Oculomotility disorders arising from disruptions in brainstem motor neuron development

The identification and analysis of pedigrees with rare congenital oculomotility syndromes has led to the definition of the congenital cranial dysinnervation disorders. These disorders appear to result from mutations in genes that are essential to the normal development and/or connectivity of cranial motoneurons. This review highlights the clinical features and genetic etiology of 3 congenital cranial dysinnervation disorders: the human homeobox A1 (HOXA1) syndromes, in which early motoneuron development is disrupted; horizontal gaze palsy with progressive scoliosis, in which there is aberrant axonal targeting onto abducens motoneurons; and congenital fibrosis of the extraocular muscles type 1, in which there is aberrant axonal targeting onto the extraocular muscles.     

Paroxysmal motor disorders of sleep: the clinical spectrum and differentiation from epilepsy

The diagnosis of paroxysmal events in sleep represents a significant challenge for the clinician, with the distinction of nocturnal epilepsy from nonepileptic sleep disorders often the primary concern. Diagnostic error or uncertainty is not uncommon in this situation, particularly with respect to nocturnal frontal lobe epilepsy (NFLE), which has a variable and often unusual presentation. Such errors can be minimized if the range of nonepileptic disorders with motor activity in sleep is fully appreciated. Here we review these disorders, before discussing the important clinical and electrographic features that allow their accurate differentiation from seizures. Particular emphasis is placed on the differentiation of nocturnal frontal lobe epilepsy from non-rapid eye movement (NREM) arousal disorders and other parasomnias. The value of recording episodes with video EEG polysomnography is discussed.     

Functional brain imaging in combined motor and sleep disorders

The pathophysiology of sleep-related motor diseases and sleep dysfunction in movement disorders is widely unknown as yet. Functional brain imaging, in particular radioisotope and magnetic resonance techniques, are powerful tools to investigate possible pathomechanisms of combined sleep and motor dysregulation. In patients with Restless legs syndrome (RLS), only a subtle striatal dopamine deficit was found in PET and SPECT despite a good treatment effect of dopaminergic drugs. Functional MRI suggested a central generator of periodic limb movements during sleep (PLMs) in RLS. In contrast, a marked striatal dopamine depletion was demonstrated in patients with REM sleep behaviour disorder (RBD) as the base for the clinical and nosological overlap of RBD with parkinsonian disorders. PET and SPECT also suggested that sleep abnormalities in Parkinson's disease (PD), such as REM sleep diminution or increased PLMs, are indirect manifestations of the primary striatal dopamine deficiency.     

The epileptic syndromes with continuous spikes and waves during slow sleep: definition and management guidelines

The authors propose to define the epileptic syndromes with continuous spikes and waves during slow sleep (CSWS) as a cognitive or behavioral impairment acquired during childhood, associated with a strong activation of the interictal epileptiform discharges during NREM sleep--whatever focal or generalized--and not related to another factor than the presence of CSWS. The type of syndrome will be defined according to the neurological and neuropsychological deficit. These syndromes have to be classified among the localization-related epileptic syndromes. Some cases are idiopathic and others are symptomatic. Guidelines for work-up and treatment are proposed.     

Paroxysmal non-epileptic motor events in childhood: a clinical and video-EEG-polymyographic study

