From hysteria to gait dementia: History of the concept of astasia-abasia.

Paul Blocq (1860-1896) and his teacher Jean-Martin Charcot (1825-1893) introduced the expression "astasia-abasia" into medical terminology in 1888 to designate a pathology they believed to be caused by hysteria. This condition makes it impossible to remain erect and to walk, whereas the ability to move the legs while lying down remains normal. At the turn of the 20th century, and now almost exclusively, this motor disturbance is recognised as a syndrome with multiple possible organic causes, and now described as "higher-level gait disorder". After briefly mentioning earlier descriptions by other authors, I will review Charcot's Tuesday lessons in 1889 that covered astasia-abasia and elucidated the beginnings of the breakdown into organic aetiologies: medial-frontal and corpus callosum tumors, damage to the cerebellar vermis, lacunar state as described by Pierre Marie (1853-1940), Parkinson's disease, and Parkinson-plus syndrome. The long history of astasia-abasia reveals a cluster of neurologists, often emerging from oblivion herein and all of whom, through the precision of their clinical examinations and their pathophysiological findings, helped advance the understanding of the mechanisms by which human beings are the only erect, constantly bipedal mammals, whether immobile or walking.

"Spreading the word of the master": the contribution of Italian physicians in the early dissemination of Jean-Martin Charcot's theories.

Jean-Martin Charcot (1825-1893) laid the foundations of modern neurology. The lectures he gave at La Salpêtrière Hospital in Paris attracted a large number of visitors from all over the world. Some of them transcribed these clinical lessons, translating and publishing them when returning home. This article discusses the contribution of some Italian physicians (Gaetano Rummo, 1853-1917; Domenico Miliotti; Giulio Melotti, 1857-19?; and Augusto Tebaldi, 1833-1895), who were pioneers in disseminating the ideas and discoveries of Charcot. The early Italian translations were based on personal handwritten notes and memories, not relying on official French versions personally revised or edited by Charcot himself. As such, their veracity cannot always be verified, particularly in the lack of other independent works reporting details on the same lectures. However, the Italian transcriptions providing information which cannot be found elsewhere in Charcot's corpus of works represent an invaluable and a unique source for fully understanding some theories by the French neurologist. Furthermore, they are the first documents providing original materials related to Charcot's teaching translated in a foreign language. The first Italian publications that included photographs of patients were deeply influenced by and clearly modeled on the famous volumes of the Iconographie photographique de la Salpêtrière and further contributed to the early dissemination of Charcot's theories.

An intact plastid genome is essential for the survival of colorless Euglena longa but not Euglena gracilis.

Euglena gracilis growth with antibacterial agents leads to bleaching, permanent plastid gene loss. Colorless Euglena (Astasia) longa resembles a bleached E. gracilis. To evaluate the role of bleaching in E. longa evolution, the effect of streptomycin, a plastid protein synthesis inhibitor, and ofloxacin, a plastid DNA gyrase inhibitor, on E. gracilis and E. longa growth and plastid DNA content were compared. E. gracilis growth was unaffected by streptomycin and ofloxacin. Quantitative PCR analyses revealed a time dependent loss of plastid genes in E. gracilis demonstrating that bleaching agents produce plastid gene deletions without affecting cell growth. Streptomycin and ofloxacin inhibited E. longa growth indicating that it requires plastid genes to survive. This suggests that evolutionary divergence of E. longa from E. gracilis was triggered by the loss of a cytoplasmic metabolic activity also occurring in the plastid. Plastid metabolism has become obligatory for E. longa cell growth. A process termed "intermittent bleaching", short term exposure to subsaturating concentrations of reversible bleaching agents followed by growth in the absence of a bleaching agent, is proposed as the molecular mechanism for E. longa plastid genome reduction. Various non-photosynthetic lineages could have independently arisen from their photosynthetic ancestors via a similar process.

Photomovement in Euglena.

