Seizures in the peripartum period: Epidemiology, diagnosis and management.

The occurrence of seizures in the peripartum period is a rare but particularly challenging situation. Seizures in the peripartum period could result from three categories of conditions: first and most frequent is the exacerbation of a known pre-existing seizure disorder, mainly epilepsy. A therapeutic evaluation is needed; second is the new onset of seizures due to a non-pregnancy-related problem. An accurate diagnosis and a specific treatment are required; third is range of pregnancy-related conditions. The present review focuses on this third category, with a special attention to disorders occurring in the peripartum period. It is structured in two sections. The first section is a focus on eclampsia since, based on ICU admission data, it appears to be the leading cause of pregnancy-related seizures. Its epidemiology, pathophysiology, clinical diagnosis, neuro-imaging features and recommended management are reviewed. The efficacy and safety of the recommended regimens of MgSO4 therapy are discussed, as well as controversies on the alteration of these regimens and the use of MgSO4 in women with mild preeclampsia. In the second section, the other causes of pregnancy-related new onset seizures are summarized. These include posterior reversible encephalopathy syndrome, reversible cerebral vasoconstriction syndrome, cerebral venous sinus thrombosis, thrombotic thrombocytopenic purpura, amniotic fluid embolism, and air embolism. Noteworthy is the fact that most of these pregnancy-related seizure conditions overlap with each other, mainly in terms of clinical presentations and neuro-imaging. Therefore, the diagnosis and the treatment options should be considered on a multidisciplinary basis.

Elderly patients with epileptic seizures: in-patient observational study of two French community hospitals.

Epileptic seizures (ESs) in the elderly are recognized as frequent, and potentially difficult to diagnose. Their clinical features and relevant diagnostic problems still remain poorly investigated in hospital populations outside the setting of tertiary referral centres. In this study we attempted to improve the understanding of these aspects in community institutions. We conducted a four-year retrospective observational study of 104 consecutive elderly patients with the diagnosis of ES, in 2 French community hospitals. Most ESs were partial (n=50; 48.07%) but generalized ESs were also clinically frequent (n=41; 39.42%). Brain imaging was highly contributive for the diagnosis of partial ESs by demonstrating causative focal structural lesions. ESs were often unprovoked (n=82; 78.84%). Fifty six of these (68.29%) were symptomatic. Stroke lesions were the most identified cause (n=17; 20.73%). In 26 patients (31.70%) aetiology was unknown. Various diagnostic problems were identified. Inter-observer agreement between neurologists and non-neurologists based on clinical judgement was only "fair" (kappa coefficient: 0.28; 95% CI; p=0.002). ESs were initially misdiagnosed in 28 patients (26.92%). The misdiagnosis rate was higher among non-neurologists (n=25; 89.28%) as compared to neurologists (n=8; 28.57%) (p<0.0001). The presence of focal neurological abnormalities was an important diagnostic indicator of a positive diagnosis of ES. In conclusion, ESs in the elderly are generally partial, unprovoked and symptomatic, and caused by stroke-related lesions. Many are still overlooked, highlighting the important role of specialist input and rigorous clinical evaluation for diagnostic confirmation.

Sleep architecture, slow wave activity and sleep spindles in mild sleep disordered breathing.

OBJECTIVE: A high degree of sleep fragmentation by arousals related to respiratory events would result in an abnormal distribution of slow wave activity (SWA) and a decrease in sleep spindle density in sleep disordered breathing (SDB) patients when compared to controls. METHODS: Eighteen mild SDB subjects (6 females and 12 males), aged 18-56 years with (5

Age at onset of narcolepsy in two large populations of patients in France and Quebec.

BACKGROUND: Narcolepsy usually starts around adolescence; however, there is great variability in the clinical presentation of narcolepsy. OBJECTIVE: To determine the age at onset in conjunction with severity of narcoleptic symptoms in two large populations of narcoleptic patients with a similar genetic background. METHODS: Information on age at onset and severity of the condition was obtained in 317 patients with well-defined narcolepsy-cataplexy from Montpellier (France) and in 202 from Montreal (Canada). RESULTS: The mean age at onset was 23.4 years in Montpellier and 24.4 in Montreal. The age at onset was bimodal in two independent patient populations: a first peak occurring at 14.7 years, and a second peak occurring at 35. Age at onset clearly differentiates patients with a positive family history of narcolepsy (early onset) from those without a family history. Other clinical and polygraphic findings may indicate that young age at onset is associated with increased severity of the condition (higher frequency of cataplexy and decreased mean sleep latency on the Multiple Sleep Latency Test). CONCLUSION: Bimodal distribution of age at onset of narcolepsy was found in two independent patient populations. Our data suggest that age at onset is genetically determined.

[Disorders of awakening. Second part: secondary disorders]. / Troubles de l'éveil.

