An unusual case of hypertensive encephalopathy

An unusual case of hypertensive encephalopathy 323 REFERENCES

Correspondence to: Janaka Seneviratne MBBS, Department of Neurosciences, 262 Amess street, North Carlton, Vic. 3054, Australia.

1. Imura H, Nakao K, Shimatu A, et al. Lymphocytic infundiburoneurohypophysitis as a cause of central diabetes insipidus. N Engl J Med 1993; 329: 683–689. 2. Thodou E, Asa SL, Kontogeorgos G, Kovacs K, Horvath E, Ezzat S. Clinical case seminar: lymphocytic hypophysitis: clinicopathological findings. J Clin Endoclinol Metab 1995; 80: 2302–2311. 3. Cosman F, Post KD, Holub DA, Wardlaw SL. Lymphocytic hypophysitis: report of 3 new cases and review of literature. Medicine 1989; 68: 249–256. 4. Hoshimaru M, Hashimoto N, Kikuchi H. Central diabetes insipidus resulting from a non-neoplastic tiny mass lesion localized in the neurohypophyseal system. Surg Neurol 1992; 38: 1–6. 5. Nishioka H, Akada K, Miki T, Akada K. A case of lymphocytic hypophysitis with massive fibrosis and the role of surgical intervention. Surg Neurol 1994; 42: 72–78. 6. Ouma JR, Farrell VJR. Lymphocytic infundibulo-neurohypophysitis with hypothalamic and optic pathway involvement: report of a case and review of the literature. Surg Neurol 2002; 57: 49–54. 7. van Havenbergh T, Robberecht W, Wilms G, et al. Lymphocytic infundibulohypophysitis presenting in the postpartum period: case report. Surg Neurol 1996; 46: 280–284. 8. Tomizawa Y, Sato N, Shimizu H, Mori M. Changes of specific and nonspecific immunological functions before and after transsphenoidal tumor excision-a case of Cushing disease [in Japanese]. Nippon Naibunpi Gakkai Zasshi 1995; 71: 673–678. 9. Colao A, Pivonello R, Faggiano A, et al. Increased prevalence of thyroid autoimmunity in patients successfully treated for Cushing’s disease. Clin Endocrinol (Oxf) 2000; 53: 13–19. 10. Morita H, Isaji M, Mune T, et al. Transient Graves disease developing after surgery for Cushing disease. Am J Med Sci 2002; 323: 162–165. 11. Reusch JE-B, Kleinschmidt-DeMasters BK, Lillehei KO, Rappe D, GutierrezHartmann A. Preoperative diagnosis of lymphocytic hypophysitis (adenohypophysitis) unresponsive to short course dexamethasone: case report. Neurosurgery 1992; 30: 268–272. 12. Tubridy N, Saunders D, Thom M, et al. Infundibulohypophysitis in a man presenting with diabetes insipidus and cavernous involvement. J Neurol Neurosurg Psychiatry 2001; 71: 798–801.

An unusual case of hypertensive encephalopathy Janaka Seneviratne MBBS, Peter Brotchie MBBS PHD FRACR, Peter Gates Paul Talman MBBS BSC FRACP PHD

MBBS FRACP,

Department of Neurosciences, Geelong hospital, Victoria, Australia

Summary This case report describes a 59-year-old male who presented with headaches, seizures and hypertension followed by coma. Initial magnetic resonance imaging showed T2 hyperintensities typical of Hypertensive Encephalopathy (HE), the follow up scans showed diffusion-weighted imaging (DWI) hyperintensities which is a rare finding in HE. DWI hyperintensities are typically suggestive of areas of cytotoxic damage, and the presence of these changes makes this case unusual, since the pathogenesis of HE is usually due to vasogenic oedema rather than cytotoxic damage of the brain tissue. ª 2004 Elsevier Ltd. All rights reserved. Journal of Clinical Neuroscience (2005) 12(3), 323–326 0967-5868/$ - see front matter ª 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2004.06.003

Keywords: Hypertensive encephalopathy, Radiological imaging, Cytotoxic oedema, Pathogenesis and hypertensive encephalopathy Received 28 December 2003 Accepted 9 June 2004

ª 2004 Elsevier Ltd. All rights reserved.