Motile microorganisms such as the green Euglena gracilis use a number of external stimuli to orient in their environment. They respond to light with photophobic responses, photokinesis and phototaxis, all of which can result in accumulations of the organisms in suitable habitats. The light responses operate synergistically with gravitaxis, aerotaxis and other responses. Originally the microscopically obvious stigma was thought to be the photoreceptor, but later the paraxonemal body (PAB, paraflagellar body) has been identified as the light responsive organelle, located in the trailing flagellum inside the reservoir. The stigma can aid in light direction perception by shading the PAB periodically when the cell rotates helically in lateral light, but stigmaless mutants can also orient with respect to the light direction, and negative phototaxis does not need the presence of the stigma. The PAB is composed of dichroically oriented chromoproteins which is reflected in a pronounced polarotaxis in polarized light. There was a long debate about the potential photoreceptor molecule in Euglena, including carotenoids, flavins and rhodopsins. This discussion was terminated by the unambiguous proof that the photoreceptor is a 400 kDa photoactivated adenylyl cyclase (PAC) which consists of two α- and two ß-subunits each. Each subunit possesses two BLUF (Blue Light receptor Using FAD) domains binding FAD, which harvest the light energy, and two adenylyl cyclases, which produce cAMP from ATP. The cAMP has been found to activate one of the five protein kinase s found in Euglena (PK.4). This enzyme in turn is thought to phosphorylate proteins inside the flagellum which result in a change in the flagellar beating pattern and thus a course correction of the cell. The involvements of PAC and protein kinase have been confirmed by RNA interference (RNAi). PAC is responsible for step-up photophobic responses as well as positive and negative phototaxis, but not for the step-down photophobic response, even though the action spectrum of this resembles those for the other two responses. Analysis of several colorless Euglena mutants and the closely related Euglena longa (formerly Astasia longa) confirms the results. Photokinesis shows a completely different action spectrum. Some other Euglena species, such as E. sanguinea and the gliding E. mutabilis, have been investigated, again showing totally different action spectra for phototaxis and photokinesis as well as step-up and step-down photophobic responses.

Abnormal bias in subjective vertical perception in a post-stroke astasia patient.

[Purpose] Post-stroke astasia is an inability to stand without external support despite having sufficient muscle strength. However, the dysfunction underlying astasia is unclear. We tested the hypothesis that astasia is the result of an abnormal bias in vertical perception, especially subjective postural vertical (SPV), mediated by somatosensory inputs. [Subjects and Methods] A patient with a right posterolateral thalamus hemorrhage had a tendency to fall toward the contralesional side during standing after 8 weeks of treatment. SPV, standing duration, and physical function were evaluated before and after a 1 week standard rehabilitation baseline period, and after a 1 week intervention period, where standing training requiring the patient to control his body orientation in reference to somatosensory inputs from his ipsilateral upper limb was added. [Results] SPV was biased toward the contralesional side before and after the 1 week baseline period. However, SPV improved into the normal range and he could stand for a longer duration after the intervention period. [Conclusion] This case suggests that abnormal SPV is one of the functional mechanisms underlying astasia, and it indicates the effectiveness of standing training with somatosensory information to improve abnormal SPV and postural disorders.

Primary Graviceptive System and Astasia: A Case Report and Literature Review.

Astasia refers to the inability to maintain upright posture during standing, despite having full motor strength. Impairment of the vestibulocerebellar pathway, graviceptive system, and cingulate motor area have been proposed to be related to astasia. However, the responsible neural pathways remain unclear. We hypothesize that there is a common neural network behind astasia. To test the hypothesis, we reviewed all reported cases with astasia, including ours, and focused on the correlation between anatomical destruction and symptom presentation. A total of 26, including ours, non-psychogenic astasia patients were identified in the English literature. Seventy-three percent of them were associated with other neurologic symptoms and sixty-two percent of reported lesions were on the right side. Contralateral lateropulsion was very common, followed by retropulsion, when describing astasia. Infarction (54%) was the most reported cause. The thalamus (65%) was the most reported location. Infarctions were the fastest to recover (mean: 10.6 days), while lesions at the brainstem needed a longer time (mean: 61.6 days). By combining the character of lateropulsion in astasia and the presentation of an interrupted graviceptive system, we concluded that the primary graviceptive system may be the common neural network behind astasia. Future studies on astasia should focus on the pathological changes in the perception of verticality in the visual world and the body.

Scale for contraversive pushing in stroke patients: pusher behavior vs Thalamic astasia differential diagnosis and psychometric properties.

