Combined brain voxel-based morphometry and diffusion tensor imaging study in idiopathic restless legs syndrome patients.

BACKGROUND AND PURPOSE: The aim of this study was to evaluate the presence of abnormalities in the brain of patients with restless legs syndrome (RLS) using voxel-based morphometry and diffusion tensor imaging (DTI). METHODS: Twenty patients and twenty controls were studied. Voxel-based morphometry analysis was performed using statistical parametric mapping (SPM8) and FSL-VBM software tools. For voxel-wise analysis of DTI, tract-based spatial statistics (TBSS) and SPM8 were used. RESULTS: Applying an appropriate threshold of probability, no significant results were found either in comparison or in correlation analyses. CONCLUSIONS: Our data argue against clear structural or microstructural abnormalities in the brain of patients with idiopathic RLS, suggesting a prevalent role of functional or metabolic impairment.

Increased prevalence of nocturnal smoking in restless legs syndrome (RLS).

OBJECTIVE: We investigated the prevalence of nocturnal smoking (NS) in patients with RLS. METHODS: One hundred RLS patients living in Emilia-Romagna (Northern Italy) and 100 matched controls, randomly selected from the general population, underwent interviews for the presence of nocturnal smoking and for obsessive-compulsive traits, depression, excessive daytime sleepiness (EDS) and subjective sleep quality. RESULTS: NS was more prevalent in RLS patients than controls (lifetime prevalence: 12% vs. 2%, P=0.012). Patients with NS had more frequently Sleep-Related Eating Disorders (SRED) than patients without NS (83.3% vs. 26.1%, P=0.0002). Pathological and borderline Maudsley Obsessive-Compulsive Inventory (MOCI) values as well as pathological values at the Beck Depression Inventory (BDI) increased from controls to RLS patients without NS to RLS patients with NS (P=0.005 and P=0.01, respectively). CONCLUSIONS: We demonstrate an increased prevalence of NS in patients with RLS, in many cases associated with increased SRED. NS may be associated with psychopathological traits in RLS and may be relevant in the management of RLS patients.

Sleep-related smoking syndrome.

OBJECTIVE: We describe six patients affected by frequent episodes from sleep associated with compulsive smoking and/or eating. Patients woke up with a desire to smoke and/or eat because of an "inner" drive. METHOD: Video-polysomnography (VPSG) was performed in three patients. RESULTS: VPSG documented a normal sleep structure with an increased arousal index. CONCLUSION: Compulsive eating during sleep has been classified as sleep-related eating syndrome or Nocturnal eating syndrome, but its association with compulsive smoking has not been previously reported.

Rare mtDNA variants in Leber hereditary optic neuropathy families with recurrence of myoclonus.

OBJECTIVE: To investigate the mechanisms underlying myoclonus in Leber hereditary optic neuropathy (LHON). METHODS: Five patients and one unaffected carrier from two Italian families bearing the homoplasmic 11778/ND4 and 3460/ND1 mutations underwent a uniform investigation including neurophysiologic studies, muscle biopsy, serum lactic acid after exercise, and muscle ((31)P) and cerebral ((1)H) magnetic resonance spectroscopy (MRS). Biochemical investigations on fibroblasts and complete mitochondrial DNA (mtDNA) sequences of both families were also performed. RESULTS: All six individuals had myoclonus. In spite of a normal EEG background and the absence of giant SEPs and C reflex, EEG-EMG back-averaging showed a preceding jerk-locked EEG potential, consistent with a cortical generator of the myoclonus. Specific comorbidities in the 11778/ND4 family included muscular cramps and psychiatric disorders, whereas features common to both families were migraine and cardiologic abnormalities. Signs of mitochondrial proliferation were seen in muscle biopsies and lactic acid elevation was observed in four of six patients. (31)P-MRS was abnormal in five of six patients and (1)H-MRS showed ventricular accumulation of lactic acid in three of six patients. Fibroblast ATP depletion was evident at 48 hours incubation with galactose in LHON/myoclonus patients. Sequence analysis revealed haplogroup T2 (11778/ND4 family) and U4a (3460/ND1 family) mtDNAs. A functional role for the non-synonymous 4136A>G/ND1, 9139G>A/ATPase6, and 15773G>A/cyt b variants was supported by amino acid conservation analysis. CONCLUSIONS: Myoclonus and other comorbidities characterized our Leber hereditary optic neuropathy (LHON) families. Functional investigations disclosed a bioenergetic impairment in all individuals. Our sequence analysis suggests that the LHON plus phenotype in our cases may relate to the synergic role of mtDNA variants.

Catathrenia (nocturnal groaning): an abnormal respiratory pattern during sleep.

