Postural Tone Research Articles

Connectivity of the supplementary motor area in juvenile myoclonic epilepsy and frontal lobe epilepsy

Subtle structural abnormalities of frontal lobe gray and white matter have been described in cryptogenic frontal lobe and idiopathic generalized epilepsies. The supplementary motor area (SMA) has a role in motor control, and its involvement during frontal lobe epileptic seizures is characterized by a typical asymmetric tonic posturing. Moreover, motor networks are dysfunctional in juvenile myoclonic epilepsy (JME). We tested the hypothesis that SMA structural connectivity is altered in focal frontal lobe epilepsy (FLE) and JME compared to healthy controls. Diffusion tensor imaging (DTI) and probabilistic tractography were used to map the structural connectivity of the SMA, defined by motor functional magnetic resonance imaging (MRI), in 15 patients with JME, 36 patients with FLE, and 18 healthy controls. Structural connectivity of the SMA was significantly reduced in JME compared to controls (reduced fractional anisotropy and increased mean diffusivity). In FLE there was no significant difference compared to controls, and in all groups there was stronger connectivity in the left hemisphere (higher fractional anisotropy) compared to the right. There was no difference in SMA connectivity between patients with medial or lateral frontal lobe epileptic foci. Reduced white matter connectivity is the structural correlate of functional frontal lobe abnormalities in JME. In FLE, the structural connectivity of the SMA was preserved, suggesting a robust motor network that is not compromised by longstanding epilepsy involving the medial frontal lobes.

Takayasu's disease presenting as convulsive syncope which had been misinterpreted as epilepsy: a case report.

IntroductionTakayasu's arteritis is a chronic vasculitis mainly involving the aorta and its main branches. The disease has protean clinical manifestation ranging from asymptomatic to catastrophic illness.Case presentationA 19-year-old woman of Asian origin was referred to our neurology out-patient department for the management of refractory seizures. She reported several episodes of a loss of consciousness with tonic posturing when she assumed an upright position, which was accompanied by constitutional symptoms. A clinical examination showed orthostatic hypotension and an investigation confirmed the diagnosis of Takayasu's disease with presentation as convulsive syncope.ConclusionOur case highlights the importance of a thorough clinical history and physical examination in order to distinguish events mimicking epileptic seizure. We also describe an unusual presentation of Takayasu's disease with convulsive syncope and systemic constitutional symptoms.

Vasovagal syncope and unexplained syncope: Concepts, treatments, and future perspectives.

