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Posterior reversible encephalopathy syndrome due to diabetic ketoacidosis
European Journal of Radiology Extra 65 (2008) 1–3
Posterior reversible encephalopathy syndrome due to diabetic ketoacidosis M´onica Ballesta Moratalla a,∗ , Bruce Shauer b a
Department of Radiology, La Fe Hospital, Avenida Campanar 21, 46009 Valencia, Spain b Mount Vernon Hospital, 22304, Alexandria, Virginia, United States
Received 19 January 2007; received in revised form 15 October 2007; accepted 24 October 2007
Abstract Posterior reversible encephalopathy syndrome it is a recently described clinicoradiological entity. Although it is clinically nonspecific, neuroimaging is very demonstrative and can be the first clue to the diagnosis. Magnetic resonance imaging plays a decisive role. The images typically show hyperintense lesions on T2-weighted images involving the parietal and occipital lobes, in a relatively symmetrical pattern. We report a case due to diabetic ketoacidosis, a very rare cause of this syndrome. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Diabetes mellitus; Encephalopathy; Magnetic resonance imaging; Computed tomography
1. Introduction Posterior reversible encephalopathy syndrome (PRES) is a recently described clinical and neuroradiological entity. Clinical signs and symptoms are not specific but neuroimaging is often demonstrative and can be the first clue to the diagnosis. The pathogenesis is not completely understood although the most widely accepted hypothesis is the auto regulation failure of the cerebral vascular circulation with development of brain edema [1]. 2. Case report The patient is a 14-year-old male with diabetes mellitus (type 1), presenting with diabetic ketoacidosis: basal glycemia 858 mg/dl, pH 6.96, pO2 96.1 mmHg, pCO2 17.1 mmHg, bicarbonate 3.7 mmol/l, base excess −26.9, oxygen saturation 92.4%. The patient was somnolent and on physical examination noted to have Kussmaul’s breathing and tachycardia. In the emergency room, the patient had the sudden onset of severe headache and visual disturbances. Computed tomography showed subtle areas of low attenuation in both occipital lobes (Fig. 1). On magnetic resonance, T2-weighted images showed high signal ∗
Corresponding author. Tel.: +34 963941937. E-mail address: monica [email protected] (M.B. Moratalla).
1571-4675/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrex.2007.10.005
intensity in the cortical areas of both occipital lobes, and cerebellar hemispheres (more prominent in the left) (Figs. 2 and 3). Diffusion images revealed the abnormalities in the same locations, showing high signal intensity lesions in the cerebellum and left thalamus (Figs. 4 and 5). After treatment, the basal glycemia was 68.8 mg/dl and other laboratory findings were normal. The headache resolved and the patient recovered normal perception. No follow-up studies were done. 3. Discussion The posterior reversible encephalopathy syndrome (PRES, also known as reversible cerebral edema [2]) is a recently proposed clinical and neuroradiological entity. It was described in 1996 by Hichey et al. The common causes are hypertensive encephalopathy, eclampsia, immunosuppressive treatment (cyclosporin A and tacrolimus) and renal failure [2–4]. Other reported causes include diabetic ketoacidosis, vasculitis, endocrine disorders, porphyria, thermal injury, scorpion envenomation, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, hypercalcemia and blood transfusion [5]. Clinical symptoms are headache, confusion, visual disturbances and seizures. Neuroimaging abnormalities predominantly involve parietal and occipital lobes [3,6]. Most patients have hypertension but some of them have mildly elevated or even normal blood pressure.
2
M.B. Moratalla, B. Shauer / European Journal of Radiology Extra 65 (2008) 1–3
Fig. 1. Axial view of the brain. Computed tomography shows bilateral hypodense areas in the parieto-occipital white matter, more prominent on the left side (arrow).
