Neurotoxin-Induced Paralysis: A Case of Tick Paralysis in a 2-Year-Old Child

BackgroundTick paralysis is an arthropod-transmitted disease causing potentially lethal progressive ascending weakness. The presenting symptoms of tick paralysis overlap those of acute inflammatory diseases of the peripheral nervous system and spinal cord; thus, the condition is often misdiagnosed, leading to unnecessary treatments and prolonged hospitalization.PatientA 2-year-old girl residing in northern New York and having no history of travel to areas endemic to ticks presented with rapidly progressing ascending paralysis, hyporeflexia, and intact sensory examination. Investigation included blood and serum toxicology screens, cerebrospinal fluid analysis, and brain imaging. With all tests negative, the child's condition was initially mistaken for botulism; however, an engorged tick was later found attached to the head skin. Following tick removal, the patient's weakness promptly improved with no additional interventions.ConclusionOur patient illustrates the importance of thorough skin examination in all cases of acute progressive weakness and the necessity to include tick paralysis in the differential diagnosis of paralysis, even in nonendemic areas.     

Tourette patients' misbelief of a tic rebound is due to overall difficulties in reliable tic rating

Objective

While in clinical interviews the vast majority of patients with Tourette syndrome (TS) report about a tic rebound after voluntary tic suppression, in recent studies in children no paradoxical tic increase could be found. We hypothesized that in adult patients there is a tic rebound after tic suppression.

Methods

We investigated the tic severity, premonitory urges and influence of attention deficit hyperactivity disorder (ADHD) before, during and after tic suppression in 22 adult patients with TS using both an objective video tic rating and subjective patient ratings for tics and premonitory urges.

Results

According to the video rating, tic suppression resulted in a significant tic reduction, but no rebound. Patients also reported no tic rebound. They erroneously believed in an absolute tic reduction 20 and 30 min after suppression, but paradoxically felt no relative tic change. Premonitory urges remained unchanged. There was no correlation between premonitory urges and tic severity. The potency for tic inhibition did not correlate with premonitory urges and tic severity. ADHD did not influence tic inhibition.

Conclusion

In adults with TS, there is no tic rebound after voluntary tic suppression. Patients also reported no rebound, but erroneously felt a tic reduction in the later course of the study. This misjudgement as well as patients' often reported (mis-)belief of a tic rebound may be caused by overall difficulties in reliable tic rating. Premonitory urges remained unchanged during tic suppression. Tic suppression was not influenced by attention deficits. Premonitory urges are no prerequisite of tic suppression.     

The prevalence of aggression in genetic syndromes: A review

Research into behavioural phenotypes identifies both environmental and organic factors as influencing aggression in children and adults with genetic disorders associated with intellectual disability. However, in contrast to self-injury there is a paucity of research that compares aggression across relevant syndromes. The primary aim of this review is to examine the association between aggression and genetic syndromes by analysis of prevalence studies. The review also examines the literature on the form of the behaviour and influence of environmental factors.Results imply that certain syndrome groups (Cri du Chat, Smith-Magenis, Prader-Willi, Angelman, Cornelia de Lange, and Fragile X syndromes; estimates over 70%) evidence a stronger association with aggression than others (e.g. Williams and Down syndromes; estimates below 15%). However, the strength of association is difficult to quantify due to methodological differences between studies. The results from examining form and environmental influences highlight the importance of phenotype–environment interactions. Research employing group comparison designs is warranted and future work on the assessment and intervention of aggression in genetic syndromes should consider the importance of phenotype–environment interactions.     

Approximate additions and working memory in individuals with Down syndrome

There is some evidence that individuals with Down syndrome (DS) may have a poorer mathematical performance and a poorer working memory (WM) than typically developing (TD) children of the same mental age. In both typical and atypical individuals, different aspects of arithmetic and their relationships with WM have been largely studied, but the specific contribution of WM to the representation and elaboration of non-symbolic quantities has received little attention. The present study examined whether individuals with DS are as capable as TD children matched for fluid intelligence of estimating numerosity both of single sets and of added sets resulting when two sequentially presented sets are added together, also considering how these tasks related to verbal and visuospatial WM. Results showed that the DS group's performance was significantly worse than the TD group's in numerosity estimation involving one set, but not when estimating the numerosity resulting from the addition. Success in the addition task was related to success in the working memory tasks, but only for the group with DS; this applied especially to the visuospatial component, which (unlike the verbal component) was not impaired in the group with DS. It is concluded that the two numerosity tasks involve different processes. It is concluded that the arithmetical and working memory difficulties of individuals with DS are not general, and they can draw on their WM resources when estimating the numerosity of additions.     

Region‐specific impairments in striatal synaptic transmission and impaired instrumental learning in a mouse model of Angelman syndrome

Angelman syndrome (AS) is a neurodevelopmental disorder characterized by mental retardation and impaired speech. Because patients with this disorder often exhibit motor tremor and stereotypical behaviors, which are associated with basal ganglia pathology, we hypothesized that AS is accompanied by abnormal functioning of the striatum, the input nucleus of the basal ganglia. Using mutant mice with maternal deficiency of AS E6‐AP ubiquitin protein ligase Ube3a (Ube3a^m?/p+), we assessed the effects of Ube3a deficiency on instrumental conditioning, a striatum‐dependent task. We used whole‐cell patch‐clamp recording to measure glutamatergic transmission in the dorsomedial striatum (DMS) and dorsolateral striatum (DLS). Ube3a^m?/p+ mice were severely impaired in initial acquisition of lever pressing. Whereas the lever pressing of wild‐type controls was reduced by outcome devaluation and instrumental contingency reversal, the performance of Ube3a^m?/p+ mice were more habitual, impervious to changes in outcome value and action–outcome contingency. In the DMS, but not the DLS, Ube3a^m?/p+ mice showed reduced amplitude and frequency of miniature excitatory postsynaptic currents. These results show for the first time a selective deficit in instrumental conditioning in the Ube3a deficient mouse model, and suggest a specific impairment in glutmatergic transmission in the associative corticostriatal circuit in AS.     

Complex regional pain syndrome of the upper limb: A review

In this paper, we present some impressions and thoughts about CRPS which we found useful in our proceedings with CRPS patients. The clinical sub-types of the CRPS are presented and differences in their characteristics are discussed. The current pathophysiological concepts for CRPS are outlined. Diagnostic criteria are presented and critically discussed. Both classification and diagnosing have translation on research and clinical practice. Treatment modalities are provided, addressing separately acute/early and chronic forms of the syndrome. The “Szczecin” protocol of management of early CRPS is presented in details. Some information about prevention of the syndrome is given. We believe that the information presented may support doctors in resolving their diagnostic dilemmas associated with CRPS.