The Kluver-Bucy Syndrome - Essay Example

Kluver - Bucy syndrome Kluver - Bucy Syndrome Epidem: Rare Sx: Full syndrome contains "psychic blindness," "hypermetamorphosis," "hyperorality," and "hypersexuality". Definition: A constellation of symptoms resulting from bilateral temporal lobectomy in humans and monkeys that include decreased fear and aggression (flattened emotions), the tendency to identify objects by oral examination rather than visual inspection, and altered sexual behavior. Synonym: Bilateral Temporal Lobe Disorder Background: In the late 1930s, Paul Bucy and Heinrich Kluver showed that temporal lobe removal, which disrupts the Papez circuit, has profound effects on the social and emotional behaviors of rhesus monkeys. In contrast to wild monkeys, the monkeys that had their temporal lobes removed seemed less aggressive as indicated by their willingness to approach humans without attempting to bite or claw them. These monkeys also failed to vocalize or show other fearful reactions to snakes, which are strongly aversive to normal monkeys. Other observation, however, indicated that this behavioral tameness was a manifestation of a more general deficit in visual recognition. This view arose because monkeys with temporal lobe lesions are unable to recognize a wide range of behaviorally relevant stimuli, a phenomenon referred to as visual agnosia or "psychic blindness". These monkeys indiscriminately place a wide range of in animate objects into their mouth and readily ingest fish, meat, feces, and other substances that normally monkeys avoid. Temporal lobectomy also disturbs their sexual behavior as indicated by repeated attempts to copulate with members of their own sex, with other species, or even inanimate objects. This constellation of behaviors subsequently became known as the Kluver-Bucy syndrome. Kluver and Bucy concluded that these behavioral changes were due to the loss of the hippocampus because it is the most salient structure in the temporal lobe. Additional studies, however, have shown that the Kluver-Bucy syndrome can be produced following removal of the amygdala alone. These findings suggest that the amygdalectomy interferes with the ability to link past experiences to stimuli that have important behavioral consequences. The amygdala receives sensory information from many cortical areas, and, thus may provide the anatomic substrate for associating behaviorally significant stimuli with their positive or negative consequences. In this context, the behavioral disruptions that define the Kluver-Bucy syndrome may represent an inability to make appropriate sensory affective associations. Literature Review: The limbic system is a perennial favorite of biological psychiatrists. The limbic system, with functions subserving emotions, exerts control over the hypothalamus. The amygdala, located in the anteromedial temporal lobe, is an important link between incoming sensory and sensory association signals and outflow to the hypothalamus, a sort of bridge between externally perceived reality and basic drives. It may help assign emotional valence to perceived objects Lesion in several related areas have profound effects on personality, mood and perceptions. Bilateral medial temporal lobe lesions can produce the Kluver - Bucy syndrome. This syndrome is characterized by placidity, hyper sexuality or altered sexual behavior, visual agnosia, hyper metamorphosis (compulsive exploration of the Environmental), hyperorality and a failure to learn from aversive stimuli. Apart from this rare, anatomically localized syndrome, abnormalities of mood and perception associated with temporal lobe lesions are more difficult to pin down. Major Cause and Effect: A Kluver -Bucy syndrome occurs in human following bilateral destruction of the amygdale resulting from herpes encephalitis, Pick's disease, or head trauma or late in the course of Alzheimer's disease. Affected individuals typically become apathetic and docile; tend to explore their environment with their hands, placing objects they encounter into their mouths; become bulimic; and become sexually preoccupied. Many develop agnosias, and nearly all shows signs of aphasia and amnesia (Lilly et al. 1983). Basic Features: The characteristic features, not all of which may be present, are: visual agnosia (e.g. misrecognition of others), also known as psychic blindness; hyperorality; hyperphagia, binge eating; hypermetamorphosis; hypersexuality; emotional changes: apathy; loss of fear, rage reactions. Demographics/Epidemiology: