Hereditary spastic paraplegia: Clinicogenetic lessons from 608 patients.

OBJECTIVE: Hereditary spastic paraplegias (HSPs) are genetically driven disorders with the hallmark of progressive spastic gait disturbance. To investigate the phenotypic spectrum, prognostic factors, and genotype-specific differences, we analyzed baseline data from a continuous, prospective cohort. METHODS: We recruited 608 HSP cases from 519 families of mostly German origin. Clinical severity was assessed by the Spastic Paraplegia Rating Scale. Complicating symptoms were recorded by a standardized inventory. RESULTS: Family history indicated dominant (43%), recessive (10%), and simplex (47%) disease. We observed a significant male predominance, particularly in simplex cases without a genetic diagnosis. Disease severity increased with disease duration. Earlier disease onset was associated with less severe disease. Specific complicating features including cognitive impairment, extrapyramidal or peripheral motor involvement, and ataxia were associated with worse disease severity. Disease severity also depended on the genotype. HSP cases maintained the ability to walk independently for a median disease duration of 22 years. Early onset cases were able to maintain free walking significantly longer and were at less risk to become wheelchair dependent. INTERPRETATION: This cross-sectional cohort study provides the first large-scale data on disease manifestation, progression, and modifying factors, with relevance for counseling of HSP families and planning of future cross-sectional and natural history studies. Later age of onset, specific complicating features, and the SPG11 genotype are strongly associated with more severe disease. Future interventional studies will require stratification for modifiers of disease progression identified in this study. Prospective longitudinal studies will verify progression rates calculated in this baseline analysis.

A high-throughput resequencing microarray for autosomal dominant spastic paraplegia genes.

Hereditary spastic paraplegias (HSP) are a heterogeneous group of neurological disorders. Insidiously progressive spastic weakness of the lower extremities is the common criterion in all forms described. Clinically, HSP is differentiated into pure (uncomplicated) and complex (complicated) forms. While pure HSP is predominantly characterized by signs and symptoms of pyramidal tract dysfunction, additional neurological and non-neurological symptoms occur in complicated forms. Autosomal dominant, autosomal recessive, and X-linked modes of inheritance have been described and at least 48 subtypes, termed SPG1-48, have been genetically defined. Although in autosomal dominant HSP families 50-60% of etiologies can be established by genetic testing, genotype predictions based on the phenotype are limited. In order to realize high-throughput genotyping for dominant HSP, we designed a resequencing microarray for six autosomal dominant genes on the Affymetrix CustomSEQ array platform. For validation purposes, 10 previously Sanger sequenced patients with autosomal dominant HSP and 40 positive controls with known mutations in ATL1, SPAST, NIPA1, KIF5A, and BSCL2 (32 base exchanges, eight small indels) were resequenced on this array. DNA samples of 45 additional patients with AD spastic paraplegia were included in the study. With two different sequencing analysis software modules (GSEQ, SeqC), all missense/nonsense mutations in the positive controls were identified while indels had a detection rate of only 50%. In total, 244 common synonymous single-nucleotide polymorphisms (SNPs) annotated in dbSNP (build 132) corresponding to 22 distinct sequence variations were found in the 53 analyzed patients. Among the 22 different sequence variations (SPAST n = 15, ATL1 n = 3, KIF5A n = 2, HSPD1 n = 1, BSCL2 n = 1, NIPA1 n = 0), 12 were rare variants that have not been previously described and whose clinical significance is unknown. In SPAST-negative cases, a genetic diagnosis could be established in 11% by resequencing. Resequencing microarray technology can therefore efficiently be used to study genotypes and mutations in large patient cohorts.

Diagnostic accuracy of plasma glial fibrillary acidic protein for differentiating intracerebral hemorrhage and cerebral ischemia in patients with symptoms of acute stroke.

