Neurosurgical Review

, Volume 33, Issue 1, pp 107–114

Hypersexuality from resection of left occipital arteriovenous malformation

Authors

  • Yong Cao
    • Department of NeurosurgeryBeijing Tiantan Hospital, affiliated to Capital Medical University
  • Zhaohui Zhu
    • PET CenterPeking Union Medical College Hospital
  • Rong Wang
    • Department of NeurosurgeryBeijing Tiantan Hospital, affiliated to Capital Medical University
  • Shuo Wang
    • Department of NeurosurgeryBeijing Tiantan Hospital, affiliated to Capital Medical University
    • Department of NeurosurgeryBeijing Tiantan Hospital, affiliated to Capital Medical University
Case Report

DOI: 10.1007/s10143-009-0232-2

Cite this article as:
Cao, Y., Zhu, Z., Wang, R. et al. Neurosurg Rev (2010) 33: 107. doi:10.1007/s10143-009-0232-2

Abstract

The authors report their experience on one patient with hypersexuality from resection of left occipital arteriovenous malformation. To the best of our knowledge, this is the first case reported in the literature. A 35-year-old right-handed female farmer suffered a sudden left occipital hemorrhage with subarachnoid and subdural hemorrhages of the left hemisphere. Transient left uncal herniation occurred at the onset and was released by conservative treatment. Digital subtraction angiography showed a brain left occipital arteriovenous malformation. After microsurgical resection of the arteriovenous malformation, the patient developed hypersexual behavior. Positron emission tomography showed hypermetabolism in the left frontal region and left posterior hippocampal gyrus and hypometabolism in the left anterior hippocampal gyrus and the left occipital surgical area. Theories concerning normal pressure perfusion breakthrough and specific areas in the brain responsible for the human sexual response are discussed.

Keywords

Arteriovenous malformationHypersexualityNormal pressure perfusion breakthroughPositron emission tomography

Introduction

Arteriovenous malformations (AVMs) of the brain are lesions composed of a coiled batch of arteries and veins, joined by arteriovenous fistulas and partially separated by sclerotic tissue [1]. AVMs are pulsatile vascular masses that impact on brain hemodynamics and physiology in many ways [1]. Removal of AVMs of the brain also can produce a variety of anatomic and physiologic changes, which include patient’s neurological deficit and neuropsychological or cognitive dysfunction. The major neurological deficit after surgical removal of AVMs includes hemiparalysis, aphasia, hemianopia, and cranial nerve dysfunction [20]. There are also a few neuropsychological or cognitive changes reported from the resection of AVM [2, 4, 10, 17]. To the best of our knowledge, there are no hypersexuality from resection of AVM reported in the literature. We reported a case of brain occipital AVM that the female patient had hypersexual behavior after microsurgical removal of the AVM. We have discussed the postoperative changes of cerebral perfusion and metabolism on perifocal and remote brain tissue in this patient.

Case report

A 35-year-old right-handed female farmer suffered a sudden and severe headache, vomiting, and impaired consciousness during playing mahjong on October 26, 2008. She was sent to a local hospital; computed tomography (CT) at that time showed the patient had left occipital hemotoma with subarachnoid and subdural hemorrhage of left hemisphere. She received conservative treatment lowering intracranial pressure and had responded well to the conservative treatment. One day later, the patient became conscious. After staying at the local hospital for 17 days, she was transferred to our hospital, Beijing Tiantan Hospital, for further treatment on November 11, 2008. Previous medical history showed she was healthy. The patient took no medications in the past and had no history of substance abuse. On admission, the neurological examination revealed she was conscious and alert, oriented to time, person, and place. There were partial left third cranial nerve palsy, including left deficit of adduction, left ptosis, and left pupillary dilatation and sluggish reaction to light. Sensory examination was normal. There was left-sided weakness, and the left extremities’ strength is IV. There was positive Babinski’ sign on the left. Neuropsychological evaluation showed mild depression (Hamilton depression scale score was 17) and no or mild anxiety (Hamilton anxiety scale score was 11). MRI demonstrated a 1.5-cm diameter hematoma in the left occipital lobe with subdural hemorrhage of the left hemisphere and middle line apparent right shift about 10 mm (Fig. 1). Four-vessel digital subtraction angiography revealed an occipital AVM on the left, which was fed by both branches of the left posterior cerebral artery and left middle cerebral artery and was drained into the superior sigmoid sinus (Fig. 2). On November 26, 2008, a left parieto-occipital craniotomy was performed; with the assistance of neuronavigation and intraoperative ultrasound, a small parenchyma hematoma was evacuated, and a vessel nidus containing venous aneurysm was found on the lateral side of the hamotoma. The branches of the artery proximal to the AVM were explored and were eliminated by bipolar coagulation; then, dissection and total removal of the AVM were accomplished. No new postoperative neurological deficit was observed. Pathologic study confirmed an AVM. Because the patient was in the period of menstruation, postoperative digital subtraction angiography was not performed. Three days before surgery, carbamazepine was started to be given with 300 mg/day to prevent seizures and was withdrawn 10 days after surgery. The patient was discharged on the 11th postoperative day without any medication.
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Fig. 1