BACKGROUND: : Few studies have investigated the psychometric properties of the Scale for Contraversive Pushing (SCP) in depth, and none have evaluated its ability to establish differential diagnosis between pusher behavior (PB) and thalamic astasia (TA). OBJECTIVES: : To study the ability of the SCP to establish differential diagnosis, its reliability, content, construct, and internal validity in the assessment of subacute stroke patients. METHODS: : 120 individuals were evaluated using the SCP over a four-week period of treatment. Intra- and inter-observer reliability, floor and ceiling effects, minimum detectable change (MDC), internal validity and sensitivity to change were explored. In addition, the Barthel Index and the Trunk Control Test were used to study their correlations with the SCP. RESULTS: : Discriminant validity provides evidence that the correlation between SCP items was large or moderate. Convergent validity demonstrated that the correlation of each item with the total score of the scale was high (at around 0.8). Sensitivity to change was large (W = 0.274). Intra- and inter-observer reliability were excellent (Intraclass Correlation Coefficient > 0.9; k > 0.8), except for items B standing and C sitting (k > 0.7). The MDC was 1.39, and ceiling (8.333%) and floor (15.833%) effects were adequate. Cronbach's alpha (α) was equal to 0.901 (0.874-0.924) and McDonald's Omega (ω) was equal to 0.883 (0.856-0.973), showing excellent internal consistency. CONCLUSIONS: : The SCP is a reliable and valid tool which can successfully establish differential diagnosis between PB and TA and evaluate the changes generated by physiotherapy treatment.

Functional gait disorders: Demographic and clinical correlations.

OBJECTIVE: We aimed to describe the prevalence and clinical-demographical features of patients with functional gait disorders (FGDs) and to compare them to patients with functional motor disorders (FMDs) without FGDs (No-FGDs). METHODS: In this multicenter observational study, we enrolled patients with a clinically definite diagnosis of FMDs in 25 tertiary movement disorders centers in Italy. Each subject with FMDs underwent a comprehensive clinical assessment, including screening for different subtypes of functional gait disorders. Multivariate regression models were implemented in order to estimate the adjusted odds ratio (OR; 95% confidence interval) of having FGDs in relation to sociodemographic and clinical characteristics. RESULTS: Out of 410 FMDs, 26.6% (n = 109) of patients exhibited FGDs. The most frequent FGDs were slow gait (n = 43, 39.4%), astasia-abasia (n = 26, 23.8%), and knee buckling (n = 24, 22%). They exhibited single FGDs in 51.4% (n = 56) or complex FGDs (more than one type of FGDs) in 48.6% (n = 53) of cases. On multivariate regression analysis, the presence of FGDs was more likely associated with older age (OR 1.03, 95% CI 1.01-1.04), functional visual symptoms (OR 2.19, 95% CI 1.08-4.45), and the diagnosis of somatic symptoms disorder (OR 2.97, 95% CI 1.08-8.17). FGDs were also more likely to undergo physiotherapy (OR 1.81, 95% CI 1.08-3.03). CONCLUSIONS: People with FMDs may present with different and overlapping types of FGDs, which may occur in older age. The association of FGDs with functional visual symptoms and somatic symptoms disorder opens up to new avenues to the understanding of the neural mechanisms of these disorders.

Postural Sway and Bobblehead Movement: Unique Presentation of Bilateral Tendo-Achilles Rupture.

The human body requires equilibrium to assume the vertical posture and balance for walking which is maintained by righting reflexes and supporting reactions, respectively. Postural movements around the ankle is responsible for maintaining forward and backward leaning in an upright posture. We report a case of postural sway and bobblehead movement following bilateral tendo-Achilles rupture.

Functional Neurologic Symptom Disorder in Children: Clinical Features, Diagnostic Investigations, and Outcomes at a Tertiary Care Children's Hospital.

OBJECTIVE: To describe the presenting symptoms and short-term outcomes of children diagnosed with functional neurologic symptom disorder and to compare the demographic and clinical characteristics of children who received neurodiagnostic testing to those who did not. STUDY DESIGN: Single center, retrospective review of 222 children who presented to the emergency department of a children's hospital, and diagnosed with functional neurologic symptom disorder, between 2010 and 2015. RESULTS: Out of 222 visits (females = 156, African Americans = 130, mean age = 13.9 years), neurodiagnostic tests were performed in 102/222 (46%) visits. The most commonly performed investigations were magnetic resonance imaging (MRI) of brain (n = 37) and electroencephalogram (EEG) (n = 56) and were noted to be unremarkable in all instances. Neurodiagnostic tests were more likely to be performed in patients who (1) were non-African American (54% vs 40%; P = .03), (2) presented with new-onset symptoms (55% vs 31%; P < .01), (3) underwent hospitalization (61% vs 17%; P < .01), and (4) were evaluated by a neurologist (59% vs 9%; P < .01) or a psychiatrist (58% vs 28%; P < .01). Common clinical presentations included seizurelike or strokelike symptoms. Short-term follow-up was possible in 20%, with an alternate diagnosis of syncope, noted in only 1 child. CONCLUSIONS: Most children who presented with a functional neurologic symptom disorder in our study were noted to have seizurelike or strokelike presentations and were adolescent females. Caucasians were more likely to undergo neurodiagnostic investigations. Radiologic and neurophysiological tests were more commonly performed when neurology and psychiatry consultations were sought. Such investigations had low diagnostic utility.