Catathrenia (nocturnal groaning) is a rare condition characterized by monotonous irregular groans occurring during sleep. Ten patients (five women; mean age: 27 +/- 7.4 years, range: 15-41) with sleep-related groaning persisting for years or decades and normal daytime fibreoptic laryngoscopy and respiratory function tests underwent videopolysomnographic recording (VPSG) analysing their respiratory patterns during sleep. After the VPSG, all patients were clinically followed up for a mean period of 4.9 +/- 3.5 years. On VPSG, all patients showed nocturnal groaning during NREM sleep and particularly during REM sleep stages. Groaning was associated with disproportionate prolonged expiration causing reduced breathing rate without oxygen desaturation. The breathing pattern with prolonged expiration and sound production alternated with a normal respiratory pattern without groaning. Endoesophageal pressure during groaning showed mildly positive swings at the initial phase of expiration suggesting a partial mild expiratory upper airway obstruction. At the end of the follow-up period, all patients reported persistent nocturnal groaning but no other clinical manifestations. Groaning confined to sleep alternating with normal breathing and the absence of long-term clinical consequences suggest that catathrenia is because of an abnormality of the internal respiratory drive system, possibly related to persistence of a neonatal (vestigial) type of breathing pattern.

Sleep--wake and body core temperature rhythms in multiple sclerosis with fatigue.

OBJECTIVE: To study sleep-wake and body core temperature (BCT) circadian rhythms in patients with multiple sclerosis (MS)-associated with chronic fatigue. METHODS: Six relapsing-remitting MS patients with chronic fatigue underwent 48 consecutive hours polysomnography (PSG) with BCT measurement, followed by a Multiple Sleep Latency Test (MSLT). All patients were relapse- and drug-free. Mood depression, brain and cervical cord enhanced MRI, dynamic spirometry and Fatigue Severity Scale (FSS) were assessed just before PSG. RESULTS: In all patients mood depression was absent and dynamic spirometry normal, but FSS confirmed fatigue. MRI showed non-enhancing lesions. Nocturnal sleep was characterized by normal architecture and mean sleep efficiency was only slightly reduced. Arousal index was normal and periodic limb movements during sleep (PLMS) were present in four patients, with an increased index (PLMS-I) in only two of them. Upon MSLT, mean sleep latency was normal in all patients with one sleep onset REM period in one patient. All patients displayed a normal BCT 24-h rhythm. Mesor, amplitude and acrophase of BCT rhythm did not show significant differences between MS and controls. CONCLUSIONS: We found substantially normal sleep-wake and BCT rhythmicity in six patients with MS and fatigue. Non-restorative sleep and abnormal BCT regulation were unlikely mechanisms of chronic fatigue in our MS patients. SIGNIFICANCE: Subjective fatigue and abnormal sleep and BCT can be independent manifestation in MS patients. The findings support the notion that objective measures of fatigue comparable to the MSLT for sleepiness do not exist.

Sleep-related breathing disorders and headache.

Obtructive sleep apnoea syndrome (OSAS) is a common disorder in the general population with an estimated prevalence in an adult population of 2% in women and 4% in men. Although several studies have suggested that headaches, particularly morning headaches, are more common in patients with OSAS than in normal subjects, others have yielded contradictory findings. When the sleep-related breathing disorder was treated with success, the headache generally disappeared, supporting a causal role of the sleep disorder for headache. Several hypotheses have been proposed to explain the relationship between OSAS and the occurrence of headache, particularly on awakening. Night-time fluctuations of oxygen saturation during the night with hypercapnia, vasodilatation, increased intracranial pressure and impaired sleep quality are all considered contributing factors. However the exact mechanisms of headache pathogenesis and the relationship between OSAS, headache and morning headaches in particular remain controversial.

Propriospinal myoclonus at sleep onset.

AIMS: To describe the clinical and polygraphic features of propriospinal myoclonus (PSM) at sleep onset. MATERIAL AND METHODS: PSM was first described in 1997 in patients with jerks occurring in the relaxation period preceding sleep. EMG showed jerks to arise in spinally innervated muscles, propagating thereafter to rostral and caudal muscles at a low speed, typical of propriospinal pathways. RESULTS: PSM arose when EEG alpha activity spread over the scalp and disappeared during either active wakefulness or actual sleep. In some patients EMG activity could sometimes remain localized to the abdominal muscles, propagating to other segments only in fully developed jerks. Neurological examination, brain and spinal MRI were usually normal and clonazepam afforded partial improvement. PSM has been recently observed also in restless legs syndrome, during relaxed wakefulness preceding falling asleep, coexisting with motor restlessness and sensory discomfort. PSM disappeared when spindles and K-complexes and typical Periodic Limb Movements appeared with EMG activity limited to leg muscles, without propriospinal propagation. CONCLUSIONS: Conceivably, PSM arises in axial muscles due to some spinal generator set into motion by facilitating influences characteristic of the wake-sleep transition and then undergoes multimeric propriospinal propagation. In the International Classification of Sleep Disorders (ICSD-2), PSM is listed in chapter VII, among the "Isolated symptoms, apparently normal variants and unresolved issues".

