Alien Hand Research Articles

Lesion network localization of free will

Our perception of free will is composed of a desire to act (volition) and a sense of responsibility for our actions (agency). Brain damage can disrupt these processes, but which regions are most important for free will perception remains unclear. Here, we study focal brain lesions that disrupt volition, causing akinetic mutism (n = 28), or disrupt agency, causing alien limb syndrome (n = 50), to better localize these processes in the human brain. Lesion locations causing either syndrome were highly heterogeneous, occurring in a variety of different brain locations. We next used a recently validated technique termed lesion network mapping to determine whether these heterogeneous lesion locations localized to specific brain networks. Lesion locations causing akinetic mutism all fell within one network, defined by connectivity to the anterior cingulate cortex. Lesion locations causing alien limb fell within a separate network, defined by connectivity to the precuneus. Both findings were specific for these syndromes compared with brain lesions causing similar physical impairments but without disordered free will. Finally, our lesion-based localization matched network localization for brain stimulation locations that disrupt free will and neuroimaging abnormalities in patients with psychiatric disorders of free will without overt brain lesions. Collectively, our results demonstrate that lesions in different locations causing disordered volition and agency localize to unique brain networks, lending insight into the neuroanatomical substrate of free will perception.

Selective Inhibition of Volitional Hand Movements after Stimulation of the Dorsoposterior Parietal Cortex in Humans

Inhibition is a central component of motor control. Although current models emphasize the involvement of frontal networks [1, 2], indirect evidence suggests a potential contribution of the posterior parietal cortex (PPC). This region is active during inhibition of upper-limb movements to undesired targets [3], and its stimulation with single magnetic pulses can depress motor-evoked potentials [4, 5]. Also, it has been speculated that alien hand movements caused by focal parietal lesions reflect a release of inhibition from PPC to M1 [6]. Considering these observations, we instructed 16 patients undergoing awake brain surgery to perform continuous hand movements while electrical stimulation was applied over PPC. Within a restricted dorsoposterior area, we identified focal sites where stimulation prevented movement initiation and instantly inhibited ongoing responses (which restarted promptly at stimulation offset). Inhibition was selective of the instructed response. It did not affect speech, hand movements passively generated through muscle electrical stimulation, or the ability to initiate spontaneous actions with other body segments (e.g., the feet). When a patient inadvertently performed a bilateral movement, a bilateral inhibition was found. When asked to produce unilateral movements, this patient presented a contralesional but not ipsilateral inhibition. This selectivity contrasted sharply with the unspecific inhibitions reported by previous studies within frontal regions, where speech and all limbs are typically affected (as we here confirm in a subset of patients) [7-10]. These results provide direct evidence that a specific area in the dorsoposterior parietal cortex can inhibit volitional upper-limb responses with high selectivity.

Alien hand syndrome.

A 94-year-old patient developed the alien hand syndrome in the left (nondominant) hand following an ischemic stroke of the right parietotemporal lobe (including postcentral gyrus, superior and inferior parietal lobule) due to an occlusion of the posterior division of the right middle cerebral artery.

Poster 284: Alien Hand Syndrome Complicated by Contralateral Limb Apraxia: A Case Report

PM&RVolume 10, Issue 9S1 p. S94-S95 Poster 284: Alien Hand Syndrome Complicated by Contralateral Limb Apraxia: A Case Report Martin D. Weaver MD, Martin D. Weaver MD Jackson Memorial Hospital / University of Miami Miller School of Medicine, Miami Springs, FL, United StatesSearch for more papers by this authorGemayaret Alvarez-Gonzalez MD, Gemayaret Alvarez-Gonzalez MDSearch for more papers by this author Martin D. Weaver MD, Martin D. Weaver MD Jackson Memorial Hospital / University of Miami Miller School of Medicine, Miami Springs, FL, United StatesSearch for more papers by this authorGemayaret Alvarez-Gonzalez MD, Gemayaret Alvarez-Gonzalez MDSearch for more papers by this author First published: 26 September 2018 https://doi.org/10.1016/j.pmrj.2018.08.295Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue9S12018 AAPM&R Annual Assembly AbstractsSeptember 2018Pages S94-S95 RelatedInformation

