- Email: [email protected]
Blood brain barrier destruction in hyperglycemic chorea in a patient with poorly controlled diabetes
Journal of the Neurological Sciences 163 (1999) 90–93
Blood brain barrier destruction in hyperglycemic chorea in a patient with poorly controlled diabetes a, b c c Atsushi Iwata *, Fumiko Koike , Keisuke Arasaki , Mitsuyuki Tamaki a
Department of Neurology, Division of Neuroscience, Graduate School of Medicine, University of Tokyo, 7 -3 -1 Hongo Bunkyoku, Tokyo, Japan b Tokyo Women’ s Medical University, Department of Neurology, 8 -1 Kawadacho Shinjyukuku, Tokyo, Japan c Department of Neurology, Kanto Teishin Hospital, 5 -9 -22 Higashigotanda Shinagawaku, Tokyo, Japan Received 25 May 1998; received in revised form 6 November 1998; accepted 25 November 1998
Abstract A case of hemichorea in a patient with poorly controlled diabetes is reported. T1-weighted magnetic resonance imaging (MRI) showed an unusual homogeneous high-intensity area in the corpus striatum. Of interest in the case was the fact that the globus pallidus, which was enhanced with gadolinium at the onset of hemichorea, showed homogeneous high-intensity on a subsequent T1-weighted image. This indicated that blood brain barrier destruction preceded the signal intensity change in the basal ganglia. As far as the authors could determine, this is the first reported case showing such enhancement during the course of diabetic hemichorea. 1999 Elsevier Science B.V. All rights reserved. Keywords: Hemichorea; Hyperglycemia; Diabetes mellitus; Blood-brain barrier
1. Introduction A case of hemichorea in a patient with poorly controlled diabetes is reported. T1-weighted magnetic resonance imaging (MRI) showed an unusual homogeneous highintensity area in the corpus striatum. Of interest in the case was the fact that the globus pallidus, which was enhanced with gadolinium at the onset of hemichorea, showed homogeneous high-intensity on a subsequent T1-weighted image. This indicated that blood brain barrier destruction preceded the signal intensity change in the basal ganglia. As far as the authors could determine, this is the first reported case showing such enhancement during the course of diabetic hemichorea. Hemichorea has been reported as a rare manifestation of nonketotic hyperglycemia [1–3]. In some reports, high signal intensity in the basal ganglia is observed on T1weighted magnetic resonance (MR) images [4–8]. The *Corresponding author. Tel.: 181-3-3815-5411, ext. 3784; fax: 181-35800-6548; e-mail: [email protected]
lesion in hemichorea is now regarded as a petechial hemorrhage from small vessels [9] and hyperglycemia is said to play some role in the evolution of such diapedesis, but the nature of the lesion remains controversial. Here we present a case of diabetic hemichorea that showed enhancement in the globus pallidus with gadopentetate dimeglumine (Gd-DTPA) on T1-weighted MR image. The enhanced area showed T1 shortening 40 days later. This indicates that blood brain barrier (BBB) destruction preceded formation of the high-intensity lesion. The finding supports the hypothesis that diapedesis is due to BBB destruction resulting from hyperosmotic state caused by hyperglycemia.