The pathogenesis is not completely understood and there are two possible mechanisms: (a) vasospasm with resulting ischemia within the involved territories, and (b) breakdown in cerebrovascular auto regulation with interstitial extravasation of fluid [3]. The major involvement of parieto-occipital lobes seems to be related to poor sympathetic innervation of the pos-
Fig. 2. Axial T2-weighted image shows hyperintense signal abnormalities located in the subcortical white matter and the cortex.
Fig. 3. Coronal FLAIR image shows the high signal intensity lesions in the occipital lobes, even more clearly than T2-weighted images.
terior circulation [3]. The resulting edema is usually vasogenic and reversible but may become cytotoxic in severe cases [7]. The computed tomography finding is the presence of bilateral and symmetric areas of low attenuation in the posterior parietal and occipital lobes. The role of magnetic resonance imaging is important [1]. Diffusion weighted images can differentiate this syndrome from ischemia/cytotoxic edema (cytotoxic edema from cerebral ischemia demonstrates decreased water mobility whereas vasogenic edema results in increased water mobility) [8]. The main finding is brain edema, symmetrical, located in the subcortical white matter and occasionally in the cortex of the occipital and parietal lobes, without infarction [2,3]. Lesions occur in
Fig. 4. Diffusion-weighted axial image show the abnormal areas as bright lesions, consistent with vasogenic edema. A bright lesion in the left thalamus is also seen.
M.B. Moratalla, B. Shauer / European Journal of Radiology Extra 65 (2008) 1–3
3
Treatment is directed to the underlying cause. Our patient was treated with normal saline solution, intravenous insulin and bicarbonate. 4. Conclusion Common causes of posterior reversible encephalopathy syndrome are hypertensive encephalopathy, immunosuppressive treatment, renal failure and eclampsia. Diabetic ketoacidosis is a less common cause. Its pathogenesis remains poorly understood. Clinical findings are not sufficiently specific to establish the diagnosis; however neuroimaging, specially magnetic resonance imaging pattern is often characteristic and represents an essential component of the diagnosis. Diagnosing PRES has important implication because of its reversibility with prompt control of blood pressure and/or withdrawing of the underlying cause. References Fig. 5. Axial view. Diffusion-weighted image. There was another bright lesion in the left cerebellar hemisphere.
both gray and white matter [3,4]. Radiological findings resolve on follow-up studies after appropriate treatment [2,3]: unfortunately no follow-up studies were done on our patient. Magnetic resonance images typically show hyperintense lesions on T2weighted images involving the parietal and occipital lobes [4]. These lesions do not enhance after gadolinium administration. FLAIR (fluid attenuated inversion recovery) images appear to be more sensitive than T2-weigthed images. Diffusion-weighted images with attenuated diffusion coefficient mapping usually show vasogenic edema [7]. Differential diagnosis of posterior reversible encephalopathy syndrome includes posterior cerebral artery territory infarcts, venous thrombosis, demyelinating disorders, vasculitis and encephalitis.
[1] Casali-Rey JI, Davalos EG, L´opez-Amalfara A, et al. Posterior reversible encephalopathy syndrome: some case reports. Rev Neurol 2003;37(3):224–7. [2] Fern´andez FJ, Machado Jr MA, Pedreira AV, et al. Reversible posterior encephalopathy syndrome: case report. Arq Neuropsiquiatr 2002;60(3A):651–5. [3] Javed MA, Sial MSH, Lingawi S, et al. Etiology of posterior reversible encephalopathy syndrome (PRES). Pak J Med Sci 2005;21(2):149–54. [4] Arora A, Chowdhury D, Daga MK, et al. Reversible posterior leukoencephalopathy syndrome: a report of 2 cases. Neurol India 2001;49(3):311–3. [5] Bakshi R. A 42-year-old woman with seizures and mental status change. Neuroimaging case challenge from medscape neurology & neurosurgery. [6] Hinchey J, Chaves C, Appignani B, et al. A reversible posterior leukoencephalopathy syndrome. N Engl J Med 1996;334:500–949. [7] Caminero AB. S´ındrome de encefalopat´ıa posterior reversible. Neurolog´ıa 2005;20(7):327–31. [8] Das CJ, Seith A. Indian Pediatr 2006;43:657–8.
