0022-3018/86/1748-0484$02.00/0 THE JOURNAL OF NERVOUS AND MENTAL DISEASE Copyright © 1986 by The Williams & Wilkins Co. Vol. 174, No. 8 Printed in U.S.A. SINGLE CASE STUDY Capgras Syndrome with Subarachnoid Hemorrhage ANTHONY BOUCKOMS, MB., Cu.B., ROBERT MARTUZA, M.D., and MARY HENDERSON, Pu.D." Capgras misidentification syndrome after subarachnoid hemorrhage and the surgical repair of a right middle cerebral artery aneurysm is described. This Capgras delusional belief in an imposter assuming the form of a familiar person may result from disruption of cortical-visual-limbic pathways in the right hemisphere. Capgras syndrome is the delusional belief in a dou- ble of one’s self or other people. It is one form of misidentification syndrome in a spectrum of disorders that includes: autoscopy (hallucinatory vision of one’s self, Maack and Mullen, 1983), reduplicative param- nesia (reduplication of a familiar place or person, Alexander et al., 1979), and prosopagnosia (misrecog- nition of familiar faces; Berson, 1984). Putative or- ganic and psychodynamic etiologies have been under critical scrutiny. Organic brain disease has been found in 26% to 42% of patients with Capgras syndrome (Merrin and Silberfarb, 1976).? Right hemispheric and frontal lesions account for most of the organic cases (Wilcox and Waziri, 1983). In contrast, psychody- namic etiologies are emphasized in a review of 133 published cases up to 1983 (Berson, 1983). The psy- chodynamics of misidentification in Capgras syn- drome are described as a psychological means of re- solving intense ambivalent feelings by the splitting of affect/identity. The goal of this case review is to describe a patient with Capgras syndrome in whom a fixed belief of doubles followed an acute right hemisphere injury. This is of interest for three reasons. It shows that a circumscribed delusional belief that discriminates be- tween individuals, without other psychopathology present, can be attributed to a specific neuroanatom- ical lesion. The neuroanatomical implications are of interest because this case imputes a clinical validity to the cortical-visual-limbic systems described by Bear (1983). Thirdly, the rarity of a circumscribed organic lesion producing Capgras syndrome deserves descrip- tion in its own right, since the first organic case of Capgras syndrome due to an organic cause was de- scribed as recently as 1968 (Gluckman, 1968). 1 Psychiatry Service and Neurosurgery Service, Massachusetts General Hospital, Boston, Massachusetts. Send reprint requests to Dr. Bouckoms, Warren 6, Massachusetts General Hospital, Boston, Massachusetts 02114. 2 Spier, S. Everything you wanted to know about Capgras syn- drome but were too oriented to ask. Psychosomatic Conference, Massachusetts General Hospital, October 14, 1983. Case Report Mrs. B. was a 66-year-old right-handed high school graduate. A widowed housewife, the mother of two daughters, one of whom (Mary) lived with her, she enjoyed good medical and psychiatric health in the past. While cleaning her car she felt a sudden head- ache and telephoned her daughter Mary to ask for help. Mary immediately went to her mother’s house and found her mother holding her head and sweating, with a marked red facial flush. She was admitted to the hospital somnolent but arousable. There was a left sixth nerve palsy and bilateral upgoing toes. A com- puted tomography (CT) scan confirmed the diagnosis of subarachnoid hemorrhage and acute hydrocephalus secondary to subarachnoid and intraventricular hem- orrhage. There were thick clots (>1 mm) in the basal frontal interhemispheric fissures and in the right am- bient cistern. Diffuse blood was present in the stem of the Sylvian fissure and the Sylvian cisterns bilat- erally as well as in the right suprasellar cistern (Figure 1). An anterior communicating artery aneurysm was suspected. However, carotid and vertebral angiogra- phy demonstrated a small right middle cerebral artery aneurysm (Figure 2). On the third hospital day, the patient became somnolent and disoriented. A CT scan demonstrated progressive hydrocephalus, and bifron- tal ventriculostomies were performed. She improved and became alert, oriented, and conversant. A left hemiparesis developed. This was attributed to vaso- spasm and improved with treatment with volume and blood pressure elevation. The ventriculostomies were removed 7 days after insertion. Six days later she became more lethargic. The CT scan showed hydro- cephalus. A repeat three vessel arteriogram showed only the right middle cerebral artery aneurysm. On the 17th day after her hemorrhage, she underwent