Sleep-related non-epileptic motor phenomena.

We describe the clinical, neurophysiological and polysomnographic characteristics of some involuntary motor nocturnal events occurring during sleep or at the transition from wakefulness to sleep.

Sleepwalking and other ambulatory behaviours during sleep.

Different pathological conditions may lead to somnambulic automatisms arising from nocturnal sleep. Video polysomnography represents the diagnostic tool but, due to the difficulty of capturing complex episodes in the sleep laboratory, audio-video recordings at home of the episodes may help in the differential diagnosis also. Sleepwalking is a disorder of arousal in which the subject arises from deep sleep, even displaying long complex behaviour, including leaving the bed and walking, with memory impairment of the event. Disordered arousal mechanisms with an inability of the brain to fully awaken from slow-wave sleep are thought to lead to these motor automatisms. REM sleep behaviour disorders begin during REM sleep and are accompanied by features of REM sleep. The motor behaviour may be violent and injurious to the patient and/or bed partner. In some patients, however, the behaviour may be similar to that observed in sleepwalking and some patients have an overlap syndrome. In nocturnal frontal lobe epilepsy in particular, and in complex partial seizures in general, stereotypic and repetitive motor attacks may recur, at any time, on the same night and on different nights, with a continuum between minimal or minor attacks and major or prolonged episodes up to agitated epileptic nocturnal wanderings.

A pilot double-blind placebo-controlled trial of low-dose pramipexole in sleep-related eating disorder.

Sleep-related eating disorder (SRED) is characterized by recurrent arousals from sleep associated with compulsive ingestion of food. No controlled therapeutic trials are available for SRED. We assessed the safety, tolerability and efficacy of pramipexole, a dopamine D3-receptor agonist, in the treatment of SRED. Eleven consecutive patients with SRED in the absence of concurrent daytime eating disorders underwent actigraphic recording and subjective sleep diary evaluation for a week before and every week for 2 weeks of treatment with pramipexole 0.18-0.36 mg or placebo, administered in a double-blind crossover randomized sequence. The primary outcomes of the trial were actigraphic measures of night sleep parameters (sleep efficiency, motor activity mean and median, number and duration of wake episodes), secondary outcomes were the number of good sleep nights/weekly, number and duration of nocturnal awakenings/night, and visual analogue preference score. Pramipexole was well tolerated without any patient withdrawing from the study. Pramipexole reduced night-time activity median (P = 0.02) and increased the number of nights of good sleep/week (P = 0.02). All other measurements remained unaffected. Pramipexole at low doses was well tolerated, improving some measures of sleep quality and reducing median night activity in SRED. Further studies with higher dosages and for longer time-periods are warranted.

Paroxysmal arousal in epilepsy associated with cingulate hyperperfusion.

A patient with nocturnal frontal lobe epilepsy characterized by paroxysmal motor attacks during sleep had brief paroxysmal arousals (PAs), complex episodes of nocturnal paroxysmal dystonia, and epileptic nocturnal wandering since childhood. Ictal SPECT during an episode of PA demonstrated increased blood flow in the right anterior cingulate gyrus and cerebellar cortex with hypoperfusion in the right temporal and frontal associative cortices.

Bilateral paramedian thalamic syndrome: abnormal circadian wake-sleep and autonomic functions.

OBJECTIVES: To describe wake-sleep and body core temperature (t degrees ) rhythm abnormalities in two patients with bilateral paramedian thalamic calcifications. METHODS: Patients underwent (18F)FDG PET scans and 24 hour polygraphic recordings of wake-sleep and t degrees. RESULTS: PET showed bilateral thalamic hypometabolism in both patients with additional basal ganglia or mesiolateral frontal and cingular hypometabolism. Wake-sleep studies showed abnormal sleep organisation and in the case with frontal and limbic PET hypometabolism, pre-sleep behaviour associated with "subwakefulness" EEG activities, lack of EEG spindles and K complexes, and features of status dissociatus. The t degrees rhythms showed increased mesor in both (37.4 degrees C and 37.75 degrees C) and inverted rhythm in one patient. CONCLUSIONS: Paramedian thalamic structures and interconnected, especially frontal and cingular, areas play a part in the organisation of the wake-sleep cycle and attendant autonomic functions.

Familial nocturnal facio-mandibular myoclonus mimicking sleep bruxism.

A mother and son presented with a multi-decade history of nocturnal tongue biting and bleeding. In both patients, video polysomnographic recordings documented bursts of electromyographic activity originating in the masseter and spreading to orbicularis oris and oculi muscles, present only during sleep. Faciomandibular myoclonic activity during sleep mimics sleep bruxism and may be familial.