Electrodiagnostic subtyping in Guillain-Barré syndrome patients in the International Guillain-Barré Outcome Study.

BACKGROUND AND PURPOSE: Various electrodiagnostic criteria have been developed in Guillain-Barré syndrome (GBS). Their performance in a broad representation of GBS patients has not been evaluated. Motor conduction data from the International GBS Outcome Study (IGOS) cohort were used to compare two widely used criterion sets and relate these to diagnostic amyotrophic lateral sclerosis criteria. METHODS: From the first 1500 patients in IGOS, nerve conduction studies from 1137 (75.8%) were available for the current study. These patients were classified according to nerve conduction studies criteria proposed by Hadden and Rajabally. RESULTS: Of the 1137 studies, 68.3% (N = 777) were classified identically according to criteria by Hadden and Rajabally: 111 (9.8%) axonal, 366 (32.2%) demyelinating, 195 (17.2%) equivocal, 35 (3.1%) inexcitable and 70 (6.2%) normal. Thus, 360 studies (31.7%) were classified differently. The areas of differences were as follows: 155 studies (13.6%) classified as demyelinating by Hadden and axonal by Rajabally; 122 studies (10.7%) classified as demyelinating by Hadden and equivocal by Rajabally; and 75 studies (6.6%) classified as equivocal by Hadden and axonal by Rajabally. Due to more strictly defined cutoffs fewer patients fulfilled demyelinating criteria by Rajabally than by Hadden, making more patients eligible for axonal or equivocal classification by Rajabally. In 234 (68.6%) axonal studies by Rajabally the revised El Escorial (amyotrophic lateral sclerosis) criteria were fulfilled; in axonal cases by Hadden this was 1.8%. CONCLUSIONS AND DISCUSSION: This study shows that electrodiagnosis in GBS is dependent on the criterion set utilized, both of which are based on expert opinion. Reappraisal of electrodiagnostic subtyping in GBS is warranted.

Electrodiagnostic subtyping in Guillain-Barré syndrome: Use of criteria in practice based on a survey study in IGOS.

Electrodiagnostic (EDx) studies are helpful in diagnosing and subtyping of Guillain-Barré syndrome (GBS). Published criteria for differentiation into GBS subtypes focus on cutoff values, but other items receive less attention, although they may influence EDx subtyping: (a) extensiveness of EDx testing, (b) nerve-specific considerations, (c) distal compound muscle action potential (CMAP)-amplitude requirements, (d) criteria for conduction block and temporal dispersion. The aims of this study were to investigate how these aspects were approached by neuromuscular EDx experts in practice and how this was done in previously published EDx criteria for GBS. A completed questionnaire was returned by 24 (of 49) members of the electrophysiology expertise group from the International GBS Outcome Study. Six published EDx criteria for GBS subtyping were compared regarding these aspects. The indicated minimal number of motor nerves to study varied among respondents and tended to be more extensive in equivocal than normal studies. Respondents varied considerably regarding usage of compression sites for subtyping (median/wrist, ulnar/elbow, peroneal/fibular head): 29% used all variables from all sites, 13% excluded all sites, and 58% used only some sites and/or variables. Thirty-eight percent of respondents required a minimal distal CMAP amplitude to classify distal motor latency as demyelinating, and 58% did for motor conduction velocity. For proximal/distal CMAP-amplitude ratio and F-wave latency, a requisite minimal CMAP amplitude was more often required (79%). Also, the various published criteria sets showed differences on all items. Practical use of EDx criteria for subtyping GBS vary extensively across respondents, potentially lowering the reproducibility of GBS subtyping.

Electrodiagnosis of Guillain-Barre syndrome in the International GBS Outcome Study: Differences in methods and reference values.