INTRODUCTION The radiological findings in Hypertensive Encephalopathy (HE) are variable. Magnetic resonance neuroimaging shows a characteristic posterior leukoencephalopathy that predominantly affects the white matter of the parieto-occipital regions.1,2 These changes are best seen in the T2 weighted images. Studies with DWI imaging show that the leukoencephalopathy is primarily due to vasogenic rather than cytotoxic oedema.3,4 The likely pathogenesis of vasogenic oedema is thought to be hypertensive cerebrovascular endothelial dysfunction, disruption of the blood–brain barrier with increased permeability, cerebral oedema and microhaemorrhage formation.3 There have been case reports of patients with HE who had hyperintensities in DWI images.5,6 It is not clear as to the underlying pathogenesis of these changes, but autoregulatory vasoconstriction leading to hypoperfusion could be a possible mechanism.7 It is not clear whether HE patients with DWI changes have a poorer prognosis.5 We report a patient with HE due to renal artery stenosis who had DWI changes in addition to typical MRI changes of HE, who went on to have complete clinical recovery.

CASE REPORT Our patient was a 59-year-old man admitted to Geelong hospital with a 6-week history of headaches, nausea and vomiting. On the day of admission, he was found confused and brought to emergency department. On presentation, he was disoriented in time and place, GCS score was 14, and he was moving all limbs symmetrically. The blood pressure was raised at 250/90, pulse 80 sinus rhythm, and afebrile. Neurological examination did not reveal any focal deficits, in particular no neck stiffness. Fundoscopy was limited but no abnormalities were detected. Other systems examination was unremarkable. He went on to have a generalised tonic clonic seizure in the emergency department and was intubated for a CT brain scan. He was transferred to the Intensive Care Unit for further management. The background medical history included right sided carotid endarterectomy in 2000 for right hemispheric TIAs and hypertension (160/100) noted six weeks prior to presentation. This was not treated at that time. Medications included Aspirin 150 mg daily. He was a smoker and had an ethanol intake approximately 60 g/day. Initial investigations on admission showed Hb 163 g/L, platelets · 109/L 338 · 109/L, wcc 12.8 · 109/L, neutrophils 9.5 · 109/L, Na 137 mmol/L, K 4.3 mmol/L, glucose 7.0 mmol/ L, urea 6.8 mmol/L and creatinine 154 mmol/L, LFT-Normal. ECG revealed sinus rhythm with no left ventricular hypertrophy (LVH), CT brain scan revealed low attenuation in the upper pons and midbrain suggestive of infarction or central pontine myelinolysis. CSF examination results: WBC 0 per mm3, protien 0.63 g/L and glucose 4.0 mmol/L, HSV PCR, VDRL, cryptococcal and mycobacterial studies were negative. MRI brain scan performed within 24 h of admission is shown in Fig. 1 which showed extensive signal abnormality throughout the brainstem, subcortical white matter and left temporal lobe. At this time, the DWI images and MR angiogram were normal. The patient was commenced on Aciclovir 700 mg IVI 8 hourly, IV phenytoin and IV methyl prednisone 1 g daily for 3 days. While in intensive care the patient’s blood pressure fluctuated quite markedly (Fig. 2). He was hypertonic in upper and lower Journal of Clinical Neuroscience (2005) 12(3)

324 Seneviratne et al.

Fig. 1 MRI films on Day 1: (A) T2 hyperintensities in posterior cortex. (B) T2 hyperintensities in brainstem and occipital lobes bilaterally. (C) Normal DWI Trace.

Blood Pressure

BP Readings of First 24 Hours of Admission 400 300 200 100 0 1

2

3 4

5 6

7

8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hours: Time from Admission Systolic

Diastolic

Fig. 2 Blood pressure readings during the first 24 h of admission.

limbs with exaggerated reflexes bilaterally, and he remained in a locked-in-state. Fundoscopy revealed bilateral papilloedema with hard exudates. Repeat CSF examination on day 3 revealed WBC 0, protein 0.81 g/L and HSV PCR was negative on the first CSF sample. Repeat MRI brain scan performed on day 3 revealed the T2 hyperintense changes within brainstem and deep cerebral white matter to had partially resolved compared with the previous scan. DWI images showed hyperintense changes in both occipital lobes suggestive of cytotoxic damage (Fig. 3). Cerebral angiogram and vasculitic screen were negative. At this stage, HSV encephalitis and Birkerstaff’s encephaJournal of Clinical Neuroscience (2005) 12(3)

litis were thought unlikely, and although MRI findings (the DWI hyperintensities) were not typical of hypertensive encephalopathy, it was thought to be the most likely cause of this man’s presentation. His BP was treated with IV phenoxybenzamine. By day 7 the patient was extubated and he was moving all limbs. He appeared to have a left sided homonymous hemianopia to direct confrontation test. His blood pressure remained normal on oral antihypertensive treatment. He was investigated further for the aetiology of hypertension. The phaeochromocytoma screen was negative, CT scan of abdomen was normal, renal angiogram revealed a significant stenosis ª 2004 Elsevier Ltd. All rights reserved.

