Navigation Links
Alien Hand Syndrome Causes Random Hand Movement

Alien hand syndrome (AHS) is a rare neurological disorder that causes hand movement without the person being aware of what is happening or having control over the action .

The afflicted person may sometimes reach for objects and manipulate them without wanting to do so, even to the point of having to use the healthy hand to restrain the alien hand.

A new study identified the areas of the brain involved in both voluntary and involuntary movement and found that neural activity was restricted to the primary motor cortex during the unconscious motor activity seen with AHS.

Led by Frederic Assal of University Hospital in Geneva, Switzerland, researchers conducted a study of a 70-year-old right-handed man who had AHS after suffering a large stroke in the right parietal lobe.

His left hand had normal motor function, with only slight weakness and clumsiness, but showed marked sensory loss. His alien movements consisted of involuntary gestures or grasping with his left hand, which he sometimes did not notice due to mild left visual neglect (a condition in which the patient is unaware of events in the left visual field even though the visual pathways are intact) as a result of the stroke.

The researchers performed two functional MRI experiments in which the patient performed simple motor tasks that allowed them to compare similar left-hand movements executed both consciously and unconsciously.

By contrasting periods with AHM with those in which the patient was not moving, the researchers found that the primary motor cortex was selectively activated, with more activity as AHM increased. Voluntary movements also activated the primary motor cortex, but other regions of the brain were activated as well.

Voluntary movements with either hand showed significant activation in the contralateral primary motor cortex and the bilateral premotor areas. In addition, right-hemisphere primary motor cortex activity was identical during voluntary and alien left hand movements.

Supplemental motor area regions on both sides were activated by left more than right movements, which suggests a greater degree of motor preparation and control when moving the affected hand, according to the authors.

To our knowledge, these fMRI results reveal for the first time the neural correlates of AHM, the authors state, and a major new finding is that AHM was associated with highly selective and isolated activation of the contralateral primary motor cortex.

The fact that motor cortex activity was identical during AHM and voluntary movements indicates that conscious and unconscious motor activity involves the same underlying brain structures and that activity in the primary motor cortex does not correlate with voluntary movement.

In addition, the study shows that while M1 [primary motor cortex] may code for limb movement planned by parietal systems, only activity in the latter (but not the former) may mediate conscious experience of motor intentions.

The authors conclude, These data open new perspectives for the comprehension of neurological and neuropsychiatric disorders associated with abnormal motor control or abnormal awareness of action, such as utilization behavior, phantom limb, anosognosia [in which a person suffers a disability due to a brain injury but is unaware of it], or delusions of control in schizophrenia.


Related medicine news :

1. Early Clue to Down Syndrome
2. Hope For Stiff-Person Syndrome
3. Restless Legs Syndrome - Help at hand
4. Severe Acute respiratory Syndrome (SARS)
5. WHO Travel Advice to prevent spread of "Severe Acute Respiratory Syndrome (SARS)
6. Treatment for Syndrome X
7. “ Economy Class Syndrome
8. Dementia and Down Syndrome
9. Understanding Restless Legs Syndrome
10. A New Option for Patients Suffering From QT Syndrome
11. Individuals With Metabolic Syndrome At Risk of Dying From Heart Disease
Post Your Comments:

(Date:6/25/2016)... Viejo, California (PRWEB) , ... June 25, 2016 , ... ... to fit their specific project," said Christina Austin - CEO of Pixel Film Studios. ... fully customizable and all within Final Cut Pro X . Simply select a ...
(Date:6/25/2016)... ... June 25, 2016 , ... ... recover from injury. Recently, he has implemented orthobiologic procedures as a method for ... is one of the first doctors to perform the treatment. Orthobiologics are substances ...
(Date:6/24/2016)... CA (PRWEB) , ... June 24, 2016 , ... A ... procedures that most people are unfamiliar with. The article goes on to state that ... but also many of these less common operations such as calf and cheek reduction. ...
(Date:6/24/2016)... ... June 24, 2016 , ... Marcy was in a crisis. Her son James, eight, was out ... family verbally and physically. , “When something upset him, he couldn’t control his emotions,” remembers ... would throw rocks at my other children and say he was going to kill them. ...
(Date:6/24/2016)... ... June 24, 2016 , ... Dr. Amanda Cheng, an ... Cheng has extensive experience with all areas of orthodontics, including robotic Suresmile technology, ... , Micro-osteoperforation is a revolutionary adjunct to orthodontic treatment. It can be ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... June 23, 2016 Research and Markets ... Issue 52" report to their offering. ... treatment creates a favourable commercial environment for MedImmune to enter. ... base that will serve to drive considerable growth for effective ... serve to cap sales considerably, but development is still in ...
(Date:6/23/2016)... 2016 , , , WHEN: ... 2016 , , , , LOCATION: , , , Online, ... , , EXPERT PANELISTS:  , , , Frost & Sullivan,s Global ... Bird; Senior Industry Analyst, Divyaa Ravishankar and Unmesh Lal, Program Manager ... pharmaceutical industry is witnessing an exceptional era. Several new demand spaces, ...
(Date:6/23/2016)... the establishment of Astellas Farma Colombia (AFC), a new affiliate with operations headquartered in Bogota. Colombia ... ... Sandra ... ... Astellas is a pharmaceutical company ...
Breaking Medicine Technology: