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Hypersomnia is a common complaint in many patients with neurodegenerative diseases and a major cause of decreased quality of life. This article discusses the prevalence and factors associated with hypersomnia in patients with a variety of neurodegenerative diseases affecting the central nervous system, including tauopathies, synucleinopathies, and other conditions. Common nocturnal sleep problems that may result in daytime hypersomnia are delineated. A clinical approach to hypersomnia in patients with neurodegenerative diseases, recommended diagnostic testing, and available treatment options are also discussed., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Sleep disorders and neurologic illness are common and burdensome in their own right; when combined, they can have tremendous negative impact at an individual level as well as societally. The socioeconomic burden of sleep disorders and neurologic illness can be identified, but the real cost of these conditions lies far beyond the financial realm. There is an urgent need for comprehensive care and support systems to help with the burden of disease. Further research in improving patient outcomes in those who suffer with these conditions will help patients and their families, and society in general., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Introduction: Cardiac parasympathetic hypofunction has been reported in autism spectrum disorders (ASD). This usually is linked to respiratory dysrhythmia which has been documented in some children with ASD., Objectives: This study evaluated the cardiorespiratory functions in ASD to elucidate the physiologic basis of behaviors., Methods: Nineteen children with ASD and 18 age matched controls underwent autonomic function monitoring at a defined resting state using the NeuroScope. The non-invasive real time beat-to-beat blood pressure was measured by Portapres and fed into the NeuroScope where heart rate, cardiac vagal tone and cardiac sensitivity to baroreceptor were derived from the EKG and blood pressure waveforms using the Vagosoft software; and respiratory rate and rhythm were measured simultaneously by plethysmograph. Respiration was analyzed breath by breath using our prior published methods., Results: Various respiratory dysrhythmias, particularly Biot's and Cheyne-Stokes respiration, were detected in children with ASD, who also exhibited greater variability in respiratory rhythm and amplitudes than controls. The respiratory dysrhythmia in children with ASD was associated with a lower cardiac vagal activity., Conclusion: The Biot's breathing and Cheyne-Stokes respiration coupled with cardiac vagal hypofunction in ASD suggest a brainstem dysfunction consistent with our previous findings. The low parasympathetic activity could explain in part the chronic sensory hyperarousal state in children with ASD., (Published by Elsevier B.V.)

This cross-sectional study explored the extent and impact of mobile device-based Sleep Time-Related Information and Communication Technology (STRICT) use among American adolescents (N = 3139, 49.3% female, mean age = 13.3 years). Nearly 62% used STRICT after bedtime, 56.7% texted/tweeted/messaged in bed, and 20.8% awoke to texts. STRICT use was associated with insomnia, daytime sleepiness, eveningness, academic underperformance, later bedtimes and shorter sleep duration. Moderation analysis demonstrated that the association between STRICT use and insomnia increased with age, the association between STRICT use and daytime sleepiness decreased with age, and the association between STRICT use and shorter sleep duration decreased with age and was stronger in girls. Insomnia and daytime sleepiness partially mediated the relationship between STRICT use and academic underperformance. Our results illustrate the adverse interactions between adolescent STRICT use and sleep, with deleterious effects on daytime functioning. These worrisome findings suggest that placing reasonable limitations on adolescent STRICT use may be appropriate., (Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.)

Restless legs syndrome (RLS) mimics cannot always be differentiated from RLS/Willis-Ekbom disease (WED) based on 4 essential criteria; hence, a fifth criterion has recently been established. RLS comorbidities may provide us important clues for understanding the neurobiology of RLS/WED. Iron-dopamine connection, hypoxia pathway activation, and dopamine-opioid interaction are important pathophysiological mechanisms in RLS; this knowledge is derived from our understanding of RLS associations with a variety of medical, neurologic, and other conditions. Clinicians must formulate an RLS differential diagnosis based on history and physical examination, but laboratory tests may sometimes be needed to arrive at a correct diagnosis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We present 2 patients in whom the predominant neurological complication following lightning strike was spinal cord injury. One patient, who was followed for 5 years, showed clinical, electrophysiologic and MRI evidence of cervical spinal cord injury. This patient had significant recovery, which in part, may be related to early and intense rehabilitation. The second patient presented with the symptoms and signs of spinal shock which then evolved into a myelopathy. Follow-up several months later showed almost complete resolution of symptoms. These patients demonstrate that the prognosis of spinal cord injury complicating a lightning strike may not be uniformly poor.