2. Case report A 64-year-old-man was admitted to Kanto Teishin Hospital on August 22, 1996, due to sudden onset of left hemichorea. He had been diagnosed with diabetes mellitus during an annual check-up 1 year prior to admission (random blood glucose 22.2 mmol / l (400 mg / dl)), but he
0022-510X / 99 / $ – see front matter 1999 Elsevier Science B.V. All rights reserved. PII: S0022-510X( 98 )00325-6
A. Iwata et al. / Journal of the Neurological Sciences 163 (1999) 90 – 93
refused medication, and even dietary control. He smoked one pack of cigarettes and consumed one can of beer every day. There was no family history of involuntary movements. On admission, his blood pressure was 130 / 69 mmHg and the pulse was 66 / min and regular; he weighed 58 kg and was 157 cm tall. He was alert and the mental state was normal. Neurological examination revealed left hemiballism– hemichorea with left-sided pyramidal signs. There was no cranial nerve involvement except for left hemifacial choreic movements. Muscle tone was decreased in the left extremities, but there was no weakness. Sensation was intact and no cerebellar sign was observed. Involuntary movement disappeared during sleep and increased with emotional tension. The following laboratory data were notable: fasting blood glucose 31.5 mmol / l (567 mg / dl), serum osmolarity 301 mmol / kg, glycosylated hemoglobin A1c 17.3%. On blood gas analysis, there was no metabolic acidosis. Urinalysis was strongly positive for glucose and ketones and negative for protein. Brain CT scan on admission (about 26 hours after the onset) showed a slight high-density area in the right putamen and the caudate head in accordance with the structures without any mass effect or edema. On MRI (Signa HORIZON HiSpeed 1.5T (General Electric, Milwaukee MI)) performed 11 days after admission, the entire right putamen and caudate head showed high-intensity on T1-weighted images (Fig. 1A) and slightly low intensity on T2-weighted images (Fig. 1B). The right globus pallidus was enhanced using Gd-DTPA (Fig. 1C). Also on day 11, a brain CT scan was performed again, and it revealed disappearance of the high-density area observed on the initial CT scan and globus pallidus showed slight low-density. Single photon emission computed tomography (SPECT) with 99m Tc-ethyl cysteinate dimer (ECD) performed 32 days after admission showed reduced accumulation in the right basal ganglia. On day 58, the entire right corpus striatum and the globus pallidus, which were previously enhanced, revealed high signal intensity on T1-weighted MRI (Fig. 1D). At this time, no enhancement was observed. On day 100 after admission, the right corpus striatum showed moderate atrophy as well as the CT scan, but the high-intensity on the T1-weighted image had not changed. The patient’s involuntary movement gradually improved with administration of haloperidol and tiapride.
3. Discussion Although the putamen is the most common site for primary intracerebral hemorrhage, hemichorea is a relatively rare symptom. Compared to diabetic hemichorea, which does not affect the internal capsule, the hypertensive putaminal hemorrhage commonly does affect it, causing
91
some degree of hemiparesis. Jones et al. reported a 42year-old man with apparent putaminal hypertensive hemorrhage (hematoma with mass effect) associated with hemichorea [10]. Unlike usual putaminal hemorrhage, the lesion spared the internal capsule to cause hemichorea without hemiparesis. In the striatum a high-intensity signal on T1-weighted MR images have been noted at the onset of hemiballism in some poorly controlled diabetic patients, but the corresponding pathology is not clear. The patients are usually in a poorly controlled diabetic state, the glycosylated hemoglobin ranges from 13.7% to 18.7% [8–13], the blood sugar measured on admission varies from 9.4 mmol / l to 63.3 mmol / l. These patients are usually in an extreme hyperglycemic state, and ketoacidosis is common. Blood osmolarity is also usually increased to as high as 325 mmol / l. The differential diagnosis of a hyperintense lesion in the basal ganglia on a T1-weighted image can involve manganese toxicity in long-term parenteral nutrition, chronic liver failure, calcification, Wilson’s disease, neurofibromatosis, fat deposit, osmotic myelinolysis, or hypoxic brain [14]. In the present case, the abnormal MR signals raised the possibility of destroyed myelin due to the release of lipids [15]. In order to exclude this possibility, we performed another scan using a fat-saturated T1-weighted imaging technique and found the same appearance as on the ordinary T1-weighted images; this indicated the absence of fat deposition. A previous report of diabetic hemichorea proposed that the intensity change was caused by abnormal deposition of calcium or some other material in neurones or glial cells [16], but in our case, the high density observed in the initial CT scan resolved within 2 weeks; the possibility of calcification was remote. The appearance of the striatal lesion in imaging studies differs from a hypertensive putaminal hemorrhage in two ways. First, there is little or no evidence of mass effect, which is usually observed in hypertensive hematoma. Second, in hypertensive hemorrhage, the lesion is usually confined to the putamen through the head of the caudate nucleus. It may occasionally extend internally to the globus pallidus and subthalamic nucleus sparing the anterior limb of the internal capsule, but it never extends to other regions as in the present case. Broderick et al. [17] reported two cases of diabetic hemichorea and concluded that the noted lesion was a hemorrhagic infarction caused by diapedesis of red blood cells through ischemic capillary endothelium without vessel rupture. They attributed the intensity change on MRI in the corpus striatum to the presence of methemoglobin from a precipitating petechial hemorrhage, with blood interspersed between the brain tissue. However, there was no clear evidence of BBB destruction, because the time of diagnosis and the first MRI images was late, and the entire lesion already demonstrated high signal intensity on T1weighted images. In the present case, the right globus
92
A. Iwata et al. / Journal of the Neurological Sciences 163 (1999) 90 – 93
Fig. 1. On day 11 following admission, the right caudate head and the greater part of the putamen shows high signal intensity on T1-weighted image (TR 300 ms, TE 9 ms) (1A), and low signal intensity on T2-weighted image (TR 3500 ms, TE 98 ms) (1B). With Gd-DTPA injection, the globus pallidus was slightly enhanced (1C). On day 58 following admission, the globus pallidus previously enhanced now shows high signal intensity on T1-weighted image (TR 300 ms, TE 9 ms) (1D).
