups. The impairment was still different among the two groups 3 months after stroke. Our results support the notion that in the acute stage after middle cerebral artery stroke there are patients with a secondary decline in general motor activity related to an enhanced sleep demand as assessed with accelerometry. This impairment was related to elevated C-reactive protein.

Sleep disruption following paramedian pontine stroke

Pontine structures are critical for the generation of rapid eye movement sleep but there are only a few reports of the effects of focal pontine lesions on sleep patterns in humans. We report the case of an 81-year-old man admitted for the acute onset of disordered speech and motor deficit in the upper right arm who developed hypersomnia within a week. A 24-hour polysomnographic study revealed a very severe disruption of both circadian rhythm and sleep organisation, and a brain MRI documented an ischaemic lesion of the anterior left paramedian portion of the pons. Our observation suggests that even small, paramedian pontine ischaemic lesions can acutely induce a very severe sleep disorder.

[The neuropathology of sleep in human neurodegenerative diseases]

The neuropathology of human sleep remains an ill-defined issue. The data concerning the main structures of human brain areas involved, or supposed to be implicated, in sleep organisation are reviewed. Five levels of organisation can be schematically recognized: (i) the ascending arousal system, (ii) the non REM and REM systems (iii) regulated by hypothalamic areas, (iv) and the biological clock, (v) modulated by a number of "allostatic" influences. These are briefly described, with emphasis on the location of structures involved in humans, and on the recently revised concepts. Current knowledge on the topography of lesions associated with the main sleep disorders in degenerative diseases is recalled, including REM sleep behavior disorders, restless legs syndrome and periodic leg movements, sleep apneas, insomnia, excessive daily sleepiness, secondary narcolepsy and disturbed sleep-wake rhythms. The lesions of sleep related structures observed in early and late stages of four degenerative diseases are then reviewed. Two synucleinopathies (Lewy lesions associated disorders, including Parkinson's disease and Dementia with Lewy bodies, and Multiple System Atrophy) and two tauopathies (Progressive Supranuclear Palsy and Alzheimer's disease) are dealt with. The distribution of lesions usually found in affected patients fit with that expected from the prevalence of different sleep disorders in these diseases. This confirms the current opinion that these disorders depend on the distribution of lesions rather than on their biochemical nature. Further studies might throw insight on the mechanism of normal and pathological sleep in humans, counterpart of the increasing knowledge provided by animal models. Specially designed prospective clinicopathological studies including peculiar attention to sleep are urgently needed.

Long-lasting sleep patterns of adult patients with minor traumatic brain injury (mTBI) and non-mTBI subjects

BACKGROUND

Sleep disturbance is a common subjective complaint of minor traumatic brain-injured (mTBI) patients, but little is known about the characteristics of sleep disturbance in adults years after the injury.

METHODS

Polysomnographic (PSG) and multiple sleep latency test (MSLT) records of 26 mTBI adult patients with normal brain computerized tomography and negative encephalographic studies, no past history of CNS pathology, no premorbid or present major psychiatric diagnosis, and no sleep apnea syndrome were compared to a matched group of apparently healthy individuals (controls).

RESULTS

Sleep patterns were disturbed in the mTBI patients. Their sleep architecture was altered, with significantly higher light-sleep non-rapid eye movement (NREM) stage 2 scores compared to controls (54.5+/-13.4% vs. 46.6+/-10.4%, respectively, p=0.03) and significantly lower REM sleep scores (21.2+/-8.4% vs. 25.4+/-4.5%, respectively, p=0.05). The MSLT findings documented significant excessive daytime episodes of falling asleep.

CONCLUSIONS

Sleep disturbances of adult patients with chronic mTBI may manifest characteristic alterations in both timing and architecture of their sleep patterns. Sleep lab evaluations may help identify subgroups of mTBI patients who would probably benefit from treatment.