Objective: To measure changes in blood pressure and pulse rate associated with periodic limb movements in sleep (PLMS) in patients with restless legs syndrome (RLS)., Methods: We measured autonomic activation as indicated by a rise in blood pressure and pulse rate during periodic limb movements in sleep (PLMS) in 8 patients (6 women average age 57.6+/-16.5 yr and 2 men average age 34+/-28 yr) with RLS. The patients had overnight polysomnographic (PSG) recordings with continuous monitoring of blood pressure (BP) and heart rate (HR). The patients were asked to perform voluntary movements mimicking PLMS (Fake PLMS) which served as controls for PLMS during PSG. We analyzed 601 movements: 145 periodic limb movements in wakefulness (PLMW), 173 periodic limb movements in sleep with cortical arousal (PLMSA), 168 periodic limb movements in sleep without cortical arousal (PLMSNA) and 115 respiratory related limb movements (RRLM)., Results: There was a statistically significant rise in systolic blood pressure (SBP), diastolic blood pressure (DBP) after PLMW (SBP 11.7+/-7.6 mm Hg), PLMSA (SBP 16.7+/-9.4 mm Hg), PLMSNA (SBP 11.2+/-8.7 mm Hg) and RRLM (SBP 18.9+/-14.9 mm Hg) which exceeded that seen with Fake PLMS (SBP 3.2+/-3.1 mm Hg) in wakefulness. There were comparable increases in heart rate that did not quite reach statistical significance., Conclusions: There is a rise in SBP, DBP and HR with PLMW, PLMSNA, PLMSA and RRLM as compared to Fake PLMS., Significance: One possibility is that the concomitant rise in the blood pressure and heart rate after periodic limb movements indicating autonomic activation may have long-term adverse cardiovascular consequences. This remains to be determined in future experiments.

Objectives: Proximal myotonic myopathy (PROMM) is a multisystem disorder that may mimic myotonic dystrophy (MD). Previously we demonstrated that the 60 s exercise test was normal in two siblings with PROMM. The test enabled distinction of PROMM from MD, as there is a well documented immediate post-exercise compound muscle action potential (CMAP) amplitude decline in MD., Methods: We now performed exercise testing using several exercise durations in 8 PROMM patients from 6 kinships, and one MD patient, extending our previous observations. Repetitive stimulation and needle electromyography findings were also recorded., Results: The 10 (n = 8), 30 (n = 5), and 60 (n = 5) s, and the 5 min (n = 1) exercise tests were normal in all PROMM patients. Specifically, the maximum post-exercise CMAP amplitude decline was 8%. In contrast, the MD patient had CMAP amplitude declines of 48% (10 s exercise test) and 26% (30 s exercise test). The distribution of repetitive stimulation and motor unit duration abnormalities were variable and less diagnostically useful., Conclusions: The 10, 30, and 60 s exercise tests help distinguish PROMM from MD. As the 10 s exercise test is rapid and easily tolerated, we recommend this test for clinical testing.

Objectives: Routine carpal tunnel electrodiagnosis frequently includes median (MPW) and ulnar (UPW) palm-wrist mixed nerve conduction latency determinations over 8 cm. Despite widespread use, normative palmar latency difference (PLD) and UPW values, and the relative utility of onset latency (OL) or peak latency (PL) measurements are controversial. The current study was conducted to determine normative values for these parameters., Methods: MPW and UPW studies were performed unilaterally in 33 normal controls. The PLD-OL and PLD-PL were calculated. The mean, range, standard deviation, and upper limits of normal were determined. 74 hands (50 patients) with both clinical and electrophysiologic median neuropathy were also studied., Results: The abnormal MPW and UPW cut-offs were both 1.8 ms (OL), and 2.3 ms (PL). The abnormal PLD cut-offs were 0.5 ms (OL and PL). Using either OL or PL, PLD parameters were similar within controls, and also within CTS patients. Using either OL or PL, UPW parameters were similar between controls and CTS patients., Conclusions: An abnormal PLD cut-off of 0.5 is recommended. This is slightly higher than some prior recommendations, however it should minimize the likelihood of false positive studies. Onset and peak latency measurements are likely to have similar clinical utility.

We describe short-term and long-term safety studies after low repetition rate magnetic brain stimulation in 10 normal subjects. We obtained quantitative EEG data, psychometric test results, serum prolactin and cortisol levels before and after brain stimulation. EEG and psychometric data were also obtained in 5 of these subjects 16-24 months after the initial experiment. Short- and long-term studies did not show any deleterious effects. Randt delayed recalls, however, showed a transient reduction in the score immediately after stimulation which resolved on retesting in 2 weeks. To address the question of fatigue we repeated Randt tests in 4 subjects before and after magnetic brain stimulation but without the other extensive psychometric, EEG and blood tests. Pre- and post-stimulation scores on this occasion showed no significant difference in these 4 subjects suggesting that the transient changes in the previous Randt score were related to fatigue. We conclude that single-pulse magnetic brain stimulation has no deleterious effects after magnetic brain stimulation.

We describe the technique of magnetic coil (MC) stimulation of the lumbosacral roots and the possible site of stimulation in 22 control subjects, and the clinical usefulness of MC stimulation in 5 patients with low back pain. We observed 2 components in the compound muscle action potential of the soleus muscle following MC stimulation over the lumbosacral region. The second component had the physiological properties of the H reflex. The conduction time from the anterior horn cells of the lumbosacral spinal cord to the site of nerve root stimulation over the lumbosacral vertebral column was indirectly calculated as between 3.9 and 4.1 msec. Assuming a conduction velocity of 50 m/sec this would represent a distance of approximately 20 cm from the spinal motor neurons. Based on our control and patient data we conclude that the MC stimulation may be an useful technique for the diagnosis of lumbosacral radiculoplexopathy.