Posterior reversible encephalopathy syndrome due to diabetic ketoacidosis M´onica Ballesta Moratalla a,∗ , Bruce Shauer b a
Department of Radiology, La Fe Hospital, Avenida Campanar 21, 46009 Valencia, Spain b Mount Vernon Hospital, 22304, Alexandria, Virginia, United States
Received 19 January 2007; received in revised form 15 October 2007; accepted 24 October 2007
Abstract Posterior reversible encephalopathy syndrome it is a recently described clinicoradiological entity. Although it is clinically nonspecific, neuroimaging is very demonstrative and can be the first clue to the diagnosis. Magnetic resonance imaging plays a decisive role. The images typically show hyperintense lesions on T2-weighted images involving the parietal and occipital lobes, in a relatively symmetrical pattern. We report a case due to diabetic ketoacidosis, a very rare cause of this syndrome. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Diabetes mellitus; Encephalopathy; Magnetic resonance imaging; Computed tomography
1. Introduction Posterior reversible encephalopathy syndrome (PRES) is a recently described clinical and neuroradiological entity. Clinical signs and symptoms are not specific but neuroimaging is often demonstrative and can be the first clue to the diagnosis. The pathogenesis is not completely understood although the most widely accepted hypothesis is the auto regulation failure of the cerebral vascular circulation with development of brain edema [1]. 2. Case report The patient is a 14-year-old male with diabetes mellitus (type 1), presenting with diabetic ketoacidosis: basal glycemia 858 mg/dl, pH 6.96, pO2 96.1 mmHg, pCO2 17.1 mmHg, bicarbonate 3.7 mmol/l, base excess −26.9, oxygen saturation 92.4%. The patient was somnolent and on physical examination noted to have Kussmaul’s breathing and tachycardia. In the emergency room, the patient had the sudden onset of severe headache and visual disturbances. Computed tomography showed subtle areas of low attenuation in both occipital lobes (Fig. 1). On magnetic resonance, T2-weighted images showed high signal ∗
Corresponding author. Tel.: +34 963941937. E-mail address: monica [email protected] (M.B. Moratalla).
1571-4675/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrex.2007.10.005
intensity in the cortical areas of both occipital lobes, and cerebellar hemispheres (more prominent in the left) (Figs. 2 and 3). Diffusion images revealed the abnormalities in the same locations, showing high signal intensity lesions in the cerebellum and left thalamus (Figs. 4 and 5). After treatment, the basal glycemia was 68.8 mg/dl and other laboratory findings were normal. The headache resolved and the patient recovered normal perception. No follow-up studies were done. 3. Discussion The posterior reversible encephalopathy syndrome (PRES, also known as reversible cerebral edema [2]) is a recently proposed clinical and neuroradiological entity. It was described in 1996 by Hichey et al. The common causes are hypertensive encephalopathy, eclampsia, immunosuppressive treatment (cyclosporin A and tacrolimus) and renal failure [2–4]. Other reported causes include diabetic ketoacidosis, vasculitis, endocrine disorders, porphyria, thermal injury, scorpion envenomation, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, hypercalcemia and blood transfusion [5]. Clinical symptoms are headache, confusion, visual disturbances and seizures. Neuroimaging abnormalities predominantly involve parietal and occipital lobes [3,6]. Most patients have hypertension but some of them have mildly elevated or even normal blood pressure.
2
M.B. Moratalla, B. Shauer / European Journal of Radiology Extra 65 (2008) 1–3
Fig. 1. Axial view of the brain. Computed tomography shows bilateral hypodense areas in the parieto-occipital white matter, more prominent on the left side (arrow).
The pathogenesis is not completely understood and there are two possible mechanisms: (a) vasospasm with resulting ischemia within the involved territories, and (b) breakdown in cerebrovascular auto regulation with interstitial extravasation of fluid [3]. The major involvement of parieto-occipital lobes seems to be related to poor sympathetic innervation of the pos-
Fig. 2. Axial T2-weighted image shows hyperintense signal abnormalities located in the subcortical white matter and the cortex.
