(2021) 15:346
Al‑Attas et al. J Med Case Reports
https://doi.org/10.1186/s13256-021-02932-0

Open Access

CASE REPORT

Klüver–Bucy syndrome secondary
to a nondominant middle cerebral artery
ischemic stroke: a case report and review
of the literature
Alawi Aqel Al‑Attas, Abdulrahman Yousef Aldayel*, Tareq Hamad Aloufi and Nabil Biary

Abstract
Background: Klüver–Bucy syndrome is a rare and complex neurobehavioral cluster that occurs in humans and
results from a temporal lobe lesion. It can be associated with a variety of causes. Stroke is a rarely reported cause of
this syndrome.
Case presentation: In this report, we present the case of a 68-year-old Saudi male who developed Klüver–Bucy
syndrome subsequent to a nondominant middle cerebral artery ischemic stroke involving right temporal lobe.
The patient manifested most of the Klüver–Bucy syndrome clinical features, including hypersexuality, hyperphagia,
hyperorality, and visual hypermetamorphosis (excessive tendency to react to every visual stimulation with a tendency
to touch every such stimulus). These neurobehavioral manifestations improved after he was started on treatment.
Conclusions: The clinical course, anatomical association relying on pathophysiology, and potential treatment
have all been deliberated in regard to the rare occurrence of Klüver–Bucy syndrome resulting from temporal lobe
pathology.
Keywords: Klüver–Bucy syndrome, Stroke, Case report, Ischemic stroke, Neurobehavioral symptoms, Temporal lobe
damage
Background
Klüver–Bucy syndrome (KBS) is a very rare and peculiar clinical entity. It is the consequence of bilateral temporal lobe lesions, particularly involving the amygdala
and hippocampus [1]. In 1937, Heinrich Klüver and
Paul Bucy first defined a neurobehavioral syndrome in
rhesus monkeys after bilateral temporal lobectomies [2,
3]. This syndrome featured hyperorality, hypersexuality,
placidity, hyperphagia, visual agnosia, and altered emotional behavior [2, 4]. Patients often present with only
*Correspondence: Ayaldayel@gmail.com
Department of Neurology, Prince Sultan Military Medical City (PSMMC),
MakkahAl Mukarramah Road, As Sulimaniyah, PO Box 7897, Riyadh, Saudi
Arabia

three or more symptoms and are designated as partial
KBS [5]. The causes of KBS vary among the previously
reported cases. These include herpes simplex encephalitis (HSE), Alzheimer’s disease, Niemann–Pick disease,
stroke, Huntington’s disease, traumatic brain injury, toxoplasmosis, shigellosis, hypoglycemia, juvenile neuronal
lipofuscinosis, acute intermittent porphyria, and tubercular meningitis [4, 6]. KBS is diagnosed clinically by the
presence of its characteristic symptoms. Brain magnetic
resonance imaging (MRI) is used to confirm the diagnosis by demonstrating bilateral temporal lobe mutilation
[4]. Furthermore, appropriate assessment to identify the
underlying etiology is part of the general management
of KBS [4]. The treatment of KBS is mainly supportive measures, including occupational therapy, selective

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serotonin reuptake inhibitors for behavioral changes, and
carbamazepine for hypersexuality [4, 7]. The first KSB
case was reported in 1975. It was a 22-year-old man with
bilateral temporal lobe damage as a result of HSE [8]. In
the literature, there are limited contemporary published
cases of KSB secondary to stroke [9–11]. In this case
report, we present an unusual case of an elderly male who
developed KBS features following an ischemic stroke in
his nondominant hemisphere.

Case presentation
A 68-year-old Saudi male known to have type 2 diabetes mellitus and hypertension for 15 years presented to
the emergency department of the Prince Sultan Military Medical City, Riyadh, Saudi Arabia, in September
16, 2018 with confusion, vomiting, left-sided weakness,
left facial palsy, and slurred speech. His symptoms had
started 2 hours and 25 minutes earlier.
On examination, the patient was conscious but confused. He had left facial weakness, gaze deviation to the
right side, left homonymous hemianopsia, dense left
hemiplegia, and left sided hemineglect, so the stroke
code was announced. Both a computed tomography
(CT) scan and a CT angiogram were performed upon
admission. The CT scan of the brain showed an ischemic
stroke of the right temporal lobe surrounded by diffuse
brain edema causing mass effect (Fig. 1). The CT angiogram revealed nonopacification of the right internal
carotid artery near its origin with extension cranially to
involve the majority of the cervical portion in addition
to the petrous, cavernous, and supraclinoid aspects. In
addition, there was nonopacification of the right middle
cerebral artery (MCA) branches, which was likely due to

