Klüver–Bucy Syndrome

Klüver–Bucy Syndrome

Definition

In 1939, Klüver and Bucy (1939) noted some striking behavio-ral changes in monkeys which had been subjected to bilateratemporal lobectomy, and in so doing described the syndrome that now bears their names. The full syndrome is characterized by hypermetamorphosis (excessive tendency to take notice and attend and react to every visual stimulus), agnosia, hyperorality, emotional placidity and hypersexuality. Some examples of the syndrome in humans follow.

The first example demonstrates hypersexuality, hyperoral-ity, agnosia and emotional placidity. The patient was a 31-year-old woman, who, after recovering from a herpes simplex encephali-tis, “made inappropriate sexual advances to female attendants, both manually and orally. At home, she was constantly chew-ing and swallowing, and all objects within reach were placed in her mouth…including toilet paper and faeces…Her affect was characterized by passivity and a pet-like compliance with those attending her” (Lilly et al., 1983).

The second example provides examples of hypermeta-morphosis, hyperorality, agnosia and hypersexuality. The pa-tient, a 58-year-old man who had suffered from Alzheimer’s disease for 6 years, “spent much of his time examining ordinary objects such as the doorstep, ashtrays, or spots on the floor. He placed many objects in his mouth and occasionally ate soil from plant containers … he rubbed his genitals so frequently that he developed an excoriation on the shaft of his penis” (Lilly et al., 1983).

Finally, there is the case of a 46-year-old man, who, during a complex partial seizure, “was observed grabbing for objects on his bedside table, and he masturbated in front of the nurs-ing staff. He also placed objects in his mouth, chewed on tissue paper, and attempted to drink from his urine container” (Nakada et al., 1984). Here, there are hypermetamorphosis, hypersexual-ity, hyperorality and agnosia

Etiology and Pathophysiology

The various causes of the Klüver–Bucy syndrome are listed in Table 33.11: in each case, bilateral damage or dysfunction of the temporal lobes has occurred. The mechanism of such bilateral damage in the case of precipitants is fairly straightforward. The neurodegenerative disorders listed have a predilection for the temporal lobes, and this is particularly the case in Pick’s dis-

cause; in some cases, the syndrome itself may ease and fronto-temporal dementia. Indeed, the appearance of the Klüver–Bucy syndrome early in the course of a dementia is a significant diagnostic clue to one of these two disorders; in the case of Alzheimer’s disease, the syndrome, if it does occur, is generally seen only late in the course. Of the miscellaneous causes, an ictal Klüver–Bucy syndrome is suggested by its exqui-sitely paroxysmal onset and by the occurrence of other symptoms typical for a complex partial seizure, such as confusion, and a postictal Klüver–Bucy syndrome by the history of an immedi-ately preceding generalized seizure. Adrenoleukodystrophy, the last in the list, is an extremely rare cause of the Klüver–Bucy syndrome.

Assessment and Differential Diagnosis

The combination of hyperorality and hypersexuality often brings the patient to medical attention: although the full syndrome presents little diagnostic difficulty, as it is not mimicked by any other condition, partial syndromes, consisting primarily of hy-permetamorphosis and hypersexuality, may suggest mania. The differential rests on the presence or absence of pressured speech and activity, findings typical of mania but absent in the Klüver– Bucy syndrome.

Epidemiology and Comorbidity

The full Klüver–Bucy syndrome is, overall, rare; in dementia clinics, however, full or partial Klüver–Bucy syndromes are commonly seen.

Course

The course depends on the underlying have a fatal outcome.

Treatment

The underlying cause, if possible, is treated. In chronic cases, neuroleptics have been reported to be helpful; there are, however, no controlled studies.