Reversible cerebral vasoconstriction syndrome associated with hormone therapy for intrauterine insemination

Introduction: Reversible cerebral vasoconstriction syndrome (RCVS) comprises a heterogeneous group of acute neurological diseases which are characterized by thunderclap headache and evidence of reversible multifocal constriction of cerebral arteries. A number of precipitating factors have been described in the literature, including recent childbirth and use of vasoactive substances.

Case description: Here we present the case of a female patient with RCVS which occurred in the setting of hormonal ovarian stimulation for intrauterine insemination.

Discussion: This case possibly contributes to the understanding of the pathophysiological mechanisms underlying reversible cerebral vasoconstriction.

A case of Sturge-Weber syndrome with symptomatic hemiplegic migraine: clinical and multimodality imaging data during a prolonged attack

Hemiplegic migraine (HM) in the setting of Sturge-Weber syndrome (SWS) has been previously described. Here, we report clinical and multimodal imaging data on a 21-year-old man with SWS and HM, who presented during an acute HM attack with a dense left-hemispheric syndrome (expressive aphasia and right sensorimotor hemiplegia), lasting for more than 10 days. Repeated EEGs were without evidence of status epilepticus. Consistent with previous findings in prolonged migraine aura, perfusion computed tomography demonstrated left-hemispheric hyperperfusion on day 7. 18F-FDG positron emission tomography (day 7) revealed left-hemispheric hypermetabolism. After 14 days, the patient was symptom-free and discharged home. Follow-up after 30 days showed normal neurological status. Our observation confirms and reinforces the comorbidity of SWS and HM and shows that prolonged HM attacks are associated with complex changes of both cerebral perfusion and glucose metabolism. A pathophysiological model explaining both the association between SWS/HM and the observed imaging changes is presented.

Ischemic stroke of the cortical "hand knob" area: stroke mechanisms and prognosis

Cortical ischemic stroke affecting the precentral "hand knob" area is a rare but well known stroke entity. To date, little is known about the underlying stroke mechanisms and the prognosis. Twenty-nine patients admitted to our service between 2003 and 2007 were included in the study on the basis of an acute ischemic infarct of the cortical "hand knob" area confirmed by diffusion-weighted magnetic resonance imaging with contralateral hand paresis. For all patients clinical, epidemiological as well as imaging data at the time point of admission were analysed retrospectively and follow-up data on all patients was obtained. The majority (n = 21/72%) had an isolated infarct of the cortical "hand knob" area. In 23 (79%) patients it was a first ever stroke. Ten patients (34%) had ipsilateral extracranial stenosis of the internal carotid artery (ICA), whereas potential cardiac embolic sources were less frequent (n = 4/14%). No patient exhibited ipsilateral MCA stenosis. All but two patients (93%) had marked atherosclerotic alterations of the ICA. Hypertension was the most prevalent vascular risk factor (n = 23/79%). At follow-up (mean 25.0 months, range 0.4-47.4 months) no patient had died and only one (3%) experienced a recurrent stroke. The majority of patients (79%) reported improvement of hand paresis, 17 (59%) were asymptomatic (modified Rankin score = 0). Only one patient was significantly disabled due to a recurrent stroke. In conclusion, ischemic infarcts affecting the cortical "hand knob" area are frequently associated with atherosclerotic changes of the carotid artery, suggesting an arterio-arterial thrombembolic stroke mechanism. It mostly reflects first ever ischemic stroke, and follow-up data suggest a rather benign course.

