By Johanna Popp
The human brain is highly intricate and there are a lot of mysteries that still need to be uncovered when it comes to its structure and function in healthy organisms. Ranging from basic functions like controlling our breathing rate to performing complex tasks such as producing speech or planning movements, this organ has a large variety of responsibilities. Sometimes, it might even seem surprising that all of these functions simultaneously run smoothly – more or less – without us even noticing. However, although this is fortunately the case for most of us, there are more than 600 known characterized neurological conditions in which the regular operation of the nervous system is impaired, and things are not proceeding as effortlessly (Lima et al., 2022). You might be familiar with more common disorders such as Alzheimer’s Disease or Parkinson’s Disease. But have you heard about Foreign Accent Syndrome, where an individual suddenly and unintentionally starts speaking in a different accent? Or did you know about Alien Hand Syndrome, a disorder characterized by uncontrollable movements of one’s hand? Here is a collection of five surprisingly bizarre disorders of the nervous system – and what they can teach us about healthy brain function.
Number one is called Cotard’s – or Walking Corpse – Syndrome. As the name might already imply, affected individuals hold false beliefs about their own existence, firmly convinced that they do not exist, that they are dead or that they have missing body parts. Sahoo & Josephs (2018) recently published a clinical report characterizing 12 affected patients: According to them, one patient “believed he died on the operating table during surgery. His proof was that the television screen light keeps fading and that this was the afterlife and he was being tested”. Yet another individual reported that they had been stabbed and killed in a nursing home and referred to their bed as a “casket”. Cotard’s Syndrome falls under the broader category of Delusional Misidentification Syndromes. These conditions might stem from disruptions in brain regions that are involved in how a person perceives themselves in their environment. This may result in difficulties connecting external stimuli with one’s own personal memories (Darby & Prasad, 2016; Sahoo & Josephs, 2018). For instance, an affected individual may look into the mirror, but the disconnections in their brain’s circuits make it hard for them to connect what they see with memories of their own appearance from the past. The absence of the anticipated familiarity with their own reflection might cause them to question their existence. Most often, damage to the frontal lobe can lead to such abnormal perceptions (Sahoo & Josephs, 2018). In general, treatments seem to be quite effective: In the mentioned clinical report, the symptoms from 11 out of 12 participants were improved or completely resolved by treatments such as psychotherapy, behavioral therapy, or medication.
For instance, an affected individual may look into the mirror, but the disconnections in their brain’s circuits make it hard for them to connect what they see with memories of their own appearance from the past
Imagine you’re fully conscious and mentally sharp, but all of your voluntary muscles, except for those responsible for vertical eye movements, are completely paralyzed. This is the reality for people suffering from Locked-in Syndrome, a condition resulting from damage to the pons, a specific part of the brainstem, most commonly caused by stroke (M Das et al., 2023). One case that drew a lot of attention involved Julia Tavalaro, a 27-year-old housewife and mother, who experienced multiple strokes which left her completely paralyzed. Since doctors thought she was brain dead, she lived in a custodial institution for several years without anyone noticing that she was still conscious and aware of her surroundings. It took almost 6 years until a speech therapist discovered that she was able to answer questions through eye movements. Following that, she was taught to communicate by moving her eyes and operating a computer which even enabled her to write poetry and publish an autobiography. Unfortunately, there is no cure or specific treatment for Locked-in Syndrome, but patients may benefit from supportive therapy including physical therapy and communication training. Full recovery is highly unlikely, but individuals might regain some motor abilities and sensation in certain areas of their body (M Das et al., 2023). For example, Julia Tavalaro recovered some ability to move her head which allowed her to touch a switch controlling a wheelchair and the previously mentioned computer.
Foreign Accent Syndrome
This third condition, known as Foreign Accent Syndrome, might seem funny and entertaining at first. This syndrome involves a sudden and very noticeable change in the way a person speaks and how they pronounce certain sounds. This can include the timing, intonation, or tongue placement during speech. For the untrained ear, it might appear as though the individual has started talking in a foreign accent, but experts can usually detect that the accent it resembles is ultimately not perfectly matched. Foreign Accent Syndrome is quite rare, and there are only about 100 confirmed cases (Keulen et al., 2016; McWhirter et al., 2019). One example case is Michelle Myers, an Arizona native who had never left the United States. On three occasions, she had gone to sleep with throbbing headaches and woke up speaking in different accents: Irish, Australian, and British. While the former two experiences didn’t last longer than a week, the latter has remained for the past two years! To date, Myers hasn’t been able to get rid of what sounds like a British accent. It might seem entertaining to wake up with a different accent until you realize what the neural origins of this condition are. In most cases, some kind of structural brain damage is the source, such as stroke, traumatic brain injury or cancer, which causes abnormal functioning of the brain areas used for speaking. Sometimes, Foreign Accent Syndrome is also associated with disruptions in normal brain activity, happening or worsening during migraines or mental health conditions such as psychosis or depression. In few cases, speech therapy with the goal of correcting or compensating the specific alterations in speech that are responsible for the accent change might reduce symptoms. Otherwise, the accent might resolve spontaneously or with an associated psychiatric disorder (Keulen et al., 2016).
