Esther Brusse

A Mutation in the Fibroblast Growth Factor 14 Gene Is Associated with Autosomal Dominant Cerebral Ataxia

Hereditary spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders for which ⩾14 different genetic loci have been identified. In some SCA types, expanded tri- or pentanucleotide repeats have been identified, and the length of these expansions correlates with the age at onset and with the severity of the clinical phenotype. In several other SCA types, no genetic defect has yet been identified. We describe a large, three-generation family with early-onset tremor, dyskinesia, and slowly progressive cerebellar ataxia, not associated with any of the known SCA loci, and a mutation in the fibroblast growth factor 14 (FGF14) gene on chromosome 13q34. Our observations are in accordance with the occurrence of ataxia and paroxysmal dyskinesia in Fgf14-knockout mice. As indicated by protein modeling, the amino acid change from phenylalanine to serine at position 145 is predicted to reduce the stability of the protein. The present FGF14 mutation represents a novel gene defect involved in the neurodegeneration of cerebellum and basal ganglia.

Pulsed high-dose dexamethasone versus standard prednisolone treatment for chronic inflammatory demyelinating polyradiculoneuropathy (PREDICT study): a double-blind, randomised, controlled trial

BACKGROUND Pulsed high-dose dexamethasone induced long-lasting remission in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in a pilot study. The PREDICT study aimed to compare remission rates in patients with CIDP treated with high-dose dexamethasone with rates in patients treated with standard oral prednisolone. METHODS In eight neuromuscular centres in the Netherlands and one in the UK, patients aged 18 years or older who had newly diagnosed definite or probable CIDP were randomly assigned to a treatment regimen of either pulsed high-dose dexamethasone or standard oral prednisolone. Randomisation was done with a random number generator. The primary outcome measure was remission at 12 months, defined as improvement of at least three points on the Rivermead mobility index and improvement of at least one point on the inflammatory neuropathy cause and treatment disability scale. Analysis was by intention to treat. This trial is registered with Current Controlled Trials, number ISRCTN07779236. FINDINGS Between December, 2003, and December, 2008, 40 patients were treated: 24 received dexamethasone and 16 received prednisolone. At 12 months, 16 patients were in remission: ten in the dexamethasone group and six in the prednisolone group (odds ratio [OR] 1.2, 95% CI 0.3-4.4). Most adverse events were minor and did not differ substantially between treatment groups; however, sleeplessness and Cushings face occurred more often in the prednisolone group. INTERPRETATION Pulsed high-dose dexamethasone treatment did not induce remission more often than prednisolone treatment. A substantial proportion of patients were in remission at 12 months in both treatment groups. High-dose dexamethasone could be considered as induction therapy in CIDP, but comparison with intravenous immunoglobulin treatment is needed. FUNDING The Prinses Beatrix Fonds (MAR01-0213) and the Department of Neurology, Academic Medical Center.

Spinocerebellar ataxia associated with a mutation in the fibroblast growth factor 14 gene (SCA27) : A new phenotype

Autosomal dominant cerebellar ataxias (ADCAs) are genetically classified into spinocerebellar ataxias (SCAs). We describe 14 patients of a Dutch pedigree displaying a distinct SCA‐phenotype (SCA27) associated with a F145S mutation in the fibroblast growth factor 14 (FGF14) gene on chromosome 13q34. The patients showed a childhood‐onset postural tremor and a slowly progressive ataxia evolving from young adulthood. Dyskinesia was often present, suggesting basal ganglia involvement, which was supported by functional imaging in 1 patient. Magnetic resonance imaging (MRI) of the brain showed only moderate cerebellar atrophy in the 2 eldest patients. Neuropsychological testing indicated low IQ and deficits in memory and executive functioning. Behavioral problems were also observed. Further investigations will have to determine the role of FGF14 in the pathogenesis of neurodegeneration and the frequency of this FGF14 mutation in SCA.

Diagnosis and management of early-and late-onset cerebellar ataxia

Cerebellar ataxias represent a heterogeneous group of neurodegenerative disorders. Two main categories are distinguished: hereditary and sporadic ataxias. Sporadic ataxias may be symptomatic or idiopathic. The clinical classification of hereditary ataxias is nowadays being replaced by an expanding genotype‐based classification. A large spectrum of degenerative and metabolic disorders may also present with ataxia early or late in the course of disease. We present a diagnostic algorithm for the adult patient presenting with subacute cerebellar ataxia, based on family history and straightforward clinical characteristics of the patient. Along with the algorithm, an overview of the autosomal dominant, autosomal recessive, X‐linked, mitochondrial, symptomatic and idiopathic subtypes of cerebellar ataxia is presented. An appropriate diagnosis is of utmost importance to such considerations as prognosis, genetic counselling and possible therapeutic implications.