Impaired plasma membrane targeting or protein stability by certain ATP1A2 mutations identified in sporadic or familial hemiplegic migraine

Mutations in three different genes have been implicated in familial hemiplegic migraine (FHM), two of them code for neuronal voltage-gated cation channels, CACNA1A and SCN1A, while the third encodes ATP1A2, the alpha(2)-isoform of the Na(+)/K(+)-ATPase's catalytic subunit, thus classifying FHM as an ion channel/ion transporter disorder. The Na(+)/K(+)-ATPase maintains the physiological gradients for Na(+) and K(+) ions and is therefore critical for the activity of ion channels and transporters involved in neurotransmitter uptake or Ca(2+) signaling. Diverse functional abnormalities have been identified for disease-linked ATP1A2 mutations, which reach far beyond simple loss-of-function. We have shown recently that ATP1A2 mutations frequently lead to changes in the enzyme's voltage-dependent properties, kinetics or apparent cation affinities. Here, we present functional data on a so far uncharacterized set of ATP1A2 mutations (G301R, R908Q and P979L) upon expression in Xenopus oocytes and HEK293FT cells, and provide evidence for a novel pathophysiological mechanism. Whereas the G301R mutant was inactive, no functional changes were observed for mutants R908Q and P979L in the oocyte expression system. However, the R908Q mutant was less effectively expressed in the plasma membrane of oocytes, making it the first missense mutation to result in defective plasma membrane targeting. Notably, the P979L mutant exhibited the same cellular expression profile as the wild-type protein, both in Xenopus oocytes and in transfected HEK293FT cells grown at 28 degrees C, but much less P979L protein was found upon cell growth at 37 degrees C, showing for the first time that temperature-sensitive effects on protein stability can underlie ATP1A2 loss-of-function.

Two common mitochondrial DNA polymorphisms are highly associated with migraine headache and cyclic vomiting syndrome

Mitochondrial dysfunction is a hypothesized component in the multifactorial pathogenesis of migraine without aura (MoA, 'common migraine') and the related condition of cyclic vomiting syndrome (CVS). In this study, the entire mitochondrial genome was sequenced in 20 haplogroup-H CVS patients, a subject group studied because of greater genotypic and phenotypic homogeneity. Sequences were compared against haplogroup-H controls. Polymorphisms of interest were tested in 10 additional CVS subjects and in 112 haplogroup-H adults with MoA. The 16519C-->T polymorphism was found to be highly disease associated: 21/30 CVS subjects [70%, odds ratio (OR) 6.2] and 58/112 migraineurs (52%, OR 3.6) vs. 63/231 controls (27%). A second polymorphism, 3010G-->A, was found to be highly disease associated in those subjects with 16519T: 6/21 CVS subjects (29%, OR 17) and 15/58 migraineurs (26%, OR 15) vs. 1/63 controls (1.6%). Our data suggest that these polymorphisms constitute a substantial proportion of the genetic factor in migraine pathogenesis, and strengthen the hypothesis that there is a component of mitochondrial dysfunction in migraine.

Genetic variation in the lymphotoxin-alpha pathway and the risk of ischemic stroke in European populations

BACKGROUND AND PURPOSE

Several genes involved in the lymphotoxin-alpha cascade (LTA, LGALS2, and PSMA6) have been linked with the risk of myocardial infarction. Here, we present a comprehensive analysis of these genes in patients with ischemic stroke (IS).

METHODS

Twenty-three single nucleotide polymorphisms (SNPs) from LTA, LGALS2, and PSMA6 were genotyped in 601 German IS patients and 736 matched controls. SNPs and haplotypes were tested for association with overall IS, large vessel stroke, and cardioembolic stroke. Significant associations were replicated in an independent sample of 843 IS cases and 933 controls from the UK.

RESULTS

Only one SNP (rs1048990 in PSMA6) showed association with overall IS, but this was not replicated in the UK sample. Three SNPs showed significant associations with stroke subtypes (P<0.05), but none of these associations could be replicated in the UK population.

CONCLUSIONS

Genetic variation in the lymphotoxin-alpha cascade (LTA, LGALS2, and PSMA6) is not a major risk factor for IS.

