Alien Hand Research Articles

Recurrent Alien Hand Syndrome in a Multiple Sclerosis Case

Alien hand syndrome is the strange feeling of one's hand behaving independently. This syndrome has rarely been reported in multiple sclerosis (MS) patients. Herein, we present a 34-year-old female MS patient who had recurrent symptoms of alien hand syndrome that were evaluated as MS attacks based on cranial magnetic resonance imaging that showed demyelinating lesions in the corpus callosum. Alien hand syndrome is classified according to the location of the lesion and the presenting symptoms. As such, our patient can best be classified as a callosal alien hand case.

Altered state of corporal consciousness related to alien hand syndrome and schizophrenic motor passivity

Altered state of corporal consciousness related to alien hand syndrome and schizophrenic motor passivity

A case of corticobasal degeneration presenting with alien limb syndrome

Alien limb syndrome (ALS) is a very rare condition where the affected persons are not able to recognise the affected limb as their own, and regard it as being foreign or alien to them. We present a patient with ALS secondary to corticobasal degeneration, which is a rare neurodegenerative parkinsonian disorder. We discuss the clinical features, neuropathology and management of corticobasal degeneration.

I move, therefore I am: A new theoretical framework to investigate agency and ownership

The neurocognitive structure of the acting self has recently been widely studied, yet is still perplexing and remains an often confounded issue in cognitive neuroscience, psychopathology and philosophy. We provide a new systematic account of two of its main features, the sense of agency and the sense of ownership, demonstrating that although both features appear as phenomenally uniform, they each in fact are complex crossmodal phenomena of largely heterogeneous functional and (self-)representational levels. These levels can be arranged within a gradually evolving, onto- and phylogenetically plausible framework which proceeds from basic non-conceptual sensorimotor processes to more complex conceptual and meta-representational processes of agency and ownership, respectively. In particular, three fundamental levels of agency and ownership processing have to be distinguished: The level of feeling, thinking and social interaction. This naturalistic account will not only allow to “ground the self in action”, but also provide an empirically testable taxonomy for cognitive neuroscience and a new tool for disentangling agency and ownership disturbances in psychopathology (e.g. alien hand, anarchic hand, anosognosia for one’s own hemiparesis).

A spam rejection scheme during SMTP sessions based on layer-3 e-mail classification

This paper proposes a scheme that rejects spam e-mails during their simple mail transfer protocol (SMTP) sessions. This scheme utilizes a layer-3 e-mail classification technique, which allows e-mail classes to be estimated before the end of SMTP sessions at receiving e-mail servers. We analyze the proposed scheme using discrete-time Markov chain analysis under varying e-mail traffic loads and service capacities. This paper also considers the effects of e-mail retransmission and illegal spam relaying by zombie systems on the performance of the proposed scheme. Results from our analysis show that e-mail server loading decreases by using the proposed technique. This allows the reduction in non-spam e-mail queuing delays and loss probability. Our scheme also protects e-mail servers from being overloaded by spam traffic and, if performed collectively over the Internet, it is capable of performing outbound spam control.

A case of tactile agnosia with a lesion restricted to the post-central gyrus

Tactile agnosia has been described after lesions of the primary sensory cortex but the exact location and extension of those lesions is not clear. We report the clinical features and imaging findings in a patient with an acute ischemic stroke restricted to the primary sensory area (S1). A 73-year-old man had a sudden onset of a left alien hand, without left hemiparesis. Neurological examination showed intact primary sensory functions, but impaired recognition of shape, size (macrogeometrical) and texture (microgeometrical) of objects; damage confined to the post-central gyrus, sparing the posterior parietal cortex was demonstrated on MRI. An embolic occlusion of the anterior parietal artery was suspected as mechanism of stroke. Tactile agnosia with impaired microgeometrical and macrogeometrical features' recognition can result from a single lesion in the primary sensory cortex (S1) in the right parietal hemisphere, sparing other regions of the cerebral cortex which presumably participate in tactile object recognition.