BACKGROUND: Glial fibrillary acidic protein (GFAP) is a biomarker candidate indicative of intracerebral hemorrhage (ICH) in patients with symptoms of acute stroke. GFAP is released rapidly in the presence of expanding intracerebral bleeding, whereas a more gradual release occurs in ischemic stroke. In this study the diagnostic accuracy of plasma GFAP was determined in a prospective multicenter approach. METHODS: Within a 1-year recruitment period, patients suspected of having acute (symptom onset<4.5 h before admission) hemispheric stroke were prospectively included into the study in 14 stroke centers in Germany and Switzerland. A blood sample was collected at admission, and plasma GFAP was measured by use of an electrochemiluminometric immunoassay. The final diagnosis, established at hospital discharge, was classified as ICH, ischemic stroke, or stroke mimic. RESULTS: The study included 205 patients (39 ICH, 163 ischemic stroke, 3 stroke mimic). GFAP concentrations were increased in patients with ICH compared with patients with ischemic stroke [median (interquartile range) 1.91 µg/L (0.41-17.66) vs 0.08 µg/L (0.02-0.14), P<0.001]. Diagnostic accuracy of GFAP for differentiating ICH from ischemic stroke and stroke mimic was high [area under the curve 0.915 (95% CI 0.847-0.982), P<0.001]. A GFAP cutoff of 0.29 µg/L provided diagnostic sensitivity of 84.2% and diagnostic specificity of 96.3% for differentiating ICH from ischemic stroke and stroke mimic. CONCLUSIONS: Plasma GFAP analysis performed within 4.5 h of symptom onset can differentiate ICH and ischemic stroke. Studies are needed to evaluate a GFAP point-of-care system that may help optimize the prehospital triage and management of patients with symptoms of acute stroke.

Eslicarbazepine Acetate as Adjunctive Therapy for Primary Generalized Tonic-Clonic Seizures in Adults: A Prospective Observational Study.

BACKGROUND: Eslicarbazepine acetate (ESL), a novel sodium channel blocker, is approved for mono and adjunctive treatment of partial epileptic seizures with or without secondary generalization. Its efficacy in primary generalized seizures has not yet been evaluated. OBJECTIVE: To evaluate the efficacy and safety of ESL in primary generalized tonic-clonic seizures (PGTCS) in an observational study. METHODS: The data were collected from a prospective population-based register. Effectiveness was measured as relative reduction in standardized seizure frequency (SSF), responder rate (≥ 50% reduction in SSF), and seizure freedom rate at 6 and 12 months after initiation of ESL. Safety and tolerability were evaluated using patients' diaries. RESULTS: Fifty-six adult patients with PGTCS were treated with ESL as adjunctive therapy. Of these, 30.4% (n = 17) had myoclonic seizures in addition to PGTCS. The retention rate after 12 months was 80.4% (n = 45). After initiating ESL therapy, reduction in SSF for PGTCS on ESL was 56.0% after 6 months and 56.9% after 12 months (p < 0.01), whereas myoclonic seizures did not show any significant improvement in frequency. The responder rate for PGTCS was 64.3% after 6 months and 66.1% after 12 months, and seizure freedom was achieved in 32.1% and 35.7%, respectively. Forty-three patients (73.2%) reported no side effects. Among the reported side effects of ESL therapy, headache (7.1%), dizziness (8.9%), tiredness (7.1%), nausea (5.4%), and hyponatremia (5.4%) were the most prevalent. CONCLUSIONS: Our data suggest that ESL may provide additional benefits in the treatment of patients with PGTCS and motivate randomized controlled trials in this indication.

Efficacy and safety of antiseizure medication in post-stroke epilepsy.

BACKGROUND: Specific antiseizure medications (ASM) would improve the outcome in post-stroke epilepsy (PSE). The aim of this multicenter observational study was to compare different antiseizure monotherapies in PSE. METHODS: We collected the data from 207 patients with PSE who did not change their initial antiseizure monotherapy during the period of 12 months. Efficacy was assessed by a standardized three month seizure frequency and seizure freedom. Safety was estimated by the reported side effects. RESULTS: The mean three month seizure frequency was 1.9 ±â€¯3.1 on eslicarbazepine, 2.1 ±â€¯3.2 on lacosamide, 3.4 ±â€¯4.4 on levetiracetam, 4.3 ±â€¯6.8 on lamotrigine, and 5.1 ±â€¯7.3 on valproate (p < 0.05 for eslicarbazepine or lacosamide in comparison with levetiracetam, lamotrigine and valproate, respectively). The lowest seizure frequency and the highest seizure freedom was observed on ASMs acting via the slow inactivation of sodium channels in comparison to other mechanisms of action (0.7 ±â€¯0.9 vs 2.2 ±â€¯2.4, p < 0.01). Among side effects, the most frequently reported were vertigo (25%) and tiredness (15.9%). They were similar in all investigated groups of ASM. The independent factors increasing seizure frequency that were identified in multiple regression analyses were increased size of infarction, cortical involvement, hemorrhagic transformation, neurological deficits at admission and functional impairment. Administration of ASM with the mechanism of action via the slow inactivation of sodium channels was an independent factor decreasing the seizure frequency. CONCLUSION: Our data show that antiseizure medications acting via the slow inactivation of sodium channels, such as lacosamide and eslicarbazepine, are well tolerated and might be associated with better seizure control in PSE.