a right ventriculovenous shunt and simultaneous clip- ping of the right middle cerebral artery aneurysm via a pterional approach opening the Sylvian fissure. The systolic blood pressure was kept above 95 mm Hg throughout the procedure, The aneurysm was fully CAPGRAS SYNDROME WITH SUBARACHNOID HEMORRHAGE 485 Fic. 1. This CT scan was performed on the day of hemorrhage and demonstrates blood in the basal cisterns, interhemispheric fissure. Sylvian fissures, ambient cisterns, and ventricles. Fic. 2. This right internal carotid arteriogram demonstrates a small middle cerebral artery aneurysm (arrow). mobilized and all vessels were completely visualized through the operating microscope. A straight Yasargil clip was used to obliterate the aneurysm and tissue adhesive was applied to a weak area of the aneurysmal neck. No vessels were compromised. The ventricular shunt was easily placed into the enlarged ventricles with one insertion. A Hakim valve with a closing pressure of 91 mm Hg was used and the distal catheter was radiologically confirmed to be in the atrium. Post- operatively she became increasingly alert and her left- sided weakness resolved. One observer noted abulia and a positive grasp reflex bilaterally. Physical and mental progress were excellent. She was oriented and conversant and had no focal deficits. A CT scan before discharge showed some persistent ventriculomegaly despite reduction in ventricular size compared with the preoperative CT scan. She was discharged home expecting a full recovery. Her daugher Mary had taken several months’ leave from work to care for her mother, who initially needed help with such tasks as dressing. A few days after discharge Mrs. B. stated that a younger girl had come into the house to masquerade as her daughter Mary. She believed this girl stayed for dinner and-was then sent away. This confusion of identities became more persistent. She said, “I know there is a younger girl in the house who looks just like Mary, my younger daugh- ter, but isn’t. I can tell that they are different by the sound of their voice even though they look almost the same.” At one moment she would speak to the real Mary and tell her about her new sister who looked almost the same as her, and at another moment would actually believe that the real Mary was not who she looked like, but the imposter. When questioned she would try to separate the two Marys by the tone of their voices, their height, or the color of their hair. But none of these differences was identified as stable trait differences. The imposter was always seen within the body of Mary, never as a separate visual halluci- nation. This confusion of identities remained limited to the daughter with whom she lived. She maintained good reality contact with her own identity as well as that of other people. The first psychiatric consultation occurred 4 months after her surgery when her daugher was trou- bled by these strange beliefs and noted her mother’s anxiety and tears when she repeatedly told her that there was one Mary, not two. The mental status examination showed a well-dressed, alert, cooperative woman with a smiling but constricted affect. Her belief in the presence of a double for her daughter was unshakable. She could not identify any specific differ- ences between the double and the real daughter. There were no other indices of psychosis, endogenous anxi- ety, or depression. There was no emotional lability, 486 BOUCKOMS et al. inappropriate social behavior, or psychomotor abnor- mality. There were no localizing neurological signs or frontal release signs. The EEG showed frequent runs of right temporal high-voltage delta and theta slowing. Neuropsychological evaluation showed there was significant impairment of frontal lobe functions, namely, difficulty establishing, maintaining, and switching conceptual sets, perseveration, and de- creased verbal fluency. Ability to plan and reason out the logical significance of details was below expecta- tion for her age. In view of her misidentification symptoms it is of particular interest that she drew inappropriate conclu- sions to account for the details she found confusing. Mrs. B. was unable to keep information in the correct temporal sequence. Although she could remember cer- tain facts, she remembered them out of context. She took one design and incorporated it in her recollection of a previous design. Thinking was very concrete. However, constructional abilities were relatively well retained. There were less pronounced impairments in memory for verbal and visuospatial material. Word finding, spelling, reading, and