Because quantitative norms for the normal audiogenic startle response to repeated stimuli have not been previously reported, we now describe a technique for eliciting the startle response and analysing its habituation with repeated stimuli. We used binaural 105 dB tones delivered in 5 blocks of 4 tones. Successive blocks were separated by a 5 min period without tones stimuli and had progressively shorter inter-stimulus intervals (ISIs) beginning with 5 min in the first block and reducing to 1 min in the final, fifth block. We contrast the response and its habituation in a group of 8 normal subjects with that in a patient with clinically exaggerated startle. Based on the differences observed, we propose that the following criteria may be used to ascertain an abnormally increased startle response: (1) excessive duration of the myogenic response; (2) persistence of extracranial responses after the initial two blocks of stimuli; and (3) reduced habituation of the response (as measured by decreases in response duration and in the area under the curve of rectified EMG for the orbicularis oculi myogenic response). Our patient was abnormal on each of these measures. This result is consistent with past qualitative reports which have indicated that abnormal startle is associated both with excessive startle and with subnormal habituation. Study of further patients with hyperekplexia will be necessary to either confirm our data or modify our proposed criteria.

In order to understand which neural elements are excited after percutaneous magnetic coil (MC) stimulation over the cervical vertebral column we have performed such study in 8 normal subjects and 4 patients. On moving the coil rostrocaudally up to 3 cm and horizontally up to 2 cm from the midline we found no change in the latencies of the compound muscle action potentials to biceps, deltoid, abductor pollicis brevis (APB) and abductor digiti minimi muscles indicating a fixed site of excitation of the spinal roots within the intervertebral foramina. F latencies to APB after stimulation of the median nerve at the wrist were always longer than the direct latencies obtained after cervical vertebral stimulation. The mean difference between indirect latency based on F technique and direct latency to APB was 0.45 msec which represented a distance of 2.7 cm distal to the anterior horn cells assuming a conduction velocity of 60 m/sec. MC stimulation in 2 patients suggested a diagnosis of cervical radiculopathy which was confirmed by imaging studies or operative findings. Both MC and needle root stimulation in one patient with diabetic brachial plexopathy and in another with diabetic polyneuropathy suggested that the needle stimulation occurred about 1.2-1.8 cm proximal to MC stimulation.

During a 20 month period, EEGs in 7 patients, ages 6-16 years, showed a distinctive posterior rhythmic slow (PRS) activity brought on by eye closure. Following eye opening for 5-10 sec, eye closure on command was followed by a rhythmic high amplitude (100-250 microV) slow wave discharge of 3-4 c/sec lasting for 1.5-3 sec after a latency of 300-500 msec. Its distribution was limited to the occipital, posterior temporal and parietal regions. It was always bilaterally synchronous, occurred symmetrically or asymmetrically and fatigued easily. Of the 7 initial EEGs, only 2 had other EEG abnormalities. One patient, in a subsequent EEG, developed spontaneous PRS unrelated to eye closure. Clinical histories on the 7 patients showed 5 with various types of seizure disorders, 1 with attention deficit disorder, and 1 with Tourette syndrome. Neurological examination was normal in all patients, while computerized tomography or radioisotope brain scan was normal in 4. We suggest that PRS after eye closure represents a variant of the non-specific spontaneously occurring PRS described by Aird and Gastaut and others. It was found only in children and was not found to be helpful in diagnosing a seizure disorder or structural abnormality. Furthermore, such a discharge should not be interpreted as epileptiform activity.

Seventeen patients with sleep apnea were studied with reference to the frequency and duration of apneic episodies, the mechanism of the apnea and the extent to which oxygen saturation was depressed by the apnea. In all patients, esophageal pressure was recorded simultaneously with respiratory magnetometer records of rib cage and abdominal motion. Thermistor records from the nose and mouth indicated the presence of apnea. Nine patients had purely obstructive apnea and eight a mixture of central and obstructive apnea. In all instances the magnetometer records alone permitted distinction between obstructive and central apnea. Inspiratory efforts against an occluded airway produced a very different pattern of motion when compared to unobstructed breathing or to central apnea. We propose that magnetometer monitoring of thoracoabdominal motion indicates upper airway obstruction reliably and provides a noninvasive and thus more acceptable alternative to esophageal pressure recording for detecting upper airway obstructive apnea.

Ten adult brain-dead patients were evaluated for the presence of clearly defined median nerve short-latency somatosensory evoked potentials (SSEPs). All met clinical criteria recommended by the President's Commission report (1981), had positive apnea tests, and had electrocerebral silent EEGs. P13-P14 and N20 were absent in all scalp-scalp channels, although 3 patients showed P13-P14 in scalp-non-cephalic channels. Of 6 patients showing N13, 3 lacked P13-P14. Our data suggest a characteristic destruction of N20 and rostral P13-P14 generators, with variable rostral-caudal loss of lower generators. SSEPs can provide valuable information about brain-stem activity in the evaluation of suspected brain-dead patients.