Kleine-Levin syndrome is associated with birth difficulties and genetic variants in the TRANK1 gene loci.

Kleine-Levin syndrome (KLS) is a rare disorder characterized by severe episodic hypersomnia, with cognitive impairment accompanied by apathy or disinhibition. Pathophysiology is unknown, although imaging studies indicate decreased activity in hypothalamic/thalamic areas during episodes. Familial occurrence is increased, and risk is associated with reports of a difficult birth. We conducted a worldwide case-control genome-wide association study in 673 KLS cases collected over 14 y, and ethnically matched 15,341 control individuals. We found a strong genome-wide significant association (rs71947865, Odds Ratio [OR] = 1.48, P = 8.6 × 10-9) within the 3'region of TRANK1 gene locus, previously associated with bipolar disorder and schizophrenia. Strikingly, KLS cases with rs71947865 variant had significantly increased reports of a difficult birth. As perinatal outcomes have dramatically improved over the last 40 y, we further stratified our sample by birth years and found that recent cases had a significantly reduced rs71947865 association. While the rs71947865 association did not replicate in the entire follow-up sample of 171 KLS cases, rs71947865 was significantly associated with KLS in the subset follow-up sample of 59 KLS cases who reported birth difficulties (OR = 1.54, P = 0.01). Genetic liability of KLS as explained by polygenic risk scores was increased (pseudo R2 = 0.15; P < 2.0 × 10-22 at P = 0.5 threshold) in the follow-up sample. Pathway analysis of genetic associations identified enrichment of circadian regulation pathway genes in KLS cases. Our results suggest links between KLS, circadian regulation, and bipolar disorder, and indicate that the TRANK1 polymorphisms in conjunction with reported birth difficulties may predispose to KLS.

How sleepy patients differ from non-sleepy patients in mild obstructive sleep apnea?

To aim is investigate whether demographic, polysomnographic or sleep behaviour data differ between non-sleepy, sleepy and very sleepy patients with mild obstructive sleep apnea. The study population consisted of 439 consecutive adult patients diagnosed with mild obstructive sleep apnea (5 ≤ apnea-hypopnea index < 15) after a complete polysomnographic evaluation. The patients were divided into three groups based on subjective sleepiness: very sleepy (Epworth Sleepiness Scale ≥ 16, n = 59); sleepy (10 < Epworth Sleepiness Scale < 16, n = 102); and non-sleepy (Epworth Sleepiness Scale ≤ 10, n = 278). Demographic, polysomnographic and sleep behaviour data were compared between the groups. There were no statistically significant differences in breathing abnormality indices and most of the demographic features between the groups. The number of arousals was significantly higher in the very sleepy group compared with the non-sleepy group (140.8 ± 105.2 versus 107.6 ± 72.2). Very sleepy patients reported feeling sleepy during the daytime more often (42.4% versus 31.7%) and sleeping significantly less during the week compared with non-sleepy patients. Also, a significantly higher proportion of sleepy (47.1%) and very sleepy patients (44.1%) reported taking naps during weekends compared with non-sleepy patients (35.6%). In a regression analysis, also total sleep time (ß = 0.045), sleep efficiency (ß = -0.160), apnea index (ß = -0.397), apnea-hypopnea index in supine position (ß = 0.044), periodic limb movement index (ß = 0.196) and periodic limb movement-related arousal index (ß = -0.210) affected subjective daytime sleepiness. The results suggest that excessive daytime sleepiness in patients with mild obstructive sleep apnea appears to be related to inadequate sleeping habits (i.e. insufficient sleep during working days) and decreased sleep quality rather than differences in breathing abnormalities.

Prevalence and characteristics of positional obstructive sleep apnea (POSA) in patients with severe OSA.

