Ever since the dawn of time man has been fascinated by dreams and their meaning. In ancient times they were associated with supernatural connotations and often believed to be portals to the spirit realm. Religious texts too are replete with instances of vexed protagonists seeking interpretations of dreams they are plagued with, à la Mahasupina Jathaka of the Tripitaka or Joseph & the Pharaoh of the Bible. In modern times the varying theories offered by researches span scientific disciplines ranging from psychiatry and psychology to neurobiology, but a unified one remains a Gordian knot which is yet to be unravelled. And thus dreams have become inextricably part and parcel of an average human beings life cycle. But what of the ones who are incapable of dreaming? Strange as it may sound there exists a condition which renders an individual so. This is known as Charcot- Wilbrand Syndrome.
During REM (Rapid Eye Movement) sleep, the brain mimics activity similar to that of the waking state. Although the eyes remain closed during this stage, they move rapidly in all directions
Charcot-Wilbrand Syndrome, also known as ‘Defective Revisualization’ or ‘Irreminescence’ is a disorder which is characterized by a combination of visual agnosia or the inability to perceive visual images and re-visualize them and the overall global cessation of dreaming. In 1883 Jean-Martin Charcot, a French physician-who is famously known as the ‘Father of modern Neurology’- was studying a patient claiming to have lost the ability to consciously recall imagery or possessing a dysfunctional ‘minds’ eye,’ which may have been due to a formation of a blood clot or ‘thrombus’ within the posterior cerebral artery. In 1887 Herman Wilbrand a German ophthalmologist encountered an elderly female subject with bilateral posterior cerebral artery thrombosis. This subject displayed a complete inability to dream coupled with an incapability to recognize familiar places, a condition known more recently as ‘topographic agnosia’. In addition a condition known currently as prosopagnosia, or the inability to recognize familiar faces was also noted in said patient. These two scientists were the first to record their findings with regard to this condition.
The causes of this affliction is multifactorial; ranging from acute onset focal brain damage due to hemorrhage, thrombosis, trauma or due to long standing chronic processes affecting the function of the brain such as a tumour growth or diseases such as Alzheimers’ Syndrome. In individuals experiencing a lack of visual imagery during sleep, lesions of the posterior regions- particularly of the occipital lobe (responsible for visual processing) & temporal region (associated with perception and recognition of auditory stimuli, memory, speech)- of the brain have been conjectured. When one considers the aspect of ‘global dream cessation’ pertaining to this syndrome the parietal lobe of the brain (connected with perception of stimuli, movement, orientation and language) is suspected.
However in certain instances, lesions involving the area between the occipital and temporal lobes also have displayed dream cessation. This leaves the exact location of the brain responsible for dreams somewhat in doubt. Various modalities of detecting this affliction exist through advancements in science in the modern age. One such modality is a Polysomnography Test (PSG) which assesses & records the biological changes during sleep through concurrent monitoring of the electrical activity of the brain via an Electroencephalogram (EEG), eye movement during sleep via Electrooculography (EOG), heart rhythm (ECG), and muscle activity through Electromyography (EMG).
The breathing pattern becomes increasingly erratic and an increase in heart rate is also seen. The EEG reading resembles that of an EEG in wake time
To better understand how a PSG test works a general idea of the sleep cycle is required. Typically the sleep cycle of a human being consists of five stages. The first four stages fall under non-REM sleep while the fifth and final stage (the deepest phase) is known as REM sleep. During REM (Rapid Eye Movement) sleep, the brain mimics activity similar to that of the waking state. Although the eyes remain closed during this stage, they move rapidly in all directions. It is during REM sleep that the most vivid dreams occur.
The breathing pattern becomes increasingly erratic and an increase in heart rate is also seen. The EEG reading resembles that of an EEG in wake time. Skeletal muscle paralysis or atonia accompanies REM sleep and it is theorized that this is an evolutionary precaution hard-wired to protect an individual from injury during sleep. The PSG test compiles a summary in the form of a ‘score’ utilizing data collected from all these various sources. This test also aids researches in identifying the REM sleep stage and are able to wake the patient mid-REM sleep to ask for dream experience; which in normal patients would enhance their recollection and dream count. The lack thereof can be suggestive of Charcot Wilbrand Syndrome. Functional Magnetic Resonance Imaging (fMRI) is another way which can be used for detection. This assesses brain activity due to alterations in blood flow and oxygenation in response to neural activity. When a particular brain area is more active it consumes more oxygen which results in an increase in blood circulation to that area and the fMRI can utilize this data to create an ‘activation map’ of the brain. The maintenance of Dream Journals is a simpler and more straightforward method which may be used to detect this condition.
Akin to the ancient shamans of yore who purportedly explored the realm of dreams, modern day scientists continue to seek answers to the phenomenon known as ‘dreams’ utilizing cutting edge technology and research methodologies. Perhaps in time, we will find the answers to these questions; questions whose answers have eluded us since the dawn of time.
(The author specialises in MO-Dialysis and serves at the Base Hospital in Tellippala)