Differential diagnosis in hypersomnia

Hypersomnia includes a group of disorders in which the primary complaint is excessive daytime sleepiness. Chronic hypersomnia is characterized by at least 3 months of excessive sleepiness prior to diagnosis and may affect 4% to 6% of the population. The severity of daytime sleepiness needs to be quantified by subjective scales (at least the Epworth sleepiness scale) and objective tests such as the multiple sleep latency test. Chronic hypersomnia does not correspond to an individual clinical entity but includes numerous different etiologies of hypersomnia as recently reported in the revised International Classification of Sleep Disorders. This review details most of those disorders, including narcolepsy with and without cataplexy, idiopathic hypersomnia with and without long sleep time, recurrent hypersomnia, behaviorally induced insufficient sleep syndrome, hypersomnia due to medical condition, hypersomnia due to drug or substance, hypersomnia not due to a substance or known physiologic condition, and also sleep-related disordered breathing and periodic leg movement disorders.

Mathematical models of periodic breathing and their usefulness in understanding cardiovascular and respiratory disorders

Periodic breathing is an unusual form of breathing with oscillations in minute ventilations and with repetitive apnoeas or near apnoeas. Reported initially in patients with heart failure or stroke, it was later recognized to occur especially during sleep. The recurrent hypoxia and surges of sympathetic activity that often occur during the apnoeas have serious health consequences. Mathematical models have helped greatly in the understanding of the causes of recurrent apnoeas. It is unlikely that every instance of periodic breathing has the same cause, but many result from instability in the feedback control involved in the chemical regulation of breathing caused by increased controller and plant gains and delays in information transfer. Even when it is not the main cause of the periodic breathing, unstable control modifies the ventilatory pattern and sometimes intensifies the recurrent apnoeas. The characteristics of disturbances to breathing and their interaction with the control system can be critical in determining ventilation responses and the occurrence of periodic breathing. Large abrupt changes in ventilation produced, for example, in the transition from waking to sleep and vice versa, or in the transition from breathing to apnoea, are potent factors causing periodic breathing. Mathematical models show that periodic breathing is a 'systems disorder' produced by the interplay of multiple factors. Multiple factors contribute to the occurrence of periodic breathing in congestive heart failure and cerebrovascular disease, increasing treatment options.

Hypersomnia

Hypersomnia, a complaint of excessive daytime sleep or sleepiness, affects 4% to 6% of the population, with an impact on the everyday life of the patient Methodological tools to explore sleep and wakefulness (interview, questionnaires, sleep diary, polysomnography Multiple Sleep Latency Test, Maintenance of Wakefulness Test) and psy-chomotor tests (for example, psychomotor vigilance task and Oxford Sleep Resistance or Osier Test) help distinguish between the causes of hypersomnia. In this article, the causes of hypersomnia are detailed following the conventional classification of hypersomnic syndromes: narcolepsy, idiopathic hypersomnia, recurrent hypersomnia, insufficient sleep syndrome, medication- and toxin-dependent sleepiness, hypersomnia associated with psychiatric disorders, hypersomnia associated with neurological disorders, posttraumatic hypersomnia, infection (with a special emphasis on the differences between bacterial and viral diseases compared with parasitic diseases, such as sleeping sickness) and hypersomnia, hypersomnia associated with metabolic or endocrine diseases, breathing-related sleep disorders and sleep apnea syndromes, and periodic limb movements in sleep.

From psychophysiological insomnia to organic sleep disturbances: a continuum in late onset insomnia - with special concerns relating to its treatment