PURPOSE: We assessed the prevalence of positional patients (PPs) and the main predictors of positional dependency in severe obstructive sleep apnea (OSA). A simulated effect of positional therapy (PT) vs. continuous positive airway pressure (CPAP) was also assessed. METHODS: Polysomnographic recordings of 292 consecutive patients with severe OSA (Apnea-Hypopnea Index (AHI) ≥ 30) who slept > 4 h and had ≥ 30 min sleep in both supine and lateral positions were assessed. PPs were defined to have a supine AHI/lateral AHI ratio ≥ two and non-positional patients (NPPs) a supine AHI/lateral AHI ratio < two. RESULTS: A total of 35.3% of the severe OSA patients were PPs. They were less obese and had less severe OSA (p < 0.001) compared with NPPs. The percentage of total apnea-hypopnea time from total sleep time (AHT%) was the most significant predictor for positional dependency. By sleeping in the lateral posture (i.e. after simulated PT), 78 (75.7%) PPs obtained significant improvement of their OSA severity and 9 (8.7%) of them became "non-OSA". Moreover, if CPAP was used only for 50% of total sleep time, 53 patients (18.2%) gained more benefit from avoiding the supine posture than from CPAP therapy. CONCLUSIONS: More than a third of the studied severe OSA patients were PPs. These patients could achieve a significant decrease in the number and severity of apneas and hypopneas by adopting the lateral posture, suggesting that PT may be a valuable therapy for a significant portion of these severe OSA patients who for whatever reason are not being treated by CPAP. TRIAL REGISTRY: ClinicalTrials.gov Identifier: NCT03232658.

Breathing abnormalities during sleep in Kleine-Levin Syndrome: fact or coincidence?

PURPOSE OF REVIEW: To highlight and critically discuss the possibility that breathing abnormalities during hypersomnolent episodes are an additional clinical feature of Kleine-Levin Syndrome (KLS). RECENT FINDINGS: A computerized literature search of breathing abnormalities in patients with KLS disclosed two old and a single recent publication describing a total of six patients with sleep apnea during hypersomnolent episodes. SUMMARY: Owing to scarce reports on complete polysomnography during and in-between hypersomnic episodes of KLS, the possibility that breathing abnormalities are an additional clinical feature of this unique episodic sleep syndrome should be further studied.

Horizontal Tonic Conjugate Gaze Deviation in a 4-Week-Old Infant: What Can the Eyes (of the Parents) Tell?

A 4-week-old healthy infant failed to make eye contact when approached from the left. When evaluated by us at the age of 11 weeks, left tonic conjugate gaze deviation was noted. Brain MRI showed a left frontotemporal large tension arachnoid cyst causing right falcial herniation. During the insertion of an Ommaya reservoir, hemosiderin was found to be coating the inner wall of the cyst, which may indicate that the asymptomatic cyst evolved to a tension cyst due to spontaneous hemorrhage. Surgical decompression resulted in complete restoration of the horizontal gaze and considerable reduction in the size of the cyst. After 3 months a cystoperitoneal shunt was placed due to increased intracranial pressure secondary to impaired drainage of the cyst. Since then the infant has done well, with normal developmental and neurological examination during his last follow-up at the age of 5 years. Although gaze central ocular motor control is still underdeveloped and chaotic eye movements are present during early infancy, the present case report reminds us that a thorough examination of eye movements should not be overlooked during neurodevelopmental evaluation.

Are we missing a simple treatment for most adult sleep apnea patients? The avoidance of the supine sleep position.