In human pathology, the full syndrome is extremely rare. This rarity may suggest that other damage may be necessary for its appearance. Components of the syndrome are occasionally reported after amygdala lesions, such cases make up a very small minority, the only exception being a series of patients who received aspiration removals of the amygdala and subsequently displayed abnormal oral symptoms (Lilly et al., 1983). DSM IV Diagnosis/symptoms: Not applicable. Nature and extent of symptoms: Experimentally, bilateral lesions affecting the temporal lobe, hippocampus, and amygdala (in particular) produce a behavioral pattern characterized by hyperorality, hypersexuality, emotional blunting, and defective visual recognition. Course of illness/disorder: More than 100 years ago, Hayman and Pavol observed that large lesions of the temporal lobe transformed normally wild and fierce monkeys into tame, indifferent creatures. Prior to surgery, the animals would assault anyone who tried to handle them. Following surgery they could be handled and teased without consequence. Later, Kluver and Bucy noted that temporal lobe lesions also resulted in psychic Blindness. Outcome or prognosis: Temporal lobe lesions produce tameness or hypoemotionality, visual agnosia, and changes in dietary and sexual behavior. Amygdala lesions interfere with the formation of intersensory associations and that the syndrome may result in part from an inability to associate stimuli across different modalities, as well as deficits in affective processing (Kalivas and Barnes, 1993). Pharmacology: Not applicable. Diseases that can cause Kluver Bucy like syndrome in humans: Alzheimer's disease Carbon monoxide poisoning Cerebral infiltrations Front temporal dementia Head injury Herpes encephalitis Systemic metabolic disorders Temporal lobe stroke Temporal lobectomy Temporal lobe tumor. Treatment approaches: Treatment is dependent upon patient. For example: Leuprolide treatment of sexual aggression in a patient with Dementia and the Kluver-Bucy Syndrome; Selective serotonin reuptake inhibitor of post-traumatic Kluver-Bucy Syndrome. Diagnostic issues (procedures): These symptoms are also prominent in patients with Pick's disease and patients with frontal lobe dementia. Dementia and other related disorders: Dementias: Occasional dementia syndromes may evolve through a phase including symptoms of the Kluver -Bucy syndrome manifested by increased or altered sexual activity. Dementia syndromes that may produce the Kluver - Bucy syndrome are listed below: Post - encephalitic syndromes after herpes encephalitis. Trauma Alzheimer's disease Frontotemporal lobar degenerations Adrenoleukodystrophy Delayed, post-anoxic leukoencephalopathy Bilateral temporal lobe stroke Post- traumatic encephalopathy Paraneoplastic limbic encephalitis Hypoglycemia and Toxoplasmosis. Related Disorders: Autism and Kluver-Bucy syndrome There have been some attempts in recent speculations concerning the causes of autism to formulate some neurological models which can subsume findings in the area so far. For example, an early study by Hooshmand et al (1974) using pneumoencephalography showed enlargement in the ventricular system in a proportion of a sample of autistic children. DeLong (1978) concedes that autism probably has multiple aetiologies but suggests that at least for a subgroup of neuropsychological interpretation is relevant. He draws attention to the similarities between symptoms in autism and in the Kluver-Bucy syndrome. This disorder occurs in man as a consequence of bilateral surgical ablations of medial temporal lobes or following herpes simplex encephalitis. "deficits in the Kluver-Bucy syndrome have been described as an incapacity for adaptive social behavior, and a loss of recognition of the significance of persons and events. Such patients shows an empty blandness, an absence of emotion or concern for family or other persons, and pursue no sustained purpose in activity" (DeLong, 1978). This description does suggest a strong parallel with the most severe and more retarded cases of autism but is less generally apt for the higher functioning group. Kluver - Bucy Syndrome (Surgical Ablation Model): As referred in the above passage, bilateral ablation of the anterior temporal lobe in monkeys produces a striking syndrome, which includes a lack of emotional responsiveness, tameness, excessive manipulation of objects, and eating of objects that would not normally be eaten. Weizkrantz showed that most of these effects could