A. Iwata et al. / Journal of the Neurological Sciences 163 (1999) 90 – 93
pallidus showed intensity change subsequent to that of the putamen and caudate head, so there was a brief interval in which to show enhancement with Gd-DTPA before the T1-value shortening. This finding is compatible with the idea that the petechial hemorrhage was followed by BBB destruction caused by hyperglycemia, supporting the idea that the diapedesis occurred as a result of the hyperglycemia. In a hypertensive hematoma, deoxyhemoglobin is converted to methemoglobin within several days. Similarly, in our patient, on day 11 MRI scans of the basal ganglia showed a hypersignal on the T1-weighted image and a hyposignal on the T2-weighted image. These findings may be explained by the presence of methemoglobin resulting from petechial hemorrhage. In the usual hematoma, a T1 high-intensity lesion at the early stage suggests the presence of intracellular methemoglobin, showing the protonelectron dipole–dipole proton relaxation enhancement (PEDDPRE) effect [18]. Usually, with the destruction of erythrocytes in the hematoma, the intracellular methemoglobin converts slowly to extracellular methemoglobin, which results in T2 elongation by the preferential T2 proton relaxation enhancement (PT2PRE) effect. However, in the late subacute phase of our patient’s condition, the lesion showed T1 shortening only, and the appearance of the T2-weighted image remained unchanged. There is no clear explanation for this finding, but the hyperosmotic state may have played an important role. That is, in the hyperosmotic state, the erythrocyte membrane might be stabilised and erythrolysis, which often occurs in the usual hematoma may not happen. The hemoglobin may be stabilised with intracellular conformation, showing the PEDDPRE effect, and may be slowly converted to hemosiderin or ferritin. At this time, there are no pathological specimens available to prove this hypothesis. The MRI finding is to some extent different from massive hypertensive hemorrhage, which affects the thalamus and the pyramidal tract at the same time. That is, compared to massive hemorrhage, intact thalamus and pyramidal tract may play an important role in the pathogenesis of the hemichorea. The functional image showed decreased activity of the right striatum and spared ipsilateral thalamus. This may cause hyperactivity of the indirect pathway of the parallel frontal–subcortical circuit in basal ganglia [19] to cause hyperactivity of the thalamus, which resulted in hemichorea.
Acknowledgements The authors would like to thank Dr Makoto Iwata, Department of Neurology, Tokyo Women’s Medical University, for his critical comments.
