Ghosts and Colorblindness

In 2002, an invisible ghost took control of a 74-year-old woman’s hand. As she was examined in a Chinese hospital, the mischievous spirit would manipulate her entire left arm, causing it to levitate and thrash about without the woman’s consent. Disturbed and fearful, she explained to the doctors that a sudden feeling of weakness numbed her left side when the ghost first took possession of her hand, leaving her unable to perform tasks that required two cooperative hands, such as lighting matches or tying shoes. Also, the ghost changed her perception of colors. When placed in front of a plain grey wall, the woman’s eyes registered six colors that weren’t there. After taking a series of magnetic resonance images (MRIs), however, perplexed doctors in the Chinese hospital discovered that brain legions, not ghosts, were to blame for her rogue appendage. Soon afterward, the elderly woman was diagnosed with alien hand syndrome (AHS), a condition in which the patient’s limb has an uncontrollable will of its own.

Since alien hand syndrome was first identified in 1972 by Brion and Jedynak, huge strides have been made in classifying various modes of the rare motor-skill syndrome, and now psychiatrists divide the cases into four categories: intermanual conflict syndrome, alien hand sign, anarchic or way-ward hand syndrome, and supernumerary hands. In a case of intermanual conflict syndrome, a patient’s affected hand interferes with the actions of the normal hand, causing severe difficulties in performing daily routines. For example, a person may not be able to put on a shirt because the affected hand attempts to take off the shirt at the same time that the normal hand is attempting to put it on. Opening doors, eating, drinking, smoking, writing, and teeth-brushing are only a handful of activities in which intermanual conflict syndrome persuades its victims to engage in a bodily civil war. The next category of AHS is called alien hand sign, and it is characterized by the sensation that the left hand (in right-handed subjects) does not belong to the patient. For example, one 50-year-old woman said this about her left arm: “I felt it belonged to someone else and wanted to hurt me because it moved towards me; I saw it quite big and distorted like a monster; I was terrified.”

While alien hand sign and intermanual conflict syndrome are both strange conditions, anarchic hand syndrome and supernumerary hands are equally bizarre categories of AHS. Anarchic hand, sometimes called the way-ward hand, is diagnosed when the patient’s arm completes seemingly purposeful and sometimes violent actions at random intervals. In Stanley Kubrick’s Dr. Strangelove, the post-Nazi scientist character, played by the late Peter Sellars, has an anarchic hand that attempts to strangle him and frequently explodes into proud Nazi salutes. In real-life, however, most actions of the anarchic hand are not subconscious slips of desire; rather, they are glitches in the brain that cause daily routines, such as unzipping a fly or waving goodbye, to occur at random times and locations. One sufferer of alien hand sign “would attempt to restrain the unwanted movements of the left hand by keeping her hands folded together or by gripping an object in the left hand.” The last and most strange category of AHS is called supernumerary hands, and it is characterized by the subjective sensation of having three or more hands. The extra hands are peculiar objects, since they don’t actually exist, but still itch, burn, and feel much like ordinary hands. Unlike anarchic hands, supernumerary hands usually don’t perform random uncontrollable acts.

A myriad of factors, virtually all of which involve lesions, determine which form of AHS a patient will experience; and they range from minor brain illnesses, such as migraines, to severe brain diseases, such as Creutzfeldt-Jakob’s. Certain diseases—chronic beryllium disease, acute cerebral vascular diseases, herpes viral encephalitis, Alzheimer’s, progressive supranuclear palsy, and epilepsies, among others—result in brain lesions, which are tissue abnormalities that cause AHS. The location of the legions on the brain’s lobes is what usually determines what variety of AHS the patient will experience. For example, legions in the frontal lobe (which controls motor skills) could cause anarchic hand or supernumerary hands, and legions in the posterior corpus callosum (which connects right and left hemispheres of the brain) could cause intermanual conflict or alien hand sign. Because the diseases that lead to AHS are clinically incurable, with the exception of migraines, AHS is incurable as well. However, some cases of alien hand sign have showed improvement with vestibular stimulation, which is a treatment that involves the patient spinning around in circles until inner-ear fluid has been distributed equally throughout the brain’s system of balance. Unfortunately, there are no known treatments for the other categories of AHS, except for invasive surgeries that attempt to cut off the troublesome legions from the brain itself. Needless to say most patients reject this option.

Even with all the knowledge scientists had collected on alien hand syndrome, the case of the 74-year-old woman in China remained puzzling because of her mysterious inability to properly discriminate between certain colors. Upon further examination of her MRIs, three neuroscientists—X. P. Wang, C. B. Fan, and J. N. Zhou—discovered only a small cluster of legions on her occipital lobe. The neuroscientists proposed that her color misperceptions were caused by the occipital legions, which is logical since the occipital lobe is the visual processing center of the brain. However, this theory has one problem: anarchic hand syndrome is caused by legions in the frontal corpus callosum, not the occipital lobe. Baffled, Wang and associates realized that they had stumbled upon a never-before-seen form of alien hand syndrome. In 2004, their findings were published in Neurology India in article titled, “Alien hand syndrome: Contradictive movement and disorder of color discrimination.” Since the publication of Wang’s article, no other cases of the rare colorblind strain of alien hand syndrome have been reported. However, as scientists make new breakthroughs in the field of neuroscience, fresh reports of cases similar to Wang’s will inevitably chase away all the ghosts of doubt that haunt his skeptics.

NOTE: See comments for bibliography.