A clinical case of neosporosis in a 4-week-old holstein friesian calf which developed hindlimb paresis postnatally.

A 4-week-old female Holstein Friesian calf presented with hindlimb paresis. Neurologic examination of spinal reflexes revealed depressed or absent reflexes of the hindlimbs. Menace responses on both sides disappeared on examination of cranial nerves. The calf was finally diagnosed with Neospora caninum infection by pathological findings including nonsuppurative inflammation associated with cysts in the cerebrum and spinal cord. High levels of antibody against recombinant surface antigen 1 of N. caninum (NcSAG1) were detected by ELISA from both serum and cerebrospinal fluid (CSF) samples. This result suggests that detection of antibodies against N. caninum by NcSAG1-ELISA in serum and CSF could be useful for the clinical diagnosis of neosporosis in calves with acquired neurological signs.

Sarcoidosis Manifestion Centered on the Thalamic Pulvinar Leading to Persistent Astasia.

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Isolated astasia caused by a localized infarction in the suprathalamic white matter.

A 73-year-old woman with essential hypertension and diabetes mellitus abruptly developed astasia. There were no other neurological abnormalities. Cranial diffusion-weighted magnetic resonance imaging demonstrated a localized infarction in the right-sided suprathalamic white matter. Under antiplatelet agent and rehabilitation, the patient became asymptomatic within 4 days. This is a first reported case of isolated astasia due to a suprathalamic white matter infarction. We speculated that disruption of the connection from the ventrolateral nucleus of the thalamus to the posterior cingulate gyrus and/or supplementary motor area might cause astasia.

Isolated astasia manifested by acute infarct of the anterior corpus callosum and cingulate gyrus.

Astasia, the inability to stand and walk, in the absence of weakness or ataxia, is uncommon and unique. This syndrome is easy to misdiagnose as vestibulocerebellar disease. We report a patient with anterior callosal and cingulate infarction presenting as isolated astasia. A 65-year-old hypertensive man was admitted to our hospital with marked truncal instability. On neurological examination, he was unable to stand and walk independently. When asked to stand up from a sitting position, he had to grasp something nearby to propel himself upwards, and could not use his axial muscles. He collapsed when support was withdrawn. The patient showed no signs of amnesia, aphasia, apraxia or hemiasomatognosia. Diffusion weighted imaging at 3days after onset demonstrated an acute infarct in the anterior part of the right-sided corpus callosum and cingulate gyrus. Magnetic resonance angiography revealed an occlusion of the right anterior cerebral artery. We discuss the possible mechanisms of astasia due to anterior callosal and cingulate infarction.

A MOLECULAR ANALYSIS OF THE EUGLENOPHYTES USING SSU RDNA.

Almost since the creation of the genus Euglena (Ehrenberg), the taxa assigned to it have been separated, split apart, and reorganized into new genera based on morphological relationships, resulting in the creation of the genera Phacus (Dujardin), Lepocinclis (Perty), Astasia (Pringsheim), and Khawkinea ( Jahn and McKibben) based on intuitive methods. In an effort to assess the validity of these genera, we have used small subunit (SSU) rDNA data to generate a phylogenetic framework for these genera, with particular attention to the genus Euglena. Using the conserved sequence areas, we performed a phylogenetic analysis using parsimony, maximum likelihood, and distance methods. These different criteria have resulted in trees of the same topology. The euglenoid clade was composed of phagotrophic euglenoids at the base, which gave rise to phototrophs that in turn gave rise to osmotrophs. Among the photosynthetic taxa, the biflagellate form diverged prior to the uniflagellate form. Additionally, the need for a revision in the taxonomy of some of these genera was demonstrated. Currently, taxa from the photosynthetic genera Euglena, Phacus, and Lepocinclis do not form monophyletic clades, but are intermixed with each other as well as with the osmotrophic taxa, Astasia and Khawkinea.