Diverse functional consequences of mutations in the Na+/K+-ATPase alpha2-subunit causing familial hemiplegic migraine type 2

Mutations in ATP1A2, the gene coding for the Na(+)/K(+)-ATPase alpha(2)-subunit, are associated with both familial hemiplegic migraine and sporadic cases of hemiplegic migraine. In this study, we examined the functional properties of 11 ATP1A2 mutations associated with familial or sporadic hemiplegic migraine, including missense mutations (T263M, T376M, R383H, A606T, R763H, M829R, R834Q, R937P, and X1021R), a deletion mutant (del(K935-S940)ins(I)), and a frameshift mutation (S966fs). According to the Na(+)/K(+)-ATPase crystal structure, a subset of the mutated residues (Ala(606), Arg(763), Met(829), and Arg(834)) is involved in important interdomain H-bond networks, and the C terminus of the enzyme, which is elongated by the X1021R mutation, has been implicated in voltage dependence and formation of a third Na(+)-binding site. Upon heterologous expression in Xenopus oocytes, the analysis of electrogenic transport properties, Rb(+) uptake, and protein expression revealed pronounced and markedly diverse functional alterations in all ATP1A2 mutants. Abnormalities included a complete loss of function (T376M), impaired plasma membrane expression (del(K935-S940)ins(I) and S966fs), and altered apparent affinities for extracellular cations or reduced enzyme turnover (R383H, A606T, R763H, R834Q, and X1021R). In addition, changes in the voltage dependence of pump currents and the increased rate constants of the voltage jump-induced redistribution between E(1)P and E(2)P states were observed. Thus, mutations that disrupt distinct interdomain H-bond patterns can cause abnormal conformational flexibility and exert long range consequences on apparent cation affinities or voltage dependence. Of interest, the X1021R mutation severely impaired voltage dependence and kinetics of Na(+)-translocating partial reactions, corroborating the critical role of the C terminus of Na(+)/K(+)-ATPase in these processes.

A high-density association screen of 155 ion transport genes for involvement with common migraine

The clinical overlap between monogenic Familial Hemiplegic Migraine (FHM) and common migraine subtypes, and the fact that all three FHM genes are involved in the transport of ions, suggest that ion transport genes may underlie susceptibility to common forms of migraine. To test this leading hypothesis, we examined common variation in 155 ion transport genes using 5257 single nucleotide polymorphisms (SNPs) in a Finnish sample of 841 unrelated migraine with aura cases and 884 unrelated non-migraine controls. The top signals were then tested for replication in four independent migraine case-control samples from the Netherlands, Germany and Australia, totalling 2835 unrelated migraine cases and 2740 unrelated controls. SNPs within 12 genes (KCNB2, KCNQ3, CLIC5, ATP2C2, CACNA1E, CACNB2, KCNE2, KCNK12, KCNK2, KCNS3, SCN5A and SCN9A) with promising nominal association (0.00041 < P < 0.005) in the Finnish sample were selected for replication. Although no variant remained significant after adjusting for multiple testing nor produced consistent evidence for association across all cohorts, a significant epistatic interaction between KCNB2 SNP rs1431656 (chromosome 8q13.3) and CACNB2 SNP rs7076100 (chromosome 10p12.33) (pointwise P = 0.00002; global P = 0.02) was observed in the Finnish case-control sample. We conclude that common variants of moderate effect size in ion transport genes do not play a major role in susceptibility to common migraine within these European populations, although there is some evidence for epistatic interaction between potassium and calcium channel genes, KCNB2 and CACNB2. Multiple rare variants or trans-regulatory elements of these genes are not ruled out.

