Validation of an algorithm of time-dependent electro-clinical risk stratification for electrographic seizures (TERSE) in critically ill patients

OBJECTIVE

The clinical implementation of continuous electroencephalography (CEEG) monitoring in critically ill patients is hampered by the substantial burden of work that it entails for clinical neurophysiologists. Solutions that might reduce this burden, including by shortening the duration of EEG to be recorded, would help its widespread adoption. Our aim was to validate a recently described algorithm of time-dependent electro-clinical risk stratification for electrographic seizure (ESz) (TERSE) based on simple clinical and EEG features.

METHODS

We retrospectively reviewed the medical records and EEG recordings of consecutive patients undergoing CEEG between October 1, 2015 and September, 30 2016 and assessed the sensitivity of TERSE for seizure detection, as well as the reduction in EEG time needed to be reviewed.

RESULTS

In a cohort of 407 patients and compared to full CEEG review, the model allowed the detection of 95% of patients with ESz and 97% of those with electrographic status epilepticus. The amount of CEEG to be recorded to detect ESz was reduced by two-thirds, compared to the duration of CEEG taht was actually recorded.

CONCLUSIONS

TERSE allowed accurate time-dependent ESz risk stratification with a high sensitivity for ESz detection, which could substantially reduce the amount of CEEG to be recorded and reviewed, if applied prospectively in clinical practice.

SIGNIFICANCE

Time-dependent electro-clinical risk stratification, such as TERSE, could allow more efficient practice of CEEG and its more widespread adoption. Future studies should aim to improve risk stratification in the subgroup of patients with acute brain injury and absence of clinical seizures.

The natural history of spinocerebellar ataxia type 1, 2, 3, and 6: a 2-year follow-up study

OBJECTIVE

To obtain quantitative data on the progression of the most common spinocerebellar ataxias (SCAs) and identify factors that influence their progression, we initiated the EUROSCA natural history study, a multicentric longitudinal cohort study of 526 patients with SCA1, SCA2, SCA3, or SCA6. We report the results of the 1- and 2-year follow-up visits.

METHODS

As the primary outcome measure we used the Scale for the Assessment and Rating of Ataxia (SARA, 0-40), and as a secondary measure the Inventory of Non-Ataxia Symptoms (INAS, 0-16) count.

RESULTS

The annual increase of the SARA score was greatest in SCA1 (2.18 ± 0.17, mean ± SE) followed by SCA3 (1.61 ± 0.12) and SCA2 (1.40 ± 0.11). SARA progression in SCA6 was slowest and nonlinear (first year: 0.35 ± 0.34, second year: 1.44 ± 0.34). Analysis of the INAS count yielded similar results. Larger expanded repeats and earlier age at onset were associated with faster SARA progression in SCA1 and SCA2. In SCA1, repeat length of the expanded allele had a similar effect on INAS progression. In SCA3, SARA progression was influenced by the disease duration at inclusion, and INAS progression was faster in females.

CONCLUSIONS

Our study gives a comprehensive quantitative account of disease progression in SCA1, SCA2, SCA3, and SCA6 and identifies factors that specifically affect disease progression.

A candidate gene study of antiepileptic drug tolerability and efficacy identifies an association of CYP2C9 variants with phenytoin toxicity

BACKGROUND AND PURPOSE

  It is widely acknowledged that individual response to antiepileptic drugs (AEDs) is influenced by genetic factors. However, most of the underlying genes and genetic variants remain unidentified to date. The purpose of this study is to examine the role of common variants in a number of candidate genes in the response to commonly prescribed AEDs.

METHODS

  We recruited 495 patients with epilepsy. Patients were classified according to their response to several AEDs. We genotyped 104 polymorphisms in 17 candidate genes for AED response. We looked for statistically significant associations between these polymorphisms and well-defined AED response phenotypes.

RESULTS

  We identified significant associations of CYP2C9 variant alleles with presence of phenytoin (PHT) adverse drug reactions (ADRs) and of GSTM1 copy number variation with the presence of carbamazepine ADRs. The latter association could not be confirmed in a replication study.

CONCLUSIONS

  Our study is the first comprehensive candidate gene association study in epilepsy pharmacogenetics. Our results confirm the role of CYP2C9 variants in PHT toxicity. No other definite associations were identified. Large-scale efforts are needed to unravel the genetic determinants of AED response.

Acute behavioural change in a young woman evolving towards cerebellar syndrome

Symptomatic paraneoplastic neurological syndromes are rare manifestations of cancers. Recently, a new type of encephalitis associated with antibodies against NMDA-glutamate receptors (A-NMDAR) was defined. The patients, usually young women, present with acute onset of psychiatric symptoms and decreased consciousness. We describe the case of a patient who presented with acute onset of delirium alternating with sub-comatose state. Blood analyses were within normal range. Lumbar puncture showed lymphocytic pleiocytosis. Brain gadolinium injected MRI, brain and full body PET scans were normal. Investigations led to suspect a paraneoplastic syndrome and a right ovarian teratoma and A-NMDAR were found and the teratoma removed. The remaining sequellae included a cerebellar syndrome seldom described before. As cerebellar and cortical neurons share the same excitatory pathway through NMDA-glutamate receptors, the cerebellar function impairment observed in our patient could be explained by a disabling action on glutamate NMDAR by the A-NMDAR.