Page 2 of 5

thrombus formation. Additionally, the brain MRI findings are illustrated in Fig. 2.
The patient was given tissue plasminogen activator (tPA) as per the stroke protocol. Later on, he was
taken for intraarterial thrombectomy, which, after five
attempts, was without significant reperfusion. He was
then intubated during the procedure, and later on transferred to the intensive care unit for postthrombolytic
protocol. A follow-up CT scan showed a malignant MCA
stroke with diffuse edema causing mass effect, midline
shift, and impending herniation. Therefore, the patient
was taken for craniotomy as the only salvageable option,
and high intracranial pressure measures were reversed.
A few days later, the edema improved, the mass effect
resolved, and the patient was weaned off sedation. Afterward, the patient started to slowly recover.
Several laboratory investigations were conducted,
including complete blood count, coagulation profile, and
electrolyte panel. Markers of vasculitis and autoimmune
disorders were unremarkable. Hemoglobin A1C was
10.2%. The lipid profile was the following: cholesterol:
4.73 mmol/L, triglycerides: 2.07 mmol/L, high-density
lipoprotein (HDL): 1.05 mmol/L, and low-density lipoprotein (LDL): 3.25 mmol/L.
On November 19, 2018, the patient was transferred
to the neurology ward. A few days later, it was noticed
that he was displaying hyperorality, hypermetamorphosis, hyperphagia, hypersexuality, and other behavioral
changes, including apathy, visual agnosia, and hallucinations. During the first few days in the ward, the patient
was unable to recognize his family members. Hence, he
was started on escitalopram 10 mg once daily together
with levetiracetam 1 g twice daily. Two months later,
the patient showed significant improvement in his

Fig.1 A Extensive hypodense lesion on the right temporal area on the axial noncontrast brain CT before thrombectomy. B Large hypodense lesion
of the right temporal area after craniotomy was done on the axial noncontrast brain CT. C Coronal brain largely affected by hypodense lesion on the
right temporal area

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Page 3 of 5

Fig. 2 A Axial section of brain MRI Fluid-Attenuated Inversion Recovery (FLAIR) image showing subacute infarction extensively affecting the right
temporal area. B Lesion in the T2-weighted MRI image. C Gradient echo showing blooming artifacts representing hemorrhagic transformation

neurobehavioral symptoms, hypersexuality, and altered
eating behavior.

Discussion
To the best of our knowledge, this is the first reported
case of KBS in Saudi Arabia as a result of a unilateral
ischemic stroke of the nondominant temporal lobe. Any
combination of three or more clinical manifestations is
suggestive of partial KBS. It is very rare to have complete
KBS in humans [12–14], and it usually exists incompletely [15]. In humans, it is commonly accompanied by
apathy and amnesia, which was observed in our case.
Although in most cases KBS has been observed following
bilateral lesions of the temporal lobe, some cases without bitemporal impairments have been reported [16–18].
The most important clinical manifestations observed in
our case were altered sexual conduct, increased dietary
intake, apathy, hyperorality of nearby items (including
inedible and sharp objects), and visual hypermetamorphosis. This accounts for five of the major features of
KBS, as reported by Rossitch, Oakes, Hreniuc et al. in
their previously published studies [10, 18].
In our case, hyperorality was observed as grasping with
the hands only. A case reported by Pilleri disclosed that
oral grasping was associated with lesions of the temporal lobe, while grasping with the hands was associated
with lesions of the frontal lobe [19]. Our patient demonstrated visual hypermetamorphosis, which is defined
as an irresistible impulse to notice and react to anything
within sight. The alteration of sexual conduct was apparent as physical hypersexuality, as observed by Chou et al.,

whereas the hypersexuality of our patient was emotional.
The increased libido seen in KBS has been attributed to
the loss of limbic system cortical inhibitory tracts [20].
Both the frontal lobe and the limbic system have projections that come from the temporal cortex, amygdala,
and thalamus. These structures are known to be related
to emotions [21]. In a previous study, the manifestation
of KBS was linked to a good prognosis in the clinical
outcome of a cerebral insult associated with loss of consciousness [22].
Anatomically, KBS is frequently due to lesions affecting
bilateral temporal lobes. In addition, the hippocampus,
uncus, cingulate gyrus, and amygdala play a significant
role in the pathogenesis of KBS. Moreover, a disturbance
of the pathways that provide the neurological connections of the limbic system, medial thalami, and frontal
lobe is accountable for impaired memory and emotions,
which also contribute to the development of KBS [23,
24]. In other cases, KBS symptoms were found after
unilateral brain lesions, such as right subdural hematoma, infarction, or lobectomy of the left temporal lobe.
In previous published studies, this syndrome is a consequence of visual input interruption to the limbic system
as described by Geschwind [25]. Müller et al. mentioned
that KBS seems to follow an obliteration of the thalamus, frontal cortex, and limbic system pathway connections [17], and Hreniuc et al. stated that their patient
has disruption in the right temporal lobe and amygdala.
However, in our case, the patient has a lesion in the temporal area of the nondominant hemisphere; this has been
reported by Hreniuc et al. in their patient [10]. Since a