93
References [1] Recter Jr. WG, Herlong HF. Nonketotic hyperglycemia appearing as choreoathetosis or ballism. Arch Intern Med 1982;142:154–5. [2] Lin JJ, Chang MK. Hemiballism–hemichorea and non-ketotic hyperglycemia. J Neurol Neurosurg Psych 1994;57:748–50. [3] Sanfield JA, Finkel J, Lewis S, Rosen SG. Alternating choreoathetosis associated with uncontrolled diabetes mellitus and basal ganglia calcification. Diabetes Care 1986;9:100–1. [4] Nagai C, Kato T, Katagiri T, Sasaki H. Hyperintense putamen on T1-weighted MR images in a case of chorea with hyperglycemia. AJNR 1995;16:1243–6. [5] Altafullah I, Pascual-Leone A, Duvall K, Anderson DC et al. Putaminal haemorrhage accompanied by hemichorea-hemiballism. Stroke 1990;21:1093–4. [6] Lai PH, Chang MH, Teng MMH. et al. Chorea-ballisms with nonketotic hyperglycemia in primary diabetes mellitus. AJNR 1996;17:1057–64. [7] Nabatame H, Nakamura K, Matsuda M et al. Hemichorea in hyperglycemia associated with increased blood flow in the contralateral striatum and thalamus. Internal Med 1994;33:472–5. [8] Nakagawa T, Mitani K, Nagura H et al. Chorea-ballism associated with nonketotic hyperglycemia and presenting with bilateral hyperintensity of the putamen on MR T1-weighted images - A case report. Clin Neurol 1994;34:52–5. [9] Chang MH, Chiang HT, Lai PH et al. Putaminal petechial haemorrhage as the cause of chorea: a neuroimaging study. J Neurol Neurosurg Psych 1997;63:300–3. [10] Jones Jr. HR, Baker RA, Kott HS. Hypertensive putaminal haemorrhage presenting with hemichorea. Stroke 1985;16:130–1. [11] Shwartz GA, Barrows LJ. Hemiballism without involvement of Luy’s body. Arch Neurol 1960;2:420–34. [12] Goldblatt D, Marksbery W, Reeves AG. Recurrent hemichorea following striatal lesions. Arch Neurol 1974;31:51–4. [13] Kase CS, Maulsby GO, de Juan E, Mohr JP. Hemichorea hemiballism and lacunar infarction in the basal ganglia. Neurology 1981;31:452–5. [14] Ho VB, Fitz CR, Yoder CC, Geyer CA. Resolving MR features in osmotic myelinolysis (central pontine and extrapontine myelinolysis). AJNR 1993;14:163–7. [15] Lai PH, Tien RD, Chang MH et al. Chorea-ballisms with nonketotic hyperglycemia in primary diabetes mellitus. AJNR 1996;17:1057– 64. [16] Yahikozawa H, Hanyu N, Yamamoto K. et al. Hemiballism with striatal hyperintensity on T1-weighted MRI in diabetic patients: a unique syndrome. J Neurol Sci 1994;124:208–14. [17] Broderick JP, Hagen T, Brott T. et al. Hyperglycemia and haemorrhagic transformation of cerebral infarcts. Stroke 1995;26:484–7. [18] Bradley WG. MR appearance of haemorrhage in the brain. Radiology 1993;189:15–26. [19] Alexander GE, DeLong MR, Strick PL. Parallel organization of functionally segregated circuit linking basal ganglia and cortex. Ann Rev Neurosci 1986;9:357–81.
Blood brain barrier destruction in hyperglycemic chorea in a patient with poorly controlled diabetes a, b c c Atsushi Iwata *, Fumiko Koike , Keisuke Arasaki , Mitsuyuki Tamaki a
Department of Neurology, Division of Neuroscience, Graduate School of Medicine, University of Tokyo, 7 -3 -1 Hongo Bunkyoku, Tokyo, Japan b Tokyo Women’ s Medical University, Department of Neurology, 8 -1 Kawadacho Shinjyukuku, Tokyo, Japan c Department of Neurology, Kanto Teishin Hospital, 5 -9 -22 Higashigotanda Shinagawaku, Tokyo, Japan Received 25 May 1998; received in revised form 6 November 1998; accepted 25 November 1998
Abstract A case of hemichorea in a patient with poorly controlled diabetes is reported. T1-weighted magnetic resonance imaging (MRI) showed an unusual homogeneous high-intensity area in the corpus striatum. Of interest in the case was the fact that the globus pallidus, which was enhanced with gadolinium at the onset of hemichorea, showed homogeneous high-intensity on a subsequent T1-weighted image. This indicated that blood brain barrier destruction preceded the signal intensity change in the basal ganglia. As far as the authors could determine, this is the first reported case showing such enhancement during the course of diabetic hemichorea. 1999 Elsevier Science B.V. All rights reserved. Keywords: Hemichorea; Hyperglycemia; Diabetes mellitus; Blood-brain barrier
1. Introduction A case of hemichorea in a patient with poorly controlled diabetes is reported. T1-weighted magnetic resonance imaging (MRI) showed an unusual homogeneous highintensity area in the corpus striatum. Of interest in the case was the fact that the globus pallidus, which was enhanced with gadolinium at the onset of hemichorea, showed homogeneous high-intensity on a subsequent T1-weighted image. This indicated that blood brain barrier destruction preceded the signal intensity change in the basal ganglia. As far as the authors could determine, this is the first reported case showing such enhancement during the course of diabetic hemichorea. Hemichorea has been reported as a rare manifestation of nonketotic hyperglycemia [1–3]. In some reports, high signal intensity in the basal ganglia is observed on T1weighted magnetic resonance (MR) images [4–8]. The *Corresponding author. Tel.: 181-3-3815-5411, ext. 3784; fax: 181-35800-6548; e-mail: [email protected]
lesion in hemichorea is now regarded as a petechial hemorrhage from small vessels [9] and hyperglycemia is said to play some role in the evolution of such diapedesis, but the nature of the lesion remains controversial. Here we present a case of diabetic hemichorea that showed enhancement in the globus pallidus with gadopentetate dimeglumine (Gd-DTPA) on T1-weighted MR image. The enhanced area showed T1 shortening 40 days later. This indicates that blood brain barrier (BBB) destruction preceded formation of the high-intensity lesion. The finding supports the hypothesis that diapedesis is due to BBB destruction resulting from hyperosmotic state caused by hyperglycemia.