The population suffering from insomnia in old age onset (LOI) is quite large. LOI might include a larger scale of syndromes ranging from typical psychophysiological insomnia to night delirium. The correlation between the biological, biochemical changes and the quantitative as well as the qualitative alterations of the sleep process through aging has not been fully explored. One can suppose that any cerebral lesion leading to a dysfunction in mental performance can also act on the sleep. The majority of LOI brain metabolic disturbances might therefore have some etiological role. The authors suggest the application of this concept in the clinical evaluation of LOI. The authors constructed a heuristic model for the pathophysiology and treatment of LOI. It is a bipolar axis containing the most typical symptoms of LOI. On the opposite margins psychophysiological insomnia and organic/metabolic insomnia (up to delirious states) are settled. The position on the axis (i.e., its distance from the "edge syndromes") gives information on the probability of its organic nature. Based on their clinical experiences and considering the data of the very few studies, they suppose that with the help of a detailed analysis of the symptoms of LOI and using some additional (electrophysiological and neuroimaging) laboratory methods most patients with LOI can get a strict diagnostic position on the LOI axis. Using the LOI axis not only a detailed evaluation of the symptomatology but also more sophisticated therapeutic interventions become possible. Symptoms on the "metabolic side" can be cured by a single evening application of any drugs improving the function of the brain (like nootropics, neuroprotective agents or even slight stimulants, e.g., caffeine) might show a "paradoxical hypnotic" effect, or in combination with sleeping pills they can cause an additive effect in LOI patients. The efficacy of this treatment can also have a diagnostic value: i.e., it helps to differentiate between the primary (organic) and psychophysiological (exogenous or emotional/psychic) forms of LOI.

[Sleep in psychiatric disorders]

Altered sleep patterns are prominent in the majority of psychiatric disorders. This article examines the psychiatric disorders that are most often associated to sleep dysfunction as it is related in clinical practice and describes the polysomnographic findings. Patient's main complaints are related to difficulty in initiating and maintaining sleep (initial or middle insomnia, respectively) and poor quality of sleep. Early awakening or terminal insomnia is most described in the depressive conditions. Hypersomnia may be the main symptom in some depressive disorders, as seasonal depression, depression with atypical features or depressive episodes in bipolar disorder. Polysomnographic evaluation shows, in general, a significative reduction in the efficiency and total time of sleep, in detriment to the amount of slow wave sleep. The reduction of rapid eye movement (REM) sleep latency is mainly described for the depression, but has also been reported in other psychiatric disorders.

Nitric oxide and sleep

Nitric oxide (NO) is a biological messenger synthesized by three main isoforms of NO synthase (NOS): neuronal (nNOS, constitutive calcium dependent), endothelial (eNOS, constitutive, calcium dependent) and inducible (iNOS, calcium independent). NOS is distributed in the brain either in circumscribed neuronal sets or in sparse interneurons. Within the laterodorsal tegmentum (LDT), pedunculopontine tegmentum and dorsal raphe nucleus, NOS-containing neurons overlap neurons grouped according to their contribution to sleep mechanisms. The main target for NO is the soluble guanylate cyclase that triggers an overproduction of cyclic guanosine monophosphate. NO in neurons of the pontine tegmentum facilitates sleep (particularly rapid-eye-movement sleep), and NO contained within the LDT intervenes in modulating the discharge of the neurons through an auto-inhibitory process involving the co-synthesized neurotransmitters. Moreover, NO synthesized within cholinergic neurons of the basal forebrain, while under control of the LDT, may modulate the spectral components of the EEG instead of the amounts of different sleep states. Finally, impairment of NO production (e.g. neurodegeneration, iNOS induction) has identifiable effects, including ageing, neuropathologies and parasitaemia.

Neuropsychological performance and sleep disturbance following traumatic brain injury

OBJECTIVE

To examine the relation between sleep disturbance and neurocognitive ability among persons with traumatic brain injury (TBI).

DESIGN

Correlational research evaluating demographic and neuropsychological predictors of sleep disturbance using multiple regression analysis and analysis of variance.

PARTICIPANTS

Eighty-seven patients with mild to severe TBI admitted to a comprehensive outpatient neurorehabilitation program.

MAIN OUTCOME MEASURES

Sleep disturbance assessed using the Pittsburgh Sleep Quality Index.

RESULTS

Hierarchical regression analysis revealed that performance on selected measures of cognitive functioning significantly improved prediction of sleep disturbance, accounting for 14% of variance beyond that accounted for by injury severity and gender. The total model accounted for 31% of the variance in Pittsburgh Sleep Quality Index scores. Patients with mild TBI reported more sleep disturbance (P < .01) than did patients with severe TBI.

