Kluver-Bucy syndrome

From Psy3241

Overview:

A rare neurological disorder occurring in humans and Rhesus monkeys (much more common in animal subjects). The full syndrome is rarely found in humans. Individuals put objects into their mouths and engage in inappropriate sexual behavior.

Other symptoms may include:

Visual agnosia (inability to visually recognize objects), loss of normal fear or anger responses, distractibility, memory loss, dementia, seizures, hypersexuality, hyperorality, altered emotional behavior, or “psychic blindness.�? (is this the same as visual agnosia??)

Possible causes:

Head trauma and herpes encephalitis are the most common causes of the condition.

History:

In 1937, Heinrich Kluver and Paul Bucy performed surgery on Rhesus monkeys, removing the temporal lobe on both sides to determine its function. The monkeys immediately developed altered sexual behavior (dramatic increase of overt behavior), emotional changes, and visual agnosia. Oral tendencies (hyperphagia) and hypermetamorphosis (desire to explore everything in their surroundings) were also present. The monkeys were more likely to examine the world with their mouths instead of their eyes, perhaps because the visual agnosia caused familiar objects and their uses to be unrecognizable. The monkeys lost fear when it would normally be acceptable and expected (known as placidity). In humans, the hypersexuality is not as intense as seen in animals.

Etiology:

Kluver-Bucy Syndrome is considered a direct consequence of bilateral anterior temporal lobe damage resulting from either injury or disease. However, lesions of the amygdala have elicited similar symptoms. Clinicians are required to document the clinical features mentioned above, as well as to prove that a bilateral lesion exists in the anterior temporal lobe or the amygdala. However, lesions are not necessary in the amygdala for KBS symptoms to exist. There have been 2 cases where neither of these regions showed damage in brain images, suggesting that KBS may involve some disruption of circuitry in the limbic areas, where mediodorsal thalamic relay occurs. All of the cases involving children were due to herpes encephalitis

Research:

KBS may resopond to carbamazepine treatment (antipsychotic pharmaceuticals), but management is challenging. In some cases, research has shown antipsychotics resulted in clinical improvement. The cases of KBS that do not have apparent brain lesions could help develop a better functional understanding of the condition.