Endoscopic resection of intraventricular ependymal cyst presenting with psychosis

ELSEVIER

ENDOSCOPIC RESECTION OF INTRAVENTRICULAR EPENDYMAL PRESENTING WITH PSYCHOSIS

CYST

Basant Pant, M.D., Tohru Uozumi, M.D., Taizo Hirohata, M.D., Kazunori Arita, M.D., Kaoru Kurisu, M.D., Toshinori Nakahara, M.D., and Kouki Inai, M.D. Department of Neurosurgery, Second Department of Pathology, Hiroshima School of Medicine, Hiroshima, Japan

Pant B, Uozumi T, Hirohata T, Arita K, Kurisu K, Nakahara T, fnai K. Endoscopic resection of intraventricular ependymal cyst pre senting with psychosis. Surg Neural 1996;46:573-8.

BACKGROUND Intracranial ependymal cysts are rare lesions generally located in the cerebral parenchyma, juxtraventricular region, or subarachnoid space; but no case of a purely intraventricular ependymal cyst has been reported. CASE REPORT A case of intraventricular ependymal cyst presenting with symptoms of psychosis is reported. The patient’s symptoms resolved almost completely following endoscopic resection of the cyst. The embryologic basisof the development of an ependymal cyst inside the ventricle and its histologic characteristics are discussed.Possible mechanism of psychosis in this case is also discussed. CONCLUSION

minimally invasive techniques, as in this case, may be useful in refractory psychotic caseswith cystic lesions. 0 1996by ElseuierScienceInc. KEY

WORDS

Endoscopicresection, ependymal cyst, psychosis.

I

ntracranial ependymal cysts are rare lesions and occur less frequently than arachnoid cysts [X2]. The cysts are generally located in the supratentorial cerebral parenchyma but are occasionally present in the juxtraventricular region [ 111, subarachnoid space [8], spinal subarachnoid space [5], or pons [9]; but no case of a pure intraventricular ependymal cyst has been reported. These lesions generally present with focal neurologic deficit or with signs of raised intracranial pressure. Here we present a case of a completely intraventricular

Address reprint requests to: Basant Pant, M.D., Department of Neurosurgery, Hiroshima University School of Medicine, l-Z-3 Kasumi, Minamiku. Hiroshima 734 Japan. Received December 28, 1994; accepted March 5, 1996. 0 1996 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010

ependymal cyst that presented like syndrome.

University

with schizophrenia-

CASEREPORT This 22-year-old-male was admitted to the psychiatric department with a S-year history of gradually worsening spells of depression. He also had behavioral problems and the treating physician had difficulty deciding whether the symptoms were attributable to depression or schizophrenia. The patient’s symptoms gradually worsened and he was unable to work and lead a normal social life and became confined to his room. He had been on antidepressive drugs for 5 years and on major tranquilizers for 1 year. EXAMINATION Neurologic examination revealed no abnormalities and there were no signs of raised intracranial pressure. During routine computed tomographic (CT) scan, a cystic mass was found in the left lateral ventricle; subsequent magnetic resonance imaging (MRI) showed it to be completely intraventricular, lying just anterior to the trigone. The temporal horn on the same side was dilated due to trapping. Metrizamide cisternography showed absence of communication between the cyst and the ventricular system (Figure 1). Electroencephalograph (EEG) done on three occasions were normal. Psychological testing in the form of revised Wechsler adult intelligence test (WAIS-R), Bender-Gestalt test, and Kraepelin test [14,15] were 63, 18, and C, respectively. The patient’s symptoms were not attributable to any definite pattern of psychiatric illness and had characteristics of both schizophrenia and depression. A lumbar puncture (LP) revealed normal cerebrospinal fluid and no increase in opening 0090-3019/96/$15.00 PI1 s0090-3019(96)0022~-5

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(A) Metrizamide CT cisternography showing absence of communication between the cyst and the ventricular system. (B) Preoperative T,-weighted MRI scan showing relation of the cyst with the ventricular system and attachment to the choroid plexus anteriorly.

pressure, but following LP there was definite improvement in the psychological function of the patient for a few days. Although a direct cause and effect relationship was not possible to establish, the odd nature of the symptoms, little or no response to medication, and improvement in symptoms following LP led to a decision to undertake a less invasive surgical approach to the lesion.