comprehension were mildly impaired. To summarize, the significant findings on her men- tal status were concreteness, inflexibility in thinking, perseveration, and impairment of her conceptual thinking. The end result was difficulty in organizing the available information in a meaningful emotional and conceptual manner. “Over the next year, evaluations showed gradual improvement in the patient’s delusional thinking. She became less anxious and less preoccupied with her belief in an imposter. Thereafter, she ceased talking about the imposter, and gradually came back to iden- tifying her daughter Mary as a single unique person. The last examination was 15 months after her original surgery. At this time there were no spontaneous com- plaints expressed by the patient or her daughter. How- ever, when Mrs. B. was questioned she still held the belief that there was an imposter and still tried to identify subtle differences between her real daughter and the imposter. She was not preoccupied with this belief and did not bother to argue with others about it or become anxious. The belief was not preoccupying, but was still there. The rest of her mental status remained normal. She had no gait disorder nor urinary symptoms to suggest normal-pressure hydrocephalus. Her neurological examination was normal. A CT scan 1 year after surgery demonstrated some persistent ventricular dilation and asymmetry, with the right frontal horn being larger than the left, suggesting possible loss of tissue in the right frontal lobe (Figure 3). Neither this nor prior CT scans demonstrated a cortical area of stroke or cortical loss. Fic. 3. This CT scan 1 year after surgery shows a right frontal shunt catheter and mild persistent ventriculomegaly with some periventricular low density. No cortical evidence for stroke is pres- ent. Discussion Mrs. B.’s belief in an imposter masquerading as her daughter conforms to the strict definition of Capgras syndrome as being a fixed delusional belief. There is no misperception or hallucination of another body, ruling out autoscopy, reduplicative paramnesia, and prosopagnosia. There were no parietal signs. Although insight is lost regarding the identity of her daughter, her sensorium was alert and oriented, excluding a generalized state. of. delirium. The absence of any past psychiatric history excludes chronic psychosis or per- sonality disorder. The presence of a visual hallucina- tion was raised by the patient’s claim that there were some varying perceptual differences (e.g., height, color of hair, voice) between her daughter and the imposter and by her occasional separation of the real daughter from the imposter, as described in the history. At those times the real Mary was identified as herself and the imposter as another separate person. This phenomenon plus the vague perceptual differences in the two Marys raises the question of hallucination rather than delusion. Even so, the primary consistent abnormality of her mental status was an intangible belief in a double daughter, that is, a delusional thought rather than a visual hallucination. Misidentification syndromes have been recognized CAPGRAS SYNDROME WITH SUBARACHNOID HEMORRHAGE 487 since the 1800s as possible sequelae to temporal lobe epilepsy, confusion, severe stress, anoxia, narcolepsy, parietal lesions, ecstasy, and hypnogogic twilight states (Critchley, 1979). Organic causes for Capgras misidenjification syndrome have been increasingly identified in up to 42% of cases.? Nondominant hem- isphere lesions, particularly the right frontoparietal area, have been the most common organic findings. The Capgras syndrome itself has been seen in both left and right temporoparietal lesions begging the question of any specific anatomical site being unique to the syndrome® (Levine and Grek, 1984). The first study of the association between a focal brain lesion and delusional thinking was reported by Levine and Grek (1984). They found that delusion after right hemispheric stroke depends on an interac- tion between a focal lesion and a more diffuse brain atrophy. They concluded that the superimposition of anew right hemispheric lesion on a diffusely atrophied brain seems to cause delusions that can be expressed verbally because the left hemisphere is relatively pre- served. This case supports Levine and Grek’s conten- tion. The strengths of the case are that there is no past psychiatric history and that we did not have to rely solely on radiographical and psychological infer- ence as to the localization of the lesion. Why might an individual with a right hemispheric lesion develop an