OBJECTIVE: To describe the heterogeneity of electrodiagnostic (EDx) studies in Guillain-Barré syndrome (GBS) patients collected as part of the International GBS Outcome Study (IGOS). METHODS: Prospectively collected clinical and EDx data were available in 957 IGOS patients from 115 centers. Only the first EDx study was included in the current analysis. RESULTS: Median timing of the EDx study was 7 days (interquartile range 4-11) from symptom onset. Methodology varied between centers, countries and regions. Reference values from the responding 103 centers were derived locally in 49%, from publications in 37% and from a combination of these in the remaining 15%. Amplitude measurement in the EDx studies (baseline-to-peak or peak-to-peak) differed from the way this was done in the reference values, in 22% of motor and 39% of sensory conduction. There was marked variability in both motor and sensory reference values, although only a few outliers accounted for this. CONCLUSIONS: Our study showed extensive variation in the clinical practice of EDx in GBS patients among IGOS centers across the regions. SIGNIFICANCE: Besides EDx variation in GBS patients participating in IGOS, this diversity is likely to be present in other neuromuscular disorders and centers. This underlines the need for standardization of EDx in future multinational GBS studies.

AISYF: first national, prospective, multicenter study of young patients with stroke in Argentina.

Up to 15% of all strokes affect young patients and the incidence of ischemic stroke in this population is rising. Nevertheless, there is limited information of cerebrovascular events in this population both in our country and in Latin America. The aim of our study was to evaluate the clinical characteristics and risk factors of young adults with stroke in Argentina. This is a prospective, multicenter study of stroke in young adults (18 - 55 years) in Argentina. Patients presenting with a cerebrovascular event within 180 days were included. Stroke subtypes were classified according to TOAST criteria. A total number of 311 patients were enrolled (men 53.9%, mean age: 43.3 years). Ischemic strokes occurred in 91.8% (brain infarcts 82.6%, transient ischemic attack 9.2%) and hemorrhagic strokes in 8.2%. The most frequent vascular risk factors (including ischemic and hemorrhagic strokes) were: hypertension 120 (41%), smoking 92 (31.4%), dyslipidemia 81 (27.6%) and, overweight/obesity: 74 (25.3%). Stroke subtypes were: large artery disease 12.3%, cardioembolism 7.5%, small artery occlusion 11.5%, other defined etiology 27.1%, and undetermined etiology 41.6%. Our study demonstrates that vascular risk factors are very frequent in young adults with stroke. Our findings underline that urgent strategies are required for primary and secondary stroke prevention in this group of patients.

Aproximadamente un 15% de todos los ataques cerebrovasculares afectan a pacientes jóvenes y su incidencia estaría en aumento. Existe escasa información sobre el ataque cerebral en esta población tanto en nuestro país como en Latinoamérica. El objetivo de nuestro estudio fue evaluar las características clínicas y los factores de riesgo de los adultos jóvenes con ictus en Argentina. Realizamos un estudio prospectivo y multicéntrico en adultos jóvenes (18-55 años) en Argentina, que presentaron un evento cerebrovascular dentro de los 180 días previos. Los subtipos de ictus se clasificaron según los criterios de TOAST. Se incluyeron un total de 311 pacientes (hombres 53.9%, edad media: 43,3 años). Los ataques cerebrovasculares isquémicos ocurrieron en el 91.8% (infartos cerebrales 82.6%, ataque isquémico transitorio 9.2%) y los eventos hemorrágicos correspondieron al 8.2%. Los factores de riesgo vascular más frecuentes (incluyendo los eventos isquémicos y hemorrágicos) fueron: hipertensión 120 (41%), tabaquismo 92 (31.4%), dislipidemia 81 (27.6%) y sobrepeso/obesidad: 74 (25.3%). Los subtipos de ictus isquémicos fueron: arteriopatía de gran vaso 12.3%, cardioembolismo 7.5%, oclusión de pequeña arteria 11.5%, otra etiología definida 27.1% y etiología indeterminada 41.6%. Los factores de riesgo vascular son muy frecuentes en los adultos jóvenes con ictus. Nuestros hallazgos subrayan que se requieren estrategias urgentes para la prevención primaria y secundaria del ictus en este grupo particular de pacientes en nuestro país.