Migraine Aura and Related Phenomena: Beyond Scotomata and Scintillations

Migraine affects the cortical physiology and may induce dysfunction both ictally and interictally. Although visual symptoms predominate during aura, other contiguous cortical areas related to less impressive symptoms are also impaired in migraine. Answers from 72.2% migraine with aura and 48.6% of migraine without aura patients on human faces and objects recognition, colour perception, proper names recalling and memory in general showed dysfunctions suggestive of prosopagnosia, dyschromatopsia, ideational apraxia, alien hand syndrome, proper name anomia or aphasia, varying in duration and severity. Symptoms frequently occurred in a successively building-up pattern fitting with the geographical distribution of the various cortical functions. When specifically inquired, migraineurs reveal less evident symptoms that are not usually considered during routine examination. Spreading depression most likely underlies the aura symptoms progression. Interictal involvement indicates that MWA and MWoA are not completely silent outside attacks, and that both subforms of migraine may share common mechanisms.

Infarctus cérébraux multiples se présentant comme une dégénérescence cortico-basale : pseudo dégénérescence cortico-basale vasculaire ?

We report on five patients with a clinical presentation of corticobasal degeneration (CBD), including gradually progressive, asymmetric, L-DOPA-resistant parkinsonism associated variously with apraxia, focal action myoclonus, focal dystonia, cortical sensory loss and alien limb phenomenon. Some patients also presented an atypical CBD clinical history or signs - notably sudden onset. The disease was however not suggestive of another diagnosis. Magnetic resonance imaging of the brain revealed extensive vascular lesions. Only five similar cases have been published to our knowledge. Although we cannot exclude underlying CBD pathology, our cases illustrate the fact that multi-infarct pathology can masquerade as CBD or alter the clinical phenotype of the disease.

At the Edge of Consciousness: Automatic Motor Activation and Voluntary Control

Conventionally, voluntary conscious acts and automatic behavior have been considered to be mediated by separate processes—and by separate brain structures. In this review, the authors consider the evidence that this might not be the case. First, they draw together disparate lines of evidence showing that visual stimuli cause automatic and unconscious motor activation. They briefly discuss the visual grasp reflex (automatic orienting of gaze to a salient visual stimulus), subliminal priming, and object affordances in healthy individuals. They also consider cases where inhibition of such reflexive behavior may be disrupted following brain lesions, as in patients demonstrating alien limb syndrome and utilization behavior. The authors argue that automatic motor activation forms an intrinsic part of all behavior, rather than being categorically different from voluntary actions. A crucial issue is how such automatic mechanisms are controlled so that the most appropriate responses are made and unwanted responses inhibited. The authors discuss some of the brain areas involved, including the supplementary motor area and the parietal cortex. Last, they review evidence that some control may actually be achieved by automatically triggered inhibition as well as modulation of unconscious processes by attention and task goals. NEUROSCIENTIST 14(5):474—486, 2008. DOI: 10.1177/1073858408314435

Involuntary masturbation and hemiballismus after bilateral anterior cerebral artery infarction

Ischemia of the areas supplied by the anterior cerebral artery is relatively uncommon. In addition, combined hemiballismus and masturbation have rarely been reported in patients with cerebrovascular disease. We describe herein a 62-year-old right-handed man simultaneously exhibiting right side hemiballismus and involuntary masturbation with the left hand after bilateral infarction of the anterior cerebral artery territory. Right side hemiballismus was related to the disruption of afferent fibers from the left frontal lobe to the left subthalamic nucleus. Involuntary masturbation using the left hand was exclusively linked to a callosal type of alien hand syndrome secondary to infarction of the right side of the anterior corpus callosum. After 2 weeks, these abnormal behaviours were completely extinguished. This report stresses the wide diversity of clinical manifestations observed after infarction of the anterior cerebral artery territory.

“Alien face” in corticobasal degeneration syndrome: extending clinical features

Corticobasal degeneration syndrome (CBDS) is a neurodegenerative disorder characterized by higher cortical dysfunctions associated with progressive asymmetric akinetic-rigid syndrome, and limb dystonia or focal myoclonus (Lang et al ., 1994). One of the most typical and specific clinical features in CBDS is considered alien limb phenomenon, usually present in advanced disease stage (Doody and Jankovic, 1992).