Syncope (transient loss of consciousness) can lead to significant psychosocial and physical impairment and have a profound impact on the quality of life of the sufferer. While infrequently attended to, a psychological perspective may have much to offer within a comprehensive treatment plan. The present article reviews 26 articles that evaluate conventional (education, medication, cardiac pacemakers) and to a greater extent, complementary treatments (orthostatic training, applied tension, psychologically oriented interventions) designed to reduce the frequency and negative consequences of vasovagal and unexplained syncope. Applied tension demonstrated the greatest efficacy in reducing the frequency of vasovagal syncope. However, this intervention applies only to patients who experience a prodrome prior to fainting. Currently, no clinically proven treatment exists for patients with unexplained syncope or with vasovagal syncope without a prodromal phase. Suggestions regarding appropriate cognitive and/or behavioural interventions are provided based on the characteristics of the patients. Keywords: vasovagal syncope, unexplained syncope, intervention, psychology, literature review Syncope refers to a loss of consciousness and postural tone followed by a rapid and spontaneous recovery (Sheldon, Koshman, Wilson, Kieser, & Rose, 1998). Syncope can occur abruptly or can be preceded by a prodrome referred to as presyncope. Amongst other symptoms, presyncope is characterised by weakness, nausea, and dizziness (Sheldon et al., 1998). Syncope accounts for 3% of emergency room visits and 1% to 6% of yearly hospitalisations in the United States (Day, Cook, Funkenstein, & Goldman, 1982). Syncope has multiple etiologies involving cardiac, orthostatic, or situational dysfunctions, anomalies in the autonomic nervous system (ANS), or medication use (Lazarus & Mauro, 1996). It is associated with psychological difficulties such as anxiety and depression that are underevaluated and undertreated by medical professionals (D'Antono et al., 2009; Kapoor, Fortunato, Hanusa, & Schulberg, 1995). Yet, patients frequently report psychological distress as a trigger of their syncope (Hupert & Kapoor, 1997; Linzer et al., 1990), and distress negatively impacts on the prognosis of afflicted individuals (D'Antono et al., 2009; Giada et al., 2005; Gracie, Newton, Norton, Baker, & Freeston, 2006; Kapoor et al., 1995). Moreover, psychologists are frequently under the misconception that loss of consciousness is incompatible with an anxiety disorder, especially those involving panic attacks. Yet, D'Antono et al. (2009) reported a panic disorder in up to 14% of their patients with recurrent syncope. Clearly, psychologists have a role to play in the comprehension and care of patients with syncope. The current article will provide background information on the nature of syncope, particularly vasovagal and unexplained syncope, review the efficacy of the various treatment approaches used in these populations, and finally suggest a multimodal approach to the treatment of syncope, particularly in patients with significant distress related to syncope. Vasovagal Syncope Vasovagal syncope (VVS) involves a dysregulation of the ANS (Grubb et al., 1991; Lazarus & Mauro, 1996; Mathias, Deguchi, & Schatz, 2001; Soteriades et al., 2002). The mechanisms involved and the precise sequence of events that lead to WS remain unknown (Grubb et al., 1991; Lazarus & Mauro, 1996). However, some research suggests that VVS involves a chain reaction wherein the sympathetic nervous system is activated, thusly elevating blood pressure and heart rate (Grubb et al, 1991 ; Lazarus & Mauro, 1996). As blood pressure increases, the baroreceptors in the heart, lungs, carotid arteries, and aortic arch trigger an opposing response in the parasympathetic nervous system. This response is characterised by a decrease in heart rate and a relaxation of smooth muscle cells in the blood vessels (vasodilation), provoking a decrease in blood pressure (Henderson & Prabhu, 1997). …

Retrospective Evaluation of Episodic Collapse in the Horse in a Referred Population: 25 Cases (1995-2009)

Episodic collapse in horses has equine welfare and human safety implications. There are, however, no published case series describing this syndrome. To characterize the cause and outcomes for horses referred for investigation of episodic collapse. Twenty-five horses referred for investigation of single or multiple episodes of collapse. Retrospective study. Clinical records from the Dick Vet Equine Hospital, University of Edinburgh from November 1995 to July 2009 were searched using the following keywords: collapse, collapsing, fall, syncope. Collapse was defined as an incident in which the horse lost postural tone with or without progression to recumbency and with or without loss of consciousness. Long-term follow-up information was obtained by telephone conversation with the owner. A final diagnosis was reached in 11 cases, namely cardiac arrhythmia (4), right-sided heart failure (1), hypoglycemia (2), generalized seizures (2), and sleep disorder (2). A presumptive diagnosis was reached in 8 cases, namely neurocardiogenic syncope (5), exercise-induced pulmonary hemorrhage (2), and generalized seizures (1). No diagnosis was reached in 6 cases despite comprehensive investigations. Three horses were euthanized at presentation. Treatment was attempted in 9 horses with 6 cases having successful outcome before discharge. Follow-up information was available for 14 of 19 horses discharged from the hospital. Only 1 of these horses was observed to collapse after discharge. Definitive diagnosis was more likely to be reached in cases with multiple episodes of collapse. Horses in which 1 episode of collapse occurred did not necessarily collapse again.

Episodic collapse in the horse

SummaryThe term ‘collapse’ can be used to describe a variety of incidents in which a horse loses postural tone with or without progression to recumbency and with or without loss of consciousness. Depending on the aetiology of the condition the episode may be self‐limiting and may or may not recur. Alternatively the collapse may be secondary to serious injury or disease and require veterinary intervention. This article mainly discusses investigation of the former scenario of self‐limiting single or multiple episodes of collapse in apparently healthy horses. An overview of the various causes of collapse is followed by a suggested approach to the diagnosis of these challenging cases.