Fig. 3. Coronal FLAIR image shows the high signal intensity lesions in the occipital lobes, even more clearly than T2-weighted images.
terior circulation [3]. The resulting edema is usually vasogenic and reversible but may become cytotoxic in severe cases [7]. The computed tomography finding is the presence of bilateral and symmetric areas of low attenuation in the posterior parietal and occipital lobes. The role of magnetic resonance imaging is important [1]. Diffusion weighted images can differentiate this syndrome from ischemia/cytotoxic edema (cytotoxic edema from cerebral ischemia demonstrates decreased water mobility whereas vasogenic edema results in increased water mobility) [8]. The main finding is brain edema, symmetrical, located in the subcortical white matter and occasionally in the cortex of the occipital and parietal lobes, without infarction [2,3]. Lesions occur in
Fig. 4. Diffusion-weighted axial image show the abnormal areas as bright lesions, consistent with vasogenic edema. A bright lesion in the left thalamus is also seen.
M.B. Moratalla, B. Shauer / European Journal of Radiology Extra 65 (2008) 1–3
3
Treatment is directed to the underlying cause. Our patient was treated with normal saline solution, intravenous insulin and bicarbonate. 4. Conclusion Common causes of posterior reversible encephalopathy syndrome are hypertensive encephalopathy, immunosuppressive treatment, renal failure and eclampsia. Diabetic ketoacidosis is a less common cause. Its pathogenesis remains poorly understood. Clinical findings are not sufficiently specific to establish the diagnosis; however neuroimaging, specially magnetic resonance imaging pattern is often characteristic and represents an essential component of the diagnosis. Diagnosing PRES has important implication because of its reversibility with prompt control of blood pressure and/or withdrawing of the underlying cause. References Fig. 5. Axial view. Diffusion-weighted image. There was another bright lesion in the left cerebellar hemisphere.
both gray and white matter [3,4]. Radiological findings resolve on follow-up studies after appropriate treatment [2,3]: unfortunately no follow-up studies were done on our patient. Magnetic resonance images typically show hyperintense lesions on T2weighted images involving the parietal and occipital lobes [4]. These lesions do not enhance after gadolinium administration. FLAIR (fluid attenuated inversion recovery) images appear to be more sensitive than T2-weigthed images. Diffusion-weighted images with attenuated diffusion coefficient mapping usually show vasogenic edema [7]. Differential diagnosis of posterior reversible encephalopathy syndrome includes posterior cerebral artery territory infarcts, venous thrombosis, demyelinating disorders, vasculitis and encephalitis.
[1] Casali-Rey JI, Davalos EG, L´opez-Amalfara A, et al. Posterior reversible encephalopathy syndrome: some case reports. Rev Neurol 2003;37(3):224–7. [2] Fern´andez FJ, Machado Jr MA, Pedreira AV, et al. Reversible posterior encephalopathy syndrome: case report. Arq Neuropsiquiatr 2002;60(3A):651–5. [3] Javed MA, Sial MSH, Lingawi S, et al. Etiology of posterior reversible encephalopathy syndrome (PRES). Pak J Med Sci 2005;21(2):149–54. [4] Arora A, Chowdhury D, Daga MK, et al. Reversible posterior leukoencephalopathy syndrome: a report of 2 cases. Neurol India 2001;49(3):311–3. [5] Bakshi R. A 42-year-old woman with seizures and mental status change. Neuroimaging case challenge from medscape neurology & neurosurgery. [6] Hinchey J, Chaves C, Appignani B, et al. A reversible posterior leukoencephalopathy syndrome. N Engl J Med 1996;334:500–949. [7] Caminero AB. S´ındrome de encefalopat´ıa posterior reversible. Neurolog´ıa 2005;20(7):327–31. [8] Das CJ, Seith A. Indian Pediatr 2006;43:657–8.