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disturbance in the level of consciousness at the time of
recovery might account for the manifestations of KBS,
the CT scan is a distinguishing imaging test for patients
who suffer brain injuries. Additionally, for those who present with neurobehavioral symptoms, MRI is necessary
to structurally visualize brain lesions [23, 26]. The clinical
manifestations of this syndrome may appear in patients
without morphological changes in the brain CT scan,
particularly the temporal lobes. For this reason, brain
evaluation by MRI scan should be considered in patients
with cerebral insults.
The clinical results of KBS are distinctive from one case
to another. It is usually reversible in patients with traumatic injury, seizures of any cause, or infection if undergoing prompt diagnosis and early onset of treatment.
The point that precocious cognition and implementation
of the treatment plan for the drastic behavior changes
requiring rehabilitation can be avoided has been entailed
in the various courses of KBS [9]. The effect of treatment
varied among KBS patients. Some cases showed dramatic
improvements when treated with antiepileptics, such as
carbamazepine, or serotonin reuptake inhibitors [4, 27].
Other cases showed persistent mental derangements,
and others may develop Korsakoff syndrome [28].

Conclusions
KBS is rarely caused by an ischemic stroke, especially
in the nondominant hemisphere. KBS, as illustrated in
our case as a consequence of an ischemic stroke of the
right temporal lobe, is supported by other previously
reported studies, and it can impart distinct insight into
the possible pathophysiology of KBS. Further studies are
needed to elucidate the pathophysiology of this disease
and, hence, help explicitly formulate potentially effective
treatments.
Abbreviations
CT: Computed tomography; HDL: High-density lipoprotein; HSE: Herpes sim‑
plex encephalitis; KBS: Klüver–Bucy syndrome; LDL: Low-density lipoprotein;
MCA: Middle cerebral artery; MRI: Magnetic resonance imaging; tPA: Tissue
plasminogen activator.
Acknowledgements
The authors would like to thank the patient and his family for their approval to
take part in this study.
Authors’ contributions
AA-A (the principal author) took the history and examined the patient,
interpreted and collected the data, and reviewed the final draft of manuscript.
AA wrote the initial draft of manuscript, contributed in data collection, and
reviewed the final draft of the manuscript. NB assessed the patient together
with Dr. A-A and reviewed the final draft of the manuscript. TA helped in writ‑
ing the manuscript and reviewed the final draft of the manuscript. All authors
read and approved the final manuscript.
Funding
None.

Page 4 of 5

Availability of data and materials
All data and materials are available upon request from the corresponding
author.

Declarations
Ethics approval and consent to participate
Not applicable.
Consent for publication
Written informed consent was obtained from the patient for publication of
this case report and any accompanying images. A copy of the written consent
is available for review by the Editor-in-Chief of this journal.
Competing interests
The authors would like to declare that they have no competing interests or
anything to disclose.
Received: 21 January 2020 Accepted: 26 May 2021