Divergent sodium channel defects in familial hemiplegic migraine

Familial hemiplegic migraine type 3 (FHM3) is a severe autosomal dominant migraine disorder caused by mutations in the voltage-gated sodium channel Na(V)1.1 encoded by SCN1A. We determined the functional consequences of three mutations linked to FHM3 (L263V, Q1489K, and L1649Q) in an effort to identify molecular defects that underlie this inherited migraine disorder. Only L263V and Q1489K generated quantifiable sodium currents when coexpressed in tsA201 cells with the human beta(1) and beta(2) accessory subunits. The third mutant, L1649Q, failed to generate measurable whole-cell current because of markedly reduced cell surface expression. Compared to WT-Na(V)1.1, Q1489K exhibited increased persistent current but also enhanced entry into slow inactivation as well as delayed recovery from fast and slow inactivation, thus resulting in a predominantly loss-of-function phenotype further demonstrated by a greater loss of channel availability during repetitive stimulation. In contrast, L263V exhibited gain-of-function features, including delayed entry into, as well as accelerated recovery from, fast inactivation; depolarizing shifts in the steady-state voltage dependence of fast and slow inactivation; increased persistent current; and delayed entry into slow inactivation. Notably, the two mutations (Q1489K and L1649Q) that exhibited partial or complete loss of function are linked to typical FHM, whereas the gain-of-function mutation L263V occurred in a family having both FHM and a high incidence of generalized epilepsy. We infer from these data that a complex spectrum of Na(V)1.1 defects can cause FHM3. Our results also emphasize the complex relationship between migraine and epilepsy and provide further evidence that both disorders may share common molecular mechanisms.

Enhanced L-arginine-induced vasoreactivity suggests endothelial dysfunction in CADASIL

BACKGROUND

Mutations in the Notch3 gene are the cause of CADASIL, a hereditary small vessel disease leading to stroke and vascular dementia. The disease is characterized by ultrastructural granular deposits within small arterial vessels and degeneration of vascular smooth muscle cells. Yet, little is known about endothelial function in CADASIL. Vasoreactivity induced by L-arginine, which is the substrate for endothelial nitric oxide synthase, is a parameter of endothelial function and has been shown to be altered in patients with cerebrovascular disease.

METHODS

To assess endothelial function in CADASIL, L-arginine-induced vasoreactivity was studied in 25 CADASIL subjects and 24 non-CADASIL control subjects without previous history of cerebrovascular disease by transcranial Doppler sonography of the middle cerebral artery.

RESULTS

Resting mean flow velocity was significantly reduced in patients (43.7 +/- 14.5 cm/s) compared to controls (57.0 +/- 10.4 cm/s) [p < 0.001]. Patients exhibited a significantly higher pulsatility index (PI = 0.94 +/- 0.19) than control subjects (PI = 0.79 +/- 0.11) [p < 0.01]. L-arginine-induced vasoreactivity was significantly increased in patients (36.1 +/- 15.5 % ) versus controls (27.9 +/- 8.5 %) [p < 0.05]. In patients, there was a significant reduction of the PI following L-arginine application (PI = 0.86 +/- 0.13) compared to resting PI [p < 0.01].

CONCLUSIONS

Our results may indicate a pathogenic role of impaired cerebral hemodynamics and endothelial dysfunction in CADASIL. Our finding of enhanced L-arginine vasoreactivity might have therapeutic implications for CADASIL and sporadic small vessel disease.

Genetic Variation in Soluble Epoxide Hydrolase ( EPHX2 ) Is Associated With an Increased Risk of Ischemic Stroke in White Europeans

Background and Purpose— Genetic variation in the EPHX2 gene region has been reported to influence susceptibility to ischemic stroke in blacks. We assessed the role of this gene region in white Europeans and performed analyses with regard to stroke subtypes.

Methods— Twenty-six single nucleotide polymorphisms in the EPHX2 gene region were genotyped in 601 patients with ischemic stroke and 736 matched controls. Cases were subtyped according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification system. Analyses were done on single markers and haplotypes using a sliding-window approach.

Results— Three single nucleotide polymorphisms showed associations with an increased risk for ischemic stroke (allelic models; all P ≤0.01). One of them retained statistical significance after correction for multiple testing. Associations were observed with large-vessel stroke and stroke of undetermined etiology but not with other stroke subtypes.

Conclusions— Our findings confirm and extend previous studies suggesting that genetic variation in or near the EPHX2 gene contributes to the risk of ischemic stroke. This association seems to be mediated predominantly by large-vessel disease.

Systematic analysis of three FHM genes in 39 sporadic patients with hemiplegic migraine

BACKGROUND

Familial (FHM) and sporadic (SHM) hemiplegic migraine are severe subtypes of migraine associated with transient hemiparesis. For FHM, three genes have been identified encoding subunits of a calcium channel (CACNA1A), a sodium-potassium pump (ATP1A2), and a sodium channel (SCN1A). Their role in SHM is unknown. Establishing a genetic basis for SHM may further the understanding of its pathophysiology and relationship with common types of migraine. It will also facilitate the often difficult differential diagnosis from other causes of transient hemiparesis.

