Case Reports / Journal of Clinical Neuroscience 21 (2014) 1455–1457 Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Appendix A. Supplementary material Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.jocn.2013.10.039. References [1] Yen CP, Khaled MA, Schwyzer L, et al. Early draining vein occlusion after gamma knife surgery for arteriovenous malformations. Neurosurgery 2010;67: 1293–302. [2] Cahan WG, Woodard HQ, Higinbotham NL, et al. Sarcoma arising in irradiated bone. Report of eleven cases. Cancer 1948;1:3–29. 1455 [3] Aanesen JP, Olofson J. Irradiation-induced tumors of the head and neck. Acta Otolaryngol (Stockh) 1979;360:178–81. [4] Berman EL, Eade TN, Brown D. Radiation-induced tumor after stereotactic radiosurgery for an arteriovenous malformation: case report. Neurosurgery 2007;61:E1099. 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Radiother Oncol 2007;83:175–7. http://dx.doi.org/10.1016/j.jocn.2013.10.037 Lower limb monochorea from a globus pallidus infarct Sanjay Pandey ⇑, Swapan Gupta Department of Neurology, RN 507, Academic Block, GB Pant Hospital, JLN Marg, New Delhi 110002, India a r t i c l e i n f o Article history: Received 13 August 2013 Accepted 27 October 2013 Keywords: Globus pallidus interna Infarct Monochorea a b s t r a c t Movement disorders are common following cerebrovascular accidents and they can be hyperkinetic, including hemichorea and hemiballismus, or hypokinetic, as seen in parkinsonian disorders. Monochorea has also been reported due to stroke, albeit rarely. We report a 47-year-old gentleman who presented with a history of sudden onset choreiform movement of his left lower limb. On clinical examination his motor power was normal and there were no abnormal movements in any other limb. MRI of his brain was suggestive of an infarct in the right globus pallidus interna extending up to the posterior limb of the internal capsule. He was treated with clonazepam and trihexyphenidyl. His movements improved significantly within 3 months. Monochorea in a lower limb due to an infarct in the globus pallidus interna is unusual and highlights the complexity of the pathophysiology of chorea. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Hyperkinetic movement disorders following ischemic and hemorrhagic stroke are common. The most common hyperkinetic disorders are hemichorea, hemiballismus, tremor, dystonia, myoclonus, athetosis, asterixis and limb shaking movements. Hemichorea and hemiballismus have similar pathophysiologies and usually involve the caudate nucleus and subthalamic nucleus, respectively. Rarely a patient may have chorea in only one limb, known as monochorea. We report a patient who presented with monochorea in the left lower limb and an infarct in the right globus pallidus interna (GPi) region. A few case reports of monochorea due to stroke involving the subthalamic nucleus, putamen, thalamus and head of the caudate nucleus are available in the literature, but to our knowledge none due to a GPi infarct. 2. Case report A 47-year-old gentleman presented with a 7 day history of sudden onset involuntary movement of the left lower limb which was ⇑ Corresponding author. Tel.: +91 97 1859 9308; fax: +91 11 2323 1010. E-mail address: sanjaysgpgi2002@yahoo.co.in (S. Pandey). causing difficulty with walking. There were no abnormal movements in any other limb, and no history of weakness or sensory deficit in any other part of the body. The patient had been taking treatment for hypertension for 5 years and for type 2 diabetes mellitus for 1 year. He used to smoke one packet of cigarettes per day for 20 years, but stopped 5 years ago. He was non-alcoholic and there was no history of major neurological disorders. Family history was not significant. On clinical examination he was conscious and speech was normal. His Mini Mental State Examination (30/ 30) was normal. Examination of his cranial nerves was also normal. Motor examination revealed normal bulk, tone and power at all muscles. There was involuntary, semirhythmic quasi-purposeful movement suggestive of chorea in the left lower limb (Supp. Video 1). Deep tendon reflexes were normal and the bilateral plantar response was downgoing. The cause of chorea was investigated, and was considered to be due to cerebrovascular accident, considering the suddenness of onset, unilateral movement and presence of risk factors, including hypertension, diabetes mellitus and smoking. MRI showed an infarct in the right GPi region extending up to the posterior limb of the internal capsule (Fig. 1). Magnetic resonance angiography of the intracranial and extracranial vessels was normal. Other investigations, including serum lipid profile, blood sugar, liver function tests, kidney function tests and twodimensional echocardiography were normal. He was given oral 1456 Case Reports / Journal of Clinical Neuroscience 21 (2014) 1455–1457 Fig. 1. T2-weighted axial (A), fluid attenuated inversion recovery axial (B), T2-weighted sagittal (C), T2-weighted coronal (D) and MRI of the brain showing an infarct in the right globus pallidus interna and posterior limb of the internal capsule. Table 1 Reports of monochorea in the literature Author Symptoms after infarct