Limited motor performance and minor neurological dysfunction at school age

To investigate the relationship between motor performance and minor neurological dysfunction (MND) at school age. Two hundred and fifty-three children (158 boys, 95 girls; mean age 8 years and 7 months) of whom 167 children received mainstream education and 86 children special education were neurologically examined according to Touwen. Special attention was paid to the severity of MND (simple or complex form) and type of dysfunction. Motor performance was assessed with the Movement Assessment Battery for Children (MABC), a parental questionnaire (Developmental Coordination Disorder Questionnaire; DCD-Q) and a teacher's questionnaire (Motor Observation Questionnaire for Teachers; MOQ-T). Total scores of MABC, DCD-Q and MOQ-T were strongly related to the severity of MND and to dysfunctional coordination and fine manipulation. Mild dysfunction in posture and muscle tone was only weakly related to limited motor performance. Children with a MABC score < 5th percentile showed significantly more often complex MND than children with scores between the 5th and 15th percentile or >15th percentile (54% vs 17% and 10%). Limited motor performance is related to the severity and type of MND. Coordination problems and fine manipulative disability are strongly related to poor motor performance, mild dysfunctions of posture and muscle tone to a lesser extent.

Stiffness Control of Balance During Quiet Standing and Dual Task in Older Adults: The MOBILIZE Boston Study

Distractions affect postural control, but this mechanism is not well understood. Diversion of resources during cognitive stress may lead to decreased motor drive and postural muscle tone. This may appear as decreased postural stiffness and increased postural sway amplitude. We hypothesized that dual tasking leads to decreased stiffness and increased sway amplitude. Postural sway (center of pressure; COP) data were used from 724 participants aged 77.9 ± 5.3 yr, a representative sample of community-dwelling older adults, the MOBILIZE Boston Study cohort. Subjects stood barefoot with eyes open for 30 s per trial on a force plate. Five trials were performed each with and without a serial subtractions-by-3 task. Sway data were fit to a damped oscillator inverted pendulum model. Amplitudes (COP and center of mass), mechanical stiffness, and damping of the sway behavior were determined. Sway amplitudes and damping increased with the dual task (P < 0.001); stiffness decreased only mediolaterally (P < 0.001). Those with difficulty doing the dual task exhibited larger sway and less damping mediolaterally (P ≤ 0.001) and an increased stiffness with dual task anteroposteriorly (interaction P = 0.004). Dual task could still independently explain increases in sway (P < 0.001) after accounting for stiffness changes. Thus the hypothesis was supported only in mediolateral sway. The simple model helped to explain the dual task related increase of sway only mediolaterally. It also elucidated the differential influence of cognitive function on the mechanics of anteroposterior and mediolateral sway behaviors. Dual task may divert the resources necessary for mediolateral postural control, thus leading to falls.

Implied motion because of instability in Hokusai Manga activates the human motion-sensitive extrastriate visual cortex: an fMRI study of the impact of visual art

The recent development of cognitive neuroscience has invited inference about the neurosensory events underlying the experience of visual arts involving implied motion. We report functional magnetic resonance imaging study demonstrating activation of the human extrastriate motion-sensitive cortex by static images showing implied motion because of instability. We used static line-drawing cartoons of humans by Hokusai Katsushika (called 'Hokusai Manga'), an outstanding Japanese cartoonist as well as famous Ukiyoe artist. We found 'Hokusai Manga' with implied motion by depicting human bodies that are engaged in challenging tonic posture significantly activated the motion-sensitive visual cortex including MT+ in the human extrastriate cortex, while an illustration that does not imply motion, for either humans or objects, did not activate these areas under the same tasks. We conclude that motion-sensitive extrastriate cortex would be a critical region for perception of implied motion in instability.