An unusual case of hypertensive encephalopathy 325

Fig. 3 MRI films on Day 3: (A) T2 hyperintensities in occipital lobes bilaterally. (B) DWI hyperintensities in the corresponding areas.

Fig. 4 MRI films 3 months later: (A) T2 hyperintensities in occipital lobes improved, but still persisting, T2 hyperintensities in brainstem have disappeared. (B) T2 hyperintensities disappeared in other areas of the brain.

of left renal artery with decreased perfusion to the left kidney on the renal captopril scan. He underwent angioplasty of the left renal artery which was uncomplicated. On day 10, the patient was transferred to the neurology ward. His cognitive status appeared normal with no focal neurological deficits apart from the visual field deficits which were already improving. He was discharged from hospital on day 13, with no neurological deficits, normal cognitive state and fully independent with daily activities. He was reviewed in the neurology out-patient department 3 months after his initial presentation. His blood pressure was normal on antihypertensive treatment (metoprolol 50 mg daily), there were no focal neurological deficits on examination, with normal cognitive function. Formal visual field testing done as an out-patient a week prior was normal, and a MRI brain scan done 2 weeks prior (Fig. 4) showed that T2 hyperintensities had disappeared in the brainstem and most of the subcortical regions and the hyperintensities of the occipital lobes had significantly improved. There were no DWI changes.

ª 2004 Elsevier Ltd. All rights reserved.

DISCUSSION In the patient we have reported the diagnosis of hypertensive encephalopathy is supported by clinical presentation, fluctuating high blood pressure readings in a man who was normotensive previously and reversible changes on radiological investigations. The patient’s hypertension was corrected by angioplasty of the left renal artery stenosis. Hypertensive encephalopathy has been described with fluctuating blood pressures,9 and tends to be less prominent in previously hypertensive individuals, because compensatory mechanisms may protect end organs from acute changes in blood pressure.3 The clinical presentation of headaches, confusion and seizures together with fundoscopic findings of hypertensive retinopathy has been well described.3 In our patient, the history of hypertension was short and there were prominent blood pressure fluctuations. The hallmark of HE is the predominant involvement of the posterior part of the cerebral hemispheres, secondary involvement of the brainstem and cerebellum and in more severe cases subcortical Journal of Clinical Neuroscience (2005) 12(3)

326 Owler et al.

white matter.1,2 Most case reports and studies show diffuse changes in the brain with normal DWI findings, suggesting that these changes are due to vasogenic oedema rather than cytotoxic oedema.3,4 One theory is that the condition begins with hyperperfusion, resulting in failure of autoregulation, and breakthrough accumulation of vasogenic oedema.5 This hypothesis is supported by the MRI findings of reversible transient oedema localised mainly in the parietal and occipital lobes.6 There have been only a few reported cases where HE was associated with high signal DWI images, suggesting cytotoxic oedema as part of the pathogenesis.5,7 In one such patient, CSF interleukin-6 activity was elevated during active CNS disease and activity decreased with recovery.10 Kon Chu et al. report a patient with HE who had high signal T2 intensities in right pons, midbrain and bilateral middle cerebral peduncles and normal posterior parietal region. These changes improved after 6 months, but clinical deficits of left hemiparesis persisted.8 In our patient, the main ongoing clinical deficit was a visual field abnormality which corresponded with the DWI changes present on the second MRI at day 4 (Fig. 2). Over a period of few weeks, the visual field changes improved to the extent that they were not detectable either by confrontation testing or with formal perimetry. The repeat MRI at 3 months showed the T2 hyperintensities to have improved significantly with normal DWI films. Interestingly, the hyperintensities over the occipital lobes, although smaller, persisted at 3 months, which suggest these changes were actually secondary to cytotoxic oedema rather than vasogenic oedema unlike described in most of the previous case reports of patients with HE. Schwartz et al. reported DWI and ADC map findings of seven patients with HE, and the conclusion was that the high signal intensities in HE are primarily composed of vasogenic oedema. There are many case reports in the literature supporting the evidence for vasogenic oedema, but only a few reports suggesting the presence of cytotoxic oedema with DWI hyperintensities. The aetiology of posterior reversible leukoencephalopathy syndrome (PRES) is not clear, but present data tend to favour the theory that the condition begins with hyperperfusion, resulting in failure of autoregulation and breakthrough accumulation of vasogenic oedema.3 Casey and Truwit et al.5 state that overly aggressive antihypertensive therapy, in the setting of disturbed cerebral blood flow autoregulation, can result in hypoperfusion, even with apparently normal blood pressures. In some severe cases, this can lead to infarction predominantly in the posterior border zones and ischaemia can also result from status epilepticus and hypoxic complications. In our patient, we could not identify any of these as the cause of cerebral ischaemia. The fact that he had a normal DWI film on presentation which became abnormal after 2 days suggests that his presenting symptoms of seizures and unconsciousness did not contribute to the occipital lobe ischaemia. Is there another explanation for cytotoxic oedema in HE? Perhaps, it is the initial cerebral vasoconstriction together with antihypertensive treatment that would lead to cerebral hypoperfusion and ischaemic changes.

