Kluver-Bucy syndrome

Definitions & Key takeaways

Kluver-Bucy syndrome is a rare neurological disorder that is caused by damage to the temporal lobes of the brain. The syndrome is characterized by a number of symptoms, including hypersexuality, excessive eating, and memory impairment. Some people with Kluver-Bucy syndrome also experience changes in their personality and become emotionally unstable.

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Introduction0:00–0:34

Klüver-Bucy syndrome is neurobehavioral condition first observed in the 1930s by Heinrich Klüver and neurosurgeon Paul Bucy.
They discovered that monkeys that had bilateral temporal lobe lobectomies developed dramatic behavior changes in their memory, as well as their social and sexual behaviors.
In retrospect, it’s not surprising that having a significant portion of the brain removed caused behavior changes in monkeys - the biggest one was probably anger at Klüver and Bucy for putting them through that!

Physiology0:34–1:25

The temporal lobe is one of the four major lobes of the brain. It has a variety of functions which are involved in sensory processing.
The ventral, or anterior, part of the temporal lobe helps process visual information, such as the recognition of objects and faces.
Whereas, the medial, or middle portion, of the temporal lobe, along with the hippocampus, is responsible for the formation of new memories.
The temporal lobe also houses the primary auditory cortex, which is needed for speech comprehension. Other important structures found within the temporal lobe include the olfactory cortex, which processes the sensation of smell, and the amygdala, which processes emotions.
The amygdala also plays a role in the reward center of the brain which motivates and reinforces behaviors that elicit positive feelings.

Pathology1:25–2:06

In Klüver-Bucy syndrome there’s a bilateral lesion of the temporal lobe. The most common cause of such a brain lesion is herpes simplex encephalitis - a viral infection that particularly affects the temporal lobes.
Other causes of Klüver-Bucy syndrome include trauma, stroke, Alzheimer's disease, and Niemann Pick disease, which is a rare metabolic condition that affects various organs of the body, including the brain.
The damage affects the amygdala which is a part of the brain that regulates emotions and reinforces behaviors related to food and sex.
Amygdala damage also causes a diminished fear response. With that in mind, there are three main symptoms caused by Klüver-Bucy syndrome: hyperphagia, hyperorality, and hypersexuality.

Symptoms2:06–3:02

Hyperphagia means compulsive overeating. Sometimes this also presents as the consumption of inedible substances like soil and chalk, a condition known as pica.
Hyperorality is a type of compulsion where one needs to examine objects by putting it in their mouth. And as the name implies, hypersexuality refers to an elevated sex drive, sometimes associated with various paraphilias, or fetishes.
In addition, damage to the ventral temporal lobe which is responsible for visual processing results in visual agnosia, or the inability to recognize familiar objects or people.
Damage to the medial ventral lobe and hippocampus which both play a role in memory formation results in amnesia. Diagnosis of Klüver-Bucy syndrome is typically made based on having the classic symptoms and is usually confirmed based on bilateral temporal lobe damage on an MRI.

Diagnosis3:02–3:12

Treatment3:12–3:30

Treatment is generally supportive and include things like assistance with daily living and occupational therapy. Selective serotonin reuptake inhibitors may help treat some of the abnormal behaviors, while carbamazepine may be given to specifically treat symptoms of hypersexuality.
Ok, quick recap: Klüver-Bucy syndrome is a neurological condition caused by bilateral lesions in the temporal lobe and symptoms include hyperphagia, hyperorality, hypersexuality, docility, visual agnosia, and impaired memory.

Review3:30–3:54

It’s associated with herpes simplex encephalitis and can be treated with selective serotonin reuptake inhibitors and carbamazepine.