Klüver–Bucy syndrome is an extremely rare syndrome, characterised by lesions affecting bilateral temporal lobes, especially the hippocampus and amygdala. Since these regions of the brain help in forming new memories, guiding behaviour related to food and sexual intercourse, and processing emotions, it causes neurological and behavioural issues such as memory loss, overeating, hypersexuality and lethargy.
Causes and Symptoms
Klüver–Bucy syndrome (KBS) presents with multiple symptoms, most of which are associated with memory and social behaviour. It is most commonly characterised by:
Hyperphagia- having a compulsive need to overeat.
Hyperorality- insertion of inappropriate objects in the mouth.
Hypersexuality- unusually extreme libido.
Visual agnosia- inability to recognize familiar objects or people.
Hypermetamorphosis- an irresistible impulse to notice and react to everything within sight.
An examination report of a patient diagnosed with visual agnosia.
Some symptoms are caused by particular locations of the lesions. These are:
Lesions in Amygdala- Amygdala has a primary role in the processing of memory, decision-making, and emotional responses. Hence, these lesions in these regions result in Docility and Lack of emotional response.
Lesions in Hippocampus- The Hippocampus plays an important role in memory consolidation; hence lesions in these regions result in Amnesia.
Pathology
The exact cause and effect of Klüver–Bucy syndrome is still controversial as it is more commonly found in rhesus monkeys, where the condition was first documented, than in humans. Due to the rarity of the syndrome, its prevalence and frequency are unknown. To know more about the pathology of KBS, research was conducted, where the medical records of 6 patients between the ages of 4 to 14 with KBS were studied over the course of 5 years in a university hospital. Hyperorality, hypersexuality, and abnormal behaviour were the most common manifestations, with most patients having a poor prognosis.
There are a few theories which aim to explain the pathology of KBS, such as:
Norman Geschwind's theory - states that inhibition of visual input to the limbic circuit results in a disconnect syndrome (a condition of the brain where the two hemispheres develop separately or at different rates), causing KBS.
Muller theory- states that the disconnection of nerve pathways which are necessary for emotional responses, and short-term and long-term memory, results in KBS.
Diagnosis and Evaluation
If a patient presents with three or more symptoms, he or she is said to have KBS. Post confirmation of diagnosis, the patient is evaluated through a medical exam which consists off:
Magnetic resonance imaging(MRI)- is used to check how much of the temporal lobe is damaged.
An electroencephalogram(EEG)- is used to study and examine the temporal lobe to identify the origin of seizures.
Healthcare professionals can use these tests to study the extent of the syndrome and create a treatment plan.
Treatment and prognosis
Currently, there is no cure for Klüver–Bucy syndrome. So, healthcare professionals prescribe drugs to control the symptoms presented by patients, depending on the severity of the syndrome, such as:
Carbamazepine and Leuprolide - help in managing problems associated with overtly-sexual behaviour.
Antidepressants and mood stabilisers - help in managing problems associated with social behaviour.
The patient’s condition may improve with the help of the medications; however, some patients experience long-term symptoms with no improvement.
While Klüver-Bucy syndrome is not fatal, it may be challenging to deal with as it has a huge impact on the patient's quality of life, especially since it’s such a rare disease. However, further research into the pathology of KBS and the management of symptoms will hopefully result in a better prognosis for patients in the future.
Written by: Sanjana Meenakshi Yogesh
Glossary:
Amygdala- the region of the brain involved with the experiencing of emotions.
Hippocampus- a region of the brain that is associated primarily with memory.
Amnesia- A condition characterised by the inability of a person to recall facts or previous experiences.
Magnetic resonance imaging - Provides precise details of your body parts, especially soft tissues, with the help of magnetic fields and radio waves.
Electroencephalogram(EEG)- A test to monitor the electric sensitivity of the brain and thereby detect disorders if any, using electrodes.
Bibliography:
Kluver- Bucy Syndrome - an Experience with Six Cases - Researchgate. https://www.researchgate.net/publication/8244199_Kluver-Bucy_syndrome_-_An_experience_with_six_cases/fulltext/023fee6a0cf2c94e537c9f1d/Kluever-Bucy-syndrome-An-experience-with-six-cases.pdf.
“Klüver-Bucy Syndrome: Causes, Symptoms & Treatment.” Cleveland Clinic, https://my.clevelandclinic.org/health/diseases/22504-kl%C3%BCver-bucy-syndrome.
“Klüver-Bucy Syndrome.” Physiopedia, https://www.physio-pedia.com/Kl%C3%BCver-Bucy_Syndrome.
Management Skills - Statpearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK544227/.
UW;, Gaul C;Jordan B;Wustmann T;Preuss. “[Klüver-Bucy Syndrome in Humans].” Der Nervenarzt, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/17492266/.
Kluver- Bucy Syndrome - an Experience with Six Cases - Neurology India. https://www.neurologyindia.com/article.asp?issn=0028-3886;year=2004;volume=52;issue=3;spage=369;epage=371;aulast=Jha.
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