Analysis of CYP7B1 in non-consanguineous cases of hereditary spastic paraplegia.

Hereditary spastic paraplegia (HSP) is a neurodegenerative condition defined clinically by lower limb spasticity and weakness. Homozygous mutations in CYP7B1 have been identified in several consanguineous families that represented HSP type 5 (SPG5), one of the many genetic forms of the disease. We used direct sequencing and multiplex ligation-dependent probe amplification to screen for CYP7B1 alterations in apparently sporadic HSP patients (n = 12) as well as index patients from non-consanguineous families with recessive (n = 8) and dominant (n = 8) transmission of HSP. One sporadic patient showing HSP as well as optic atrophy carried a homozygous nonsense mutation. Compound heterozygosity was observed in a recessive family with a clinically pure phenotype. A heterozygous missense change segregated in a small dominant family. We also found a significant association of a known coding polymorphism with cerebellar signs complicating a primary HSP phenotype. Our findings suggest CYP7B1 alterations to represent a rather frequent cause of HSP that should be considered in patients with various clinical presentations.

REEP1 mutation spectrum and genotype/phenotype correlation in hereditary spastic paraplegia type 31.

Mutations in the receptor expression enhancing protein 1 (REEP1) have recently been reported to cause autosomal dominant hereditary spastic paraplegia (HSP) type SPG31. In a large collaborative effort, we screened a sample of 535 unrelated HSP patients for REEP1 mutations and copy number variations. We identified 13 novel and 2 known REEP1 mutations in 16 familial and sporadic patients by direct sequencing analysis. Twelve out of 16 mutations were small insertions, deletions or splice site mutations. These changes would result in shifts of the open-reading-frame followed by premature termination of translation and haploinsufficiency. Interestingly, we identified two disease associated variations in the 3'-UTR of REEP1 that fell into highly conserved micro RNA binding sites. Copy number variation analysis in a subset of 133 HSP index patients revealed a large duplication of REEP1 that involved exons 2-7 in an Irish family. Clinically most SPG31 patients present with a pure spastic paraplegia; rare complicating features were restricted to symptoms or signs of peripheral nerve involvement. Interestingly, the distribution of age at onset suggested a bimodal pattern with the appearance of initial symptoms of disease either before the age of 20 years or after the age of 30 years. The overall mutation rate in our clinically heterogeneous sample was 3.0%; however, in the sub-sample of pure HSP REEP1 mutations accounted for 8.2% of all patients. These results firmly establish REEP1 as a relatively frequent autosomal dominant HSP gene for which genetic testing is warranted. We also establish haploinsufficiency as the main molecular genetic mechanism in SPG31, which should initiate and guide functional studies on REEP1 with a focus on loss-of-function mechanisms. Our results should be valid as a reference for mutation frequency, spectrum of REEP1 mutations, and clinical phenotypes associated with SPG31.

Screening of hereditary spastic paraplegia patients for alterations at NIPA1 mutational hotspots.

Mutations in NIPA1 cause hereditary spastic paraplegia type 6 (SPG6 HSP). Sequencing of the whole gene has revealed alterations of either of two nucleotides in eight of nine SPG6 HSP families reported to date. By analysing CpG methylation, we provide a mechanistic explanation for a mutational hotspot to underlie frequent alteration of one of these nucleotides. We also developed PCR RFLP assays to detect recurrent NIPA1 changes and screened 101 independent HSP patients, including 45 index patients of autosomal dominant HSP families. Our negative finding in this cohort for which several other causes of HSP had been excluded suggests NIPA1 alterations at mutational hotspots to be less frequent than previously thought. Nevertheless, the assays introduced represent a valid pre-screen easily implementable in the molecular diagnosis of HSP.

Does the recruitment of excitation and inhibition in the motor cortex differ?