REFERENCES 1. Schwartz RB, Mulkern RV, Gudbjartsson H, Jolesz F. Diffusion weighted imaging in Hypertensive encephalopathy: clues to pathogenesis. AJNR Am J Neuroradiol 1998; 19: 859–862. 2. Schaefer PW, Buonanno FS, Gonzalez RG, Schwamm LH. diffusion weighted imaging discriminates between cytotoxic and vasogenic oedema in a patient with eclampsia. Stroke 1997; 28: 1082–1085. 3. Skinhoj E, Standgoard S. Pathogenesis of hypertensive Encephalopathy. Lancet 1973: 461–462. 4. Scwartz RB, Jones KM, Kalina P, et al. Hypertensive encephalopathy: findings on CT, MRI, and SPECT imaging in 14 cases. AJR Am J Roentol 1992; 159: 379–383.

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5. Casey S, Truwut C. Pontine reversible edema: A newly recognized imaging variant of Hypertensive Encephalopathy? AJNR 2000; 21: 243–245. 6. Sungren C, Edvardsson B, Holtas S. Serial investigations of perfusion disturbance and vasogenic oedema in hypertensive encephalopathy by diffusion and perfusion weighted imaging. Neuroradiology 2002; 44: 340–343. 7. Chu K, Kang DW. Diffusion weighted MR findings in brainstem hypertensive encephalopathy: a possibility of cytotoxic edema? Eur. Neurol. 2001; 46(4): 220–222. 8. Hinchey J, Chaves C, Appignani B, et al. A reversible posterior leukoencephalopathy syndrome. New Eng J Med 1996; 334: 494–500. 9. de seze Jerome, Mastain Bruno. Unusual MRI findings of brainstem in arterial Hypertension. AJNR Am J Neuroradiol 2002; 21: 391–394. 10. Takano T, Ohno M. Cytotoxic edema and interleukin-6 in hypertensive encephalopathy. Paediatr Neurol 2002; 26(1): 71–73.

Cerebellar liponeurocytoma Brian K. Owler1,2 MBBS, John M. Makeham1 Meena Shingde3 MBBS MD (PATH), Michael Besser1,2 AM FRACS FRCSC (CAN) FACS

BMED,

1 Department of Neurosurgery and Neurology, Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Sydney, 2 Department of Surgery, University of Sydney, Sydney, 3 Department of Anatomical Pathology, Royal Prince Alfred Hospital, Sydney, Australia

Summary A case of cerebellar liponeurocytoma in a 34-year-old man is reported. There are only 19 other cases reporting this entity in the medical literature. The diagnostic, radiological and clinical features associated with this tumour are reviewed and discussed in relation to our case. The differences in behaviour and prognosis between medulloblastoma and cerebellar liponeurocytoma are presented with the corresponding implications for management. ª 2004 Elsevier Ltd. All rights reserved. Journal of Clinical Neuroscience (2005) 12(3), 326–329 0967-5868/$ - see front matter ª 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2004.05.017

Keywords: cerebellar liponeurocytoma, lipidised medulloblastoma Received 31 March 2004 Accepted 27 May 2004 Correspondence to: Brian K. Owler MBBS, Department of Neurosurgery and Neurology, Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW 2050 Sydney, Australia. Tel.: +61 295 156 111; Fax: +61 295 157 564; E-mail: [email protected]

INTRODUCTION Cerebellar liponeurocytomas were recognised in the revised WHO classification of tumours of the central nervous system, 2000, as a distinct pathological entity.1 A favourable prognosis with less aggressive therapy distinguishes it from tumours of its previous category of primitive neuroectodermal tumours. Since the original description in 1978 by Bechtel et al.2 only 18 other cases have been reported in the literature.3–14 These lesions, which may occur throughout the cerebellum, are characterised by numerous lipidised cells scattered or clustered between small neoplastic cells. Both neuronal and glial differentiation is present as evidenced by immunohistochemical staining, and mitotic activity is generally low. We present a case of cerebellar liponeurocytoma with some aberrant characteristics and ª 2004 Elsevier Ltd. All rights reserved.