Cause Outcome Tseng et al. 2010 [2] Choi et al. 2003 [3] Kim et al. 1999 [4] Milandre et al. 1993 [5] Ikeda et al. 1991 [6] Right upper limb monochorea for 6 months Left upper limb monochorea for 5 months Right lower limb monochorea for 20 days Transient monochorea Left cerebral peduncle and subthalamic nucleus hematoma Pallidotomy eliminated monochorea Right putaminal infarct Pallidotomy eliminated monochorea Hemorrhage of cavernoma of left striatum with adjacent venous angioma Thalamic infarct Haloperidol diminished the monochoreic movement Details not available Left upper limb chorea 2 months after stroke Old infarct in head of right caudate nucleus Unchanged after 10 years clonazepam (0.5 mg twice daily for 3 months), trihexyphenidyl (2 mg three times daily for 2 months), aspirin (150 mg daily) and atorvastatin (20 mg daily). The involuntary movements slowly resolved over 3 months. 3. Discussion Cerebrovascular disease is a common cause of non-genetic chorea in adults, but chorea is a rare complication of stroke [1]. Hemichorea is the most common manifestation in this clinical setting but monochorea is very rare. We could find only five case reports in a PubMed search (Table 1). In three patients chorea was present in an upper limb, in one patient a lower limb was involved, and in another patient it was not clear from the case report whether an upper limb or lower limb was involved, but chorea was transient in this patient [2–6]. Intracerebral hematoma occurred in the cerebral peduncle and subthalamic region of one patient, and monochorea was present for 6 months after this hemorrhagic stroke [2]. In the patient with monochorea of the lower limb, brain MRI revealed hemorrhage of a cavernous angioma of the left striatum with an adjacent venous angioma [4]. In the other three patients, infarct occurred in either the putaminal, thalamic, or caudate region [3,5,6]. Pallidotomy was successfully carried out in two patients as a treatment for monochorea [2,3]. Interestingly in our patient the infarct was predominantly in the right GPi region extending up to the posterior limb of the internal capsule. Normal muscle tone and motor power was suggestive of clinically non-significant involvement of the posterior limb of the internal capsule. A lesion in the GPi region commonly causes dystonia. In a study of 17 patients with globus pallidus lesions, two patients who had unilateral lesions suffered from contralateral hemidystonia or contralateral tremor, six patients who had bilateral lesions had dystonia, and the remaining patients had behavioral abnormalities [7]. Classically the lesions associated with hemichorea occur in the lentiform nucleus, thalamus and subthalamic nucleus, leading to deficient GPi inhibitory input to the motor component of the thalamus, causing excessive thalamocortical motor movement. However all choreas are not explained by this model. A classic example is chorea due to levodopa-induced dyskinesia in Parkinson’s disease, which improves following pallidotomy rather than worsening. The monochorea in the two patients discussed above also improved following pallidotomy [2,3]. In primate models of chorea and human dopa-induced choreform dyskinesia it has been shown that GPi neuronal activity is decreased overall [8]. So this model is complex and it is possible that different temporal and spatial firing patterns of the GPi are responsible for chorea [9]. It is not possible to conclude definitively that monochorea may originate from a GPi infarct from this one patient but there is a need to investigate this. Involvement of a single limb, as seen in monochorea, indicates a somatotopic localization in the basal ganglia region, which needs further study. 4. Conclusion Hemichorea and hemiballistic movements are the most common movement disorders following cerebrovascular accident. Monochorea due to stroke has been reported previously in the subthalamic nucleus, putamen, caudate nucleus and thalamus but an infarct in the GPi region has not been reported to our knowledge. The pathophysiology of chorea is complex and there is a need to further investigate the role of the GPi. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Appendix A. Supplementary material Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.jocn.2013.10.038. Case Reports / Journal of Clinical Neuroscience 21 (2014) 1457–1459 References [1] Lee MS, Marsden CD. Movement disorders following lesions of the thalamus or subthalamic region. Mov Disord 1994;9:493–507. [2] Tseng KY, Tang CT, Chang CF, et al. Treatment of delayed-onset post-stroke monochorea with stereotactic pallidotomy. J Clin Neurosci 2010;17:779–81. [3] Choi SJ, Lee SW, Kim MC, et al. Posteroventral pallidotomy in medically intractable postapoplectic monochorea: case report. Surg Neurol 2003;59: 486–90. [4] Dong-Wook Kim, Jae-Young Kang, Mi-Suk Kim, et al. A case of monochorea caused by a striatal lesion. J Kor Neurol Ass 1999;17:585–7. 