2. Case report A 64-year-old-man was admitted to Kanto Teishin Hospital on August 22, 1996, due to sudden onset of left hemichorea. He had been diagnosed with diabetes mellitus during an annual check-up 1 year prior to admission (random blood glucose 22.2 mmol / l (400 mg / dl)), but he
0022-510X / 99 / $ – see front matter 1999 Elsevier Science B.V. All rights reserved. PII: S0022-510X( 98 )00325-6
A. Iwata et al. / Journal of the Neurological Sciences 163 (1999) 90 – 93
refused medication, and even dietary control. He smoked one pack of cigarettes and consumed one can of beer every day. There was no family history of involuntary movements. On admission, his blood pressure was 130 / 69 mmHg and the pulse was 66 / min and regular; he weighed 58 kg and was 157 cm tall. He was alert and the mental state was normal. Neurological examination revealed left hemiballism– hemichorea with left-sided pyramidal signs. There was no cranial nerve involvement except for left hemifacial choreic movements. Muscle tone was decreased in the left extremities, but there was no weakness. Sensation was intact and no cerebellar sign was observed. Involuntary movement disappeared during sleep and increased with emotional tension. The following laboratory data were notable: fasting blood glucose 31.5 mmol / l (567 mg / dl), serum osmolarity 301 mmol / kg, glycosylated hemoglobin A1c 17.3%. On blood gas analysis, there was no metabolic acidosis. Urinalysis was strongly positive for glucose and ketones and negative for protein. Brain CT scan on admission (about 26 hours after the onset) showed a slight high-density area in the right putamen and the caudate head in accordance with the structures without any mass effect or edema. On MRI (Signa HORIZON HiSpeed 1.5T (General Electric, Milwaukee MI)) performed 11 days after admission, the entire right putamen and caudate head showed high-intensity on T1-weighted images (Fig. 1A) and slightly low intensity on T2-weighted images (Fig. 1B). The right globus pallidus was enhanced using Gd-DTPA (Fig. 1C). Also on day 11, a brain CT scan was performed again, and it revealed disappearance of the high-density area observed on the initial CT scan and globus pallidus showed slight low-density. Single photon emission computed tomography (SPECT) with 99m Tc-ethyl cysteinate dimer (ECD) performed 32 days after admission showed reduced accumulation in the right basal ganglia. On day 58, the entire right corpus striatum and the globus pallidus, which were previously enhanced, revealed high signal intensity on T1-weighted MRI (Fig. 1D). At this time, no enhancement was observed. On day 100 after admission, the right corpus striatum showed moderate atrophy as well as the CT scan, but the high-intensity on the T1-weighted image had not changed. The patient’s involuntary movement gradually improved with administration of haloperidol and tiapride.