Obstructive sleep apnea (OSA) is a sleep disorder which has been gradually accepted as an important cause of increased morbidity and mortality. The treatment of moderate-severe OSA has improved dramatically since the introduction of continuous positive airway pressure (CPAP) devices; however, the adherence of patients to CPAP treatment is relatively low. Adherence appears to be even worse in patients with mild or asymptomatic OSA. The failure to identify and treat mildly symptomatic or asymptomatic OSA patients may be costly, as such patients comprise about 20% of the general adult population. OSA patients could be divided into positional and non-positional patients. Positional patients show most of their breathing abnormalities while sleeping in the supine position. Simply, by sleeping in the lateral postures, they eliminate or reduce significantly the number of apneas and hypopneas. On the contrary, non-positional patients suffer from breathing abnormalities in the supine and lateral postures, and as a consequence those are the most severe OSA patients for whom CPAP is the treatment of choice. In this paper we intend to argue that positional therapy, i.e., avoidance of the supine posture during sleep, could represent a valuable therapy mainly for mild-moderate OSA. Considering the fact that the vast majority of mild-moderate OSA patients are positional patients (between 65 and 87%), positional therapy may be a simple, cheap and effective solution for them. High-quality research regarding this issue is needed to evaluate the real effectiveness of this mode of therapy.

Obstructive sleep apnoea in adults: body postures and weight changes interactions.

The aim of this work was to study the relationship between changes of body posture dominance and changes of body weight overtime in adults with obstructive sleep apnoea. The participants were 112 non-treated adults with obstructive sleep apnoea who underwent two polysomnographic evaluations at our Sleep Disorders Unit during an average of 6.2years interval. Positional patients - having most of their breathing abnormalities in the supine posture and who became non-positional patients - had a significant gain in weight and a significant increase in apnoea-hypopnoea index, mainly in lateral apnoea-hypopnoea index. On the contrary, non-positional patients who became positional patients had a significant decrease in weight (but less than the increase in weight of positional patients who became non-positional patients) and showed a significant improvement in apnoea-hypopnoea index, again mainly in lateral apnoea-hypopnoea index. These non-positional patients who became positional patients initially had a less severe disease, as judged by apnoea-hypopnoea index, lateral apnoea-hypopnoea index and minimum SaO(2) during non-rapid eye movement sleep, and were less obese than non-positional patients who remained non-positional patients. The later were the patients who showed initially the worst disease and were more obese than the rest of the patients, and their condition did not change significantly over time. Non-positional patients who converted to positional patients showed a decrease in body weight and improvement of obstructive sleep apnoea, while positional patients who converted to non-positional patients showed an increase in body weight and worsening of obstructive sleep apnoea. It appears that weight changes have a modulatory effect on positional dominance, and lateral apnoea-hypopnoea index appears to be a sensitive parameter of these changes.

Myasthenia gravis and return to flying status.

INTRODUCTION: Myasthenia gravis (MG) is a common primary disorder of neuromuscular transmission. Although MG was once a fatal disease, today treatment with immunomodulating agents and cholinomimetic medications with good supportive care have improved the prognosis and the ability of patients to adapt to their workplaces, including the flight environment. CASES: The diagnosis of MG in two aircrew members illustrates the range of severity for MG from isolated ocular symptoms to relentlessly progressive generalized disease, as well as the unpredictability of the disease and difficulty in treatment. Nevertheless, both patients were returned to limited flying status. DISCUSSION: MG presents the potential for subtle progression with resulting effects on flight performance. In addition to the disease itself, flight surgeons must also consider problems related to treatment and its side effects. Progression and exacerbations of MG can develop during the course of the disease, requiring careful adjustments to treatment regimens. Taking all these factors into consideration, including the unpredictability of this disease, pilots with apparently stabilized MG should nevertheless be assigned only to duties during which the patient would be able to maintain and use his flying capabilities without risking the mission, himself, and other crewmembers.

Oral and dental considerations of combat-induced PTSD: a descriptive study.