METHODS

We systematically scanned 39 well-characterized patients with SHM without associated neurologic features for mutations in the three FHM genes. Functional assays were performed for all new sequence variants.

RESULTS

Sequence variants were identified in seven SHM patients: one CACNA1A mutation, five ATP1A2 mutations, and one SCN1A polymorphism. All six mutations caused functional changes in cellular assays. One SHM patient later changed to FHM because another family member developed FHM attacks.

CONCLUSION

We show that FHM genes are involved in at least a proportion of SHM patients without associated neurologic symptoms. Screening of ATP1A2 offers the highest likelihood of success. Because FHM gene mutations were also found in family members with "nonhemiplegic" typical migraine with and without aura, our findings reinforce the hypothesis that FHM, SHM, and "normal" migraine are part of a disease spectrum with shared pathogenetic mechanisms.

Subarachnoid hemosiderosis and superficial cortical hemosiderosis in cerebral amyloid angiopathy

Cerebral amyloid angiopathy (CAA) is an important cause of intracerebral hemorrhage. Its definite diagnosis still requires histopathologic demonstration of vascular amyloid. Thus, further improvement of noninvasive imaging methods would be desirable. Here we present 3 patients with histologically proved CAA, in which superficial cortical hemosiderosis and subarachnoid hemosiderosis were present in T2*-weighted MR images. Thus, we propose that these 2 findings might be valuable as noninvasive diagnostic markers for CAA.

Ischemic stroke and peripheral arterial thromboembolism in a patient with Crohn's disease: a case presentation

Both ischemic stroke and peripheral arterial thromboembolism have been described as extraintestinal complications of inflammatory bowel disease. Here, we present the first case with direct cooccurrence of ischemic stroke and peripheral thromboembolism in a 39-year-old patient with Crohn's disease. A pathophysiological model explaining this cooccurrence as well as the significance of prothrombotic risk factors ("hypercoaguable state") in the setting of inflammatory bowel disease and stroke are discussed.

Effects of short term atorvastatin treatment on cerebral hemodynamics in CADASIL

BACKGROUND

HMG-CoA-reductase-inhibitors (statins) exhibit pleiotropic beneficial effects on the vascular system including induction of endothelial nitric oxide synthase (eNOS) expression which is critical for vasodilation. Recent studies suggest a beneficial effect of statins on cerebral vasoreactivity in patients with cerebral small vessel disease (SVD). CADASIL is a monogenic form of SVD caused by mutations in the Notch3 gene. Treatment options are limited and little is known about the therapeutic role of statins in CADASIL.

METHODS

Twenty-four CADASIL subjects were treated with atorvastatin for 8 weeks. Treatment was started with 40 mg, followed by a dosage increase to 80 mg after 4 weeks. Transcranial Doppler sonography measuring mean flow velocity (MFV) in the middle cerebral artery was performed at baseline and the end of the treatment period. Vasoreactivity was assessed by hypercapnia and intravenous application of l-Arginine, which is the substrate for eNOS.

RESULTS

There was no significant treatment effect on MFV (p=0.5) or cerebral vasoreactivity as assessed by hypercapnia (p=0.5) and intravenous l-Arginine (p=0.4) in the overall cohort. However, an inverse correlation was found between vasoreactivity at baseline and changes of both CO2 and l-Arginine-induced vasomotor response (both p<0.05).

CONCLUSIONS

Short term treatment with atorvastatin resulted in no significant improvement of hemodynamic parameters in the overall cohort of CADASIL subjects.