The unfolding clinical spectrum of POLG mutations

Background: Mutations in the DNA polymerase-γ (POLG) gene are a major cause of clinically heterogeneous mitochondrial diseases, associated with mtDNA depletion and multiple deletions. Objective: To determine the spectrum of POLG mutations in our Dutch patient cohort, to evaluate the pathogenicity of novel mutations, and to establish genotype–phenotype correlations. Results: The authors identified 64 predominantly recessive mutations in 37 patients from a total of 232 patients, consisting of 23 different mutations. The substitution p.A467T was most frequently observed (n = 23), but was as frequent in childhood cases as in adult cases. Five new pathogenic recessive mutations, p.Lys925ArgfsX42, p.R275X, p.G426S, p.A804T and p.R869Q were identified. The known dominant chronic progressive external ophthalmoplegia (CPEO) mutation p.R943H was for the first time associated with premature ovarian failure as well. In 19 patients the authors identified only a single recessive mutation, or a sequence variant with unclear clinical significance. The data substantiate earlier observations that in POLG patients a fatal status epilepticus and liver failure can be triggered by sodium valproate. It is therefore important to exclude POLG mutations before administering this treatment. Conclusion: The clinical features of the patient are the most important features to select putative POLG mutation carriers and not the presence of mtDNA deletions or OXPHOS (oxidative phosphorylation) activity. The authors conclude that POLG mutations are an important cause of heterogeneous mitochondrial pathology and that more accurate genotype–phenotype correlations allow a more rapid genetic diagnosis and improved prognosis for mutation carriers.

Long-term remission of CIDP after pulsed dexamethasone or short-term prednisolone treatment

Objective: Achieving long-term remission after a limited more intense treatment period would prevent prolonged use of corticosteroids or IV immunoglobulin (IVIg) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). In this prospective cohort study we present long-term follow-up data on patients included in a multicenter randomized controlled trial comparing 6 monthly pulses of dexamethasone with 8 months of daily prednisolone. Methods: Treatment effect was assessed with the Inflammatory Neuropathy Cause and Treatment disability scale and the Rivermead Mobility Index and was categorized using the CIDP Disease Activity Status (CDAS) scale. Results: By March 2011, 39 out of 40 patients were included with a median follow-up of 4.5 years. Cure (>5 years off treatment) or remission according to the CDAS criteria after 1 or 2 courses of pulsed dexamethasone or daily prednisolone was achieved in 10 out of 39 patients (26%). Half of the patients who were in remission after initial treatment experienced a relapse (median treatment-free interval: 17.5 months for dexamethasone, 11 months for prednisolone). Alternative diagnosis was made in 7 out of 12 (58%) who did not respond to any therapy and in none of the treatment-responsive patients. Conclusions: Cure or long-term remission can be achieved in about one-quarter of patients with CIDP after 1 or 2 courses of pulsed dexamethasone or 8-month daily prednisolone. In treatment-nonresponsive patients, the diagnosis CIDP should be reconsidered. Classification of Evidence: This study provides Class IV evidence that pulsed dexamethasone or 8-month daily prednisolone can lead to long-term remission in CIDP.

Autosomal dominant adult neuronal ceroid lipofuscinosis: parkinsonism due to both striatal and nigral dysfunction.

We describe a family with adult neuronal ceroid lipofuscinosis, with apparent autosomal dominant inheritance, observed in six affected individuals in three generations. Disease onset was usually in the fifth decade, but was earlier in the youngest generation. Early symptoms consisted of myoclonus in face and arms, epilepsy, auditory symptoms, cognitive decline, or depression. Parkinsonism occurred a few years after disease onset, with stooped posture, shuffling gait, bradykinesia, and mask face. Four subjects deteriorated to a state of severe handicap, with severe dementia, contractures, dysphagia, and dysarthria. Leg weakness evolved to flaccid paraparesis in two patients. Diagnosis was confirmed by brain biopsy in one patient and full autopsy in two patients. Abundant intraneuronal storage of autofluorescent material was found throughout the brain. Electron microscopy showed granular osmiophilic deposits and scarce fingerprint profiles. Striking loss of neurons in the substantia nigra pars compacta and reticulata was found. 123I‐IBZM Single photon emission computed tomography in two patients showed loss of postsynaptic D2 receptor binding in the striatum. We conclude that parkinsonism in ANCL is likely to be caused by both presynaptic nigral cell loss and postsynaptic striatal degeneration.