OBJECTIVE: Stress experienced as an intense and traumatic event can increase the odds of orofacial morbidities that may affect oral, periodontal, or masticatory system health. The aim of this study was to evaluate the dental, periodontal, oral, and bruxism situation among Israeli posttraumatic stress disorder (PTSD) war veterans. METHOD AND MATERIALS: This retrospective cohort pilot study aimed to examine the oral and facial manifestations in 71 Israeli veterans with combat PTSD. All patients underwent full dental, oral, and periodontal examination. Signs of parafunctional activity were also evaluated, accompanied by a full set of periapical and/or panoramic radiographs. RESULTS: The patients were 37 to 77 (mean 60.7 ± 10.15) years of age and presented a poor overall oral hygiene status (Plaque Index 0.75 ± 0.26). All patients (100.0%) suffered from periodontal disease, and most of them (66.0%) were severely affected. A significant correlation was found between signs of parafunctional activity and severe periodontal disease (P = .035). The patients had a high decayed, missing, and filled teeth (DMFT) score (20.06 ± 8.86), which was mainly attributed to the large number of "filled" (F) teeth (11.95 out of 20.06). The DMFT score was significantly lower among light smokers than among heavy, former, or nonsmokers (P = .012). Most patients (90%) had signs and symptoms of parafunctional activities. A significant positive and dose-dependent correlation was found between smoking and periodontal disease (P = .012). CONCLUSIONS: An association was found between combat PTSD and oral, dental, and periodontal morbidity.

Obstructive Sleep Apnea: Do Positional Patients Become Nonpositional Patients With Time?

OBJECTIVES: Obstructive sleep apnea (OSA) patients with breathing abnormalities only or mainly in the supine posture are designated positional patients (PPs), whereas nonpositional patients (NPPs) have many breathing abnormalities in both lateral and supine postures. Positional therapy (PT), the avoidance of the supine posture during sleep, is the obvious treatment for PPs. The stability over time of being PP and leading factors that are involved in converting a PP to an NPP are addressed. METHODS: We analyzed polysomnographic (PSG) recordings of 81 consecutive adult patients with OSA who were judged to be PPs at the first PSG evaluation, and their follow-up PSGs were obtained after an average period of 6.6 years. RESULTS: The follow-up PSGs indicated that 57 PPs (70.4%) remained PPs, whereas 24 (29.6 %) converted to NPPs. Among PPs and NPPs, body mass index (P ≤ 0.05), overall Apnea-Hypopnea Index (AHI, P ≤ 0.087), and lateral AHI (P ≤ 0.046) increased and minimum SpO2 during rapid eye movement (REM) sleep (P ≤ 0.028) decreased significantly during the follow-up. However, among patients who became NPPs, the changes in these parameters were significantly (P ≤ 0.05) more pronounced compared to the patients who remained PPs. CONCLUSION: After an average of 6.6 years, 70.4% of PPs remained PPs. Therefore, if adherence for PT is good, they could continue to benefit from this therapy. For those who turned to NPPs, PT will not be the optimal treatment anymore; thus, these patients should be frequently monitored. Furthermore, an early treatment of PPs with PT would be highly beneficial to prevent worsening of their OSA. LEVEL OF EVIDENCE: 2b Laryngoscope, 130:2263-2268, 2020.

Power spectral densities of nocturnal pulse oximetry signals differ in OSA patients with and without daytime sleepiness.

BACKGROUND: As nocturnal hypoxemia and heart rate variability are associated with excessive daytime sleepiness (EDS) related to OSA, we hypothesize that the power spectral densities (PSD) of nocturnal pulse oximetry signals could be utilized in the assessment of EDS. Thus, we aimed to investigate if PSDs contain features that are related to EDS and whether a convolutional neural network (CNN) could detect patients with EDS using self-learned PSD features. METHODS: A total of 915 OSA patients who had undergone polysomnography with multiple sleep latency test on the following day were investigated. PSDs for nocturnal blood oxygen saturation (SpO2), heart rate (HR), and photoplethysmogram (PPG), as well as power in the 15-35 mHz band in SpO2 (PSPO2) and HR (PHR), were computed. Differences in PSD features were investigated between EDS groups. Additionally, a CNN classifier was developed for identifying severe EDS patients based on spectral data. RESULTS: SpO2 power content increased significantly (p < 0.002) with increasing severity of EDS. Furthermore, a significant (p < 0.001) increase in HR-PSD was found in severe EDS (mean sleep latency < 5 min). Elevated odds of having severe EDS was found in PSPO2 (OR = 1.19-1.29) and PHR (OR = 1.81-1.83). Despite these significant spectral differences, the CNN classifier reached only moderate sensitivity (49.5%) alongside high specificity (80.4%) in identifying patients with severe EDS. CONCLUSIONS: We conclude that PSDs of nocturnal pulse oximetry signals contain features significantly associated with OSA-related EDS. However, CNN-based identification of patients with EDS is challenging via pulse oximetry.