Two cases of symptomatic cluster-like headache suggest the importance of sympathetic/parasympathetic balance

Despite several reports on symptomatic cluster-like headache, there is no clear explanation of how different lesions thought to be causative are related to cluster-like headache. On the basis of two additional cases of symptomatic cluster headache, we discuss the possibility that an acute imbalance of the autonomic nervous system, namely a net overactivity of the parasympathetic system, may be able to trigger these headache attacks in patients who probably have an additional individual predisposition to react with a cluster-like headache. Such an imbalance can be due to an increase in parasympathetic tone (e.g. stimulation of parasympathetic fibres) or to a reduction of the sympathetic tone (e.g. a lesion of the sympathetic fibres).

The novel p.L1649Q mutation in the SCN1A epilepsy gene is associated with familial hemiplegic migraine: genetic and functional studies. Mutation in brief #957. Online

Familial hemiplegic migraine (FHM) is a severe subtype of migraine with hemiparesis during attacks. We scanned 10 families with FHM without mutations in the CACNA1A (FHM1) and ATP1A2 (FHM2) genes. We identified the novel p.L1649Q mutation (c.4946T>A) in Na(v)1.1 sodium channel gene SCN1A (FHM3) in a North American kindred with FHM without associated ataxia or epilepsy. Functional analysis of the mutation, introduced in the highly homologous human SCN5A, revealed markedly slowed inactivation and a two-fold faster recovery from fast inactivation predicting enhanced neuronal excitation. Our findings establish the role of neuronal Na(v)1.1 sodium channels in FHM and reinforce the involvement of ion channel dysfunction in the pathogenesis of this episodic brain disorder.

Genetik der Migräne

Twin and family studies provide evidence of a genetic component in migraine, in particular migraine with aura (MA). Familial hemiplegic migraine (FHM) is a rare monogenic subtype of MA for which three causative genes have been identified: CACNA1A (FHM1), ATP1A2 (FHM2), and SCN1A (FHM3). Mutations in these genes are also found in some patients with sporadic hemiplegic migraine. Linkage studies have identified several gene loci for the more common forms of migraine; however, identification of the respective causative genes is still pending. This review summarizes recent developments in the genetics of migraine and their implications for molecular genetic testing. We further discuss the roles of CACNA1A, ATP1A2, and SCN1A in the pathophysiology of cortical spreading depression, which is the likely correlate of migraine aura.

1H-MRS alterations in the cerebellum of patients with familial hemiplegic migraine type 1

BACKGROUND

About 20% of patients with familial hemiplegic migraine (FHM) develop progressive cerebellar signs. Genetic studies have established an association with mutations in the CACNA1A gene. However, the mechanisms underlying cerebellar involvement are largely unknown.

OBJECTIVE

To use proton MR spectroscopy (1H-MRS) to investigate metabolic alterations in the cerebellum as well as cortical regions known to be involved in the propagation of migraine aura.

METHODS

Fifteen CACNA1A mutation carriers from three FHM families and 17 healthy control subjects were studied. Eleven patients had clinical signs of cerebellar involvement. LCModel fits were used to estimate absolute concentrations of N-acetyl aspartate (NAA), myo-inositol (mI), glutamate (Glu), choline-containing compounds, total creatine, and lactate in the superior cerebellar vermis (SCV), parietal cortex, and occipital cortex. To control for atrophy effects, automated image segmentation was performed using SPM99. The brain parenchyma fraction (BPF) was determined for all three regions.

RESULTS

Compared with controls, the brain parenchyma fraction (BPF), NAA, and Glu were significantly reduced and mI was significantly elevated in the SCV of patients with FHM. In contrast, no metabolite alterations were found in supratentorial regions. BPF and NAA in the SCV significantly correlated with cerebellar scores, in particular, gait ataxia.

CONCLUSIONS

The findings suggest that there is a regionally distinct neuronal impairment in the superior cerebellar vermis that exceeds macroscopic tissue loss. Correlations with clinical scores emphasize the functional relevance of localized atrophy (brain parenchyma fraction) and N-acetyl aspartate levels. These measures may be useful to monitor disease progression. The observed reduction in glutamate may in part reflect impaired glutamatergic neurotransmission.