CONCLUSIONS

Sleep disturbance among patients with TBI may be associated with a particular constellation of neuropsychological abilities. These issues are discussed in relation to prior findings that indicate the involvement of additional neuropsychiatric factors associated with sleep disturbance in mild TBI.

Behavioral disorders in the frontal and temporal variants of frontotemporal dementia

OBJECTIVE

To compare the behavioral features and to investigate the neuroanatomic correlates of behavioral dysfunction in anatomically defined temporal and frontal variants of frontotemporal dementia (tvFTD and fvFTD).

METHODS

Volumetric measurements of the frontal, anterior temporal, ventromedial frontal cortical (VMFC), and amygdala regions were made in 51 patients with FTD and 20 normal control subjects, as well as 22 patients with Alzheimer disease (AD) who were used as dementia controls. FTD patients were classified as fvFTD or tvFTD based on the relative degree of frontal and anterior temporal volume loss compared with controls. Behavioral symptoms, cerebral volumes, and the relationship between them were examined across groups.

RESULTS

Both variants of FTD showed significant increases in rates of elation, disinhibition, and aberrant motor behavior compared with AD. The fvFTD group also showed more anxiety, apathy, and eating disorders, and tvFTD showed a higher prevalence of sleep disturbances than AD. The only behaviors that differed significantly between fvFTD and tvFTD were apathy, greater in fvFTD, and sleep disorders, more frequent in tvFTD. FvFTD was associated with greater frontal atrophy and tvFTD was associated with more temporal and amygdala atrophy compared with AD, but both groups showed significant atrophy in the VMFC compared with AD, which was not associated with VMFC atrophy. In FTD, the presence of many of the behavioral disorders was associated with decreased volume in right-hemispheric regions.

CONCLUSION

FvFTD and tvFTD show many similarities in behavior, which appear to be associated with damage to right frontal and temporal structures.

Sleep disorders in Parkinson's disease

Depression, dementia, and physiologic changes contribute to the high prevalence of sleep disturbances in patients with Parkinson's disease (PD). Antiparkinsonian drugs also play a role in insomnia by increasing daytime sleepiness and affecting motor symptoms and depression. Common types of sleep disturbances in PD patients include nocturnal sleep disruption and excessive daytime sleepiness, restless legs syndrome, rapid eye movement sleep behavior disorder, sleep apnea, sleep walking and sleep talking, nightmares, sleep terrors, and panic attacks. A thorough assessment should include complete medical and psychiatric histories, sleep history, and a 1- to 2-week sleep diary or Epworth Sleepiness Scale evaluation. Polysomnography or actigraphy may also be indicated. Treatment should address underlying factors such as depression or anxiety. Hypnotic therapy for sleep disturbances in PD patients should be approached with care because of the risks of falling, agitation, drowsiness, and hypotension. Behavioral interventions may also be useful.

Sleep Apnea and Other Sleep-Wake Disorders in Stroke

Sleep-disordered breathing (SDB) and sleep-wake disturbances (SWD) are frequent in stroke patients. They deserve attention, because they may significantly influence rehabilitation process and functional outcome. In addition, SDB may increase the risk of stroke recurrence. More than 50% of stroke patients have SDB, mostly obstructive sleep apnea (OSA). In some patients, stroke recovery is accompanied by an improvement of SDB. The treatment of choice for OSA is continuous positive airway pressure. Oxygen, theophylline, and other forms of ventilation may be helpful in patients with other forms of SDB (eg, Cheyne-Stokes breathing). In at least 20% to 40% of stroke patients, SWD are present, mainly in form of increased sleep needs (hypersomnia), excessive daytime sleepiness, or insomnia. Depression, anxiety, SDB, stroke complications (eg, nocturia, dysphagia, and urinary or respiratory infections), and drugs may contribute to SWD and should be addressed first. In patients with SWD of primary neurologic origin, treatment with stimulants or dopaminergic drugs and hypnotics or sedating antidepressants, respectively, can be attempted.