Aim The aim of this article was to describe the phenomenology and polymyographic features of paroxysmal non‐epileptic motor events (PNMEs) observed in a series of typically developing and children with neurological impairment. Method We conducted a retrospective evaluation of 63 individuals (29 females; 34 males) affected by PNMEs at the National Neurological Institute ‘C. Besta’ between 2006 and 2008. Individuals were included in the study if they had PNMEs documented by a video‐electroencephalography–polymyographic study and were aged between 1 month and 18 years (mean age at the time of video‐electroencephalography–polymyography: 5y 10mo). Results In 45 of the 63 participants (71%), PNMEs were associated with other neurological conditions (secondary) including epilepsy, whereas in 18 participants PNME was the only neurological symptom (primary). Clinical features allowed classification of the motor disturbance into usual movement disorder categories in 31 individuals (49%); in the remaining 32 (51%), the movement disorder was characterized on the basis of polymyographic pattern of ‘jerks’ or ‘sustained contraction’. The most frequent PNMEs were paroxysmal dyskinesias, followed by startle, stereotypies, shuddering, sleep myoclonus, psychogenic movement disorders, and benign myoclonus of early infancy; the last syndrome was also observed in children with neurological impairment. In eight participants, PNMEs remained unclassified. Interpretation PNMEs may occur in both healthy and children with neurological impairment and are caused by a wide range of static and progressive conditions. In the majority of children with neurological impairment with associated epilepsy, the PNMEs do not fit into the usual movement disorders categories. A video‐electroencephalography–polymyography is therefore useful for characterizing them.     

Conversational assessment in memory clinic encounters: interactional profiling for differentiating dementia from functional memory disorders

Objectives: In the UK dementia is under-diagnosed, there is limited access to specialist memory clinics, and many of the patients referred to such clinics are ultimately found to have functional (non-progressive) memory disorders (FMD), rather than a neurodegenerative disorder. Government initiatives on ‘timely diagnosis’ aim to improve the rate and quality of diagnosis for those with dementia. This study seeks to improve the screening and diagnostic process by analysing communication between clinicians and patients during initial specialist clinic visits. Establishing differential conversational profiles could help the timely differential diagnosis of memory complaints.

Method: This study is based on video- and audio recordings of 25 initial consultations between neurologists and patients referred to a UK memory clinic. Conversation analysis was used to explore recurrent communicative practices associated with each diagnostic group.

Results: Two discrete conversational profiles began to emerge, to help differentiate between patients with dementia and functional memory complaints, based on (1) whether the patient is able to answer questions about personal information; (2) whether they can display working memory in interaction; (3) whether they are able to respond to compound questions; (4) the time taken to respond to questions; and (5) the level of detail they offer when providing an account of their memory failure experiences.

Conclusion: The distinctive conversational profiles observed in patients with functional memory complaints on the one hand and neurodegenerative memory conditions on the other suggest that conversational profiling can support the differential diagnosis of functional and neurodegenerative memory disorders.     

Stertorous breathing is a reliably identified sign that helps in the differentiation of epileptic from psychogenic non-epileptic convulsions: an audit

Stertorous breathing may occur after epileptic convulsions, but does not typically occur after psychogenic non-epileptic convulsions. During an 18-month audit at a tertiary referral centre in the United Kingdom, we analysed 75 convulsions arising in 45 patients and found that nursing and ancillary staff can be easily trained to reliably identify the presence or absence of stertorous breathing after a convulsion. No patient with a final diagnosis of purely psychogenic non-epileptic seizures (17 out of 45 patients) was judged to have stertorous respiration. Stertorous breathing was present in 41 out of 44 interpretable video recordings from patients with epileptic convulsions proven on videotelemetry. We suggest that a history or evidence (e.g. video) of stertorous breathing may help in distinguishing epileptic from psychogenic non-epileptic convulsive seizures.     

Contribution of concurrent Doppler and EEG in differentiating occipital epileptic discharges from migraine.

In a young woman, episodes of visual symptoms were accompanied by simultaneous nonspecific EEG alterations. Concurrent Doppler sonography showed increased blood flow velocity with latency of a few seconds in the posterior cerebral arteries only. This is typical for local autoregulatory hyperperfusion due to increased neuronal activity, thus indicating focal epileptic discharges and excluding migrainous attacks.     