The level of excitability within the motor cortex can be described as a balance between excitation and inhibition, but it is unknown how well both processes correlate. To address this question, the authors measured motor cortical excitability and inhibition in healthy human subjects, comparing the recruitment of motor evoked potentials (MEPs) and the duration of the cortical silent period (CSP) after transcranial magnetic stimulation (TMS). Single-pulse "focal" TMS was applied at intensities varying between 90% and 200% of motor thresholds to the right motor cortex of 15 healthy volunteers. The peak-to peak size of MEP responses and the duration of the CSP were measured in small hand muscles. Stimulus-response (S-R) curves were constructed by plotting the MEP size and CSP duration against stimulus intensities. The absolute duration of CSP and the size MEPs correlated significantly and to a similar extent with stimulus intensity (r = 0.60 and 0.53, respectively). The slope of the MEP-S-R was steeper compared with CSP-S-R, particularly at low stimulation intensities. CSP duration saturated earlier and CSP-S-Rs were shifted upwards at a given stimulus intensity compared with MEP-S-Rs. The findings suggest that recruitment of inhibition and excitation within the sensorimotor cortex correlate. However, inhibitory effects are recruited at lower intensities and saturate earlier than excitation.

Holter-electrocardiogram-monitoring in patients with acute ischaemic stroke (Find-AFRANDOMISED): an open-label randomised controlled trial.

BACKGROUND: Atrial fibrillation is a major risk factor for recurrent ischaemic stroke, but often remains undiagnosed in patients who have had an acute ischaemic stroke. Enhanced and prolonged Holter-electrocardiogram-monitoring might increase detection of atrial fibrillation. We therefore investigated whether enhanced and prolonged rhythm monitoring was better for detection of atrial fibrillation than standard care procedures in patients with acute ischaemic stroke. METHODS: Find-AFrandomised is an open-label randomised study done at four centres in Germany. We recruited patients with acute ischaemic stroke (symptoms for 7 days or less) aged 60 years or older presenting with sinus rhythm and without history of atrial fibrillation. Patients were included irrespective of the suspected cause of stroke, unless they had a severe ipsilateral carotid or intracranial artery stenosis, which were the exclusion criteria. We used a computer-generated allocation sequence to randomly assign patients in a 1:1 ratio with permuted block sizes of 2, 4, 6, and 8, stratified by centre, to enhanced and prolonged monitoring (ie, 10-day Holter-electrocardiogram [ECG]-monitoring at baseline, and at 3 months and 6 months of follow-up) or standard care procedures (ie, at least 24 h of rhythm monitoring). Participants and study physicians were not masked to group assignment, but the expert committees that adjudicated endpoints were. The primary endpoint was the occurrence of atrial fibrillation or atrial flutter (30 sec or longer) within 6 months after randomisation and before stroke recurrence. Because Holter ECG is a widely used procedure and not known to harm patients, we chose not to assess safety in detail. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01855035. FINDINGS: Between May 8, 2013, and Aug 31, 2014, we recruited 398 patients. 200 patients were randomly assigned to the enhanced and prolonged monitoring group and 198 to the standard care group. After 6 months, we detected atrial fibrillation in 14% of 200 patients in the enhanced and prolonged monitoring group (27 patients) versus 5% in the control group (nine of 198 patients, absolute difference 9·0%; 95% CI 3·4-14·5, p=0·002; number needed to screen 11). INTERPRETATION: Enhanced and prolonged monitoring initiated early in patients with acute ischaemic stroke aged 60 years or older was better than standard care for the detection of atrial fibrillation. These findings support the consideration of all patients aged 60 years or older with stroke for prolonged monitoring if the detection of atrial fibrillation would result in a change in medical management (eg, initiation of anticoagulation). FUNDING: Boehringer Ingelheim.

Antiepileptic drug use in nursing home residents: a cross-sectional, regional study.

The use of antiepileptic drugs (AED), their primary indication, comorbid conditions, and concomitant medications were collected from 565 nursing homes (NH) residents of six NH located around the city of Mainz, Germany representing 5.05% of all NH residents in the area. Data were collected from the electronic pharmacy files and by reviewing all available medical records. Average age was 82.2 +/- 2.4 years, 85.5% were women. Of 565 NH residents 28 (4.96%) received AED therapy, of which in 17 (63%) AED were prescribed for a seizure-related diagnosis. In 76.5% seizure types were unspecified and a distinction in focal and generalized epilepsy was made in only 23.5% of patients. Three patients never had epileptic seizures and in four residents the reason for AED use was unclear. AEDs most frequently prescribed were carbamazepine (37.1%), valproic acid (25.9%), and phenytoin (14.8%). Five patients received benzodiazepines (18.5%), newer generation AED were used in only four (14.8%) cases. Residents on average took n = 5.6 +/- 3.3 other drugs. Opportunities exist for health care professionals to improve the medical management of nursing facility residents receiving AEDs.