Secondary disorders of awakening should be distinguished from primary disorders, narcolepsy, idiopathic hypersomnia, recurrent hypersomnia, the causes of which are still unknown despite regular progress in the knowledge of the pathophysiology of narcolepsy. By definition secondary disorders of awakening are due to clearly identified causes of various origins. Two main types of secondary disorders of awakening have been distinguished: those depending on more or less voluntary sleep curtailment or on psychotropic or non psychotropic medications and those consecutive to different disorders, respiratory, neurologic, traumatic, psychotropic, infectious, metabolic, endocrinologic, and insomnia. Some of these disorders, frequent or very frequent, are polysomnographically investigated, night and day, enabling to assess in each case the type and severity of sleepiness. Others are only clinically evaluated. Disorders of awakening secondary to neurologic conditions and to a lesser extent to infectious conditions offer a special opportunity to study the anatomical basis of these disorders. They are granted more space.

[Advanced sleep phase syndrome]. / Le syndrome d'avance de phase du sommeil.

The Advanced Sleep Phase Syndrome (ASPS) is a sleep disorder characterized by an early sleep onset and early awakening without any disturbance of the sleep structure. The management of this disease requires clinical and laboratory investigations in an attempt to confirm the phase advance of body core temperature and melatonin rhythm. The use of light therapy, possibly associated with chronotherapy or melatonin intake has been proposed. The evolution is variable. Seven subjects, aged 15 to 72 were diagnosed in our sleep disorders unit by mean of sleep log, actigraphy, sleep and temperature recording. The sleep onset and sleep offset times were approximately the same according to sleep log, actigraphy and night polysomnography. The nadir of body core temperature was at 01:38 +/- 01:03. Two familial cases were identified of which 1 was investigated in constant routine condition with hourly blood sampling. An advanced phase of melatonin and cortisol was evidenced. The disease temporarily improved in 3 cases with light therapy and in one case with the association of light therapy and chronotherapy. These data show the difficulties of the management and the treatment of this rarely diagnosed disease.

EEG arousals and awakenings in relation with periodic leg movements during sleep.

It is known that periodic leg movements are frequently accompanied by full awakenings or by signs of EEG arousals. The time relationship of these EEG arousals with leg movements varies from patient to patient. They may precede or follow leg movements or occur simultaneously. It is not clear whether these arousals trigger leg movements or, alternatively, whether both EEG arousals and leg movements are separate expressions of a common pathophysiological mechanism. We investigated the temporal relationship of five EEG arousals, such as alpha activity, K-complexes, spindles, K-alpha, K-spindle activities and awakenings, with leg movements in 10 periodic leg movement patients. These EEG arousals were considered to be associated with leg movements if they occurred 10 s before/after or simultaneously with the onset of right or left tibialis muscle EMG potentials. It was found that 49.19% of EEG arousals occurred before leg movements, 30.61% occurred simultaneously and 23.18% occurred just after leg movements. The number of EEG arousals was significantly higher in the 10 s preceding leg movement than simultaneously or in the 10 s following. Alpha activity was the phenomenon associated most frequently with leg movements, irrespective of its temporal organization and was significantly higher during the 10 s preceding movement. Spindle and K-spindle activities were significantly higher before leg movement, whereas K-complex activity was significantly more frequent during leg movements. The number of awakenings was significantly higher after leg movements than simultaneously. These results indicated that leg movements are not primary, but rather are a phenomenon associated with an underlying arousal disorder.

Are periodic leg movements during sleep (PLMS) responsible for sleep disruption in insomnia patients?

On the basis of polygraphic findings, it has been suggested that periodic leg movements during sleep are not responsible for sleep impairment (Lugaresi et al., 1972). However, for some authors it is an important cause of insomnia (Guilleminault et al., 1975; Coleman, 1982). Thus, the relationship between periodic leg movements during sleep, sleep disruption and the complaint of patients is particularly complex. We investigated the macro- and micro-structure of sleep with and without leg movements in 10 PLMS patients complaining of insomnia to clarify whether periodic leg movements are responsible for sleep disruption. The total sleep time without periodic leg movements was significantly longer than sleep time with leg movements. Sleep time without leg movements was longer than sleep time with leg movements in stage 2, slow wave sleep (SWS) and rapid eye movement (REM) sleep. Short lasting awakenings were significantly more frequent during periodic leg movements associated sleep whilst long lasting awakenings were equally frequent during sleep with and without periodic leg movements. The percentage of the four electroencephalogram (EEG) activities (delta, theta, alpha and spindles) did not show any significant difference between periodic leg movements associated and not associated with sleep stages and total sleep time. The lack of significant differences in both the macro- and micro-structure of sleep and EEG activity content regarding the association with movements confirm the hypothesis that periodic leg movements did not primarily cause sleep disturbance.

Sleep architecture, slow wave activity, and sleep spindles in adult patients with sleepwalking and sleep terrors.