Circadian rhythm sleep disorders: lessons from the blind

As totally blind people cannot perceive the light-dark cycle (the major synchroniser of the circadian pacemaker) their circadian rhythms often "free run" on a cycle slightly longer than 24 h. When the free-running sleep propensity rhythm passes out of phase with the desired time for sleep, night-time insomnia and daytime sleepiness result. It has recently been shown that daily melatonin administration can entrain the circadian pacemaker, thereby correcting this burdensome circadian sleep disorder. The primary purpose of this review is to elevate awareness of circadian sleep disorders in totally blind people (especially free-running rhythms) and to provide some guidance for clinical management. An additional goal is to show how research on sleep and circadian rhythms in the totally blind can contribute insights into the scientific understanding of the human circadian system. 2001 Harcourt Publishers Ltd     

REM sleep behavior disorder: Association with motor complications and impulse control disorders in Parkinson's disease

ObjectiveClinical phenotypes such as old age, longer disease duration, motor disability, akineto-rigid type, dementia and hallucinations are known to be associated with REM sleep behavior disorder (RBD) in Parkinson's disease (PD). However, the relationship between motor fluctuations/impulse control and related behaviors (ICRB) and RBD is not clear. We designed this study to elucidate the clinical manifestations associated with RBD to determine the implications of RBD in PD.DesignIn a cross-sectional study, a total of 994 patients with PD were interviewed to determine the presence of RBD and their associated clinical features including motor complications and ICRB.ResultsOf the 944 patients, 578 (61.2%) had clinical RBD. When comparing the clinical features between patients with RBD (RBD group) and without RBD (non-RBD group), older age, longer disease duration, higher Hoehn and Yahr stage (H&Y stage), higher levodopa equivalent daily dose (LEDD), and the existence of wearing off, dyskinesia, freezing, and ICRB, especially punding, were associated with the RBD group compared to the non-RBD group (P < .05 in all). Multivariate analysis showed that motor complications including wearing off, peak dose dyskinesia, and diphasic dyskinesia were the only relevant factors for RBD after adjusting for age and disease duration.ConclusionMotor complications and ICRB are more frequent in patients with RBD than in patients without RBD. In addition, motor complications are related to RBD even after adjusting for age and disease duration.     

Distinguishing sleep disorders from seizures: diagnosing bumps in the night

BACKGROUND: Abnormal paroxysmal events in sleep may be parasomnias or epileptic seizures. In nocturnal frontal lobe epilepsy (NFLE), the unusual seizure features often lead to diagnostic confusion with nonepileptic parasomnias; video-electroencephalography monitoring is usually required to make the diagnosis. OBJECTIVE: To examine the reliability of the clinical history in diagnosing NFLE, using the Frontal Lobe Epilepsy and Parasomnias (FLEP) scale. DESIGN: The FLEP scale, comprising specific questions reflecting the diagnostic features of NFLE and parasomnias, was developed by an expert panel following review of the literature. It was then validated in a sample of individuals with firmly diagnosed nocturnal events. SETTING: Patients were recruited after appropriate diagnostic workup in tertiary sleep and epilepsy referral centers in Melbourne, Australia. PARTICIPANTS: Sixty-two patients (45 males) [corrected] with paroxysmal nocturnal events. Intervention Two independent interviews were conducted in each case, with the patient and a witness, by researchers blinded to the diagnosis. MAIN OUTCOME MEASURE: The diagnosis obtained from scores on the FLEP scale was compared with the confirmed diagnosis in each patient. RESULTS: Nocturnal frontal lobe epilepsy was correctly diagnosed from the FLEP score in 31 of 31 patients, with a sensitivity of 1.0 (95% confidence interval [CI], 0.85-1.00), specificity of 0.90 (95% CI, 0.73-0.97), positive predictive value of 0.91 (95% CI, 0.75-0.97), and negative predictive value of 1.00 (95% CI, 0.85-1.00). CONCLUSIONS: A diagnosis of NFLE can be made reliably using the clinical features identified in the FLEP scale. This may reduce the requirement for tertiary referral and extensive inpatient monitoring.