be attributed to ablation of the amygdala. Bilateral amygdalectomy in monkeys impairs conditioning to both positive and negative reinforcers (produces a deficit in learning to associate neutral stimuli with a primary reinforcer, reward, or punisher). After Kluver and Bucy described the syndromes in monkeys, the same syndrome were described in humans. This is one of the interesting situations in which the development of the animal model appears to have preceded the full recognition of the syndrome in humans. Rolls (1998) suggests that the symptoms of the Kluver-Bucy syndromes including the emotional changes are due to a deficit in learning stimulus-reinforcement associations and the deficit are due to bilateral damage to the amygdala. Bilateral amygdala lesions in rodents impair behavior that is based on the association between neutral stimuli and positive or negative reinforcers, but do not impair the behavior to primary reinforcers. This applied to sexual responses, drug seeking behavior, and feeding behavior. General Effects: Oral behaviors are especially prominent in the Kluver Bucy syndrome. The monkeys with bilateral temporal lesions not only examined objects by mouth but also ate previously rejected foods. Marlow et al first described the Kluver Bucy syndrome in a human patient with meningoencephalitis. Their patient examined objects, including his hands, by placing them in his mouth and sucking or chewing them. He had an insatiable appetite and ate almost everything within his grasp, including plastic wrappers, ink, clearing materials, dog food and feces. The extent of this hyperorality can be severe and life threatening. Mendez and Foti described two patients with the Kluver-Bucy syndrome; one asphyxiated after stuffing his mouth with surgical gauze, towels, toilet paper, and Styrofoam cups, and the other aspirated after over ingestion of a large amount of food. Human patients with amygdaloid lesions exhibit behavioral changes that is remarkably similar to those seen in nonhuman primates. Amygdalectomy causes humans to become complacent and, for this reason, was often used in the past to treat individuals with a history of violent behaviors. Human patients with amygdaloid lesions also exhibit visual, auditory, or tactile agnosia and have an increased tendency to sniff objects and place them in their mouth. Damage to the amygdala also increases inappropriate sexual behavior, which takes the form of suggestive remarks and ill-conceived attempts to make sexual contact. Thus, the evidence from clinical and experimental data suggests that damage to the amygdala may interfere with the ability to link sensory stimuli to past social or emotional experiences. Larger lesions of the temporal lobe, which also damages the hippocampus may also cause amnesia. In cases where the entire temporal lobe has been damaged, the patient is also likely to become aphasic because Wernicke's area has been affected. Conclusion: The Kluver Bucy syndrome is not diagnostically specific; the symptom complex may also be seen with head trauma, Alzheimer's disease, and Pick's disease. The behavioral alterations in herpes simplex encephalitis are typically less extreme than the full Kluver-Bucy syndrome and they consist of episodically inappropriate behavior, personality changes, delusions, and hyposexuality. Such behavioral sequelae frequently are viewed as psychogenic by the family and may be resistant to traditional forms of psychiatric treatment. REFERENCES: 1. Aichner F: Die Phenomenologie des nach Klver und Bucy benannaten Syndroms beim Menshchen [Phenomenology of the the Klver-Bucy syndrome in man]. Fortschr Neurol Psychiatr 1984; 52:375-397 2. DeLong: The Temporal Lobe and Limbic System. New York, Oxford University Press, 1978. 3. Hayman LA, Rolls JL, Pavol MA, et al: Klver-Bucy syndrome after selective damage of the amygdala and its cortical connections J Neuropsychiatry Clin Neurosci 1998; 10:354-358 4. Hooshmand H, Sepdham T, Vries JK: Klver-Bucy syndrome: successful treatment with carbamazepine (letter). JAMA 1974; 229:1782 5. Kalivas PW, Barnes CD, eds. Limbic Motor Circuits and Neuropsychiatry Boca Raton, FL, CRC Press, 1993 6. Klver H, Bucy PC: Preliminary analysis of functions of the temporal lobes in monkeys. Arch Neurol Psychiatry 1939; 42:979- 1000. 7. Lilly R, Cummings JL, Benson DF, et al: The human Klver -Bucy syndrome. Neurology 1983; 33:1141-1145. 8. Stewart JT: Carbamazepine treatment of a patient with Klver-Bucy syndrome. J Clin Psychiatry 1985; 46:496-497 Read More