Neurophysiologie de la dégénérescence corticobasale

Corticobasal degeneration (CBD) is a neurodegenerative disorder of mid- to late-adult life. From a clinical standpoint, CBD is characterized by (i) an insidious onset and a slowly progressing, unilateral, levodopa-unresponsive parkinsonian syndrome with dystonia or myoclonus and (ii) cerebral features such as apraxia, alien limb phenomena and cortical sensory loss. Decisive clinical diagnostic criteria are not available and thus a neuropathological study remains essential for accurate CBD diagnosis. Consequently, additional non-clinical criteria must be identified in order to improve diagnosis while patients are still alive. Electrophysiological exploration can yield functional information on a number of brain structures (both cortical and sub-cortical) involved in CBD. The disorder features a specific cortical (frontoparietal) alteration which could help with differential diagnoses for other extrapyramidal syndromes. Hence, exploration of a patient's myoclonus can provide some specific arguments for CBD. Indeed, myoclonus displays a number of clinical and electromyographical characteristics which are consistent with a cortical origin (a shorter latency of the cortical C response, for example). However, some typical cortical features are missing (giant somesthesic evoked potentials, and cortical potentials preceding myoclonus in jerk-locked back-averaging studies). Some authors explain these abnormalities in terms of a sub-cortical origin for the myoclonus. The frontoparietal alteration in CBD has also been explored in studies of oculomotor movement. Indeed, asymmetric lengthening of the lateral ocular saccade latency argues more in favour of CBD than progressive supranuclear palsy. Moreover, cognitive function is also compromised in the early stages of CBD, although it is sometimes difficult to distinguish between CBD, PSP and frontotemporal dementia. Studying cognitive potentials enables one to confirm subcorticofrontal abnormalities and to dissociate CBD patterns from PSP patterns. Other electrophysiological tests (such as the exploration of dysautonomia, the palmomental reflex and the blink reflex) produce results which overlap with those seen in extrapyramidal syndromes and synucleinopathies (polysomnography), prompting discussion of the physiopathological mechanisms of these various diseases. Electrophysiological exploration is of value for diagnosing CBD in general and for studying specific, frontoparietal dysfunctions in particular. These techniques could also significantly contribute to our understanding of the physiopathology of CBD.

The syndrome of progressive posterior cortical dysfunction: A multiple case study and review.

Dementia presenting with prominent higher order visual symptoms may be observed in a range of neurodegenerative conditions and is often challenging to diagnose.ObjectivesTo describe cases of progressive dementia presenting with prominent visual cortical symptoms.MethodsWe conducted a retrospective search of cases of progressive dementia with predominant visual symptoms, seen at our dementia unit from 1996 to 2006.ResultsTwelve patients (5 men, 7 women) were identified, with ages ranging from 49 to 67 years. At the first examination, the duration of the symptoms ranged from one to ten years and the Mini-Mental State Examination scores from 7 to 27. Eleven patients presented with predominant visuospatial symptoms (partial or complete Balint syndrome) and one with visuoperceptive impairment. Other reported manifestations were: constructional apraxia in 11 patients, partial or complete Gerstmann syndrome in ten, ideomotor apraxia in nine, hemineglect or extinction in four patients, alien hand phenomenon in three, and prosopagnosia in one patient. Memory loss was reported by ten patients, but was not the main complaint in any of these cases. Insight was relatively preserved in five patients even after a long period following the onset of symptoms. Six patients developed parkinsonism during evolution. Clinical diagnoses were possible or probable AD in seven patients, cortico-basal degeneration in four, and dementia with Lewy body in one.ConclusionsClinicians should consider this condition especially in presenile patients with slowly progressive higher-order visual symptoms. Although described in association with different conditions, it may also occur in Alzheimer disease.

Moving with or without will: functional neural correlates of alien hand syndrome

Alien hand syndrome is a rare neurological disorder in which movements are performed without conscious will. By using functional magnetic resonance imaging in a patient with alien hand syndrome after right parietal lesion, we could identify brain regions activated during involuntary or voluntary actions with the affected left hand. Alien hand movements involved a selective activation of contralateral primary motor cortex (M1), presumably released from conscious control by intentional planning systems. By contrast, voluntary movements activated a distributed network implicating not only the contralateral right M1 and premotor cortex but also the left inferior frontal gyrus, suggesting an important role of the dominant hemisphere in organizing willed actions.