Paraneoplastic cerebellar degeneration mimicking acute post-infectious cerebellitis.

Acute cerebellitis is a monophasic non-progressive encephalitis restricted to the cerebellum, while paraneoplastic cerebellar degeneration is a subacute progressive disorder, which may either accompany or herald Hodgkin's disease. In the present report, we describe a young man with clinical and laboratory features of acute post-infectious cerebellitis in whom the progressive relapsing course subsequently led to the diagnosis of Hodgkin's disease. Dynamic changes observed on repeated MRIs during the protracted clinical course imply the presence of early active inflammation and subsequent neuronal atrophy.

Bihemispheric leftward bias in a visuospatial attention-related network.

Asymmetry of spatial attention has long been described in both disease (hemispatial neglect) and healthy (pseudoneglect) states. Although right-hemisphere specialization for spatial attention has been suggested, the exact neural mechanisms of asymmetry have not been deciphered yet. A recent functional magnetic resonance imaging study from our laboratory serendipitously revealed bihemispheric left-hemifield superiority in activation of a visuospatial attention-related network. Nineteen right-handed healthy adult females participated in two experiments of visual half-field presentation. Either facial expressions (experiment 1) or house images (experiment 2) were presented unilaterally and parafoveally for 150 ms while subjects were engaging a central fixation task. Brain regions previously associated with a visuospatial attention network, in both hemispheres, were found to be more robustly activated by left visual field stimuli. The consistency of this finding with manifestations of attention lateralization is discussed, and a revised model based on neural connectivity asymmetry is proposed. Support for the revised model is given by a dynamic causal modeling analysis. Unraveling the basis for attention asymmetry may lead to better understanding of the pathogenesis of attention disorders, followed by improved diagnosis and treatment. Additionally, the proposed model for asymmetry of visuospatial attention might provide important insights into the mechanisms underlying functional brain lateralization in general.

On fish oil and omega-3 supplementation in children: the role of such supplementation on attention and cognitive dysfunction.

In recent years we are facing a dramatic rise in the use of "behind the counter" medications to combat aging and improve memory and life quality. Many parents to children with learning difficulties, behavioral aberrations and those who are diagnosed with developmental disorders such as attention deficit, poor motor coordination and pervasive disorder are frequently advised by both professionals and lay persons to supplement their children with fish oil and or commercial preparations of omega-3, omega-6, or both polyunsaturated fatty acids (PUFA) in various combinations. The common logic is that "being a natural product, even if it does not help it should be safe to use". Indeed, this statement may well be true. In this paper a short description of the basic biochemistry and physiology of PUFA will be followed by a critical review of the presently known "evidence based" data on the value of this popular supplementation. At present the theoretical basis for supplementing children with the developmental disorders mentioned above is shaky and the evidence for its efficacy is still in doubt.

Kleine-Levin syndrome; An update and mini-review.

Since 1962, when Critchley and Hoffman coined the term Kleine-Levin Syndrome (KLS) for the triad of hypersomnia, excessive eating and "often abnormal behavior" which they have observed in 11 adolescent boys, the number of patients recognized with this rare syndrome expanded, the spectrum of the clinical presentation, disease course, prognosis, gender specificity and the presence of familial cases were established. However, in spite of the progress made in neuroscience, the search for the cause, neuroanatomy, pathophysiology and drug treatment of KLS is still ongoing. In this mini-review we will describe in some detail the scientific efforts made to understand in depth the complex symptomatology of KLS and refer also to updated findings reached up till now.