illusion of doubles to selected peo- ple? The connection between misidentification of se- lected familiar people and right hemispheric lesions lies with the neuroanatomical pathways connecting the frontal cortex, limbic system, temporoparietal lobes and sensory cortex (visual in this case). The temporoparietal cortex receives projections from all the sensory association areas and projects widely to frontal cortex and limbic structures. There are two main cortical visuolimbic systems—dorsal and ventral (Bear, 1983). The dorsal (parietofrontal) system con- nects the dorsolateral frontal cortex with the cingulate gyrus, the parietal lobule, and the visual cortex. It is responsible for the surveillance of the environment and arousal to affectively relevant stimuli. Abulia results from a lesion to this system. The ventral (temporofrontal) system connects the orbital frontal cortex with the amygdala, hippocampus, and visual cortex. It is responsible for sequential temporal rela- tionships and storage of visual emotional associations. This system is responsible for weighing alternative drive responses. A lesion in this system may result in a reflexive release of emotion to environmental stimuli without consideration of learned consequences. In Mrs. B.’s case, the lesion may involve the dorsal 3 Joseph, A. B., and Kucharski, A.: Neuropsychiatric evaluation of 25 patients with misidentification. Unpublished manuscript. system, as suggested by the constriction of affect. Clinically, the ventral system may also be impaired in that the patient does suffer from abnormalities in ordering temporal relationships and storage of visual emotional associations. This is suggested by Bear’s model of the neurology of emotion (Bear, 1983). These clinical findings and neuroanatomical path- ways lead us to propose that Capgras syndrome may result from disruption of the sensory-temporoparietal limbic system. The patient’s inability to maintain attention and to select the affectively important in- coming stimuli results in a subcortical confusion. There is limbic anxiety, poor memory, and affective rigidity. The resultant feeling is one of “sentiments @etrangete” as described by Capgras in 1923. The question arises concerning the ill understood awareness of changes in thinking and feelings results in the attribution of confusion about the identity of a particular person. The hypothesis is that the patient experienced a sense of loss of something very impor- tant to her, in this case her intact cognitive function- ing. She felt badly that she had lost something ex- tremely valuable. Loss of clear thinking is a major stress to an elderly person. She identified the loss as something she knew was important to her, namely her daughter. This daughter was chosen because, in the context of the forced regression of the illness, there was ambivalence toward the person on whom she was forced to be dependent. In other words, the loss was displaced. This mechanism is different from dissocia- tion, projection, splitting, paranoia, and autism as seen in typical functional psychosis. Conclusion This case report demonstrates that the specific de- lusional belief of Capgras may result from right frontal hemispheric pathology in the context of more diffuse cognitive impairment without having to invoke any functional psychological cause. However, the psycho- logical mechanism of displacement is operative and explains why familiar individuals become the focus of confusion. A person with a cerebral lesion can discrim- inate among individuals. Disorders of belief (delusion) are not the exclusive realm of functional psychosis. Organic brain disorders are subject to the same het- erogeneity of expression as functional psychotic syn- dromes. Capgras syndrome may be the clinical mani- festation of disruption of cortical-visuo-limbic brain pathways. The evaluation of the patient with misiden- tification syndrome should include a thorough neuro- logical, neuropsychological, and psychiatric evalua- tion. 488 BOUCKOMS et al. References Alexander MP, Stuss DT, Benson DF (1979) Capgras syndrome: A reduplicative phenomenon. Neurology 29:334-339. Bear DM (1983) Hemispheric specialization and the neurology of emotion. Arch Neurol 40:195-202. Berson RJ (1983) Capgras’ syndrome. Am J Psychiatry 140:969- Berson RJ (1984) Dr. Berson replies (letter). Am J Psychiatry 141:616-617. Critchley M (1979) The idea of a presence. In The divine banquet of the brain (pp 1-12). New York: Raven. Gluckman IK (1968) A case of Capgras syndrome. Aust NZ J Psychiatry 2:39-43. 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