3. Discussion Although the putamen is the most common site for primary intracerebral hemorrhage, hemichorea is a relatively rare symptom. Compared to diabetic hemichorea, which does not affect the internal capsule, the hypertensive putaminal hemorrhage commonly does affect it, causing
91
some degree of hemiparesis. Jones et al. reported a 42year-old man with apparent putaminal hypertensive hemorrhage (hematoma with mass effect) associated with hemichorea [10]. Unlike usual putaminal hemorrhage, the lesion spared the internal capsule to cause hemichorea without hemiparesis. In the striatum a high-intensity signal on T1-weighted MR images have been noted at the onset of hemiballism in some poorly controlled diabetic patients, but the corresponding pathology is not clear. The patients are usually in a poorly controlled diabetic state, the glycosylated hemoglobin ranges from 13.7% to 18.7% [8–13], the blood sugar measured on admission varies from 9.4 mmol / l to 63.3 mmol / l. These patients are usually in an extreme hyperglycemic state, and ketoacidosis is common. Blood osmolarity is also usually increased to as high as 325 mmol / l. The differential diagnosis of a hyperintense lesion in the basal ganglia on a T1-weighted image can involve manganese toxicity in long-term parenteral nutrition, chronic liver failure, calcification, Wilson’s disease, neurofibromatosis, fat deposit, osmotic myelinolysis, or hypoxic brain [14]. In the present case, the abnormal MR signals raised the possibility of destroyed myelin due to the release of lipids [15]. In order to exclude this possibility, we performed another scan using a fat-saturated T1-weighted imaging technique and found the same appearance as on the ordinary T1-weighted images; this indicated the absence of fat deposition. A previous report of diabetic hemichorea proposed that the intensity change was caused by abnormal deposition of calcium or some other material in neurones or glial cells [16], but in our case, the high density observed in the initial CT scan resolved within 2 weeks; the possibility of calcification was remote. The appearance of the striatal lesion in imaging studies differs from a hypertensive putaminal hemorrhage in two ways. First, there is little or no evidence of mass effect, which is usually observed in hypertensive hematoma. Second, in hypertensive hemorrhage, the lesion is usually confined to the putamen through the head of the caudate nucleus. It may occasionally extend internally to the globus pallidus and subthalamic nucleus sparing the anterior limb of the internal capsule, but it never extends to other regions as in the present case. Broderick et al. [17] reported two cases of diabetic hemichorea and concluded that the noted lesion was a hemorrhagic infarction caused by diapedesis of red blood cells through ischemic capillary endothelium without vessel rupture. They attributed the intensity change on MRI in the corpus striatum to the presence of methemoglobin from a precipitating petechial hemorrhage, with blood interspersed between the brain tissue. However, there was no clear evidence of BBB destruction, because the time of diagnosis and the first MRI images was late, and the entire lesion already demonstrated high signal intensity on T1weighted images. In the present case, the right globus
92
A. Iwata et al. / Journal of the Neurological Sciences 163 (1999) 90 – 93
Fig. 1. On day 11 following admission, the right caudate head and the greater part of the putamen shows high signal intensity on T1-weighted image (TR 300 ms, TE 9 ms) (1A), and low signal intensity on T2-weighted image (TR 3500 ms, TE 98 ms) (1B). With Gd-DTPA injection, the globus pallidus was slightly enhanced (1C). On day 58 following admission, the globus pallidus previously enhanced now shows high signal intensity on T1-weighted image (TR 300 ms, TE 9 ms) (1D).
A. Iwata et al. / Journal of the Neurological Sciences 163 (1999) 90 – 93
pallidus showed intensity change subsequent to that of the putamen and caudate head, so there was a brief interval in which to show enhancement with Gd-DTPA before the T1-value shortening. This finding is compatible with the idea that the petechial hemorrhage was followed by BBB destruction caused by hyperglycemia, supporting the idea that the diapedesis occurred as a result of the hyperglycemia. In a hypertensive hematoma, deoxyhemoglobin is converted to methemoglobin within several days. Similarly, in our patient, on day 11 MRI scans of the basal ganglia showed a hypersignal on the T1-weighted image and a hyposignal on the T2-weighted image. These findings may be explained by the presence of methemoglobin resulting from petechial hemorrhage. In the usual hematoma, a T1 high-intensity lesion at the early stage suggests the presence of intracellular methemoglobin, showing the protonelectron dipole–dipole proton relaxation enhancement (PEDDPRE) effect [18]. Usually, with the destruction of erythrocytes in the hematoma, the intracellular methemoglobin converts slowly to extracellular methemoglobin, which results in T2 elongation by the preferential T2 proton relaxation enhancement (PT2PRE) effect. However, in the late subacute phase of our patient’s condition, the lesion showed T1 shortening only, and the appearance of the T2-weighted image remained unchanged. There is no clear explanation for this finding, but the hyperosmotic state may have played an important role. That is, in the hyperosmotic state, the erythrocyte membrane might be stabilised and erythrolysis, which often occurs in the usual hematoma may not happen. The hemoglobin may be stabilised with intracellular conformation, showing the PEDDPRE effect, and may be slowly converted to hemosiderin or ferritin. At this time, there are no pathological specimens available to prove this hypothesis. The MRI finding is to some extent different from massive hypertensive hemorrhage, which affects the thalamus and the pyramidal tract at the same time. That is, compared to massive hemorrhage, intact thalamus and pyramidal tract may play an important role in the pathogenesis of the hemichorea. The functional image showed decreased activity of the right striatum and spared ipsilateral thalamus. This may cause hyperactivity of the indirect pathway of the parallel frontal–subcortical circuit in basal ganglia [19] to cause hyperactivity of the thalamus, which resulted in hemichorea.