Serum IgG levels in IV immunoglobulin treated chronic inflammatory demyelinating polyneuropathy

Objective To determine the variability of serum IgG in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods All 25 CIDP patients had active but stable disease and were treated with individually optimised fixed dose IVIg regimens. IgG was measured by turbidimetry and variability was defined as coefficient of variation (CV). Results The intra-patient variability of the pre-treatment IgG levels, post-treatment levels and increase in serum IgG shortly after IVIg (ΔIgG) was low (mean CV=3%, 4%, 10%). The inter-patient variability between patients treated with the same dose and interval was low in pre-treatment, post-treatment and ΔIgG level (mean CV=13%, 11%, 20%). The ΔIgG levels were associated with IVIg dosage (rs=0.78, p<0.001). Conclusions Clinically stable CIDP patients show a steady-state in serum IgG after serial IVIg infusions. The low intra- and inter-patient variability in IgG may indicate that constant levels are required to reach this stability.

A new locus for a childhood onset, slowly progressive autosomal recessive spinocerebellar ataxia maps to chromosome 11p15

he cerebellar ataxias are a heterogeneous group of neurodegenerative disorders, characterised by symptoms and signs of cerebellar degeneration, pyramidal and extrapyramidal features, and variable polyneuropathy. Prominent clinical features are signs of cerebellar ataxia, such as uncoordinated gait and uncontrolled co-ordination of hand, speech, and eye movements, while (extra) pyramidal signs, such as retinal, cardiac, muscle and/or neuronal involvement, are less common. The clinical picture shows a large variation in age at onset and disease progression. Sporadic ataxias may be attributed to various toxic, inflammatory, paraneoplastic, metabolic, endocrinal, or malabsorption conditions. Hereditary ataxias consist of a large number of autosomal dominant ataxias and ataxias with an autosomal recessive and X-linked mode of inheritance. The remaining ataxias of unknown cause are referred to as idiopathic sporadic cerebellar ataxias. Most symptomatic ataxias can be diagnosed on the basis of a typical history or by simple laboratory tests. In hereditary ataxias family history is important. However, a negative family history cannot rule out autosomal recessive or X-linked ataxia and even autosomal dominantly inherited ataxia may be missed because of reduced penetrance, the early death of gene carriers before the onset of symptoms, imprinting effects, variable expression, adoption, or nonpaternity. 1

Fatigue in spinocerebellar ataxia: Patient self-assessment of an early and disabling symptom

Objective: To identify the prevalence and severity of fatigue and predicting factors for severe fatigue in autosomal dominant spinocerebellar ataxia (SCA). Methods: We studied a cross-section of 123 patients with SCA. Six functional scales were used in a self-assessment: the Fatigue Severity Scale (FSS); the Beck Depression Inventory (BDI); the Rotterdam Handicap Scale (RHS); the Short Form–36 health survey, distinguishing a norm-based physical and mental component score (Nb-PCS and Nb-MCS); the Pittsburgh Sleep Quality Index (PSQI); and the Epworth Sleepiness Scale (ESS). A subset of 58 patients was clinically evaluated, measuring severity of ataxia with the Scale for the Assessment and Rating of Ataxia and cognitive functioning with the Mini-Mental State Examination. Results: Severe fatigue (FSS ≥5) was present in 69% of patients and FSS value correlated with the scores on RHS, Nb-PCS, Nb-MCS, BDI, PSQI, and ESS. There was no relation with disease duration, gender, or medication use. Multivariate analysis revealed that Nb-PCS and BDI were the best independent predictors for severe fatigue. Interestingly, the presence of visual symptoms was related to FSS value in the clinically evaluated subgroup. Conclusion: Fatigue is a severe and disabling symptom in adult patients with SCA, even early in the course of disease. Physical functioning and depression are the strongest predictors of fatigue. In treatment strategies, all treatable factors for fatigue should be addressed, especially depression, visual symptoms, and sleeping disorders.