1457 [5] Milandre L, Brosset C, Gabriel B, et al. Transient involuntary movement disorders and thalamic infarction. Rev Neurol (Paris) 1993;149:402–6. [6] Ikeda M, Tsukagoshi H. Monochorea caused by a striatal lesion. Eur Neurol 1991;31:257–8. [7] Bhatia KP, Marsden CD. The behavioural and motor consequences of focal lesions of the basal ganglia in man. Brain 1994;117:859–76. [8] Mink JW. The basal ganglia and involuntary movements: impaired inhibition of competing motor patterns. Arch Neurol 2003;60:1365–8. [9] Cardoso F, Seppi K, Mair KJ, et al. Seminar on choreas. Lancet Neurol 2006;5: 589–602. http://dx.doi.org/10.1016/j.jocn.2013.10.038 Mistaken identity: Granular cell astrocytoma masquerading as histiocytosis of the central nervous system Robert N. Campbell a, Mun Sem Liew a, Hui K. Gan a, Lawrence Cher a,b,⇑ a b Joint Austin-Ludwig Oncology Unit, Level 4 Olivia Newton-John Cancer & Wellness Centre, Austin Hospital, 145 Studley Road, Heidelberg, VIC 3084, Australia Neurology Unit, Austin Health, VIC, Australia a r t i c l e i n f o Article history: Received 13 November 2012 Accepted 18 October 2013 Keywords: Erdheim-Chester disease Glioma Granular cell astrocytoma a b s t r a c t Granular cell astrocytoma (GCA) is an uncommon malignant glial tumour that is associated with a poor prognosis. GCA cells have some morphological and immunohistochemical similarities to macrophages. In this case, a small biopsy contained no typical astrocytoma and large rounded lesional cells were interpreted as negative for glial fibrillary acidic protein and S100 and positive for CD68, a commonly used marker for macrophages. A diagnosis of a histiocytosis was made. When the patient failed to respond to first and second line therapy, tumour resection was undertaken and the pathology then showed typical morphologic and immunohistochemical features of glioblastoma (astrocytoma World Health Organization grade IV). Ó 2014 Elsevier Ltd. All rights reserved. 1. Case report A 58-year-old man presented to hospital with a 2 day history of confusion and mild nominal aphasia. This was associated with headaches, nausea and vomiting. Past medical history was significant only for a distant history of migraines. Examination found that the patient had a right homonymous hemianopia and occasional left-right disorientation. MRI of the brain showed multiple enhancing lesions within the left temporal and parieto-occipital lobes with associated vasogenic oedema (Fig. 1A–C). The patient was started on dexamethasone 16 mg daily with resolution of his symptoms. A stereotactic open biopsy of the left temporal lesion was performed and showed cerebral tissue diffusely infiltrated by large rounded cells, with abundant pale staining cytoplasm, rounded nuclei and occasional nucleoli. These were accompanied by predominantly perivascular lymphocytic infiltration. There was no necrosis or microvascular proliferation and mitotic figures were difficult to find (Fig. 2A). Immunohistochemical staining for glial fibrillary acidic protein (GFAP) was interpreted as negative (Supp. Fig. 1A), while there was cytoplasmic staining for CD68, a commonly used marker for macrophages. Active demyelination was excluded with a Luxol Fast Blue stain and staining for infective organisms, including Mycobacteria, were negative. A presumptive diagnosis of histiocytosis was made. On balance, since stains for S100 and CD1a were negative, a non-Langerhans histiocytosis and in particular Erdheim-Chester disease (ECD) were considered. ⇑ Corresponding author. Tel.: +61 3 9496 5763; fax: +61 3 9457 6698. E-mail address: lmcher@mac.com (L. Cher). Aspects of the initial biopsy that didn’t fit entirely with this diagnosis included the lack of Touton giant cells and foamy lipid laden microphages, which are classical findings of ECD. Additionally, the initial MRI showed no orbital mass and normal signal intensity of the orbital fat, abnormalities of which are cardinal radiologic features of ECD. Staging bone marrow biopsy, bone scan, CT scan and positron emission tomography scan showed no evidence of extra-cranial disease. The patient was started on standard first line therapy interferon alpha (three million units three times per week) with Pneumocystis jirovecii prophylaxis. One month later, the patient re-presented with increased forgetfulness and restaging MRI of the brain showed the lesion had continued to enlarge. His therapy was changed to cladribine (0.007 mg/kg over 5 days). However, after the first cycle of cladribine, the patient suffered a perforated diverticular abscess requiring laparoscopic washout and Hartmann’s procedure. Post-operatively, the patient required a prolonged stay in intensive care for multiple complications. Subsequently, a repeat MRI 1 month after his initial dose of cladribine again showed progression of his disease. However, an additional feature was the emergence of a large, peripherally enhancing and centrally necrotic lesion within the posterior left cerebral hemisphere (Fig. 1D–F). The radiological appearance of this new lesion was strongly suggestive of a high grade glioma. Given these developments, the patient underwent partial tumour resection. Histological appearance was now typical for astrocytoma World Health Organization grade IV. The tumour was highly cellular, with sheets of elongate pleomorphic GFAP-positive tumour cells (Supp. Fig. 1B). These displayed a high mitotic rate, microvascular proliferation and palisaded necrosis