Paroxysmal Dyskinesia With Deja Vu Aura

Paroxysmal Dyskinesia With Deja Vu Aura

To avoid fainting: cross the legs and not the fingers

This editorial refers to ‘Prospective evaluation of non-pharmacological treatment in vasovagal syncope’ by J.J.C.M. Romme et al. , on page 567. Vasovagal syncope (VVS) represents by far the most common cause of syncope as it is diagnosed in ∼50% of all patients admitted in hospitals for syncope.1 Furthermore, the prevalence of VVS is certainly underestimated because many patients with this type of syncope are not hospitalized or even do not visit a physician.2 The mechanism leading to loss of consciousness in VVS is transient global cerebral ischaemia.3 In the case of VVS, this mechanism is elicited by severe hypotension associated or not with inadequate bradycardia or even ventricular pauses.3 Although impressive, these mechanisms are considered benign and there are no well-documented reports of sudden death directly attributable to VVS. In fact, VVS is a benign condition at the frontier between physiology and pathology.4 Studies in different animal species have demonstrated that vasovagal reactions are common and helpful to discourage predators by simulating death.5 In humans, VVS could also in some instances be considered an involuntary solution to temporarily escape from an unbearable world (for example, intolerable pain or insupportable vision). In these cases, VVS could be considered ‘physiological’. However, these situations are not always present and VVS may occur in the absence of evident context except generally upright position. In these cases and particularly when recurrences are frequent, VVS should be considered ‘pathological’. Because mechanisms leading to VVS are not life threatening, the only potential adverse effects of VVS are injuries and impaired quality of life. Injuries secondary to the loss of postural tone are not uncommon, generally without any significant … *Corresponding author. Tel: +33 2 98 34 73 92; fax: +33 2 98 34 78 03, Email: jean-jacques.blanc{at}univ-brest.fr

Familial frontal lobe epilepsy and its relationship with other nocturnal paroxysmal events

Familial frontal lobe epilepsy and its relationship with other nocturnal paroxysmal events

An Assessment of Rotational Mobility of the Trunk among Teenagers with Faulty Posture

An Assessment of Rotational Mobility of the Trunk among Teenagers with Faulty Posture Body posture is determined by many factors, including central regulation connected with anti-gravitational mechanism which develops in ontogenesis. Postural disorders arise as a result of a compensatory anti-gravitational mechanism, in which the main component is reduced postural tone (volume and distribution disorders). Compensation mechanisms consist in improper alignment of particular body segments (distribution disorders) (e.g., increase or decrease of spinal curvatures, external or internal rotation of the lower limbs, valgus and varus deformity of the knees and feet). Such disorders may constitute a reason for abnormal component development, thus limiting trunk rotational mobility. An aim of the study was to assess the range of trunk rotational mobility. Pupils (n=123) aged 13-15 underwent the following parameter evaluations: 1. Posture according to Kasperczyk's scoring method, 2. Postural tone volume by analysis of pelvis control in the long sitting, 3. Range of trunk rotation with use of upper tension test (muscle latissimus dorsi and thoracolumbar fascia). Positive tension test was recorded in 32 children (21 unilateral and 11 bilateral). Diversification of statistical averages of scoring for body posture, from the lowest (x=6.41) in 91 subjects with negative tension test, to the highest (x=7.72) in 11 subjects with double-sided positive result was recorded. Statistical analyzes confirmed significance of correlation between body posture's quality and trunk's rotational mobility (r=0.286 at p=0.001), as well as between volume of postural tone and range of trunk's rotational mobility. Coefficients of correlation amount to, respectively, for tension test and free sitting position r=0.187, p=0.038; and for tension test and corrected sitting position r=0.253, p=0.05. Disorders of muscle tone volume and distribution cause limitation of trunk rotational mobility development.