References
1. Garrett KD, Irani F, Libon DJ, Swenson R, Wambach DM. Klüver-Bucy syn‑
drome. In: Kreutzer JS, DeLuca J, Caplan B, editors. Encyclopedia of clinical
neuropsychology. New York, NY: Springer; 2011. p. 1405–10.
2. Klüver H, Bucy P. Preliminary analysis of functions of the temporal lobes in
man. Arch J Comp Neurol. 1939;42:979–1000.
3. Bucy PC, Klüver H. An anatomical investigation of the temporal lobe in
the monkey (Macacamulatta). J Comp Neurol. 1955;103:151–251.
4. M Das J, Siddiqui W. Kluver Bucy syndrome. [Updated 2019 Jun 16]. In:
StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019.
5. Kar SK, Jaiswal A, Panda AK. A case report of partial Kluver-Bucy syndrome
with anterior opercular syndrome in childhood: a sequel of limbic
encephalitis. J Indian Assoc Child Adolesc Ment Health. 2013;9:80–8.
6. Duggal HS, Jain R, Sinha VK, Haque NS. Post-encephalitic Kluver-Bucy
syndrome. Ind J Pediatrics. 2000;62:74–6.
7. Hooshmand H, Sepdham T, Vries JK. Klüver-Bucy syndrome: successful
treatment with carbamazepine. JAMA. 1974;229(13):1782. https://​doi.​org/​
10.​1001/​jama.​1974.​03230​51005​6026.
8. Marlowe WB, Mancall EL, Thomas JJ. Complete Kluver-Bucy syndrome in
man. Cortex. 1975;11:53–9.
9. Chou CL, Lin YJ, Sheu YL, Lin CJ, Hseuh IH. Persistent Kluver-Bucy
syndrome after bilateral temporal lobe infarction. Acta Neurol Taiwan.
2008;17:199–202.
10. Hreniuc NC, et al. Clinical manifestations and morphological changes
in one case with post-stroke Klüver-Bucy syndrome. Rom J Morphol
Embryol. 2017;58(2):665–9.
11. Ozdemir H, Rezaki M. Klüver-Bucy-like syndrome and frontal symp‑
toms following cerebrovascular disease. Turk psikiyatri dergisi.
2007;18(2):184–8.
12. Nicolai A, Lazzarino LG, Alari E. Partial Klüver-Bucy syndrome arising
from a multicentric glioblastoma: anatomo-clinical study of a case with
unusual involvement of CNS. Clin Neuropathol. 1991;10(1):16–20.
13. Rossitch E Jr, Carrazana EJ, Ellenbogen R, Alexander E 3rd. Klüver-Bucy
syndrome following recovery from transtentorial herniation. Br J Neuro‑
surg. 1989;3(4):503–6.
14. Burns A, Jacoby R, Levy R. Psychiatric phenomena in Alzheimer’s disease.
IV: disorders of behaviour. Br J Psychiatry. 1990;157:86–94
15. Ghika-Schmid F, Assal G, De Tribolet N, Regli F. Klüver-Bucy syn‑
drome after left anterior temporal resection. Neuropsychologia.
1995;33(1):101–13.
16. Salim A, Kim KA, Kimbrell BJ, Petrone P, Roldán G, Asensio JA. KlüverBucy syndrome as a result of minor head trauma. South Med J.
2002;95(8):929–31.
17. Müller A, Baumgartner RW, Röhrenbach C, Regard M. Persistent KlüverBucy syndrome after bilateral thalamic infarction. Neuropsychiatry
Neuropsychol Behav Neurol. 1999;12(2):136–9.

Al‑Attas et al. J Med Case Reports

(2021) 15:346

18. Rossitch E Jr, Oakes WJ. Klüver-Bucy syndrome in a child with bilateral
arachnoid cysts: report of a case. Neurosurgery. 1989;24(1):110–2.
19. Pilleri G. Orale Einstellung nach Art des Klüver-Bucy Syndroms bei hirnat‑
ropischen Prozessen. Schweiz Arch Neurol Psychiat. 1961;87:286–98.
20. Gerstenbrand F, Poewe W, Aichner F, Saltuari L. Klüver-Bucy syndrome
in man: experiences with posttraumatic cases. Neurosci Biobehav Rev.
1983;7(3):413–7.
21. Rajmohan V, Mohandas E. The limbic system. Indian J Psychiatry.
2007;49(2):132–9. https://​doi.​org/​10.​4103/​0019-​5545.​33264.
22. Formisano R, Saltuari L, Gerstenbrand F. Presence of Klüver-Bucy
syndrome as a positive prognostic feature for the remission of trau‑
matic prolonged disturbances of consciousness. Acta Neurol Scand.
1995;91(1):54–7.
23. Jha S, Patel R. Klüver-Bucy syndrome—an experience with six cases.
Neurol India. 2004;52(3):369–71.
24. Anson JA, Kuhlman DT. Post-ictal Klüver-Bucy syndrome after temporal
lobectomy. J Neurol Neurosurg Psychiatry. 1993;56(3):311–3.

Page 5 of 5

25. Geschwind N. Disconnection syndromes in animals and man. Brain.
1965;88(2):237–94.
26. Weisberg LA. Klüver-Bucy syndrome after minor brain injury. South Med J.
2012;95(8):794–5.
27. Slaughter J, Bobo W, Childers MK. Selective serotonin reuptake
inhibitor treatment of post-traumatic Klüver-Bucy syndrome. Brain Inj.
1999;13:59–62.
28. Davis Garrett K, Irani F, Libon DJ, Swenson R, Wambach DM. Klüver-Bucy
syndrome. In: Kreutzer JS, DeLuca J, Caplan B, editors. Encyclopedia of
clinical neuropsychology. New York: Springer Verlag; 2011. p. 1405–10.

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