OPERATION A small craniectomy was made in the parietal region and a 4 mm rigid endoscope (Olympus Co.) with a bridge providing three channels was introduced after gradual dilatation of the ventriculostomy with bougies. The cyst was translucent, thin walled, and had few vessels over the surface. The surface was grasped with a biopsy forceps and multiple tears were made. A clear fluid was seen coming out of the cyst. The wall was removed partially by avulsing it from its attachment that was at the choroid plexus. There was little bleeding from the avulsed surface that stopped spontaneously after irrigation with warm Ringer’s solution. Communication was established between the cyst and the body of the lateral ventricle anteriorly, but no shunting procedure was carried out. Light microscopy of the specimen showed a single layer of cuboidal cells with absence of basement membrane and presence

Postoperative T,-weighted MRf scan showing disapH pearance of mass effect with some residual dilatation of the posterior horn.

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(A) Histology of the specimen showing single layrer of cuboidal cell and presence of cilia like structures. (B) Electron micrography showing presence of micr ‘0% rilli (X 2000).

of cilia-like structures. Electron microscopic examination showed the presence of microvilli (Figure 3). The patient had a mild homonymous hemianopia postoperatively, which recovered fully within 2 weeks. Psychological testing showed definite improvement postoperatively (WAIS-R-96, Bender-Gestalt-lo, and Kraepelin test-bF) all within normal limits, and the dose of antidepressant drugs was reduced to one-third. The patient was able to return to work within a few weeks of surgery and has had no relapse during the l-year follow-up period.

DISCUSSION This case is unique in the sense that it is a completely intraventricular epend~al cyst, presented with a long history of psychosis alone and no neurologic deficit. It is surprising that there has been no report of a purely intraventricular ependymal cyst in the English literature when such an occurrence is very likely from the hypothesis of its development [7]. The usual origin of the cyst is from

the short segment of the wall of the neural tube from which the tela choroidea develops f3,12]. Therefore, these cysts may contain different components of tissue such as the presence or absence of either cilia, choroid plexus, or glial tissue. A partial resection will only show the part that is within the given segment of the specimen. The present case also supports this hypothesis and adds to the picture of its development; it does not support the theory that it is merely an out-pouching of the lateral ventricle [ 151. With some exceptional reports during infancy [4,5] it is still not clear why symptoms develop only during adulthood, and once developed why the progression is so rapid. The presence of numerous pinocytotic vesicles denotes transcellular fluid transportation and Friede suggested the theory of active secretion [3], whereas Jakubiak suggested hyperosmolality of the cyst fluid that draws water from the surrounding tissue; but both failed to explain why secretion only occurs during adulthood. Behavioral problems as a presenting symptom are sometimes seen with intraventricular cysts in which the symptoms re-

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solved postoperatively [8,13]. There have been few reports of ependymal cysts associated with psychiatric symptoms in the form of confusion, disturbance of memory [3]; mental slowness, poor concentration [2], irritability, and personality disturbance, which improved after surgery [9]. The theory of psychosis due to trapping of the ventricle leading to ischemia and subsequent partial complex psychomotor seizure is not applicable in this case as EEG readings were normal and symptoms were constantly present with no relation to position of the head [13]. Seizures still cannot be ruled out as scalp electrode alone may not detect seizures generating from deep medial structures. Direct pressure causing dysfunction of the amygdalahippocampal complex or trapping of the trigone causing disturbance of normal metabolism of monoamines locally may be the possible mechanism of behavioral disturbance in this case, which gave rise to psychotic symptoms alone without any neurologic deficit. Minimally invasive techniques as in this case, may be useful in refractory psychotic cases with cystic lesions in which medication fails to control the symptoms. REFERENCES 1. Barth PG, Uylings HBM, Stam FC. Interhemispheric neuroepithelial (Glio-ependymai) cysts, associated with agenesis of the corpus callosum and neocortical maldevelopment: a case study. Child’s Brain 1984;ll: 312-9. 2. Bouch DC, Mitchell I, Maloney AFJ. Ependymal lined paraventricular cerebral cysts; a report of three cases. J Neurol Neurosurg Psychiatry 1973;36:611-17. 3. Friede RL, YaSargil MG: Supratentorial intracerebral epithelial (epend~a1) cysts: review, case reports, and fine structures. J Neurol Neurosurg Psychiatry 1977;40:127-37. 4. Haddad FS, Abla A, AIlam C. Ependymal brain cyst. Surg Neurol 1982;18:246-9. 5. Klump TE. Neuroenteric cyst in the cervical spinal canal of a lo-week-old boy: case report. J Neurosurgery 1971;35:472-6. 6. Kuhnley EJ, White DH, Granoff AL: Psychiatric presentation of an arachnoid cyst. J Clin Psychiatry 1981;42: 167-8. 7. Niwa J, Tohru 0, Shimizu K, Hirai H: Glio-ependymal cyst in the lateral ventricle complicated by agenesis of the corpus callosum. No Shinkei Geka 1991;19(4): 359-63. 8. Pascal CR, Suttel BJ. The Bender-Gestalt test. Quantification and validity for adults. New York: Grune & Stratton, 1955. 9. Patrick B.S.Epedymal cyst of the Sylvian fissure: case report. J Neurosurgery 1971;35:751-54. 10. Rillet B, Berney J. Benign ependymal cyst of the pons. Child’s Brain 1981;8:1-8. 11. Shuangshoti SP, Roberts MP, Netsky MC. Neuroepithelial (colloid) cysts: pathogenesis and relation to