A rare saccade velocity profile in Stiff-Person Syndrome with cerebellar degeneration.

Stiff-Person Syndrome (SPS) is an immune-mediated disorder of the central nervous system characterized by muscle rigidity, episodic muscle spasms, and high titers of antibodies against glutamic acid decarboxylase (GAD). The presence of cerebellar ataxia in SPS is extremely rare, but occurs. Clinical observations of ocular motor abnormalities have been noted in a few SPS patients. The purpose of this study is to provide a detailed quantitative documentation of ocular motor abnormalities in a patient with SPS and progressive cerebellar signs. Detailed clinical assessment of a woman with SPS and precise eye movement recordings using the magnetic search coil technique was performed. In addition to other ocular motor abnormalities that included longer latencies for saccades, downbeat nystagmus, and loss of downward smooth pursuit, a rare saccade velocity profile consisting of multi-component saccades was observed. We postulate that these ocular motor findings are related to impairment of GABAergic neurotransmission because antibodies to glutamic acid decarboxylase (GAD-Abs) have been implicated in the pathogenesis of both SPS and some cases of cerebellar ataxia. In addition, this unusual saccadic velocity profile may have important implications for modeling the saccadic system and furthering a complete understanding of saccade generation.

The neurology of cobalamin deficiency in an elderly population in Israel.

OBJECTIVES: To evaluate the neurological status in elderly subjects with cobalamin deficiency (CblD) compared with matched non-deficient subjects before and after cobalamin (Cbl) supplementation. METHODS: Participants completed a questionnaire on activities of daily living, level of education, medical history, alcohol, nicotine, caffeine, and medication usage and prior consumption of vitamins. They underwent a detailed programmed neurological evaluation which was repeated after 6-9 months of Cbl therapy. RESULTS: There were 113 subjects with blood Cbl < or =147 pmol/L, methylmalonic acid > or =0.24 mumol/L, and 212 nondeficient subjects (controls). The mean age of the patients and controls was 79.5 +/- 6.9 and 79.5 +/- 5.9 years, respectively. Fifty patients (44.4 %) and 56 controls (26.4%) were found to have mild sensory neuropathy (SN).When subjects with diabetes mellitus (DM) were excluded, however, only 30 (26.5%) patients and 23 (10.8 %) controls had SN. A history of confusional state was more common among the patients than among the controls (12.4 % and 3.3%, respectively) as was a low mini-mental state examination (MMSE) score (20.2% and 15.2%, respectively). No patient had clinical signs compatible with subacute combined degeneration (SCD). Supplementation of Cbl for 6-9 months did not alter the neurological findings,while the biochemical deficiency was corrected. CONCLUSIONS: Mild SN rather than SCD is the main neurological impairment in elderly people with CblD. Short-term supplementation of CbL can correct the biochemical deficiency without affecting the neurological impairment.

Could steroids mask the diagnosis of cerebrotendinous xanthomatosis?

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder of bile acid synthesis, caused by impaired hydroxylation of cholesterol side chains due to deficiency of the mitochondrial enzyme sterol 27-hydroxylase (CYP27A1), leading to accumulation of cholestanol and cholesterol in brain and other tissues. Elevated plasma cholestanol serves as a key marker for the clinical diagnosis of CTX. In the present report we describe a young man with CTX who was on high dose steroids for a misdiagnosed chronic inflammatory demyelinating polyneuropathy (CIDP) and had normal level of serum cholestanol. When steroids were discontinued, markedly elevated serum cholestanol was measured concomitant with marked clinical worsening. This observation may imply that steroids can lower plasma cholestanol, possibly by directly inducing residual CYP27A1 activity or by inducing alternative pathways for cholestanol elimination.