Body image perception and sense of agency: notes from the alien hand experiment

Body image perception comprises stable and dynamic representational features. Here, we examined whether a stable body image (BI) measure correlates to a dynamic sense of agency (SoA) score. Moreover, we tested whether differential BI perception scores predicts SoA performance under sensory conflict conditions. A total of 21 university students (age M=25.9, SD=9.29) completed the Brazilian version of the Silhouette Figures Scale (SFS) and participated in The Alien Hand Experiment (TAHE). TAHE is a task that manipulates participants’ hand movement SoA. A Bayesian correlation matrix revealed substantial negative correlation probability between BI perception and SoA confidence in accuracy responses, specifically in experimental conditions where agency was manipulated. Based on the SFS scores, participants were divided into groups with and without evidences of BI distortion. Bayesian Independent Samples T-Tests evidenced substantial differential probability between groups. Analyzes confirmed lower SoA confidence among subjects with BI distortion greater than ±3 kg/m².

Bringing order to higher order motor disorders

Majority of movements in everyday situations are complex and involve volition, planning of the movement and selection of the motor programme, all occurring before movement execution. Higher order motor disorders may be defined as abnormal motor behaviours resulting from disruption of any of the cortical processes that precede execution of the motor act. They are common in patients with neurodegenerative disorders, psychiatric diseases and structural brain lesions. These abnormal behaviours may be overlooked in the clinic, unless specifically evoked by the examiner. We discuss clinical and pathophysiological aspects of higher order motor disorders including: (1) disorders of disinhibition, such as grasp reflex and grasping behaviour, utilisation and imitation behaviour, motor preservations and paratonia; (2) disorders of motor intention such as motor neglect and motor impersistence; (3) alien limb syndrome; and (4) motor overflow phenomena, such as mirror movements and synkinesias. A video illustration of each phenomenon is provided. We place the findings from recent neurophysiological studies within the framework of theories of motor control to provide better insight into pathophysiology of different disorders.

Analysis on the clinical, neuroimaging and pathological characteristics in patients with corticobasal syndrome

Objective To investigate the clinical, neuroimaging and pathological features of patients with corticobasal syndrome (CBS). Methods Three CBS patients underwent neuropsychological assessment, MRI scan, 18F-FDG PET scan, and 11C-PiB PET scan, and the test results were analyzed. Results All three patients showed poor response to levodopa treatment and asymmetric dyskinesia including rigidity, tremor, dystonia and abnormalities in posture and gait.One patient showed apraxia and three patients presented with cognitive impairment.The crania MRI demonstrated mild cerebral atrophy which was slightly more severe in the contralateral side of the initially affected limb.The (18)F-FDG PET/CT scan revealed asymmetric decreased metabolism in the frontal, parietal, temporal, and insular lobe, as well as in basal ganglia.The results of (11)C-PiB) PET showed that amyloid beta-peptide (A Beta) deposition in the cortex was positive in one patient, and negative in the other two patients. Conclusions Corticobasal syndrome is characterized by asymmetric dyskinesia and cognitive impairment, and often associated with apraxia, cortical sensory deficits, and alien limb phenomena.The MRI and FDG PET are helpful for CBS diagnosis, and the PiB PET facilitates the pathological diagnosis. Key words: Pathology; Neuroimaging; Corticobasal syndrome

Effects of Modulations of the Visual Conditions on Subjects’ Perception of Their Own and Another Person’s Hand