It might seem entertaining to wake up with a different accent until you realize what the neural origins of this condition are…
Next up is Capgras Syndrome which, similarly to Cotard’s Syndrome, is also categorized as a Delusional Misidentification Syndrome (Shah et al., 2023). Here, the affected individual believes that a person close to them, such as a family member or friend, has been replaced by an identical-looking imposter (Josephs, 2007). In one such case, Mary, a middle-aged woman, refused to take care of her 9-year-old daughter Sarah, because she was convinced that her ‘real daughter’ was taken into custody by Child Protective Services and had been replaced by an imposter. In one instance, she even showed up at Sarah’s school refusing to pick her up, screaming: “Give me my real daughter, I know what you’ve done”. As medication and interventions were not helping Mary’s delusion, Social Services eventually sought guardianship of her daughter, Sarah. This condition was first identified in 1923 by the French psychiatrist Joseph Capgras, who reported the case of a woman who was convinced that her husband was replaced by a double. The underlying causes are complex, but oftentimes Capgras Syndrome is accompanied by structural brain damage or organic degeneration in bifrontal, right limbic, and temporal regions, which are involved in memory function, self-monitoring and reality perception. This is thought to cause deficits in recognizing faces and integrating emotional information (Shah et al., 2023): Normally, one would expect an emotional reaction when seeing the face of a familiar person. However, people with Capgras Syndrome recognize their loved ones’ faces without experiencing the expected warm emotions. This causes distress, and they start believing that the actual reason for them not to feel the proper emotions when seeing this person is that they must have been replaced by an imposter. Affected individuals might benefit from psychotherapy, antipsychotic medications or therapy involving family members and support groups with persons facing similar challenges (Shah et al., 2023).
Speaking in a foreign accent, firmly believing that someone has been replaced by an imposter or experiencing uncontrollable movements of one’s body parts – all of these conditions are fascinating in their own way
Alien Hand Syndrome
Last but not least, let’s consider Alien Hand Syndrome, a condition in which one of the patient’s hands operates autonomously, performing uncontrollable movements, regardless of the individual’s intention or control. Karen, a 55-year-old woman suffering from this condition shared her experience: “I’d light a cigarette, balance it on an ashtray, and then my left hand would reach forward and stub it out. It would take things out of my handbag, and I wouldn’t realize so I would walk away. I lost a lot of things before I realized what was going on”. In Karen’s case, the strange behavior of her left hand had started after a brain surgery, where her corpus callosum – the structure linking both brain hemispheres – was cut to cure her epilepsy symptoms. In most cases, Alien Hand Syndrome has neurodegenerative causes, but can also be triggered by stroke and – as in Karen’s case – neurosurgical interventions (Hassan & Josephs, 2016). A number of treatment options are available including medications and physical or cognitive therapies including, for example, mirror box therapy. Here, the patient positions their normally functioning hand in front of a mirror while hiding the ‘alien hand’. The reflected motion in the mirror is interpreted as if it was their alien hand and sensorimotor features of the intact hand can be associated with it, significantly improving motor function. Karen’s case also had a happy ending: after 18-years of experiencing Alien Hand Syndrome, her symptoms were finally mitigated by medications.
Speaking in a foreign accent, firmly believing that someone has been replaced by an imposter or experiencing uncontrollable movements of one’s body parts – all of these conditions are fascinating in their own way. However, even if some symptoms may appear amusing on the surface, having learned more about their severity and understanding the underlying neurological causes emphasizes not only the profound impact these conditions can have on a patient’s daily life, but also highlights how often we underestimate the importance of a healthy-functioning brain. Ultimately, it is imperative to approach these conditions with empathy and respect for the individuals involved.
Written by Johanna Popp
Illustrated by Katie Cooke
Edited by Zoë Dobler, Dhruv Mehrotra and Lauren Wagner
Short video clips describing each disorder in more detail:
Foreign Accent Syndrome:
Alien Hand Syndrome:
Darby, R., & Prasad, S. (2016). Lesion-Related Delusional Misidentification Syndromes: A Comprehensive Review of Reported Cases. The Journal of Neuropsychiatry and Clinical Neurosciences, 28(3), 217–222. https://doi.org/10.1176/appi.neuropsych.15100376
Hassan, A., & Josephs, K. A. (2016). Alien Hand Syndrome. Current Neurology and Neuroscience Reports, 16(8), 73. https://doi.org/10.1007/s11910-016-0676-z
Josephs, K. A. (2007). Capgras Syndrome and Its Relationship to Neurodegenerative Disease. Archives of Neurology, 64(12), 1762–1766. https://doi.org/10.1001/archneur.64.12.1762
Keulen, S., Verhoeven, J., De Witte, E., De Page, L., Bastiaanse, R., & Mariën, P. (2016). Foreign Accent Syndrome As a Psychogenic Disorder: A Review. Frontiers in Human Neuroscience, 10, 168. https://doi.org/10.3389/fnhum.2016.00168
Lima, A. A., Mridha, M. F., Das, S. C., Kabir, M. M., Islam, Md. R., & Watanobe, Y. (2022). A Comprehensive Survey on the Detection, Classification, and Challenges of Neurological Disorders. Biology, 11(3), 469. https://doi.org/10.3390/biology11030469
M Das, J., Anosike, K., & Asuncion, R. M. D. (2023). Locked-in Syndrome. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK559026/
McWhirter, L., Miller, N., Campbell, C., Hoeritzauer, I., Lawton, A., Carson, A., & Stone, J. (2019). Understanding foreign accent syndrome. Journal of Neurology, Neurosurgery & Psychiatry, 90(11), 1265–1269. https://doi.org/10.1136/jnnp-2018-319842
Sahoo, A., & Josephs, K. A. (2018). A Neuropsychiatric Analysis of the Cotard Delusion. The Journal of Neuropsychiatry and Clinical Neurosciences, 30(1), 58–65. https://doi.org/10.1176/appi.neuropsych.17010018
Shah, K., Jain, S. B., & Wadhwa, R. (2023). Capgras Syndrome. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK570557/