AISYF: first national, prospective, multicenter study of young patients with stroke in Argentina / AISYF: primer estudio nacional, prospectivo y multicéntrico de pacientes jóvenes con ataque cerebral en Argentina

Abstract Up to 15% of all strokes affect young patients and the incidence of ischemic stroke in this population is rising. Nevertheless, there is limited information of cerebrovascular events in this population both in our country and in Latin America. The aim of our study was to evaluate the clinical characteristics and risk factors of young adults with stroke in Argentina. This is a prospective, multicenter study of stroke in young adults (18 - 55 years) in Argentina. Patients presenting with a cerebrovascular event within 180 days were included. Stroke subtypes were classified according to TOAST criteria. A total number of 311 patients were enrolled (men 53.9%, mean age: 43.3 years). Ischemic strokes occurred in 91.8% (brain infarcts 82.6%, transient ischemic attack 9.2%) and hemorrhagic strokes in 8.2%. The most frequent vascular risk factors (including ischemic and hemorrhagic strokes) were: hypertension 120 (41%), smoking 92 (31.4%), dyslipidemia 81 (27.6%) and, over weight/obesity: 74 (25.3%). Stroke subtypes were: large artery disease 12.3%, cardioembolism 7.5, small artery occlusion 11.5%, other defined etiology 27.1%, and undetermined etiology 41.6%. Our study demonstrates that vascular risk factors are very frequent in young adults with stroke. Our findings underline that urgent strategies are required for primary and secondary stroke prevention in this group of patients.

Resumen Aproximadamente un 15% de todos los ataques cerebrovasculares afectan a pacientes jóvenes y su incidencia estaría en aumento. Existe escasa información sobre el ataque cerebral en esta población tanto en nuestro país como en Latinoamérica. El objetivo de nuestro estudio fue evaluar las características clínicas y los factores de riesgo de los adultos jóvenes con ictus en Argentina. Realizamos un estudio prospectivo y multicéntrico en adultos jóvenes (18-55 años) en Argentina, que presentaron un evento cerebrovascular dentro de los 180 días previos. Los subtipos de ictus se clasificaron según los criterios de TOAST. Se incluyeron un total de 311 pacientes (hombres 53.9%, edad media: 43,3 años). Los ataques cerebrovasculares isquémicos ocurrieron en el 91.8% (infartos cerebrales 82.6%, ataque isquémico transitorio 9.2%) y los eventos hemorrágicos correspondieron al 8.2%. Los factores de riesgo vascular más frecuentes (incluyendo los eventos isquémicos y hemorrágicos) fueron: hipertensión 120 (41%), tabaquismo 92 (31.4%), dislipidemia 81 (27.6%) y sobrepeso/obesidad: 74 (25.3%). Los subtipos de ictus isquémicos fueron: arteriopatía de gran vaso 12.3%, cardioembolismo 7.5%, oclusión de pequeña arteria 11.5%, otra etiología definida 27.1% y etiología indeterminada 41.6%. Los factores de riesgo vascular son muy frecuentes en los adultos jóvenes con ictus. Nuestros hallazgos subrayan que se requieren estrategias urgentes para la prevención primaria y secundaria del ictus en este grupo particular de pacientes en nuestro país.

Intravenous immunoglobulin treatment for mild Guillain-Barré syndrome: an international observational study.

OBJECTIVE: To compare the disease course in patients with mild Guillain-Barré syndrome (GBS) who were treated with intravenous immunoglobulin (IVIg) or supportive care only. METHODS: We selected patients from the prospective observational International GBS Outcome Study (IGOS) who were able to walk independently at study entry (mild GBS), treated with one IVIg course or supportive care. The primary endpoint was the GBS disability score four weeks after study entry, assessed by multivariable ordinal regression analysis. RESULTS: Of 188 eligible patients, 148 (79%) were treated with IVIg and 40 (21%) with supportive care. The IVIg group was more disabled at baseline. IVIg treatment was not associated with lower GBS disability scores at 4 weeks (adjusted OR (aOR) 1.62, 95% CI 0.63 to 4.13). Nearly all secondary endpoints showed no benefit from IVIg, although the time to regain full muscle strength was shorter (28 vs 56 days, p=0.03) and reported pain at 26 weeks was lower (n=26/121, 22% vs n=12/30, 40%, p=0.04) in the IVIg treated patients. In the subanalysis with persistent mild GBS in the first 2 weeks, the aOR for a lower GBS disability score at 4 weeks was 2.32 (95% CI 0.76 to 7.13). At 1 year, 40% of all patients had residual symptoms. CONCLUSION: In patients with mild GBS, one course of IVIg did not improve the overall disease course. The certainty of this conclusion is limited by confounding factors, selection bias and wide confidence limits. Residual symptoms were often present after one year, indicating the need for better treatments in mild GBS.

Regional variation of Guillain-Barré syndrome.