According to current concepts, the execution of expedient actions well-coordinated in space becomes possible owing to the creation of a system for internal representation, which includes a body coordinate system, in the central nervous system. The goal of this study was to assess the effects induced by the exclusion of vision and a left-right inversion in visual space on the accuracy in the internal representation of hands and on aimed arm movements. The study cohort included 16 participants aged from 18 to 25 years. The experiment consisted of two test series. In the first series, a subject placed his/her left hand under a transparent plexiglass screen. Upon the experimenter’s command, the subject had to indicate the position of his/her left wrist and the terminal phalanges of the thumb, middle and little fingers with his/her right index finger on the plexiglass, which was accompanied by the corresponding marks displayed on the screen. The positional accuracy in the subject’s perception of his/her own hand position was recorded in the conditions of a leftright inversion of visual space, which were created by wearing prismatic spectacles and the exclusion of visual control. In the second case, the subject’s left hand was replaced on the table under the transparent screen by a similarly shaped left hand belonging to another person. It has been shown that the positions of the middle fingertip and the wrist were sufficiently precisely perceived by the subject through prismatic spectacles. However, the position of the tips of the thumb and little finger relative to the axis connecting the wrist and the terminal phalanx of the middle finger (the hand axis) was perceptually inverted. The accuracy of the indication was reduced for all fingers when the eyes were closed. In testing another person’s hand, a left–right inversion in the visual space created an illusory 90° turn of the hand’s axis and an illusory bias relative to the wrist towards elongation in the marker points corresponding to another person’s fingers. We can suggest that when the alien hand replaced the subject’s own hand, in accordance with the modulations in the motor task conditions, the egocentric system of coordinates was replaced by the allocentric system. The role of vision in the execution of spatially oriented and accurate hand movements increased in this case.

Síndromes do Corpo Caloso

Introdução: O entendimento da anatomia integral do sistema de conexão do corpo caloso permite que as principais síndromes calosas sejam melhor compreendidas. Objetivo: Realizar uma revisão das principais síndromes calosas com ênfase na síndrome da mão alienígena baseado nas diferentes partes do corpo caloso seguindo a divisão proposta por Witelson em 1989. Material e Métodos: Os autores realizaram uma revisão sobre a síndrome da mão alienígena após busca de dados no PUBMED e MEDLINE. Conclusão: O conhecimento da anatomia e da função do corpo caloso pode auxiliar na detecção de patologias neurológicas que cursam com distúrbios do movimento, além de doenças psiquiátricas.

125 Short Duration Monoballismus

AbstractStudy ObjectiveWhile monoballismus has been reported to be associated with hemorrhagic lesions in the subthalamic nucleus (Ohnishi, 2009) and multiple sclerosis (MS) (Rosa, 2011), the duration has been reported to be at least six days (Soysal, 2012). A patient with epochs of monoballismus lasting for 45 minutes is presented.MethodsCase Study: A 57 year old right handed female with attention deficit hereditary disorder predominantly inattentive on amphetamine sulphate, presented with two years of memory loss. For instance, after ordering food in restaurants, by the time the food arrives, she could not recall what she ordered. At the onset of this symptom, she noted three epochs of her left arm jerking for 45 minutes. The jerking would begin with low amplitude and low frequency and rapidly progress to the forearm and arm of greater magnitude and low frequency. With her right hand she would try to hold down her left arm without success. There was no associated paresis, sensory phenomena, headaches, dizziness, presyncope, loss of consciousness, or strong emotions. She admitted to frequent jamais vu.ResultsAbnormalities: Neurological Examination: Mental Status Examination: Memory: Immediate Recall: 5 digits forward and 2 digits backwards. Cranial Nerve (CN) Examination: CN I: Alcohol Sniff Test 8 (hyposmia). CN XII: tongue tremor on protrusion. Motor Examination: Drift Test: positive right pronator drift. Gait Examination: Tandem Gait: unstable. Reflexes: 0-1 throughout. Neuropsychiatric Examination: Go-No-Go Test: 6/6 (normal). Animal Fluency Test: 15 (normal). Clock Drawing Test: 3 (abnormal). Center for Neurologic Study Lability Scale: 16 (pseudobulbar affect). Other: MRI with and without infusion: normal.ConclusionTransient tonic-clonic movements of one limb have been described with focal epilepsy associated with diabetic non-ketotic hyperglycemia (Grant, 1985). A metabolic abnormality such as transient hypoglycemia or hyperkalemia can cause a focal dystonia (Soysal, 2012), which theoretically could manifest with monoballismus. This could be a somatic manifestation of underlying conflict, conversion disorder, or as a result of a physical manifestation of panic attack with hyperventilation and tetany (Mihai, 2008). This may be the first manifestation of a generalized cerebral disorder associated with chorea or ballismus such as Wilson’s disease, or Huntington’s Chorea (Mihai, 2008). It is possible that this is a variant of Alien Hand Syndrome with parietal lobe involvement (Shrestha, 2015). But this is unlikely given the absence of hemineglect or hemiagnosia. It is possible that amphetamines may have induced a monochorea. Chronic amphetamine use has been demonstrated to cause chorea (Klawans, 1974) and it theoretically could have caused ballismus movements in this case. In patients who present with short duration monoballismus, evaluation for subthalamic nuclei function, seizure disorders and other origins of ballismus are warranted.Funding AcknowledgementsSmell & Taste Treatment and Research Foundation

