Alien Hand Syndrome (AHS) is a rare neurological disorder characterised by complete loss of control of one limb, usually the left hand, wherein the arm begins to move by itself at random, being "alien" to the affected person and seemingly having a mind of its own. This condition is also medically designated as alien limb syndrome (ALS) and anarchic hand. Commonly, this ailment is termed as Dr. Strangelove Syndrome or Strangelovian Hand, from the popular English feature film, Dr. Strangelove, directed by legendary filmmaker Stanley Kubrick in 1964, in which the protagonist suffers from Alien Hand Syndrome.

This nervous system illness mostly occurs in adults, in both men and women, with only seldom cases being reported in children. Although the defining trait of alien hand syndrome wherein the left arm moves abruptly may resemble those in epilepsy such as jerking limb motions, in AHS, the motions are rather coordinated, such as picking up an object from a shelf, moving things placed on a table, among others. It is thus necessary to understand the causes, symptoms of alien hand syndrome, to ensure the precise diagnosis of the condition and seek prompt medical treatment, to address the discomforting symptoms in the patient.

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Causes Of Alien Hand Syndrome

The chief causes of alien hand syndrome are trauma to the head, skull and brain, besides stroke, brain tumours, neurodegenerative disorders like Alzheimer’s, dementia. Surgeries of the corpus callosum, a portion of the brain that partitions the right and left hemispheres in the brain also trigger AHS.

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The underlying reason is damage to the primary motor cortex portions of the brain, which are responsible for controlling and coordinating muscle movement of the limbs in the hands and legs. When this control centre for muscle activity becomes faulty, a parallel set of nerves with a separate signalling mechanism seem to take over the actions of the left arm, influencing how it behaves in every situation.

Symptoms

The distinguishing feature of alien hand syndrome is the left arm acting on its own free will, independently of the other limbs and muscles in the body. The movements are involuntary but in a synchronized manner, unlike fits or tremors, appearing to be controlled by a whole other individual or as though it has a mind of its own. The motions of the left hand occur without any central cognitive monitor and are the result of a complete lack of awareness.

Activities of the left hand include opposing motions to the right arm, such as shutting a door or window that was just opened, removing a tie that was just worn neatly, etc. The left hand may also suddenly float about, being very obstinate and suffering from extreme incoordination. The left limb may also reach out and pick up an object from the floor repeatedly for no logical reason, like in obsessive compulsive disorder.

Diagnosis

Alien hand syndrome is fundamentally a neurological ailment but does not possess a distinct psychological component, for the other limbs of the affected person function normally and their brain, memory, cognition, mental and emotional operations are also healthy. Since AHS is not a behavioural syndrome or a psychiatric condition, it is sometimes challenging to diagnose it accurately.

The doctor keenly observes the actions of the patient, then assesses the frequency and intensity of random and sometimes embarrassing actions carried out by the affected individual. These comprise minor activities like abrupt levitation of the left arm or more serious motions, such as stealing another person’s wallet with their left hand, although unintentionally and being out of control of the cognitive centre of the brain.

Treatment

Presently, there exists no cure for alien hand syndrome. However, the condition can be controlled by means of medications and behavioural therapy. Prescription drugs to control nervous system muscles and block them from enabling random motions of the limbs are given by the physician.

Behavioural therapy for alien hand syndrome involves activities to prevent moving the left hand, such as holding onto an object in the arm at all times or keeping the arm close to the body for an extended period to avoid any spontaneous actions. These treatment procedures, when advised by a team of professional counsellors, therapists, psychologists, help in keeping the movement of the left hand in control and alleviating the symptoms of alien hand syndrome in the patient.