Mutation in the neuronal voltage-gated sodium channel SCN1A in familial hemiplegic migraine

BACKGROUND

Familial hemiplegic migraine is an autosomal dominant severe subtype of migraine with aura characterised by some degree of hemiparesis during the attacks. So far, mutations in two genes regulating ion translocation-CACNA1A and ATP1A2-have been identified in pedigrees with this disease.

METHODS

To identify additional genes for familial hemiplegic migraine, we did a genome-wide linkage analysis of two disease pedigrees without mutations in CACNA1A and ATP1A2. Ion channel genes in the candidate interval were analysed for mutations, and the functional consequences of the recorded sequence alteration were determined.

FINDINGS

We identified a novel locus for familial hemiplegic migraine on chromosome 2q24. Sequencing of candidate genes in this region revealed a heterozygous missense mutation (Gln1489Lys) in the neuronal voltage-gated sodium channel gene SCN1A, mutations of which have been associated with epilepsy. This same mutation was present in three families with familial hemiplegic migraine. It results in a charge-altering aminoacid exchange in the so-called hinged-lid domain of the protein, which is critical for fast inactivation of the channel. Whole-cell recordings in transiently transfected tsA201 cells expressing the highly homologous SCN5A sodium channel showed that the mutation induces a two-fold to four-fold accelerated recovery from fast inactivation without altering any of the other channel parameters investigated.

INTERPRETATION

Dysfunction of the neuronal sodium channel SCN1A can cause familial hemiplegic migraine. Our findings have implications for the understanding of migraine aura. Moreover, our study reinforces the molecular links between migraine and epilepsy, two common paroxysmal disorders.

Variability of familial hemiplegic migraine with novel A1A2 Na+/K+-ATPase variants

A1A2 Na+/K+-ATPase mutations cause familial hemiplegic migraine type 2 (FHM2). The authors identified three putative A1A2 mutations (D718N, R763H, P979L) and three that await validation (P796R, E902K, X1021R). Ten to 20% of FHM cases may be FHM2. A1A2 mutations have a penetrance of about 87%. D718N causes frequent, long-lasting HM, and P979L may cause recurrent coma. D718N and P979L may predispose to seizures and mental retardation. A1A2 does not play a major role in sporadic HM; only one variant, R383H, occurred in 1 of 24 cases.

Treatment of episodic ataxia type 2 with the potassium channel blocker 4-aminopyridine

Patients with episodic ataxia type 2 (EA2) can often be successfully treated with acetazolamide. The authors report three patients with EA2 (two with proven mutations in the CACNA1A gene) whose attacks were prevented with the potassium channel blocker 4-aminopyridine (4-AP; 5 mg tid). Attacks recurred after treatment was stopped; subsequent treatment alleviated the symptoms (mean follow-up time 6 months). These effects might be due to an improvement of the impaired functioning of Purkinje cells.

Different activities of type I interferons on hepatitis B virus core promoter regulated transcription

The type I interferons (IFNs) are a group of closely related cytokines which have different signal transduction pathways and different biological activities. Using transient transfection of human hepatoma cells with reporter plasmids containing the firefly/renilla luciferase genes under the control of the HBV-Enhancer (Enh) I, Enh II and core promoter we have investigated the biological activities of 10 recombinant (r) type I IFNs on transcription. Low concentrations of IFN (0.025 ng/ml) had a significant and specific inhibitory effect but the potencies of the different recombinant type I IFNs differed markedly with IFNalpha8 and IFNbeta being six-fold more potent than the least effective subtype (IFNalpha1). However, the addition of IFNalpha5-the subtype produced predominantly in the human liver-did not cause any synergistic effects.The non-natural consensus IFN displayed a more pronounced inhibition of HBV-regulated transcription than IFNalpha8 or IFNalpha2 but not IFNbeta. The INF-induced inhibitory effect was not dependent on the presence of the HBV-Enh1 and in particular of an interferon stimulated response element (ISRE)-like sequence. The characterization of different effects among type I interferons on HBV-regulatory elements may implicate an IFN-subtype-specific role for the pathogenesis and treatment of HBV-infection.