Guillain-Barré syndrome is a heterogeneous disorder regarding the clinical presentation, electrophysiological subtype and outcome. Previous single country reports indicate that Guillain-Barré syndrome may differ among regions, but no systematic comparative studies have been conducted. Comparative studies are required to identify factors determining disease susceptibility, variation and prognosis, and to improve diagnostic criteria. The International Guillain-Barré Syndrome Outcome Study is a prospective, observational cohort study including all patients within the diagnostic spectrum, aiming to describe the heterogeneity of Guillain-Barré syndrome worldwide. The current study was based on the first 1000 inclusions with a follow-up of at least 1 year and confirmed the variation in clinical presentation, course and outcome between patients. The full clinical spectrum of Guillain-Barré syndrome was observed in patients from all countries participating in the International Guillain-Barré Syndrome Outcome Study, but the frequency of variants differed between regions. We compared three regions based on geography, income and previous reports of Guillain-Barré syndrome subtypes: 'Europe/Americas', 'Asia' (without Bangladesh), and 'Bangladesh'. We excluded 75 (8%) patients because of alternative diagnoses, protocol violations, or missing data. The predominant clinical variant was sensorimotor in Europe/Americas (n = 387/562, 69%) and Asia (n = 27/63, 43%), and pure motor in Bangladesh (n = 74/107, 69%). Miller Fisher syndrome and Miller Fisher-Guillain-Barré overlap syndrome were more common in Asia (n = 14/63, 22%) than in the other two regions (Europe/Americas: n = 64/562, 11%; Bangladesh: n = 1/107, 1%) (P < 0.001). The predominant electrophysiological subtype was demyelinating in all regions (Europe/Americas: n = 312/573, 55%; Asia: n = 29/65, 45%; Bangladesh: n = 38/94, 40%). The axonal subtype occurred more often in Bangladesh (n = 34/94, 36%) than in Europe/Americas (n = 33/573, 6%) and other Asian countries (n = 4/65, 6%) (P < 0.001). In all regions, patients with the axonal subtype were younger, had fewer sensory deficits, and showed a trend towards poorer recovery compared to patients with the demyelinating subtype. The proportion of patients able to walk unaided after 1 year varied between Asia (n = 31/34, 91%), Europe/Americas (n = 334/404, 83%) and Bangladesh (n = 67/97, 69%) (P = 0.003). A similar variation was seen for mortality, being higher in Bangladesh (n = 19/114, 17%) than in Europe/Americas (n = 23/486, 5%) and Asia (n = 1/45, 2%) (P < 0.001). This study showed that factors related to geography have a major influence on clinical phenotype, disease severity, electrophysiological subtype, and outcome of Guillain-Barré syndrome.

Prevalence of Fabry Disease in Young Patients with Stroke in Argentina.

BACKGROUND: Fabry disease (FD) is an underdiagnosed cause of stroke in young adults, but the frequency of this association is largely unknown. We estimated the prevalence of FD in a nationwide cohort of young adults who had stroke and transient ischemic attack (TIA) in Argentina. METHODS: This was a prospective, multicenter study of stroke and FD in young adults (18-55 years) conducted in Argentina between 2011 and 2015. Patients were enrolled if they had had a TIA or an ischemic or hemorrhagic stroke within the previous 180 days. FD was diagnosed by measuring α-galactosidase A activity (males) and through genetic studies (females). RESULTS: We enrolled 311 patients (54% men, mean age: 41 years). Ischemic events occurred in 89% of patients (80% infarcts, 9% TIA) and hemorrhagic strokes in 11%. One female (.3% of the total group, 1% of the cryptogenic ischemic strokes) had the pathogenic mutation c.888G>A/p.Met296Ile /Exon 6 on the GAL gene. Her only other manifestation of FD was angiokeratoma. Eighteen females had nonpathogenic intronic variations: c.-10C>T, c.-12G>A, or both. Two patients had the nonpathogenic mutation D313Y, while a third had the likely benign mutation S126G. CONCLUSIONS: FD was identified in 1 patient (.3%) in this first Latin American study. The patient presented with a late-onset oligo-symptomatic form of the disease. A large number of nonpathogenic mutations were present in our cohort, and it is essential that they not be mistaken for pathogenic mutations to avoid unnecessary enzyme replacement treatment.