a Preoperative MRI, T2-weighted image, showing left occipital hemotoma with subdural hemorrhage of left hemisphere and middle line apparent right shift about 10 mm. b Preoperative MRI, T2-weighted image, showing that there was no definite abnormal signal in the left uncus and hippocamp. c Preoperative MRI, T2-weighted image, showing that there was no definite abnormal signal in the left frontal lobe. d Preoperative MRI, T2-weighted image, showing that there was no definite abnormal signal in the left frontal lobe

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Fig. 2

a Four-vessel digital subtraction angiography revealing an occipital AVM on the left, which was fed by branches of the left posterior cerebral artery, was drained into the superior sigmoid sinus. b Four-vessel digital subtraction angiography revealing an occipital AVM on the left, which was fed by branches of the left middle cerebral artery

On the second day after surgery, the patient became sexually aroused. She developed increasing libido and turned increasingly preoccupied with sex. Her desire for sexual activity increased from once per week before surgery to all day after surgery. She had increasing agitation whenever a male was nearby. The patient was strongly tortured by this desire and reproached herself bitterly. After returning home, she had to engage herself in various household works and even walked around the surrounding farmland to drive off the libido. Her embarrassed family members even resorted to Chinese herb medicine and acupuncture, but they did not work. She had no seizure onset. On February 15, the patient returned to our hospital for check up. Her left third cranial nerve palsy was improved a lot to almost normal. Her mental status examination revealed normal attention with intact language, memory, and calculation. She was embarrassed extremely and asked repeatedly whether her hypersexuality could be curable. Neuropsychological evaluation showed moderate depression (Hamilton depression scale score is 22) and mild anxiety (Hamilton anxiety scale score is 17). We administered a sexual functioning questionnaire, the Female Sexual Function Index (FSFI) [15] to the patient and rated her sexual functioning at 32.8 out of a possible 36. The domain with the most significant dysfunction was in sexual desire (Table 1). There was no previous personal or family history of mood disorder. Electrolytes, liver function test results, and complete blood counts were normal. The patient was not on any drugs, and the concentration of Carbamazepine in blood serum was low and could not be detected. The serum hormone including total thyroxine 3, total thyroxine 4, thyroid stimulating hormone, free thyroxine 3, free thyroxine 4, prolactin, luteinizing hormone, follicle-stimulating hormone, estradiol, progesterone, human growth hormone, cortisol, and testosterone were within the normal range. CT and CT angiography (Fig. 3) showed normal for postoperative status and there were no AVM residual. CT perfusion imaging (Fig. 4) showed, except the surgical area, the parameters of cerebral hemodynamics including cerebral blood flow, cerebral blood volume, mean transit time, and time to peak were in the normal range.
Table 1