Luigi Luciani (1840-1919) - the Italian Claude Bernard with German shaping, and his studies on the cerebellum with projections to nowadays / Luigi Luciani (1840-1919) - o italiano Claude Bernard com formação alemã, e seus estudos sobre o cerebelo com projeções na atualidade

Luigi Luciani (1840-1919) was an illustrious Italian citizen and physiologist whose research scope covered mainly cardiovascular subjects, the nervous system, and fasting. He published in 1891 a modern landmark of the study of cerebellar physiology - "Il cervelletto: nuovistudi di normal and pathología physiology" / "The cerebellum: new studies on normal and pathological physiology." In his experiment, a dog survived after cerebellectomy, reporting a triad of symptoms (asthenia, atonia, and astasia). In this way, the eminent neurophysiologist improved the operative technique and sterile processes to redirect the issue of cerebellar symptoms. Luciani died at age 78, a hundred years ago, and left mainly the understanding of the role of the cerebellum in regulating postural tone and muscle strength, which represented a step forward in understanding cerebellar motor physiology. In recent decades, cognitive / affective function has been added to the cerebellar motor, and there has also been a better understanding of cerebellar circuits.

Luigi Luciani (1840-1919) foi um ilustre cidadão e fisiologista italiano, cujo escopo de pesquisa abrangia principalmente assuntos cardiovasculares, sistema nervoso e jejum. Ele publicou em 1891 um marco moderno do estudo da fisiologia do cerebelo - "Il cervelletto: nuovistudi di fisiologia normale and patologica" / "O cerebelo: novos estudos sobre fisiologia normal e patológica". Em seu experimento, um cão sobreviveu após a cerebelectomia, com o relatório de uma tríade de sintomas (astenia, atonia e astasia). Dessa maneira, o eminente neurofisiologista aprimorou a técnica operatória e os processos estéreis para redirecionar a questão dos sintomas cerebelares. Luciani morreu aos 78 anos, cem anos atrás, e deixou principalmente a compreensão do papel do cerebelo na regulação do tônus postural e da força muscular, o que representou um passo adiante na compreensão da fisiologia motora cerebelar. Nas últimas décadas, a função cognitivo / afetiva foi adicionada à motora cerebelar e, também, houve uma melhor compreensão dos circuitos do cerebelo.

Caudal cingulate infarction manifesting astasia.

INTRODUCTION: Astasia is a rare presenting symptom of stroke, usually known as 'thalamic astasia', induced by a lesion in the ventrolateral thalamus. We report a case of caudal cingulate infarction manifesting astasia. CASE PRESENTATION: A 58-year-old male presented with inability to sit, stand and walk (astasia). No apparent motor weakness was noticed in the extremities. MRI revealed cerebral infarction in the caudal cingulate gyrus, which was located between the vertical commissure anterior (VCA) line and vertical commissure posterior (VPC) line. His symptoms persisted for 1 year to a lesser degree. CONCLUSION: Lesions in the caudal cingulate gyrus can present with astasia. The responsible lesion is located in the cingulate gyrus between the VCA and VPC line, which might correspond to the caudal cingulate zone in humans. We should keep in mind that astasia can be a presenting symptom of stroke.

The role of the thalamus in the human subcortical vestibular system.

Most of our knowledge concerning central vestibular pathways is derived from animal studies while evidence of the functional importance and localization of these pathways in humans is less well defined. The termination of these pathways at the thalamic level in humans is even less known. In this review we summarize the findings concerning the central subcortical vestibular pathways in humans and the role of these structures in the central vestibular system with regard to anatomical localization and function. Also, we review the role of the thalamus in the pathogenesis of higher order sensory deficits such as spatial neglect, pusher syndrome or thalamic astasia and the correlation of these phenomena with findings of a vestibular tone imbalance at the thalamic level. By highlighting thalamic structures involved in vestibular signal processing and relating the different nomenclatures we hope to provide a base for future studies on thalamic sensory signal processing.

Combined thalamic ptosis and astasia.

Isolated cases of astasia or ptosis have each been reported in ischemic or hemorrhagic strokes involving the thalamus. We report a 70-year-old man with a medical history of hypertension who presented with left ptosis and gait disturbance despite intact motor strength in the legs and normal sensory function. MRI of the brain showed an evolving subacute infarction confined to the anteromedial-medial part of the left thalamus with no other areas of recent infarction identified. To our knowledge, combined ptosis and astasia in thalamic infarction has not been reported in the English literature. We identified 11 patients with thalamic ptosis and 21 with thalamic astasia in the literature. Patients who had ptosis, or gait abnormality which would not be related to thalamic stroke, were excluded; for example, evidence of infarction in the hypothalamus, midbrain, pons, cerebellum, or cingulate gyrus.