Posterior variant alien hand sign with prominent focal dystonia: A case report

Background: Alien hand sign (AHS) is classified into frontal, callosal, and posterior variants. Posterior variant has been rarely documented.

Rehabilitation of Stroke Recovery Complicated by Alien Limb Syndrome

To identify rehabilitation challenges and treatment strategies associated with alien limb syndrome in stroke recovery.

P 36 Structural and functional imaging findings in somatoparaphrenia

Background With regard to somatosensory delusion, neglect or deficits of body integrity a great number of overlapping pathophysiological concepts exist. Moreover, the range of assumed underlying psychiatric and neurologic syndromes only partially is thought to be related to even diverse neuroanatomical structures so far: Alien Hand Syndrome, Body Dysmorphic Disorder (BDD), Body Integrity Identity Disorder (BIID), Depersonalization, Somatoparaphrenia and Xenomelia. Specific deafferentiation within temporal regions, the insula or representational structures of the somatosensory cortex of the right parietal lobe is thought to be related only in some variants. We report a case of a 58-year old right-handed woman that experienced a progressive left-sided hemiparesis which initially could be related to a space occupying lesion and edema in the right central region of the brain. After anti-edematous therapy and consecutive surgical evacuation a cortical and subcortical defect in between the right postcentral gyrus junction to the precentral gyrus resulted into inanimate, not inherent sensations especially of the left forearm and knee without anosognosia after complete recovery of motor function and sensitivity. The neuropsychological assessment showed no impairments. Methods We demonstrate structural (conventional MRI) and functional imaging findings (diffusion tensor imaging; DTI, and, motor and somatosensory functional MRI) in relation to the subject”s somatosensory delusions. Results Structural MRI displayed a well-defined cortical and subcortical lesion in deep central sulcus surrounded by gliosis and hemosiderin deposits. DTI revealed a marked reduction of structural inter-connection between precentral and postcentral gyrus. In fMRI the motor paradigm series of dorsal flexion of the feet or clenching the fists showed no difference in activation of the correspondent precentral gyrus. The sensor paradigm series in contrast revealed a lower posterior activation of the right postcentral area during brushing the planta pedis and the left forearm. Discussion The hereby presented case possesses rare clinically segregated symptoms of somatoparaphrenia without anosognosia or hemiparesis in conjunction with a well-defined postcentral lesion. The symptoms may be related to a corresponding reduced postcentral activation and restricted functional interconnection between motor and sensory cortex. From our point of view these results document the essential requirement of postcentral gyrus activation and regional conduction for regular experience of sensorial authenticity.

Corticobasal syndrome like presentation of Hashimoto encephalopathy with cortical ribboning

Abstract Hashimoto encephalopathy (HE) and corticobasal syndrome (CBS) are heterogeneous disorders characterized by variable presentation; seizure, stroke like symptoms, myoclonus, alien limb phenomena, dystonia, limb apraxia, although extrapyramidal features and alien limb phenomena are rare in HE. Here we are reporting a 70 years female who presented with 3 months history of asymmetrical onset rapidly progressive disease associated with alien limb behaviour, myoclonic jerks, dystonia, seizure, speech impairment, asymmetrical extrapyramidal features (left > right), gait ataxia and cortical ribboning on brain imaging without visual disturbances, cognitive decline or neuropsychiatric abnormalities. EEG did not show any periodic discharges or slowing. Neuronal antibody VGKC was negative but she had euthyroid state with high titre of anti TPO antibody 590 IU/ml (normal upto 95 IU/ml). Therefore, diagnosis of Hashimoto encephalopathy in a probable sporadic case of corticobasal syndrome was made. Patient was treated with antiepileptic and IV steroid for 5 days. At the time of discharge she was conscious and followed verbal commands. In every case of rapidly progressive neurodegenerative disease like CBS, investigations for HE should be planned.