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12. 13. 14. 15. 16. 17. 18.

choroid plexus and ependyma. Archs Path 1965; 80:214-24. Takeshita M, Miyazaki T, Kubo 0, Kagawa M, Saito Y, Kitarnura K. P~aventricuIar cyst in an infant. Surg Neurol 1982;17:123-6. Takeuchi T, Kumakawa H, Kimura S, Satoh S, Kobayashi M. Occipital lobe ependymal cyst-case report. Neurol Med Chir (Tokyo) 1989;29:417-23. Uchida-Kraeplin psychiatric examination text. Kaneco Shoboku, ed. Toyohiko Sotooka, 1973. Wechsler D. Manual of Wechler Adult Intelligence Scale. New York: The Psychological Corporation, 1955. Wilkins RH. Ependymal cysts. In: Wilkins RH, Rengachary SS, eds. Neurosurgery, vol 3. New York: McGraw-Hill, 1985, pp 2171-2. Wong C, Ko S, Wai Y. Arachnoid cyst of the lateral ventricle manifesting positional psychosis. Neurosurgery 1993;32:841-3. Jakubiak P, Dunsmore RH, Beckett RS. Supratentorial brain cysts. J Neurosurgery 1968;28:129-36.

COMMENTARY

As the authors indicate, ependymal cysts of the brain are indeed rare. While these lesions are located in the substance of the brain, in the subarachnoid region, or in the lateral ventricles, they have no direct communication with the cerebrospinal fluid; and the protein in the fluid of the cyst is often higher than that of the spinal fluid. The capsule of the cyst contains a single layer of ependymal cells. Although they are rare, there are still a considerable number of reports in the literature of essentially similar histologic structures, with different nomenclature. For example, in addition to the cyst located in the third ventricle, which is known as a “colloid cyst of the third ventricle,” these lesions are also reported as “epithelial cysts of the brain” [ 2,6], or simply as cerebral or brain cysts [4]. The authors report an ependymal cyst located entirely in the left lateral ventricle. In a detailed, though not exhaustive, literature search, we too were unable to find any reports of purely intraventricular cysts. Coincidentally, however, we also had a very similar case of a 43-year-old man in whom the cyst was located in the right lateral ventricle; it was excised in 1992. A cyst of the choroid plexus located in the lateral ventricle, also a rare lesion, may have a somewhat similar appearance [3]. It is important to note that these lesions are quite different from arachnoid cysts; it is preferable to excise them completely whenever possible, since simple puncturing of the cyst wall or opening it into the lateral ventricle may be associated with recurrence [4,6]. In this article, the authors indicate that their patient had suffered from psychosis (i.e., depression and a schizophrenia-like syndrome). Our patient

Endoscopic Resection of Ependymal Cyst

A IC T

P GP

NA

CN

u

Simplified diagram depicting the circuitry likely to play a rote in compensatory ~y~erd~paminergia associated with stress. Note b~dire~~io~ai arrows indicating inter-co~~ectjons existing in several major sites, atlowing for feedback regulation. (PFC: prefrontal cortex; CN: caudate nucleus; P: putamen; GP: globus pallidus; NA: nucleus acc~mbens; T: t~a~amus; IC: internal capsule; A: amygda~a; L\i: lateral ventricle; Hp: hippocampus.)