高齢で補足運動野発作を発症した進行性核上性麻痺の１例

We report a 75-year-old, right-handed man, presenting with supplementary motor area (SMA) seizure. The patient had suffered from frequent attacks of transient inability to speak and move without loss of awareness. On admission, he presented with vertical gaze paresis, axial rigidity, paratonia of extremities and gait disturbance. The attacks were preceded by discomfort on the head, followed by inability to move the whole body and arrest of vocalization with tonic posture and exaggerated breathing. Consciousness and cognitive function were preserved throughout the attacks. Electroencephalography recorded intermittently slow theta waves in the bifrontal regions. Brain MRI showed atrophy of the midbrain tegmentum with lacunar state suggesting progressive supranuclear palsy. SPECT with 123I-iomazenil revealed decreased uptake in the medial frontal areas including SMA, bilaterally. The seizures resolved completely following treatment with carbamazepine. Based on clinical features and neuroimagings, we speculated that the negative motor area within SMA was responsible for his seizure. Physicians should keep in mind that SMA seizure comprising negative motor phenomenon can occur in the elderly.

Intravenous Methylprednisolone Reduces the Risk of Propofol-Induced Adverse Effects During Wada Testing

The adverse effects and risks associated with intracarotid propofol injection during Wada testing were retrospectively compared in two groups of patients with (n = 75) and without (n = 58) intravenous methylprednisolone administered before intracarotid propofol injection. The incidences of all adverse effects were decreased in the methylprednisolone group. In particular, severe adverse effects such as increased muscle tone with twitching and rhythmic movements or tonic posture, which could adversely affect Wada test results, were seen in one patient in the methylprednisolone group and seven patients in the control group, indicating 92% risk reduction. This study suggests that Wada testing using intravenous methylprednisolone administration prior to propofol injection is a safe approach to the preoperative evaluation of brain tumors, epilepsy, and arteriovenous malformations.

Squid dances: an ethogram of postures and actions of Sepioteuthis sepioidea squid with a muscular hydrostatic system

A taxonomy of the movement possibilities for any species, within the constraints of its neural and skeletal systems, should be one of the foundations of the study of its behaviour. Caribbean reef squid, Sepioteuthis sepioidea, appear to have many degrees of freedom in their movement as they live in a three-dimensional habitat and have no fixed skeleton but rather a muscular hydrostatic one. Within this apparent lack of constraints, there are regularities and patterns of common occurrences that allow this article to describe an ethogram of the movements, postures and positions of squid. Squid have a combination of bent, spread and twisted maintained postures of the eight arms and two tentacles that enhance camouflage. Their body–arm posture combinations are actively maintained in the water but also influenced by gravity. Positions related to conspecifics are stereotyped and important for communication. For locomotion, squid use a well-coordinated dual fin–jet locomotion system. This motor system uses tonic postures for camouflage and maintains body position in courtship, though squid seldom touch. The interdependence of movement control by different units is seen in fins and jet propulsion, and bilateral symmetry is maintained even for the eight arms. It is argued that the repertoire is well adapted for a soft-bodied animal in its three-dimensional, open but near-shore demersal habitat.

Acute Transient Deafness Representing a Negative Epileptic Phenomenon

We report herein 2 children who presented with acute deafness heralding an epileptic event manifesting thereafter by loss of consciousness and tonic generalized posturing, possibly reflecting a negative epileptic phenomenon. The first previously healthy male had 2 paroxysmal episodes 7 months apart, starting with acute deafness lasting for a few minutes followed by loss of consciousness and generalized tonic posturing for 10 minutes. Electroencephalography (EEG) during the second episodes demonstrated generalized epileptiform discharges. The second with previously controlled partial complex seizures presented with episodes of complete deafness lasting for a few minutes followed by loss of consciousness and focal tonic posturing lasting 10 minutes. Such acute deafness represented an aura of a focal seizure substantiated by right focal temporal epileptic discharges within the region of the primary auditory cortex. Therefore, EEG should be performed in any case of acute transient deafness, even in the absence of accompanying overt clinical seizures.

Motor cortical hyperexcitability in idiopathic scoliosis: could focal dystonia be a subclinical etiological factor?