OBJECTIVES: A very strong SWS intensity reflected by both an increased level of SWA and an abnormal sleep spindles distribution would be responsible for the major difficulty of parasomniac subjects in waking up from SWS, leading to episodes of parasomnia. METHODS: Eleven adult parasomniac subjects, 6 females and 5 males, with sleepwalking (SW) and/or sleep terrors (ST) and 11 age- and sex-matched control subjects underwent polysomnography (PSG) during 2 consecutive nights. After an habituation and selection night followed by a 16 h period of controlled wakefulness, the sleep EEGs of the parasomniac and control subjects were analyzed on the second night by computer-aided visual scoring (integrated digital filtering analysis, IDFA) and spectral analysis (fast Fourier transform, FFT). Throughout the night subject behaviour was controlled and recorded by means of a video infra-red camera and videotape recorder. RESULTS: Fifteen episodes of parasomnia were recorded during the second night in the 11 subjects. Sleep analysis showed significantly (P<0.05) decreased sleep efficiency and stage 2 sleep (absolute values and percentage of total sleep time) and increased (P<0.05) slow wave sleep (absolute values and percentage of total sleep time). Arousal index and wake-time after sleep onset were significantly higher in parasomniac subjects. Sleep fragmentation was mainly concentrated in stages 3 and 4. The slow wave activity (SWA) absolute values averaged during the 2 min immediately preceding an episode of parasomnia were significantly higher than the SWA averaged during 2 min in the same stage 10 min before an episode of parasomnia. Moreover, SWA was higher in the slow wave sleep (SWS) episodes preceding the episode of parasomnia than in the episodes preceding an awakening without an episode of parasomnia. The temporal course of SWA showed a slower exponential decay in both groups, but the time constant of the curve was larger in parasomniacs than in controls. Finally, in control subjects the sleep spindle index increased from the beginning to the end of the night while it was equally distributed in parasomniacs. CONCLUSIONS: An abnormal deep sleep associated with a high SWS fragmentation might be responsible for the occurrence of SW or ST episodes.

[Arousal of respiratory origin and upper airway resistance syndrome: pathophysiological and diagnostic aspects]. / Arousals de origen respiratorio y síndrome de aumento de resistencia de la vía aérea superior: aspectos fisiopatológicos y diagnósticos.

INTRODUCTION: The description of Upper Airway Resistance Syndrome (UARS) let us to recognize the importance of the pair 'respiratory effort-arousal' on sleep-disordered breathing pathophysiology. DEVELOPMENT: First part of this paper reviews knowledge about respiratory arousal pathophysiology. Arousal response is normally needed to end obstructive respiratory episodes, but it is also the cause of sleep fragmentation. Among respiratory stimuli able to provoke arousal (respiratory effort, hypoxemia and hypercapnia), respiratory effort is the most constant. Neurophysiological mechanisms involved in arousal, sleep and vegetative consequences, and the possible role of non visible arousals, are also discussed. In UARS, because of the absence of apnea/hypopnea and significative O2 desaturations, arousals are induced by the increased respiratory effort. Diagnosis needs the simultaneous recording of polysomnography and esophageal pressure. Some symptoms and signs of UARS are similar to those of Obstructive Sleep Apnea Syndrome. However, UARS shows any differences: a lower Body Mass Index, less constant snoring, males and females are similarly affected or higher frequency of craniofacial abnormalities. Diagnostic difficulties may be due to confusion between hypopneas and episodes of increased resistance of upper airway, or to the lack of definitive diagnostic criteria. Finally, differential diagnosis needs a broad knowledge of disorders of excessive daytime sleepiness.

Idiopathic hypersomnia.

Identification of idiopathic hypersomnia dates back 20 years only. It typically consists of prolonged nocturnal sleep, great difficulty waking up in the morning or at the end of a nap, and constant or recurrent excessive daytime sleepiness. Complete and incomplete forms are encountered. Twenty-three subjects fulfilling ICSD criteria are reported with clinical, polysomnographic and immunogenetic data. Considering differential diagnosis is an important step in the diagnosis of idiopathic hypersomnia. Idiopathic hypersomnia is much less frequent than narcolepsy. A strong genetic component is suggested by the high proportion of familial cases. No association with HLA has been evidenced to date.

[Benign multiple sclerosis with childhood onset]. / Sclérose en plaques bénigne à début infantile.

We report a case of multiple sclerosis which began at the age of 12 years. Clinical symptoms at onset were acute, regressive cerebellovestibular ataxia and optic neuritis. Twenty-four years later vertigo, motor and sensory deficit of the right lower limb and grand mal seizures developed. CSF and MRI were suggestive of multiple sclerosis. The patient is now free of neurological symptoms with an 8 years' follow-up.

Hypersomnia associated with mood disorders: a new perspective.

Thirty-six subjects affected with hypersomnia associated with mood disorders, 31 with a diagnosis of dysthymia, 4 with a diagnosis of bipolar disorder and one with a diagnosis of major recurrent depression underwent standardized polysomnographic procedures including night 1, MSLT and night 2 (uninterrupted). 36.1% of these subjects had a reduced or intermediate mean sleep latency on the MSLT and 13.8% slept over 9 hr at night. In addition 17 of these subjects underwent prolonged polysomnography during day 2. In comparison with eight subjects affected with idiopathic hypersomnia, mean sleep latency on the MSLT was significantly longer and total sleep time during night 2 and during night 2 plus day 2 was significantly lower in subjects affected with hypersomnia associated with mood disorders. It is concluded that a positive diagnosis of hypersomnia associated with a mood disorder requires both behavioral observation and polysomnography. Among these subjects there may be subjects with well-documented hypersomnia and subjects with anergia facilitating or mimicking sleep.