The spectrum of KIAA0196 variants, and characterization of a murine knockout: implications for the mutational mechanism in hereditary spastic paraplegia type SPG8.

BACKGROUND: The hereditary spastic paraplegias (HSPs) are rare neurodegenerative gait disorders which are genetically highly heterogeneous. For each single form, eventual consideration of therapeutic strategies requires an understanding of the mechanism by which mutations confer pathogenicity. SPG8 is a dominantly inherited HSP, and associated with rather early onset and rapid progression. A total of nine mutations in KIAA0196, which encodes the WASH regulatory complex (SHRC) member strumpellin, have been reported in SPG8 patients so far. Based on biochemical and cell biological approaches, they have been suggested to act via loss of function-mediated haploinsufficiency. METHODS: We generated a deletion-based knockout allele for E430025E21Rik, i.e. the murine homologue of KIAA0196. The consequences on mRNA and protein levels were analyzed by qPCR and Western-blotting, respectively. Motor performance was evaluated by the foot-base angle paradigm. Axon outgrowth and relevant organelle compartments were investigated in primary neuron cultures and primary fibroblast cultures, respectively. A homemade multiplex ligation-dependent probe amplification assay enabling identification of large inactivating KIAA0196 deletion alleles was applied to DNA from 240 HSP index patients. RESULTS: Homozygous but not heterozygous mice showed early embryonic lethality. No transcripts from the knockout allele were detected, and the previously suggested compensation by the wild-type allele upon heterozygosity was disproven. mRNA expression of genes encoding other SHRC members was unaltered, while there was evidence for reduced SHRC abundance at protein level. We did, however, neither observe HSP-related in vivo and ex vivo phenotypes, nor alterations affecting endosomal, lysosomal, or autophagic compartments. KIAA0196 copy number screening excluded large inactivating deletion mutations in HSP patients. The consequences of monoallelic KIAA0196/E430025E21Rik activation thus differ from those observed for dominant HSP genes for which a loss-of-function mechanism is well established. CONCLUSIONS: Our data do not support the current view that heterozygous loss of strumpellin/SHRC function leads to haploinsufficiency and, in turn, to HSP. The lethality of homozygous knockout mice, i.e. the effect of complete loss of function, also argues against a dominant negative effect of mutant on wild-type strumpellin in patients. Toxic gain-of-function represents a potential alternative explanation. Confirmation of this therapeutically relevant hypothesis in vivo, however, will require availability of appropriate knockin models.

AP5Z1/SPG48 frequency in autosomal recessive and sporadic spastic paraplegia.

Hereditary spastic paraplegias (HSP) constitute a rare and highly heterogeneous group of neurodegenerative disorders, defined clinically by progressive lower limb spasticity and pyramidal weakness. Autosomal recessive HSP as well as sporadic cases present a significant diagnostic challenge. Mutations in AP5Z1, a gene playing a role in intracellular membrane trafficking, have been recently reported to be associated with spastic paraplegia type 48 (SPG48). Our objective was to determine the relative frequency and clinical relevance of AP5Z1 mutations in a large cohort of 127 HSP patients. We applied a targeted next-generation sequencing approach to analyze all coding exons of the AP5Z1 gene. With the output of high-quality reads and a mean coverage of 51-fold, we demonstrated a robust detection of variants. One 43-year-old female with sporadic complicated paraplegia showed two heterozygous nonsynonymous variants of unknown significance (VUS3; p.[R292W];[(T756I)]). Thus, AP5Z1 gene mutations are rare, at least in Europeans. Due to its low frequency, systematic genetic testing for AP5Z1 mutations is not recommended until larger studies are performed to add further evidence. Our findings demonstrate that amplicon-based deep sequencing is technically feasible and allows a compact molecular characterization of multiple HSP patients with high accuracy.

The safety and efficacy of add-on levetiracetam in elderly patients with focal epilepsy: a one-year observational study.