Acute brachial plexus neuropathy with involvement of cranial nerves IX, X, XI and XII.

INTRODUCTION: Acute brachial plexus neuropathy is characterized by acute onset of shoulder girdle and arm pain, followed by weakness of the shoulder and arm muscles. It affects primarily nerves of the upper trunk of the brachial plexus and the long thoracic nerve. Cranial nerve involvement is an infrequent association and implies a diagnostic challenge. We report a unique case of acute brachial plexus neuropathy with involvement of the cranial nerves IX, X, XI and XII. CASE REPORT: Fifty six year-old woman who developed acute dysphonia, dysphagia and left shoulder pain, followed, six days later, by left arm weakness. Needle examination showed only fibrillation potentials and positive sharp waves in the left deltoid muscle. MRI of the brachial plexus shows enlargement of the trunks, cords and terminal branches, with mild gadolinium enhancement. DISCUSSION: This case illustrates the unique presentation of neuralgic amyotrophy with involvement of nerves outside the brachial plexus, and the importance of MRI for diagnosis, in the absence of electrophysiologic involvement.

Two-dimensional speckle tracking echocardiography for early detection of myocardial damage in young patients with Fabry disease.

Fabry disease (FD) is characterized by left ventricular hypertrophy (LVH). Conventional echocardiography is not sensitive enough to perform the preclinical diagnosis To assess whether longitudinal myocardial strain of the left ventricle (LV), using speckle tracking, is useful to detect early myocardial involvement in FD. Forty-four patients with FD who were diagnosed with genetic testing were prospectively included and were compared to a sex-matched control group. They were divided into three groups: 22 with LVH (Group I), 22 without LVH (Group II), and 22 healthy volunteers (Group III). LV longitudinal strain was measured from the apical views. An ANOVA test was used for multiple comparisons for variables with a normal distribution, and a Kruskal-Wallis test was used for variables with non-Gaussian distribution. Longitudinal LV strain was different in the three groups: it was ≥-15% in at least one segment in all Group I patients, in 50% of patients of Group II and in no patient of Group III. Seventy percent of the segments with abnormal strain in Group II were located in the basal regions (32/46). These findings show that the presence of at least one strain value ≥-15% demonstrates subclinical myocardial dysfunction in patients with preclinical FD. Longitudinal myocardial LV strain measured with speckle tracking is a useful tool to detect early myocardial involvement in young patients with FD. This information allows the detection and treatment of myocardial dysfunction at an early stage, which is of high clinical importance.

Amyotrophic lateral sclerosis-immunoglobulins selectively interact with neuromuscular junctions expressing P/Q-type calcium channels.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by a gradual loss of motoneurons. The majority of ALS cases are associated with a sporadic form whose etiology is unknown. Several pieces of evidence favor autoimmunity as a potential contributor to sporadic ALS pathology. To gain understanding concerning possible antigens interacting with IgGs from sporadic ALS patients (ALS-IgGs), we studied immunoreactivity against neuromuscular junction (NMJ), spinal cord and cerebellum of mice with and without the Ca(V) 2.1 pore-forming subunit of the P/Q-type voltage-gated calcium (Ca(2+)) channel. ALS-IgGs showed a strong reactivity against NMJs of wild-type diaphragms. ALS-IgGs also increased muscle miniature end-plate potential frequency, suggesting a functional role for ALS-IgGs on synaptic signaling. In support, in mice lacking the Ca(V) 2.1 subunit ALS-IgGs showed significantly reduced NMJ immunoreactivity and did not alter spontaneous acetylcholine release. This difference in reactivity was absent when comparing N-type Ca(2+) channel wild-type or null mice. These results are particularly relevant because motoneurons are known to be early pathogenic targets in ALS. Our findings add further evidence supporting autoimmunity as one of the possible mechanisms contributing to ALS pathology. They also suggest that serum autoantibodies in a subset of ALS patients would interact with NMJ proteins down-regulated when P/Q-type channels are absent.

Brain MRI findings in patients with Fabry disease.