What Reaching Teaches: Consciousness, Control, and the Inner Zombie

What is the role of conscious visual experience in the control and guidance of human behaviour? According to some recent treatments, the role is surprisingly indirect. Conscious visual experience, on these accounts, serves the formation of plans and the selection of action types and targets, while the control of ‘online’ visually guided action proceeds via a quasi-independent non-conscious route. In response to such claims, critics such as (Wallhagen [2007], pp. 539-61) have suggested that the notions of control and guidance invoked are unacceptably vague, and that that the image of ‘zombie systems’ guiding action fails to take account of the possibility that there is genuine but unconceptualized, unnoticed, and/or unreportable experience taking place and guiding or controlling the actions. I address both sets of concerns. I try to show that refining and clarifying the key notions of control and guidance leaves the original argument intact, as does the appeal to unconceptualized, unnoticed, or unreportable experiences. The exercise serves, however, to highlight an important complex of considerations concerning the relations between control, agency, and experience. Better understanding these relations is, I suggest, an important source of insights concerning the nature of phenomenal experience.

Alien limb following posterior cerebral artery stroke: Failure to recognize internally generated movements?

We describe two rare cases of alien limb syndrome following right posterior cerebral artery (PCA) stroke. Both patients present with left hemianopia, visual neglect and proprioceptive loss in addition to their alien limb symptoms. Lesion subtraction from seven control PCA patients revealed that medial parietal-occipital and thalamic areas were selectively damaged in the alien limb patients. We propose that loss of the sense of motor intention and internal model of the current state of the arm, combined with deficient proprioceptive and visual feedback of the moving limb, are critical for genesis of posterior alien limb and discuss how affected regions normally function to ensure awareness of self-generated motor activity.

Asymmetrical alien hands in corticobasal degeneration

There are several forms of alien limb, but alien limb in corticobasal degeneration (CBD) is not well understood. We studied a patient with CBD who demonstrated two different types of alien limb. With his right hand he demonstrated a tactile avoidance response with levitation. With his left hand, he demonstrated continuous tactile pursuit of the examiner's hand ("tactile mitgehen"). Mitgehen is often associated with frontal dysfunction, but avoidance response and levitation are often associated with parietal dysfunction.

Validity of using reaction time as a basis for determining motor laterality

To the Editor: In a recent letter to the editor, [Dr. Derakhshan (2006)][1] responded to a study conducted by [Gonzalez and colleagues (2006a)][2] that explored a potential hemispheric specialization for the visual control of action independent of subject handedness. In his letter, Dr. Derakshan

Whether feeling or seeing is more accurate depends on tracking direction within the perception-action cycle

Coordination in biological systems requires a continuous updating of the perception-action cycle. How the different sources of sensory information contribute uniquely to performance is still debated. Here, we directly compared the role of vision and kinesthesis by means of a tracking task in which the left wrist mimicked the passive motions imposed on the right wrist with a torque motor. The passive movements were perceived visually (alien hand) or kinesthetically (own hand), or a combination thereof (own hand, feel and see). Tracking occurred according to the same (isodirectional) or opposite (mirror-image) directions. Findings revealed that visual tracking was performed most successfully in the isodirectional and kinesthetic tracking in the mirror-image mode. Tracking was most successful when both sources of sensory information were present. These results suggest that vision and proprioception obey direction-dependent constraints that are consistent with extrinsic and intrinsic reference frames within which the perception-action cycle resides. Thus, each sensory modality contributes uniquely as a function of the spatial requirements of the tracking task, rather than one being superior over the other.

Mixed alien hand syndrome coexisting with left‐sided extinction secondary to a left corpus callosal lesion: A case report

Alien hand syndrome (AHS) is actually two distinct syndromes with distinct clinical and anatomic features, that is, a frontal type and a callosal type. Frontal AHS occurs in the dominant hand; is associated with reflexive grasping, groping, and compulsive manipulation of tools. Callosal AHS is characterized primarily by intermanual conflict. We report a case of right frontal AHS and left callosal AHS (mixed AHS) secondary to ischemic stroke of the left corpus callosum (lesion extending from the genu to splenium) and right corpus callosum (minimal lesion in the splenium) in a 67-year-old male patient who also presented with left-sided tactile extinction. To our knowledge, rare reports have documented mixed AHS coexisting with nondominant side extinction secondary only to unilateral (left) callosal lesion, as in our case.