Body schema and corporeal self-recognition in the alien hand syndrome.

The alien hand syndrome (AHS) is a rare neuropsychological disorder characterized by involuntary, yet purposeful, hand movements. Patients with the AHS typically complain about a loss of agency associated with a feeling of estrangement for actions performed by the affected limb. The present study explores the integrity of the body representation in AHS, focusing on 2 main processes: multisensory integration and visual self-recognition of body parts. Three patients affected by AHS following a right-hemisphere stroke, with clinical symptoms akin to the posterior variant of AHS, were tested and their performance was compared with that of 18 age-matched healthy controls. AHS patients and controls underwent 2 experimental tasks: a same-different visual matching task for body postures, which assessed the ability of using your own body schema for encoding others' body postural changes (Experiment 1), and an explicit self-hand recognition task, which assessed the ability to visually recognize your own hands (Experiment 2). As compared to controls, all AHS patients were unable to access a reliable multisensory representation of their alien hand and use it for decoding others' postural changes; however, they could rely on an efficient multisensory representation of their intact (ipsilesional) hand. Two AHS patients also presented with a specific impairment in the visual self-recognition of their alien hand, but normal recognition of their intact hand. This evidence suggests that the AHS following a right-hemisphere stroke may involve a disruption of the multisensory representation of the alien limb; instead, self-hand recognition mechanisms may be spared. (PsycINFO Database Record

Feeling touch on the own hand restores the capacity to visually discriminate it from someone else' hand: Pathological embodiment receding in brain-damaged patients

The sense of body ownership, i.e., the belief that a specific body part belongs to us, can be selectively impaired in brain-damaged patients. Recently, a pathological form of embodiment has been described in patients who, when the examiner's hand is located in a body-congruent position, systematically claim that it is their own hand (E+ patients). This paradoxical behavior suggests that, in these patients, the altered sense of body ownership also affects their capacity of visually discriminating the body-identity details of the own and the alien hand, even when both hands are clearly visible on the table. Here, we investigated whether, in E+ patients with spared tactile sensibility, a coherent body ownership could be restored by introducing a multisensory conflict between what the patients feel on the own hand and what they see on the alien hand. To this aim, we asked the patients to rate their sense of body ownership over the alien hand, either after segregated tactile stimulations of the own hand (out of view) and of the alien hand (visible) or after synchronous and asynchronous tactile stimulations of both hands, as in the rubber hand illusion set-up. Our results show that, when the tactile sensation perceived on the patient's own hand was in conflict with visual stimuli observed on the examiner's hand, E+ patients noticed the conflict and spontaneously described visual details of the (visible) examiner's hand (e.g., the fingers length, the nails shape, the skin color…), to conclude that it was not their own hand. These data represent the first evidence that, in E+ patients, an incongruent visual-tactile stimulation of the own and of the alien hand reduces, at least transitorily, the delusional body ownership over the alien hand, by restoring the access to the perceptual self-identity system, where visual body identity details are stored.

A Wolf in Sheep's Clothing: An "Alien Leg" in Corticobasal Syndrome.

BackgroundAlien limb phenomenon occurs in 50–60% of patients with corticobasal syndrome (CBS) and usually presents with an “alien hand” phenomenon. The “alien foot” presentation is rarer and may be misdiagnosed, as foot involvement can lead to erroneous localization of the clinical problem to the knee, hip, or back. Subsequently misdiagnoses such as myelopathy, radiculopathy, functional disorder, stiff leg syndrome, neuromyotonia, and painful leg moving toes syndrome may occur.Case reportWe describe two patients with alien foot symptoms that resulted in multiple opinions from different specialists, multiple diagnostic and therapeutic procedures, and delayed diagnosis. Eventually a diagnosis of CBS was made in both. Alien foot symptoms may be more common than initially thought and can result in a delayed diagnosis of CBS.ConclusionThe inclusion of this clinical finding in recently proposed diagnostic criteria highlights the need for increased clinical awareness.