FSFI domain scores and full-scale scores: first versus second

Domain

Questions

First individual domain scores

Second individual domain scores

First score

Second score

Desire

1, 2

10

7

6

4.2

Arousal

3, 4, 5, 6

18

12

5.4

3.6

Lubrication

7, 8, 9, 10

18

14

5.4

4.2

Orgasm

11, 12, 13

14

9

5.6

3.6

Satisfaction

14, 15, 16

13

9

5.2

3.6

Pain

17, 18, 19

13

12

5.2

4.8

Full-scale score

   

32.8

24.0

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Fig. 3

a Postoperative axial CT angiography with the slices including hippocampal gyrus, showing normal for postoperative status. b Postoperative axial CT angiography with the slices including surgical area and frontal lobe, showing normal for postoperative status and no AVM residual. c Postoperative axial CT angiography with the slices including surgical area and frontal lobe, showing normal for postoperative status and no AVM residual. d Postoperative axial CT angiography with the slices including surgical area and frontal lobe, showing normal for postoperative status and no AVM residual. e Postoperative axial CT angiography with the slices including surgical area and frontal lobe, showing normal for postoperative status and no AVM residual. f Postoperative axial CT angiography with the slices including surgical area and frontal lobe, showing normal for postoperative status and no AVM residual. g CT angiography with three-dimensional reconstruction, showing normal for postoperative status and no AVM residual

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Fig. 4

CT perfusion imaging showing, except the surgical area (white arrow), that the parameters of cerebral hemodynamics were in the normal range

For further evaluation, the patient underwent 18F-flurodeoxyglucose (FDG) positron emission tomography (PET). The PET scanner was an ECAT Exact HR+ system (Siemens Medical Solutions, Knoxville, TN), with a full width at half maximum spatial resolution of nearly 5 mm. After intravenous injection of 259 MBq (7 mCi) 18F-FDG, the patient rested in a warm dark room for 40 min. Then, she was positioned in the scanner and accepted a 6-min emission acquisition in three-dimensional mode and another 3-min transmission acquisition for attenuation correction after segmentation processing. The images were reconstructed with ordered subset expectation maximization method and were displayed in axial, coronal, and sagittal views for reading. In addition to the hypometabolism in the surgical area of the left occipital lobe, hypermetabolism was observed in the left frontal lobe, especially in the left middle frontal gyrus and the inferior frontal gyrus (Fig. 5a). PET also showed hypometabolism in the left anterior hippocampal gyrus and hypermetabolism in left posterior hippocampal gyrus (Fig. 5b).
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Fig. 5

a PET showing hypermetabolism in the left frontal lobe (white arrow). b PET showing hypometabolism in the left anterior hippocampal gyrus (white arrow) and hypermetabolism in left posterior hippocampal gyrus (black arrow)

We treated the patient with sertraline hydrochloride tablets, 50 mg/day orally, and risperidone tablets 1 mg orally at bedtime. After 30 days, the patient showed relief of hypersexual symptoms to some extent. On June 22, 2009, she completed the FSFI questionnaire once more; her FSFI score dropped to 24.0 (Table 1).

Discussion

AVMs can cause widespread derangements of the cerebral circulation [3, 7]. Lower resistance and high-flow malformations may produce relative ischemia in the brain adjacent to or distant from the malformation. Clinically, this may produce episodes of transient ischemia, or chronic ischemia may result in insidious cognitive decline [7]. Resection of AVMs may have an effect on the cerebral circulation. Abrupt removal of the AVM from the cerebral circulation by either open or endovascular surgery is complicated by a transient circulatory derangement commonly called normal pressure perfusion breakthrough (NPPB) in approximately 10% of cases [7]. In mild forms, NPPB produces migraine-like headaches and may be associated with seizures. In more severe cases, NPPB may result in extensive brain edema, hemorrhage, or both in regions of the brain adjacent to or distant from the AVM [9]. The decreased perfusion in areas distant from an AVM and the reperfusion of hypoperfused tissue following obliteration of AVM feeding arteries can produce a few neuropsychological or cognitive changes [2, 4, 7, 10, 17]. We reported one case of hypersexuality from resection of left occipital AVM, which was not reported in the literature to our knowledge.

