Neuro-oddities: Four rare diseases affecting the brain
Written by Evrydiki Asimaki
Neuro-oddities: Four rare diseases affecting the brain
It is undeniable that a human brain can do miracles. Comprising about 100 billion neurons and one quadrillion synapses, it is considered to be the most powerful computer known. Apart from being the most powerful computer, it is also more complex than any other known structure. Dysregulation of such a complicated and powerful organ can therefore lead to consequences that we cannot easily grasp and comprehend. These include the development of a variety of rare brain diseases that have raised questions in the scientific field concerning their origin, their causes and even their treatment. Let’s learn more about four of these rare brain syndromes, their possible aetiology and treatment.
Alice in Wonderland Syndrome (AIWS)
This syndrome was first conceptualised in 1955 by a psychiatrist named Dr. John Todd. Lewis Carroll based inspiration of the syndrome’s name on the famous novel: “Alice in Wonderland”. The story revolves around a teenage girl who experiences some unexplained events like change in her body size, as she could expand or shrink at demand. This syndrome shares few common characteristics with Alice’s experiences such as distorted perception of the body image (micropsia/macrosomatognosia), derealization and depersonalization. Patients were also reported to experience visual distortions, “seeing” objects with the wrong size or shape. Among other symptoms, patients also displayed ataxia (loss of control of bodily movements), myoclonic jerks and rapidly progressive dementia.
Only 180 cases of patients displaying the Alice in Wonderland Syndrome were reported since it was first described in 1955. This is one of the reasons why its aetiology is not thoroughly investigated yet. Speculations amongst the scientific society state that AIWS can be a manifestation of brain infarction, brain tumour(s), temporal lobe epilepsy or even typical migraine. Until today, there is no evidence of a proven effective treatment.
Phantom limb syndrome
This syndrome is characterised by sensations coming from a body part that has been amputated. Initially, doctors used to believe that these sensations had mostly psychological aetiology. However, in later times it was discovered that they originated in the spinal cord and brain. In certain cases, these sensations can evolve into mild or even severe pain, which cannot be treated.
The number of people suffering from this syndrome after an amputation is quite astonishing, with 79.9% reporting “phantom” sensation or pain. The aetiology of the syndrome remains unclear. Many theories over the time were proposed, however none of them have been confirmed. The predominant one suggests that these sensations derive from the severed nerve endings at the amputated limb. There is also evidence that the central nervous system is involved, where remaining activity of the brain is detected in the areas associated with the amputated limb.
Face recognition in most cases is as easy as breathing; we do not make any effort to remember or memorise the faces of people we meet, we just do. Differences in facial expressions, style and clothing would also not pose a problem. Facial recognition has always played a fundamental role in forming relationships or friendships, as part of our social interactions.
Patients suffering from a disease called “Prosopagnosia” have difficulties recognizing people’s faces, both faces well known to them and those that they recently encountered. Prosopagnosia is described as a selective visual agnosia caused by abnormalities, damage, or impairment in the right fusiform gyrus, which is responsible for the coordination of the neural system controlling facial perception and memory. Dr. Oliver Wolf Sacks, a British neurologist, has described a case history of a patient suffering from prosopagnosia in his book called: “The Man Who Mistook His Wife for a Hat and Other Clinical Tales”. He himself admitted that he suffered from the same pathology, failing to recognize faces of familiar people. Surprisingly, he discovered about his condition only when he reached middle age. Interestingly, prosopagnosia may affect up to 2 percent of the population, a fact that suggests that millions of people may be suffering from a moderate to a most severe version of the disease. Although there is not currently any treatment of this condition, patients have developed many compensatory strategies for identifying people’s faces using training programs developed to help improve facial recognition.
Alien hand syndrome (AHS)
It was not earlier than 1908 when a female patient, after recovering from a stroke, started experiencing something peculiar. She noticed that her left hand suddenly had its own will. It started from spontaneous movements like face or eyes wiping to involuntary actions like grasping objects and not being able to release them. She later described the incident, stating that it felt like someone else was moving her hand, without her own will. This case was described in detail by the German neuro-psychiatrist Kurt Goldstein.
Dr. Goldstein proposed a theory “doctrine of motor apraxia”, in which he discussed how voluntary actions are generated and proposed that there are different brain sites controlling spatial contextual awareness, will and other cognitive processes. In this theory, he proposed that object perception and voluntary actions on external objects require a structure organising both the body and external space.
Today, the most common reported causes of the syndrome are stroke, neurodegeneration, prion disease, tumours, demyelination, seizures and iatrogenic causes. Despite the lack of a real “cure” for AHS, there are therapies and pharmacological approaches to manage and reduce the symptoms. These include muscle control therapies like botulinum toxin (Botox), neuromuscular blocking agents, mirror box therapy and cognitive and behavioural therapies.
Psychoactive drugs like benzodiazepines have also been proven effective in some cases.
Rare or not, these clinical cases are peculiar enough to make the scientific community still wonder about the origin and treatment of these syndromes. Nevertheless, we are reminded of how complex and powerful the human brain is, and how many paths towards further scientific discoveries remain unexplored.
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Written by Evrydiki Asimaki; Edited by Debbie Shi. Featured Image: NGC/Design.