Autism spectrum disorders in the DSM-V: better or worse than the DSM-IV?

The DSM-V-committee has recently published proposed diagnostic criteria for autism spectrum disorders. We examine these criteria in some detail. We believe that the DSM-committee has overlooked a number of important issues, including social imagination, diagnosis in infancy and adulthood, and the possibility that girls and women with autism may continue to go unrecognised or misdiagnosed under the new manual. We conclude that a number of changes need to be made in order that the DSM-V-criteria might be used reliably and validly in clinical practice and research.     

Features of developmental dyspraxia in the general speech-impaired population?

A typical clinical population with speech impairment was investigated to determine the extent of the presence of features of developmental dyspraxia and its interaction between the severity of impairment. Thirty diagnostic features of developmental dyspraxia were identified from the post-1981 literature and two scales of severity were devised. First the severity of these 30 features was measured (feature severity rating, FSR), and secondly severity of speech impairment was based on percentage of consonants correct (PCC). Using these features and severity ratings a retrospective file audit was conducted of 50 paediatric clients aged 2–8 years with impaired articulation or phonology. It was found that many characteristics regarded as diagnostic for developmental dyspraxia occur in the general speech-impaired population. The relationship between the variables was analysed, and support was found for the hypotheses that: (a) there is a relationship between the number of dyspraxic features expressed and the severity of impairment of speech production and (b) developmental dyspraxia is not characterized by severe impairment, but may occur in a range of severities from mild to severe.     

Features of developmental dyspraxia in the general speech-impaired population?

A typical clinical population with speech impairment was investigated to determine the extent of the presence of features of developmental dyspraxia and its interaction between the severity of impairment. Thirty diagnostic features of developmental dyspraxia were identified from the post-1981 literature and two scales of severity were devised. First the severity of these 30 features was measured (feature severity rating, FSR), and secondly severity of speech impairment was based on percentage of consonants correct (PCC). Using these features and severity ratings a retrospective file audit was conducted of 50 paediatric clients aged 2-8 years with impaired articulation or phonology. It was found that many characteristics regarded as diagnostic for developmental dyspraxia occur in the general speech-impaired population. The relationship between the variables was analysed, and support was found for the hypotheses that: (a) there is a relationship between the number of dyspraxic features expressed and the severity of impairment of speech production and (b) developmental dyspraxia is not characterized by severe impairment, but may occur in a range of severities from mild to severe.     

Implicit and Explicit Memory in Autism: Is Autism an Amnesic Disorder?

Medial temporal lobe amnesic disorder is characterized by an impairment in explicit memory (e.g., remembering a shopping list) and intact implicit memory (e.g., a woman seems familiar although you cannot remember having met her before). This study examined whether children with high-functioning autism have this same dissociation between explicit and implicit memory abilities. Children with autism and normal development participated in three memory tasks: one implicit task (perceptual identification) and two explicit tasks (recognition and recall). Children with autism showed intact implicit and explicit memory abilities. However, they did not show the typical pattern of recalling more items from both the beginning and end of a list and instead only recalled items from the end of the list. These results do not support the theory that high-functioning autism is a type of medial temporal lobe amnesia. However, these findings suggest that persons with autism use different organizational strategies during encoding or retrieval of items from memory.     

Is long-term electroencephalogram more appropriate than standard electroencephalogram in the elderly?

Objective

To compare the diagnostic accuracy of standard (st) and long-term video (lt) EEG in elderly patients with suspected non-convulsive seizures.

Is the Ability to Integrate Parts into Wholes Affected in Autism Spectrum Disorder?

There is considerable debate about whether people with autism spectrum disorder (ASD) are biased toward local information and whether this disrupts their ability to integrate two complex shapes elements into a single figure. Moreover, few have examined the relationship between integration ability and ASD symptom severity. Adolescent/adult males with ASD and age and IQ-matched controls were compared on their performance of a simple silhouette-to-shape matching task and a higher-order shape-integration task. Relative to basic silhouette-to-shape matching, ASD participants were disproportionately slower than controls on shape-integration. Moreover, this relative slowing correlated with increased symptom severity in ASD participants. These findings support the notion that integrating local information is disproportionately more challenging in ASD; this weakness may play a role in ASD symptomatology.     

Is essential tremor a Purkinjopathy? The role of the cerebellar cortex in its pathogenesis

Essential tremor (ET) encompasses a group of progressive neurological diseases in which the primary clinical feature is kinetic tremor of the arms. There is accumulating evidence to suggest that the cerebellum is involved in the pathogenesis of ET; the clinical presentation, neurophysiological data, and functional and metabolic abnormalities revealed by neuroimaging studies all point toward the dysregulation of cerebellar circuits. Recent neuropathological findings at postmortem demonstrate that Purkinje neurons, and some brainstem neurons, play an integral role in the pathogenesis of this common neurological disorder. The assessment of Purkinje cell linear density shows that Purkinje density is abnormal in ET brains. Specific efforts need be devoted to understanding the molecular and cellular events occurring in the Purkinje neurons of the cerebellar cortex, which are emerging as being of particular importance in the pathogenesis of ET in a subgroup of patients. © 2013 International Parkinson and Movement Disorder Society.     

Is the endovascular treatment of carotid stenosis in high-risk patients really safer than carotid endarterectomy?