When Playing Is a Problem: An Atypical Case of Alien Hand Syndrome in a Professional Pianist.

Alien hand syndrome (AHS) is a neurological illness characterized by limb movements which are carried out without being aware of it. Many patients describe these movements as aggressive and some perceive a strong feeling of estrangement and go so far as to deny ownership. The sense of body ownership is the perception that parts of one’s body pertain to oneself, despite it is moving or not and if movement is intentional or unintentional. These anomalous self-experiences may arise in patients with focal brain lesions and provide unique opportunities to disclose the neural components underlying self-body perception. The feeling of foreignness described in AHS is often observed in post-central cortical lesions in the non-dominant hemisphere and is typical of the “posterior alien hand variant”. We used Diffusion-Tensor magnetic resonance imaging (DT-MRI) in an unusual case of posterior AHS of the dominant hand in a professional pianist with corticobasal syndrome (CBS). The patient showed uncontrolled levitation with the right arm while playing the piano and perceived as if her hand had a “mind of its own” which prevented her from playing. MRI-scans show asymmetric brain atrophy, mainly involving left post-central regions and SPECT-Tc99m-ECD patterns of hypometabolism over the left parietal-occipital cortices. DT-MRI revealed extensive damage which comprised left fronto-temporal cortex and extends into the ipsilateral parietal cortex causing a disruption of corpus callosum (CC) projections from the rostrum to the splenium. Our case illustrates that posterior AHS may occur in the dominant hemisphere due to widespread damage, which exceed parietal cortex. The parietal lobe has been recognized as a multimodal association region that gets input from several networks and organizes motor output. We suggest that the disturbance to this pathway could result in disruption of motor output and associate an abnormal motor control and anomalous self-body perception.

Letter re: The magnetic apraxia of Denny-Brown.

In their Video NeuroImage, Peluso et al.1 reported a patient with right hand magnetic apraxia attributed to parietal lobe dysfunction.2 Magnetic apraxia is a variant of alien hand syndrome caused by lesions in the frontal lobe.3 It typically manifests with unilateral grasping and groping of the dominant (usually right) hand. In contrast, alien hand syndrome due to parietal lobe lesions, most commonly corticobasal syndrome or stroke, tends to manifest with limb levitation and noncomplex movements accompanied by other parietal deficits.4 The video shown is consistent with magnetic apraxia, but would thus need to be attributed to the patient's frontal lobe lesion. If attributed to the parietal lobe, by definition it is not the magnetic apraxia of Denny-Brown.

Subliminal modulation of voluntary action experience: A neuropsychological investigation

Human voluntary actions are often associated with a distinctive subjective experience termed ‘sense of agency’. This experience could be a reconstructive inference triggered by monitoring one's actions and their outcomes, or a read-out of brain processes related to action preparation, or some hybrid of these. Participants pressed a key with the right index finger at a time of their own choice, while viewing a rotating clock. Occasionally they received a mild shock on the same finger. They were instructed to press the key as quickly as possible if they felt a shock. On some trials, trains of subliminal shocks were also delivered, to investigate whether such subliminal cues could influence the initiation of voluntary actions, or the subjective experience of such actions. Participants' keypress were always followed by a tone 250 ms later. At the end of each trial they reported the time of the keypress using the rotating clock display. Shifts in the perceived time of the action towards the following tone, compared to a baseline condition containing only a keypress but no tone, were taken as implicit measures of sense of agency. The subliminal shock train enhanced this “action binding” effect in healthy participants, relative to trials without such shocks. This difference could not be attributed to retrospective inference, since the perceptual events were identical in both trial types. Further, we tested the same paradigm in a patient with anarchic hand syndrome (AHS). Subliminal shocks again enhanced our measure of sense of agency in the unaffected hand, but had a reversed effect on the ‘anarchic’ hand. These findings suggest an interaction between internal volitional signals and external cues afforded by the external environment. Damage to the neural pathways that mediate interactions between internal states and the outside world may explain some of the clinical signs of AHS.