PURPOSE: The long-term safety and efficacy of levetiracetam (LEV) was evaluated as add-on therapy in focal epilepsy patients (n=491) aged at least 65 years who failed at least one monotherapy. METHODS: Patients (n=491) with focal epilepsy treated with at least one antiepileptic drug in monotherapy with insufficient seizure control were included in this prospective open-label study. The recommended LEV dose range was 1000-3000 mg per day. Follow-up visits were done approximately after 3, 6 and 12 months. Safety and efficacy was analysed based on all patients who received LEV (safety population, n=491) and all patients who were seen at all visits and completed the trial (per protocol population, n=364). RESULTS: Patients (53% men, median age 71 years) had a total of 97 adverse events (AEs) reported in 53 patients. The most common AEs were fatigue and restlessness (9.7% each of all AEs). A total of 35 serious AEs occurred in 19 patients (3.9% of the safety population), all but one unrelated to the study medication. Mean monthly seizure frequency dropped significantly from 7.0 (SD 8.7, range 1-85, median 4) at baseline to 1.7 (SD 2.9, range 0-29, median 1) at 3 month, 1.2 (SD 2.6, range 0-30, median 0) at 6, and 1.4 (SD 6.6, range 0-99, median 0) at 12 months, corresponding to a reduction of 75.7%, 82.9%, and 80.0% relative to baseline. Seizure freedom was reported by 42%, 57.7%, and 58% of patients during the previous period at 3, 6 and 12 months follow-up, respectively. CONCLUSIONS: Add-on treatment with LEV in elderly patients with focal epilepsy was safe and efficient. Levetiracetam might be considered as a suitable drug in the elderly.

Sex differences in early carotid atherosclerosis (from the community-based Gutenberg-Heart Study).

The objectives of this study were to describe gender differences in intima-media thickness (IMT) in a community-based population study and to define normal IMT values for healthy men and women. In total, 4,814 participants (aged 35 to 74 years; 2,433 men, 2,381 women) from the Gutenberg-Heart Study (GHS) were included. IMT was measured at both common carotid arteries using an edge detection system. Median IMT was 0.62 mm (25th percentile 0.55, 75th percentile 0.70) in women and 0.65 mm (25th percentile 0.57, 75th percentile 0.75) in men and was significantly associated with age (p <0.0001). On multivariate analysis, advanced age, smoking, and arterial hypertension were positively associated with higher IMT in men and women. A subgroup of 1,025 subjects without cardiovascular risk factors or previous cardiovascular disease was analyzed to define normal IMT values. Nomograms were calculated according to age and gender. For each age group, IMT >95th percentile was defined as abnormal. In this subgroup, gender differences in IMT became nonsignificant at older ages. At the age of 35 years, IMT was 0.71 mm in men and 0.61 mm in women at the 95th percentile. In comparison, at the age of 74 years, IMT at the 95th percentile was 0.90 mm in men and 0.89 mm in women. In conclusion, men had higher carotid IMT than women, but predictors of early carotid atherosclerosis were similar across genders. In young subjects without cardiovascular risk factors, normal values for IMT were lower in women compared with men. In contrast, in older subjects, gender differences in IMT became nonsignificant.

A total of 220 patients with autosomal dominant spastic paraplegia do not display mutations in the SLC33A1 gene (SPG42).

The most frequent causes of autosomal dominant (AD) hereditary spastic paraplegias (HSP) (ADHSP) are mutations in the SPAST gene (SPG4 locus). However, roughly 60% of patients are negative for SPAST mutations, despite their family history being compatible with AD inheritance. A mutation in the gene for an acetyl-CoA transporter (SLC33A1) has recently been reported in one Chinese family to cause ADHSP-type SPG42. In this study, we screened 220 independent SPAST mutation-negative ADHSP samples for mutations in the SLC33A1 gene by high-resolution melting curve analysis. Conspicuous samples were validated by direct sequencing. Moreover, copy number variations affecting SLC33A1 were screened by multiplex ligation-dependent probe amplification assay. We could not identify potentially disease-causing mutations in our patients either by mutation scanning or by gene dosage analysis, as for the latter specific positive controls are not available to date. As our sample represents ADHSP patients for whom SPAST mutations and almost in all cases ATL1 and REEP1 mutations had been excluded, we consider SLC33A1 gene mutations as being very rare in a European ADHSP cohort, if present at all. To date, as SPG42 has still not been identified in a second, unrelated family, systematic genetic testing for SLC33A1 mutations is not recommended.

Recruitment of motor cortex inhibition differentiates between generalized and focal epilepsy.