BACKGROUND: We assess the outcomes of patients who would have been considered at high-risk from carotid endarterectomy (CEA), who have undergone endovascular treatment. METHODS: High-risk patients were classed as those with occlusion of the contralateral internal carotid artery, recurrent stenosis following CEA, stenosis secondary to neck irradiation or treatment prior to coronary bypass surgery. RESULTS: 103 procedures fulfilled at least one inclusion criterion. 58.3% had symptomatic disease. The all stroke/death rate was 9.7%. The major disabling stroke/stroke-related death rate was 3.9%. 63 had a contralateral occlusion, 15 post-CEA, 17 post-radiation and 33 pre-coronary surgery. The major disabling stroke/stroke-related death rates for each subset were 4.8, 6.7, 0 and 0%, respectively. CONCLUSIONS: These results suggest that this category of patients is at high-risk of stroke regardless of method of carotid intervention.     

Is the Autism-Spectrum Quotient a Valid Measure of Traits Associated with the Autism Spectrum? A Rasch Validation in Adults with and Without Autism Spectrum Disorders

The Autism-Spectrum Quotient (AQ) is among the most widely used scales assessing autistic traits in the general population. However, some aspects of the AQ are questionable. To test its scale properties, the AQ was translated into Swedish, and data were collected from 349 adults, 130 with autism spectrum disorder (ASD) and 219 without ASD, and analysed with Rasch. Several scale properties of the AQ were satisfactory but it did not meet the criterion of a unidimensional measure of autistic traits. The Rasch analysis showed that the 50-item AQ could be reduced to a 12-item subset with little loss of explanatory power, with the potential to efficiently measure the degree to which adults with and without ASD show autistic traits.     

Brief Report: Do the Nature of Communication Impairments in Autism Spectrum Disorders Relate to the Broader Autism Phenotype in Parents?

Extensive empirical evidence indicates that the lesser variant of Autism Spectrum Disorders (ASD) involves a communication impairment that is similar to, but milder than, the deficit in clinical ASD. This research explored the relationship between the broader autism phenotype (BAP) among parents, an index of genetic liability for ASD, and proband communication difficulties. ASD probands with at least one BAP parent (identified using the Autism Spectrum Quotient) had greater structural and pragmatic language difficulties (assessed using the Children’s Communication Checklist-2) than ASD probands with no BAP parent. This finding provides support for the position that genetic liability for ASD is associated with increased communication difficulties across structural and pragmatic domains.     

What Features of Limb Movements are Encoded in the Discharge of Cerebellar Neurons?

This review examines the signals encoded in the discharge of cerebellar neurons during voluntary arm and hand movements, assessing the state of our knowledge and the implications for hypotheses of cerebellar function. The evidence for the representation of forces, joint torques, or muscle activity in the discharge of cerebellar neurons is limited, questioning the validity of theories that the cerebellum directly encodes the motor command. In contrast, kinematic parameters such as position, direction, and velocity are widely and robustly encoded in the activity of cerebellar neurons. These findings favor hypotheses that the cerebellum plans or controls movements in a kinematic framework, such as the proposal that the cerebellum provides a forward internal model. Error signals are needed for on-line correction and motor learning, and several hypotheses postulate the need for their representations in the cerebellum. Error signals have been described mostly in the complex spike discharge of Purkinje cells, but no consensus has emerged on the exact information signaled by complex spikes during limb movements. Newer studies suggest that simple spike firing may also encode error signals. Finally, Purkinje cells located more posterior and laterally in the cerebellar cortex and dentate neurons encode nonmotor, task-related signals such as visual cues. These results suggest that cerebellar neurons provide a complement of information about motor behaviors. We assert that additional single unit studies are needed using rich movement paradigms, given the power of this approach to directly test specific hypotheses about cerebellar function.     

Is the cerebellum relevant in the circuitry of neuropsychiatric disorders?

Contemporary mechanistic models of several psychiatric disorders propose abnormalities in the structure and function of distinct neural networks. The cerebellum has both anatomic and functional connections to the prefrontal cortex, the subcortical limbic structures and monoamine-producing brainstem nuclei. Conspicuously, however, the cerebellum has been underemphasized in neuropsychiatric research. A growing confluence of scientific data indicate that the cerebellum may not be irrelevant, which suggests that an integrated model of neuropsychiatric disorders should include a role for the cerebellum and its relevant neural connections. This review summarizes the published data describing and characterizing the putative role of the cerebellum in normal and abnormal mood regulation, with specific attention to states of psychosis, depression and mania. The available evidence suggests that a functional role for the cerebellum should be considered in future neuropsychiatric studies.     

Is Emotion Recognition Impaired in Individuals with Autism Spectrum Disorders?

Researchers have argued that individuals with autism spectrum disorders (ASDs) use an effortful “systematizing” process to recognize emotion expressions, whereas typically developing (TD) individuals use a more holistic process. If this is the case, individuals with ASDs should show slower and less efficient emotion recognition, particularly for socially complex emotions. We tested this account by assessing the speed and accuracy of emotion recognition while limiting exposure time and response window. Children and adolescents with ASDs showed quick and accurate recognition for most emotions, including pride, a socially complex emotion, and no differences emerged between ASD and TD groups. Furthermore, both groups trended toward higher accuracy when responding quickly, even though systematizing should promote a speed-accuracy trade-off for individuals with ASDs.