Responsiveness of different rating instruments in spinocerebellar ataxia patients

OBJECTIVE

To determine the longitudinal metric properties of recently developed clinical assessment tools in spinocerebellar ataxia (SCA).

METHODS

A subset of 171 patients from the EUROSCA natural history study cohort (43 SCA1, 61 SCA2, 37 SCA3, and 30 SCA6) were examined after 1 year of follow-up. Score changes and effect size indices were calculated for clinical scales (Scale for the Assessment and Rating of Ataxia [SARA], Inventory of Non-Ataxia Symptoms [INAS]), functional tests (SCA Functional Index [SCAFI] and components), and a patient-based scale for subjective health status (EQ-5D visual analogue scale [EQVAS]). Responsiveness was determined in relation to the patient's global impression (PGI) of change and reproducibility described as retest reliability for the stable groups and smallest detectable change.

RESULTS

Within the 1-year follow-up period, SARA, INAS, and SCAFI but not EQVAS indicated worsening in the whole group and in the groups with subjective (PGI) worsening. SCAFI and its 9-hole pegboard (9HPT) component also deteriorated in the stable groups. Standardized response means were highest for 9HPT (-0.67), SARA (0.50), and SCAFI (-0.48) with accordingly lower sample size estimates of 143, 250, or 275 per group for a 2-arm interventional trial that aims to reduce disease progression by 50%. SARA and EQVAS performed best to distinguish groups classified as worse by PGI. All scales except EQVAS reached the criterion for retest reliability.

CONCLUSION

While both the Scale for the Assessment and Rating of Ataxia and the SCA Functional Index (SCAFI) (and its 9-hole pegboard component) had favorable measurement precision, the clinical relevance of SCAFI and 9-hole pegboard score changes warrants further exploration. The EQ-5D visual analogue scale proved insufficient for longitudinal assessment, but validly reflected patients' impression of change.

Spinocerebellar ataxia types 1, 2, 3, and 6: disease severity and nonataxia symptoms

OBJECTIVE

To identify factors that determine disease severity and clinical phenotype of the most common spinocerebellar ataxias (SCAs), we studied 526 patients with SCA1, SCA2, SCA3. or SCA6.

METHODS

To measure the severity of ataxia we used the Scale for the Assessment and Rating of Ataxia (SARA). In addition, nonataxia symptoms were assessed with the Inventory of Non-Ataxia Symptoms (INAS). The INAS count denotes the number of nonataxia symptoms in each patient.

RESULTS

An analysis of covariance with SARA score as dependent variable and repeat lengths of the expanded and normal allele, age at onset, and disease duration as independent variables led to multivariate models that explained 60.4% of the SARA score variance in SCA1, 45.4% in SCA2, 46.8% in SCA3, and 33.7% in SCA6. In SCA1, SCA2, and SCA3, SARA was mainly determined by repeat length of the expanded allele, age at onset, and disease duration. The only factors determining the SARA score in SCA6 were age at onset and disease duration. The INAS count was 5.0 +/- 2.3 in SCA1, 4.6 +/- 2.2 in SCA2, 5.2 +/- 2.5 in SCA3, and 2.0 +/- 1.7 in SCA6. In SCA1, SCA2, and SCA3, SARA score and disease duration were the strongest predictors of the INAS count. In SCA6, only age at onset and disease duration had an effect on the INAS count.

CONCLUSIONS

Our study suggests that spinocerebellar ataxia (SCA) 1, SCA2, and SCA3 share a number of common biologic properties, whereas SCA6 is distinct in that its phenotype is more determined by age than by disease-related factors.

SCA Functional Index: a useful compound performance measure for spinocerebellar ataxia

OBJECTIVE

To evaluate the usefulness of functional measures in patients with spinocerebellar ataxia (SCA).

METHODS

We assessed three functional measures-8 m walking time (8MW), 9-hole peg test (9HPT), and PATA repetition rate-in 412 patients with autosomal dominant SCA (genotypes 1, 2, 3, and 6) in a multicenter trial.

RESULTS

While PATA rate was normally distributed (mean/median 21.7/20.5 per 10 s), the performance times for 8MW (mean/median 10.8/7.5 s) or 9HPT (mean/median 47.2/35.0 s in dominant, 52.2/37.9 s in nondominant hand) were markedly skewed. Possible learning effects were small and likely clinically irrelevant. A composite functional index (SCAFI) was formed after appropriate transformation of subtest results. The Z-scores of each subtest correlated well with the Scale for the Assessment and Rating of Ataxia (SARA), the Unified Huntington's disease Rating Scale functional assessment, and disease duration. Correlations for SCAFI with each of these parameters were stronger (Pearson r = -0.441 to -0.869) than for each subtest alone. Furthermore, SCAFI showed a linear decline over the whole range of disease severity, while 9HPT and 8MW had floor effects with respect to SARA. Analysis of possible confounders showed no effect of genotype or study site and only minor effects of age for 8MW.