The aetiology of idiopathic scoliosis (IS) remains unknown; however, there is a growing body of evidence suggesting that the spine deformity could be the expression of a subclinical nervous system disorder. A defective sensory input or an anomalous sensorimotor integration may lead to an abnormal postural tone and therefore the development of a spine deformity. Inhibition of the motor cortico-cortical excitability is abnormal in dystonia. Therefore, the study of cortico-cortical inhibition may shed some insight into the dystonia hypothesis regarding the pathophysiology of IS. Paired pulse transcranial magnetic stimulation was used to study cortico-cortical inhibition and facilitation in nine adolescents with IS, five teenagers with congenital scoliosis (CS) and eight healthy age-matched controls. The effect of a previous conditioning stimulus (80% intensity of resting motor threshold) on the amplitude of the motor-evoked potential induced by the test stimulus (120% of resting motor threshold) was examined at various interstimulus intervals (ISIs) in both abductor pollicis brevis muscles. The results of healthy adolescents and those with CS showed a marked inhibitory effect of the conditioning stimulus on the response to the test stimulus at interstimulus intervals shorter than 6 ms. These findings do not differ from those reported for normal adults. However, children with IS revealed an abnormally reduced cortico-cortical inhibition at the short ISIs. Cortico-cortical inhibition was practically normal on the side of the scoliotic convexity while it was significantly reduced on the side of the scoliotic concavity. In conclusion, these findings support the hypothesis that a dystonic dysfunction underlies in IS. Asymmetrical cortical hyperexcitability may play an important role in the pathogenesis of IS and represents an objective neurophysiological finding that could be used clinically.

State-dependent vs. central motor effects of ethanol on breathing

Ethanol, one of the most widely used drugs in Western society, worsens obstructive sleep apnea in humans. No studies, however, have distinguished between two primary mechanisms that could mediate suppression of genioglossus (GG) activity with ethanol. We test the hypothesis that ethanol suppresses GG activity by effects at the hypoglossal motor pool and/or by state-dependent regulation of motor activity via independent influences on sleep/arousal processes. Intraperitoneal injections of ethanol (1.25 g/kg, n = 6 rats) resulted in maximum blood levels of 125.5 +/- 15.8 mg/dl, i.e., physiologically relevant levels for producing behavioral impairment in rats and humans. Ethanol decreased wakefulness, reduced sleep latency, and increased non-rapid eye movement sleep (P < 0.001, n = 10 rats) and significantly reduced postural muscle tone and electroencephalogram frequencies, consistent with sedation. Ethanol also caused a state-dependent (wakefulness only) decrease in respiratory-related GG activity (P = 0.018) but did not affect diaphragm amplitude or rate, with the magnitude of GG decrease related to baseline activity (P < 0.0002). Ethanol did not alter GG activity when applied to the hypoglossal motor pool (0.025-1 M, n = 16 isoflurane-anesthetized rats). In conclusion, ethanol promoted sleep and altered electroencephalogram and postural motor activities, indicative of sedation. The lack of effect on GG with ethanol at the hypoglossal motor pool indicates that the GG and postural motor suppression following systemic administration was mediated via effects on state-dependent/arousal-related processes. These data show that ethanol can suppress GG by primary influences on state-dependent aspects of central nervous system function independent of effects on the respiratory network per se, a distinction that has not previously been identified experimentally.

Evaluation and Management of Syncope

Syncope is a transient loss of consciousness precipitated by cerebral hypoperfusion, which is associated with a brief absence of postural tone and usually followed by a complete recovery. This clinical condition is a common medical problem and may be attributed to a multitude of disease processes. Risk stratification identifies the safest setting for the initial evaluation as well as which patients are most likely to have a life-threatening event. Establishing the diagnosis of syncope is important so that specific treatment can be instituted to prevent future recurrences and eliminate the underlying predisposing disease. This article reviews the etiology, risk stratification, diagnosis, and therapeutic management of syncope.

A hemispherotomy for intractable startle epilepsy characterized by infantile hemiplegia and drop attacks

Startle epilepsy is provoked by unexpected sensory stimuli, mainly auditory, and reveals subsequent tonic posturing of the limbs. We present a case of intractable startle epilepsy with infantile hemiplegia and discuss the indications for a hemispherotomy.