BACKGROUND: To evaluate the presence of ischemic and hemorrhagic lesions in brain MRI of patients with Fabry disease (FD). METHODS: Brain MRI studies in 46 consecutive patients were evaluated using classic sequences as well as GRE-weighted images, for ischemic lesions and chronic microbleed detection. Of the 36 adult patients (15 males, mean age 31.2 years; 21 females, mean age 41.6 years). All had signs or symptoms of FD but lacked history of stroke or TIA. RESULTS: Ten patients under 20 years of age initially presented a normal MRI. One child developed a hyperintense occipital lesion on T2-weighted imaging during control MRI. Sixteen adult patients (44.4%) had brain MRI evidence of small vessel disease in the basal ganglia, corona radiata, thalamus or brainstem, as well as in the periventricular white matter. Patients with MRI abnormalities were older (45.6 vs 30.9 years, p=0.005), with more vascular risk factors (1.2 vs 0.6 p=0.043). Three women (mean age 59.5 years) presented deep chronic microbleeds identified by GRE. Moreover, Flair and T2-weighted images revealed white matter disease and deep gray matter involvement. CONCLUSION: 44.4% of adult patients with FD without clinical history of CVA or prior dialysis had evidence of small vessel disease on MRI and 11% showed cerebral microbleeds. FD is a treatable disorder that should be routinely included in the differential diagnosis of ischemic and microhemorrhagic lesions in young adults.

[Sleep related eating disorders as a side effect of zolpidem]. / Síndrome de ingesta nocturna como efecto colateral del zolpidem.

Zolpidem is a hypnotic drug used in sleep disorders. It binds selectively to alpha 1 subunit of the GABA A benzodiazepine receptor. Zolpidem reduces sleep latency, number of arousals and increases the total time of sleep. However, it is considered that it may increase phase 3 of non rapid eye movement sleep, where somnambulism can take place. Our aim is to report 8 cases of sleep related eating disorders associated with the use of this drug. We have evaluated the medical history of 8 patients who had received zolpidem for sleeping disorders and who have presented sleep related eating disorders. Eight patients (6 women, 2 men) aged between 32 to 72 years old, which received 10 mg of zolpidem/night except 1 that received 12.5 mg, were presented. They have referred strange eating behavior compatible to sleep related eating disorder. Symptoms appeared at a mean of 39.8 days after starting the medication. The numbers of nocturnal episodes recorded by the family or by the patient were 1 to 8 episodes of nocturnal eating per night. The morning after, patients found leftovers from the night before which they did not recall to have eaten. The remission was complete after discontinuing zolpidem. Zolpidem may induce sleep related eating disorder in about 1% of patients, although we consider there may be a subdiagnosis of this phenomenon. It will be important to bear in mind and look for this side effect because all the episodes could easily be controlled by withdrawing the drug.

Síndrome de ingesta nocturna como efecto colateral del zolpidem / Sleep related eating disorders as a side effect of zolpidem

El zolpidem es una droga hipnótica utilizada para el tratamiento del insomnio. Disminuye la latencia del sueño, el número total de despertares y aumenta el tiempo total del sueño respetando en general su arquitectura. Se cree que aumenta la fase 3 del sueño lento profundo. Nuestro objetivo es comunicar 8 casos de síndrome de ingesta nocturna relacionado al sueño y conductas automáticas complejas asociadas a sonambulismo como efecto colateral del zolpidem. Se analizaron las historias clínicas de 8 pacientes tratados con zolpidem que referían ingesta nocturna de alimentos con amnesia total o parcial del episodio. Se presentan 6 mujeres y 2 hombres, entre 32 y 72 años (media: 58 años), 7 tratados con zolpidem 10 mg/noche y 1 con zolpidem 12.5 mg/noche de liberación prolongada. El tiempo de exposición previo al desarrollo de eventos fue de 1 a 180 días (media de 39.8). El número de episodios relatados era de 1 a 8/noche (media 2.5) asociado con amnesia. Los episodios desaparecieron por completo en el 100% de los casos al suspender la medicación. El síndrome de ingesta nocturna relacionado al sueño es una parasomnia de sueño lento profundo que consiste en episodios de ingesta de alimento o bebida durante la noche, con amnesia parcial o completa del episodio. El zolpidem podría inducir el síndrome de ingesta nocturna relacionado al sueño en aproximadamente el 1% de pacientes, aunque creemos que es un efecto adverso que está subdiagnosticado. Se resuelve simplemente suspendiendo la medicación.