Hypersexuality, which is characterized by an unbearable need for frequent genital stimulation, is often manifested as an increase in frequency or change in types of sexual behaviors, which fail to produce long-term sexual and emotional satisfaction. These behaviors include compulsive masturbation, compulsive sex with prostitutes, anonymous sex with multiple partners, multiple affairs outside a committed relationship, frequent patronizing of sexually oriented establishments, habitual exhibitionism, habitual voyeurism, inappropriate sexual touching, sexual abuse of children, and rape. In addition to these, fantasy sex, prostitution, pedophilia, masochism, fetishes, and sex with animals may also be associated behaviors. It is a combination of these behaviors along with the compulsivity that comprises hypersexuality [12].

As is the case with many other psychiatric disorders, the etiology of hypersexuality is complex and involves a variety of physiological and psychological mechanisms. Frontal lobe dysfunction can lead to disinhibition of sexual behavior and hypersexual behavior. Temporal lobe abnormalities, which have been associated with hypersexuality, also seem to be involved in development of various fetishes, paraphilias, and pedophilia. Head traumas, brain surgeries, and medications have been associated with hypersexuality. Onset of hypersexuality has been associated with frontal lobe lesions, frontal and temporal lesions, temporal lobe epilepsy, dementia, Klüver–Bucy syndrome, multiple lesions in multiple sclerosis, and treatment of Parkinson’s disease with dopaminergic agents [6, 8, 9, 11, 13, 14, 16, 19].

Our patient’ behaviors met the definition for hypersexuality resulting from removal of left occipital AVM. We do not think it is the surgical injury to the occipital lobe that is the cause of the hypersexuality. There are no reports that occipital lobe is associated with sexual behavior. Besides the surgical damage to the occipital lobe, there were two major events in the patient. Firstly, there was an uncal herniation before the surgery, which might have injury to the left uncus and hippocamp of temporal lobe. Secondly, it is the abrupt removal of the AVM from the cerebral circulation might lead to NPPB in regions of the brain adjacent to or distant from the AVM. Although CT perfusion imaging did not show any hemodynamic changes in the patient, the PET of the brain, which seemed to be more sensitive showed hypermetabolism in the left frontal region and left posterior hippocamp and hypometabolism in anterior hippocamp, which all areas related with human sexual response. PET seemed to provide imaging evidences to explain the patient’s disinhibition of sexual behavior and hypersexual behavior. We supposed that, in our case, the hypermetabolism in the frontal lobe may have two possibilities: One was that the reperfusion of frontal lobe after the resection of occipital AVM led to active brain function, and the other was that it was secondary to functional change in the uncus and hippocamp. The hyper- or hypo-metabolism in the hippocamp was more complicated; it might be the result of a mix of the injury of hippocamp from uncal herniation and reperfusion of hippocamp. We think that both of the events contributed to the hypersexuality of the patient. Derangements of the cerebral circulation and reperfusion of hypoperfused tissue following obliteration of AVM may facilitate development of preexisting injury of the uncus and hippocamp of the temporal lobe. NPPB perhaps triggered the symptom of hypersexuality. This could explain why hypersexuality happened 1 day after the resection of the AVM and not after the onset of the uncal herniation.

Specific areas in the brain responsible for the human sexual response are poorly understood and much of our information comes from lesion studies in animals. Animal studies are not completely applicable to humans, however, and even non-human primates have sexual behaviors that differ markedly from those of men and women [5]. Hyposexuality is common with injury to the brain, although the lesions seen with this condition are sufficiently variable that it is difficult to identify one specific area in the brain responsible for the diminished sexual interest, whereas hypersexual behavior are much less common following brain injury [11]. Study of hypersexuality in humans after focal brain injury will give valuable clues about areas of the brain involved in the normal sexual response. Case studies and the literature provide evidence that different brain systems may play a role in this disorder. Frontal lesions may be accompanied by disinhibition, including impulsive hypersexual response to external cues [18]. Our patient’s presentation feature is only the development of increasing libido with fairly normal cognitive function; meanwhile, the brain PET presented local hot spot in the frontal lobe that did not directly surgically damaged, which will contribute to the understanding of this evolving and complex field.

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© Springer-Verlag 2009