Our report has several limitations. First, it is a case report andmore evidence is needed to prove our hypothesis. Second, as hersymptoms had totally subsided, the patient declined follow-upMRA. We were unable to demonstrate the reversibility of cerebralvasoconstriction, but the clinical evidence was strongly in favor ofthe diagnosis of RCVS. Third, dural puncture and angiography werenot performed for the reasons mentioned previously. Although un-likely, the possibility of aneurysm with repetitive sentinel leakscould, therefore, not be totally excluded.

Acknowledgements

The authors are grateful to Dr. Shen-Ing Liu for advice in thepreparation of the manuscript.

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doi:10.1016/j.jocn.2010.01.052

Case Reports / Journal of Clinical Neuroscience 17 (2010) 1351–1352 1351

Craniopagus parasiticus: A rare case

Ritesh Kansal *, Chirag Kale, Atul GoelDepartment of Neurosurgery, King Edward Memorial Hospital & Seth Gordhandas Sunderdas Medical College, Acharya Donde Marg, Parel, Mumbai 400 012, India

a r t i c l e i n f o

Article history:Received 12 January 2010Accepted 31 January 2010

Keywords:Conjoined twinsCraniopagus parasiticusSiamese twins

a b s t r a c t

Conjoined twins or Siamese twins are identical twins whose bodies are joined in the uterus. Craniopagusis a condition in which the heads of the two twins are joined. Craniopagus parasiticus is a rare conditionin which one of the twins is rudimentary in form and parasitic on the other. Few cases of craniopagusparasiticus are reported in literature; here, we present one such rare occurrence.

� 2010 Elsevier Ltd. All rights reserved.

1. Introduction

Conjoined twins are a rare type of twin with numerous varia-tions; craniopagus is an infrequently occurring condition in whichthe heads of the twins are joined. Craniopagus parasiticus is a sel-dom-seen type of craniopagus in which one of the twins is degen-erated.1 We present one such occurrence and discuss the relevantliterature.

2. Case report

A 20-year-old male with two heads presented to the outpatientdepartment of our facility. Enquiry revealed that the child wasborn with two heads in a village, and was not investigated untilhe presented to our facility. As the patient had grown up, the addi-tional head had grown in size. On examination, the patient did not

* Corresponding author. Tel.: +91 22 2412 9884; fax: +91 22 2414 3435.E-mail address: drkansal@yahoo.co.in (R. Kansal).

demonstrate any neurological deficit. It was also observed that thetwin head had a fully developed nose, mouth and ears, although itseyes were closed (Fig. 1). The head of the twin did not have anyvoluntary neurological control and its limbs and trunk were notdeveloped. The patient was advised to undergo MRI for further sur-gical consideration; however, this was declined for religiousreasons.

3. Discussion

Craniopagus is a rare anomaly and occurs in only 4 to 6 of every10 million live births.2 It may result from the development of twofetuses from one zygote, with incomplete separation of the cranialends in the second week of gestation. Others believe that it resultsfrom abnormal fusion of two separate embryos at the end of fourthweek of gestation, at the anterior open neuropore.3 Conjoinedtwins are identical in both appearance and sex, and may be fusedat the vertex, forehead or side of the head.

Fig. 1. Photograph of the patient showing the attached parasitic twin head at thevertex to have a well-developed nose, mouth and ears.

1352 Case Reports / Journal of Clinical Neuroscience 17 (2010) 1351–1352

Craniopagus parasiticus is a rare condition. There are only nineinstances reported in the literature.1 The first known case of thismalformation was Everard Home’s famous twin-headed boy ofBengal, whose skull is preserved at the Hunterian Museum.4 Theterm defines a condition in which one twin, being underdeveloped,acts as a parasite on the other, developed sibling.

doi:10.1016/j.jocn.2010.01.053

There is a definite male predominance in the reported data,with seven of the nine known presentations being male.1 To date,only a few known individuals with this condition have survived,with most being stillborn. Given the current literature findings, itmay be that our patient is the longest surviving individual withcraniopagus parasiticus. Successful surgical separation has, so far,only been reported in one instance.1 The venous anatomy is themost important consideration of surgical management, as bleedingis the most likely complication expected during surgery. Early liga-tion of the parasitic twin’s arterial supply may improve the surgicaloutcome.1

These few recorded instances of craniopagus parasiticus pro-vide significant insight into the embryology of twin births andmay improve our understanding of this unusual condition.

References

1. Lotfy M, Sakr SA, Ayoub BM. Successful separation of craniopagus parasiticus.Neurosurgery 2006;59:E1150.

2. Sathekge MM, Venkannagr RR, Clauss RP. Scintigraphic evaluation ofcraniopagus twins. Br J Radiol 1998;71:1096–9.

3. Spencer R. Theoretical and analytical embryology of conjoined twins: part 1:embryogenesis. Clin Anat 2000;13:36–53.

4. Bondeson J, Allen E. Craniopagus parasiticus. Everard home’s two-headed boy ofBengal and some other cases. Surg Neurol 1989;31:426–34.