The Tuberous Sclerosis 2000 Study: presentation, initial assessments and implications for diagnosis and management

AIMS

The Tuberous Sclerosis 2000 Study is the first comprehensive longitudinal study of tuberous sclerosis (TS) and aims to identify factors that determine prognosis. Mode of presentation and findings at initial assessments are reported here.

METHODS

Children aged 0-16 years newly diagnosed with TS in the UK were evaluated.

RESULTS

125 children with TS were studied. 114 (91%) met clinical criteria for a definite diagnosis and the remaining 11 (9%) had pathogenic TSC1 or TSC2 mutations. In families with a definite clinical diagnosis, the detection rate for pathogenic mutations was 89%. 21 cases (17%) were identified prenatally, usually with abnormalities found at routine antenatal ultrasound examination. 30 cases (24%) presented before developing seizures and in 10 of these without a definite diagnosis at onset of seizures, genetic testing could have confirmed TS. 77 cases (62%) presented with seizures. Median age at recruitment assessment was 2.7 years (range: 4 weeks-18 years). Dermatological features of TS were present in 81%. The detection rate of TS abnormalities was 20/107 (19%) for renal ultrasound including three cases with polycystic kidney disease, 51/88 (58%) for echocardiography, 29/35 (83%) for cranial CT and 95/104 (91%) for cranial MRI. 91% of cases had epilepsy and 65% had intellectual disability (IQ<70).

CONCLUSIONS

Genetic testing can be valuable in confirming the diagnosis. Increasing numbers of cases present prenatally or in early infancy, before onset of seizures, raising important questions about whether these children should have EEG monitoring and concerning the criteria for starting anticonvulsant therapy.

Epilepsy in autism: features and correlates

BACKGROUND

Epilepsy occurs in a significant minority of individuals with autism, but few long-term follow-up studies have been reported, so the prevalence, features (type of seizures, age at onset and severity, etc.) and correlates (IQ history of regression, family history) have only partially been identified.

AIMS

To undertake a long-term follow-up study of individuals with autism in order to better characterise the features and correlates of epilepsy in individuals with autism.

METHOD

One hundred and fifty individuals diagnosed with autism in childhood were followed up when they were 21+ years of age. All individuals were screened for a history of possible seizures by parental/informant questionnaire. An epilepsy interview was undertaken and medical notes reviewed for individuals with a history of possible seizures. The features and correlates of epilepsy were examined using survival and regression analysis.

RESULTS

Epilepsy developed in 22% of participants. In the majority, seizures began after 10 years of age. Generalised tonic-clonic seizures predominated (88%). In over a half (19/33), seizures occurred weekly or less frequently and in the majority of individuals (28/31) they were controlled with the prescription of one to two anticonvulsants. Epilepsy was associated with gender (female), intellectual disability and poorer verbal abilities. Although the presence of epilepsy in the probands was not associated with an increased risk of epilepsy in their relatives, it was associated with the presence of the broader autism phenotype in relatives. This indicates that the familial liability to autism was associated with the risk for epilepsy in the proband.

CONCLUSIONS

Epilepsy is an important medical complication that develops in individuals with autism. Seizures may first begin in adolescence or adulthood. Putative risk factors for epilepsy in autism were identified and these will require further investigation in future studies.

Constipation in children

INTRODUCTION

Prevalence of chronic constipation has been estimated at 1-5% of children in the UK and USA, most of whom have no obvious aetiological factors. A third of children with chronic constipation continue to have problems beyond puberty. Half of children with chronic faecal impaction and soiling have experienced an episode of painful defecation, and many children with chronic constipation exhibit withholding behaviour.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments for children with chronic constipation? What are the effects of treatments for clearing the bowel in children with faecal impaction? We searched: Medline, Embase, The Cochrane Library and other important databases up to June 2005 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 15 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: anal dilatation, behavioural treatments (biofeedback, diaries, or toilet training), bulk-forming laxatives, faecal softeners, fiber, oral fluids, osmotic laxatives, stimulant laxatives.

Repetitive and stereotyped behaviours in pervasive developmental disorders

BACKGROUND

Repetitive and stereotyped behaviours are a heterogeneous group of behaviours present in many neuropsychiatric disorders. Despite their core significance in PDD, it is not clear whether there are distinct groups of these behaviours with different specificity to autism.

METHODS

A two-factor model of the repetitive behaviours, namely sensory/motor (lower-order) and cognitive rigidity (higher-order), was conceptualised. The model's goodness of fit to the data was examined in a clinic population of children with PDD, with and without mental retardation, and of those with only mental retardation (MR).

RESULTS

Subjects with PDD had higher rates of all repetitive behaviours compared to those with MR only. The existence of two independent 'lower-order' and 'higher-order' sub-groups of the repetitive behaviours was confirmed only in the MR group. The lower-order behaviours appear to be associated more with global developmental problems, whereas the higher-order behaviours were significantly associated with ruminations in the PDD group.

CONCLUSIONS

This study suggests that there may be two distinct sub-groups of repetitive behaviours whereby the sensory and motor repetitive behaviours are generally associated with lower developmental age and less specific to the autistic syndrome whereas the 'higher-order' behaviours may be a more 'autism specific' feature. The co-occurrence of the lower- and higher-order behaviours in PDD might reflect the end result of diffuse altered neural networks in these disorders thus being a specific feature of PDD. There is a need for more systematic studies of these behaviours not only in autistic disorders but also in other neuropsychiatric disorders.