Acknowledgements The authors would like to thank Dr Makoto Iwata, Department of Neurology, Tokyo Women’s Medical University, for his critical comments.
93
References [1] Recter Jr. WG, Herlong HF. Nonketotic hyperglycemia appearing as choreoathetosis or ballism. Arch Intern Med 1982;142:154–5. [2] Lin JJ, Chang MK. Hemiballism–hemichorea and non-ketotic hyperglycemia. J Neurol Neurosurg Psych 1994;57:748–50. [3] Sanfield JA, Finkel J, Lewis S, Rosen SG. Alternating choreoathetosis associated with uncontrolled diabetes mellitus and basal ganglia calcification. Diabetes Care 1986;9:100–1. [4] Nagai C, Kato T, Katagiri T, Sasaki H. Hyperintense putamen on T1-weighted MR images in a case of chorea with hyperglycemia. AJNR 1995;16:1243–6. [5] Altafullah I, Pascual-Leone A, Duvall K, Anderson DC et al. Putaminal haemorrhage accompanied by hemichorea-hemiballism. Stroke 1990;21:1093–4. [6] Lai PH, Chang MH, Teng MMH. et al. Chorea-ballisms with nonketotic hyperglycemia in primary diabetes mellitus. AJNR 1996;17:1057–64. [7] Nabatame H, Nakamura K, Matsuda M et al. Hemichorea in hyperglycemia associated with increased blood flow in the contralateral striatum and thalamus. Internal Med 1994;33:472–5. [8] Nakagawa T, Mitani K, Nagura H et al. Chorea-ballism associated with nonketotic hyperglycemia and presenting with bilateral hyperintensity of the putamen on MR T1-weighted images - A case report. Clin Neurol 1994;34:52–5. [9] Chang MH, Chiang HT, Lai PH et al. Putaminal petechial haemorrhage as the cause of chorea: a neuroimaging study. J Neurol Neurosurg Psych 1997;63:300–3. [10] Jones Jr. HR, Baker RA, Kott HS. Hypertensive putaminal haemorrhage presenting with hemichorea. Stroke 1985;16:130–1. [11] Shwartz GA, Barrows LJ. Hemiballism without involvement of Luy’s body. Arch Neurol 1960;2:420–34. [12] Goldblatt D, Marksbery W, Reeves AG. Recurrent hemichorea following striatal lesions. Arch Neurol 1974;31:51–4. [13] Kase CS, Maulsby GO, de Juan E, Mohr JP. Hemichorea hemiballism and lacunar infarction in the basal ganglia. Neurology 1981;31:452–5. [14] Ho VB, Fitz CR, Yoder CC, Geyer CA. Resolving MR features in osmotic myelinolysis (central pontine and extrapontine myelinolysis). AJNR 1993;14:163–7. [15] Lai PH, Tien RD, Chang MH et al. Chorea-ballisms with nonketotic hyperglycemia in primary diabetes mellitus. AJNR 1996;17:1057– 64. [16] Yahikozawa H, Hanyu N, Yamamoto K. et al. Hemiballism with striatal hyperintensity on T1-weighted MRI in diabetic patients: a unique syndrome. J Neurol Sci 1994;124:208–14. [17] Broderick JP, Hagen T, Brott T. et al. Hyperglycemia and haemorrhagic transformation of cerebral infarcts. Stroke 1995;26:484–7. [18] Bradley WG. MR appearance of haemorrhage in the brain. Radiology 1993;189:15–26. [19] Alexander GE, DeLong MR, Strick PL. Parallel organization of functionally segregated circuit linking basal ganglia and cortex. Ann Rev Neurosci 1986;9:357–81.