also had a short intern of behavioral alteration and depression, which improved after excision of the lesion. However, this does not seem to be an unusual occurrence, ~eha~o~al changes in the form of depression or psychotic manifestations are not an uncommon condition associated with pathologic alteration of the brain, especially with lesions located in the temporal lobe. These mental changes can occur with various lesions, located in di~erent areas of the brain. Such lesions could be degenerative in nature or could cause local cerebral compression [ 11. The authors suggest that direct pressure caustic ~~dysf~nctio~ of amy~da~a-hippocampal complex” by trapping the trigon of the lateral ventricle could cause “disturbance of normal metabolism of monoamines” as the reason for psychosis in their patients While such a mechanism is a possibiIity, there is no data mentioned in this paper to support such a hypothesis.

1. Davison K. Schizophrenia-Iike psychoses associated with organic cerebral disorders: a review. Psychiat Devel 1983;1:1-34. 2. Ghatak NR, Hirano A, Kasoff SS, Zimmerman HM. Fine structure of an intracerebral epitheUa1 cyst+ 3 Nemosurg 197~41:7S-$2. 3. Giorgi C. Symptomatic cyst of the choroid plexus of the lateral ventricle. Neurosurge~ 19?9;5:53-6. 4. Handa H, Bucy PC. Benign cysts of the brain simulating brain tumor. J Neurosurg 1956; 13~469-99. 5. Jaku~i~k P, Dunsmore RH, Beckett RS. S~pratentori~ brain cysts. J Neurosurg 196~2~~29-36. 6. MacGregor BJL, Gawler J, South JR Intracranial epithelial cysts. Report of two cases. J Neurosur~ 1976;44: 109-15. The authors report a unique case of int~aventricufar ependymal cyst presenting with psychotic s~ptoms that resalved after endoscopie resection of the cyst. The authors contend that psychosis is the result of disturbance of monoami~es’ metabolism caused by dysfunction of the amygdalahippocampal complex when the cyst exerts direct

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pressure and trapping of the trigon. This explanation seems plausible if we take into account that

compensatory hyperdopaminergia after the disruption of the co~icostriato-thalamocortica~ loop, as a mechanism for the emergence of a secondary psychotic disorder (Figure I).

these structures are essential for sensory appraisal and memory formation. Furthermore, the hippocampal formation, given its periventricular tion, is vulnerable not only to breaches

locain the

Ovidio

A. De Leih,

blood-brain barrier, but also to direct pressure that results in hypoperfusion and hypoxia. Deutch et al [3] pointed

out that afferents from the amyg-

dala and the hippocampus reach the nucleus accumbens, and it is likely that these structures subserve the affective component associated with stress. Roth et al [4] have shown that moderate stressors cause dopamine release in the nucleus accumbens, and Cummings [2] postulated that interruption of these tracts may result in mesolimbic dopamine receptor denervation hypersensitivity. It has also been hypothesized that when the mesolimbic-mesostriatal dopaminergic system is activated, a co~icostriat~thalamocortical negative feedback loop causes a disinhibition of a thalamic filter [ 11,allowing more information to flow into the cortex, leading to the emergence of psychotic symptoms.

This case, aptly discussed

REFERENCES Carlsson M, Carlsson A. Interactions between glutamatergic and mono~inergic systems within the basal ganglia. Implications for schizophrenia and Parkinson’s disease. Trends in Neurosciences 1990;13:272-6. Cummings JL. Organic psychoses: delusional disorders and secondary mania. Psychiatric Clin North Am 1986;9:293-311. Deutch AY, Bourdelais AJ, Zahn DS. The nucleus accumbens core and sheh: accumbal compartments and their functional attributes. In: Kalivas PW, Barnes CD, eds. Limbic motor circuits and neuropsychiat~. Boca Raton, Florida: CRC Press 1993; pp. 45-88. Roth RH, Tam S, Ida Y, Yang J, Deutch AY. Stress and the mesocorticolimbic dopamine systems. In: Kalivas PW, Nemeroff CB, eds. The mesocorticolimbic dopamine system: Annals of the New York Academy of Sciences. New York: The New York Academy of Sciences, 1988;537:138-47.

by Pant and

coworkers, offers support to the hypothesis of a

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