Zolpidem is a hypnotic drug used in sleep disorders. It binds selectively to alpha 1 subunit of the GABA A benzodiazepine receptor. Zolpidem reduces sleep latency, number of arousals and increases the total time of sleep. However, it is considered that it may increase phase 3 of non rapid eye movement sleep, where somnambulism can take place. Our aim is to report 8 cases of sleep related eating disorders associated with the use of this drug. We have evaluated the medical history of 8 patients who had received zolpidem for sleeping disorders and who have presented sleep related eating disorders. Eight patients (6 women, 2 men) aged between 32 to 72 years old, which received 10 mg of zolpidem/night except 1 that received 12.5 mg, were presented. They have referred strange eating behavior compatible to sleep related eating disorder. Symptoms appeared at a mean of 39.8 days after starting the medication. The numbers of nocturnal episodes recorded by the family or by the patient were 1 to 8 episodes of nocturnal eating per night. The morning after, patients found leftovers from the night before which they did not recall to have eaten. The remission was complete after discontinuing zolpidem. Zolpidem may induce sleep related eating disorder in about 1% of patients, although we consider there may be a subdiagnosis of this phenomenon. It will be important to bear in mind and look for this side effect because all the episodes could easily be controlled by withdrawing the drug.

Misdiagnosis in Fabry disease.

OBJECTIVE: To evaluate the most frequent diagnostic errors in patients with Fabry disease and the types of specialists most often consulted before diagnosis. STUDY DESIGN: We evaluated 45 consecutive symptomatic patients with Fabry disease confirmed by enzymatic tests in males and genetic studies in females. We interviewed the patients, their mothers, or both regarding symptoms, age at onset, medical consultations, and recommended treatments. RESULTS: Neuropathic pain was the most frequent initial complaint, and rheumatic fever was the most common diagnosis. Seven patients were treated with penicillin for many years. Ten patients sought medical consultation because of abdominal pain and were diagnosed with food intoxication or nonspecific pain. Six patients sought consultation because of anhidrosis, considered of unclear cause, and angiokeratomas diagnosed as petechiae. Internists and pediatricians were the most frequently consulted specialists. The correct diagnosis was obtained after a mean of 19.7 years. CONCLUSIONS: Pediatricians as well as internists commonly misdiagnose Fabry disease. Neuropathic pain, hypohidrosis, and recurrent abdominal pain in childhood or adolescence should include Fabry disease in the differential diagnosis to facilitate earlier diagnosis and treatment of these patients.

Calcium signaling pathways mediating synaptic potentiation triggered by amyotrophic lateral sclerosis IgG in motor nerve terminals.

Sporadic amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects particularly motoneurons. Several pieces of evidence suggested the involvement of autoimmune mechanisms mediated by antibodies in ALS. However, the significance of those antibodies in the disease and the underlying mechanisms are unknown. Here we showed that IgG purified from a group of sporadic ALS patients, but not familial ALS patients, specifically interact with the presynaptic membrane of motoneurons through an antigen-antibody interaction and modulated synaptic transmission. Immunoreactivity against nerve terminals showed strong correlation with synaptic modulation ability. In addition, several controls have ruled out the possibility for this synaptic modulation to be mediated through proteases or nonspecific effects. Effective IgG potentiated both spontaneous and asynchronous transmitter release. Application of pharmacological inhibitors suggested that activation of this increased release required a nonconstitutive Ca2+ influx through N-type (Cav2.2) channels and phospholipase C activity and that activation of IP3 and ryanodine receptors were necessary to both activate and sustain the increased release. Consistent with the notion that ALS is heterogeneous disorder, our results reveal that, in approximately 50% of ALS patients, motor nerve terminals constitutes a target for autoimmune response.

Multifocal motor neuropathy, type 1 diabetes and asymptomatic Hashimoto's thyroiditis: an unusual association.

Immune mediated mechanisms play a role in some forms of diabetic neuropathies. We studied a 17-year-old man who developed asymmetric weakness and atrophy in both upper arms soon after the diagnosis of type 1 diabetes. Nerve conduction studies demonstrated multifocal motor conduction blocks, and serological investigations revealed subclinical Hashimoto's thyroiditis. Therapy with intravenous immunoglobulin and cyclophosphamide led to clinical recovery. This is the first observation of an association between type 1 diabetes, multifocal motor neuropathy and Hashimoto's thyroiditis.