CONCLUSION

The proposed functional measures and their composite SCAFI have favorable properties to assess patients with spinocerebellar ataxia.

Pharmacogenetics in neuropsychiatric diseases: epilepsy as a model

Individual drug responses are the result of interactions of multiple environmental and genetic factors. Pharmacogenetics studies the influence of genetic variation on interindividual differences in drug efficacy, adverse events and dosing. This article discusses general strategies for candidate gene selection and pharmacogenetic association studies. A summary of the major pharmacogenetic associations reported in neuropsychiatric disease is presented. The example of epilepsy pharmacogenetics will be covered in more detail, including an overview of epilepsy pharmacogenetic candidate genes and results of association studies reported so far. With the advent of large-scale, rigorously designed association studies, it is hoped that genetic factors will be identified that will lead to a targeted, more efficacious and safer treatment, and perhaps to the development of new and more efficacious drugs for neuropsychiatric diseases.

Guidelines for the management of epilepsy in the elderly

Seizures starting in patients over 60 years old are frequent. Diagnosis is sometimes difficult and frequently under- or overrated. Cerebrovascular disorders are the main cause of a first seizure. Because of more frequent comorbidities, physiologic changes, and a higher sensitivity to drugs, treatment has some specificity in elderly people. The aim of this paper is to present the result of a consensus meeting held in October 2004 by a Belgian French-speaking group of epileptologists and to propose guidelines for the management and the treatment of epilepsy in elderly people.

Scale for the assessment and rating of ataxia: development of a new clinical scale

OBJECTIVE

To develop a reliable and valid clinical scale measuring the severity of ataxia.

METHODS

The authors devised the Scale for the Assessment and Rating of Ataxia (SARA) and tested it in two trials of 167 and 119 patients with spinocerebellar ataxia.

RESULTS

The mean time to administer SARA in patients was 14.2 +/- 7.5 minutes (range 5 to 40). Interrater reliability was high, with an intraclass coefficient (ICC) of 0.98. Test-retest reliability was high with an ICC of 0.90. Internal consistency was high as indicated by Cronbach's alpha of 0.94. Factorial analysis revealed that the rating results were determined by a single factor. SARA ratings showed a linear relation to global assessments using a visual analogue scale, suggesting linearity of the scale (p < 0.0001, r(2) = 0.98). SARA score increased with the disease stage (p < 0.001) and was closely correlated with the Barthel Index (r = -0.80, p < 0.001) and part IV (functional assessment) of the Unified Huntington's Disease Rating Scale (UHDRS-IV) (r = -0.89, p < 0.0001), whereas it had only a weak correlation with disease duration (r = 0.34, p < 0.0002).

CONCLUSIONS

The Scale for the Assessment and Rating of Ataxia is a reliable and valid measure of ataxia, making it an appropriate primary outcome measure for clinical trials.

The -1021C->T DBH gene variant is not associated with epilepsy or antiepileptic drug response

Dopamine beta-hydroxylase (DBH) catalyzes the conversion of dopamine to norepinephrine (NE). Animal studies show that genes in the NE pathway are candidates for susceptibility to epilepsy and antiepileptic drug (AED) response. The authors genotyped the -1021C-->T major functional polymorphism in the DBH gene in 675 patients with epilepsy and 1,087 controls. The authors found no association with epilepsy, several epilepsy subtypes, or AED response. The results suggest that the -1021C-->T variant does not contribute to epilepsy.

The long term retention of levetiracetam in a large cohort of patients with epilepsy

Levetiracetam (Lev) is a new antiepileptic drug with a distinct mechanism of action, shown in regulatory trials to be effective. These controlled trials do not always predict how useful a drug will be in day to day clinical practice. Retention rates can provide a better indication of efficacy and tolerability in everyday use. Patients attending a tertiary referral centre for epilepsy and who received Lev in the first 2 years of its marketing were assessed (n = 811) to determine continuation rates of treatment with this drug. At the last follow up, 65% of patients were still taking Lev, and the estimated 3 year retention rate was 58%. In total, 11% attained seizure freedom of at least 6 months. Patients taking greater numbers of concurrent antiepileptic drugs (AEDs) were more likely to discontinue Lev, and those reaching higher maximum daily dosages were less likely to discontinue Lev. The retention rate for Lev compares favourably with that of other new AEDs.

Familial temporal lobe epilepsy with febrile seizures

Described are the clinical, EEG, MR, and genetic characteristics of 106 members of a family with autosomal dominant temporal lobe epilepsy (TLE) and febrile seizures (FS), with 22 affected individuals. Eleven patients had a history of FS, and 10 patients had TLE. EEG showed epileptic activity in five. None had hippocampal sclerosis. There was no evidence for linkage to 13 candidate loci. This large family with autosomal dominant TLE has a distinct phenotype and shows no linkage to known candidate regions for familial partial epilepsy and FS.