Intracortical disinhibitory mechanisms play a crucial role in epilepsy. Therefore, the recruitment of motor cortical excitability was evaluated to distinct between focal and generalized epileptic syndromes. Twenty-five untreated patients with epilepsy and 20 controls were enrolled. Classification into focal (FE, n=10) or idiopathic generalized (IGE, n=15) epilepsy was based on seizure semiology, EEG and MRI. The recruitment of motor cortical inhibition and facilitation was measured by varying the stimulus intensity (SI) of the first conditioning stimulus in a paired-pulse transcranial magnetic stimulation (TMS) paradigm producing stimulus-response (S-R) curves of intracortical excitability. S-R curves were then compared with other commonly used TMS measures of cortical excitability [cortical silent period (CSP) and motor threshold (MT)]. In patients with IGE, inhibition occurred only at higher conditioning SIs compared to patients with focal epilepsy and controls. Recruitment of inhibition was unchanged in patients with focal epilepsy compared to controls. Recruitment of facilitation (ICF), CSP duration and MT, were not different between patients with FE or IGE or between patients and controls. These results suggest that the recruitment for motor cortical inhibition in patients with IGE is less effective. This may reflect a disturbed access to or an increased threshold of inhibitory neurons within the motor cortex. Impaired recruitment of inhibition might be a helpful parameter to access cortical excitability in newly diagnosed patients with generalized or focal epilepsy.

Decreased dopamine D2/D3-receptor binding in temporal lobe epilepsy: an [18F]fallypride PET study.

PURPOSE: Although animal data are suggestive, evidence for an alteration of the extrastriatal dopaminergic system in human focal epilepsy is missing. METHODS: To quantify D2/D3-receptor density, we studied seven patients with temporal lobe epilepsy (TLE) and nine age-matched controls with positron emission tomography (PET) by using the high-affinity dopamine D2/D3-receptor ligand [18F]Fallypride ([18F]FP) suitable for imaging extrastriatal binding. TLE was defined by interictal and ictal video-EEG, magnetic resonance imaging (MRI), and [18F]fluorodeoxyglucose ([18F]FDG)-PET and was due to hippocampal sclerosis (HS), based on histology in all patients. Primary analysis was based on regions of interest (ROIs) defined on individual MRIs. For each patient, binding potential (BP) was calculated by using the simplified reference tissue model, and the epileptogenic was compared with the unaffected hemisphere in each ROI. To confirm the results, an additional voxel-based group analysis was performed by using statistical parametric mapping. RESULTS: Compared with controls, [18F]FP BP was significantly decreased in the epileptogenic temporal lobe in all patients. On ROI analysis, this reduction was evident in areas surrounding the seizure-onset zone at the pole (-34.2%) and lateral aspects (-32.9%) of the temporal lobe. Although the hippocampus [18F]FDG uptake (-8.1%) and hippocampal MR volume (-35.1%) were significantly reduced, no significant decrease of [18F]FP BP was found. Reduction of [18F]FP BP did not correlate with hippocampal atrophy. CONCLUSIONS: D2/D3-receptor binding is reduced at the pole and in lateral aspects of the epileptogenic temporal lobe in patients with mesial TLE and HS. This area might correspond to "the irritative zone," indicating that D2/D3 receptors might play a specific role in the pathophysiology of mesial TLE.

Early onset autosomal dominant spastic paraplegia caused by novel mutations in SPG3A.

Hereditary spastic paraplegia (HSP) is a group of neurodegenerative disorders mainly characterized by progressive spasticity of the lower limbs. The major features of HSP are a marked phenotypic variability both among and within families and an extended genetic heterogeneity. More than 20 HSP loci and 10 spastic paraplegia genes (SPG) have been identified to date, including the genes responsible for the two most frequent forms of autosomal dominant spastic paraplegia (AD-HSP), encoding spastin (SPG4) and atlastin (SPG3A), respectively. To date, only eight mutations have been described in the atlastin gene, which was reported to account for about 10% of all AD-HSP families. We investigated 15 German and French AD-HSP families, including the 3 large pedigrees that allowed the mapping and subsequent refinement of the SPG3A locus. Three novel mutations were found in exons 4, 9, and 12 of the atlastin gene and the common R239C mutation located in exon 7 was confirmed in a 7th family of European origin. Overall, the comparison of the clinical data for all SPG3A-HSP families reported to date failed to reveal any genotype/phenotype correlation as demonstrated for other forms of AD-HSP. However, it confirmed the early onset of this form of HSP, which was observed in almost all affected individuals with a mutation in the atlastin gene.