- Email: [email protected]
Non-herpetic fulminant meningoencephalitis with periodic lateralised epileptiform discharges
Case reports
Non-herpetic fulminant meningoencephalitis with periodic lateralised epileptiform discharges Akinori Nakamura, Takao Hashimoto, Masayuki Matsuda, Kazuhide Shimada, Nobuo Yanagisawa, Shu-ich Ikeda Third Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
Summary This report concerns two patients with fulminant meningoencephalitis presenting in status epilepticus with periodic lateralised epileptiform discharges (PLEDs) observed on electroencephalogram. The titer of herpes simplex virus type 1 antibody was not elevated in either serum or cerebrospinal fluid, and acyclovir was not effective for either patient. Corticosteroid therapy was dramatically effective, however, suggesting that autoimmune inflammatory diseases were the underlying systemic disorders. PLEDs can thus be associated with steroid-responsive inflammatory meningoencephalitis. & 2002, Elsevier Science Ltd. All rights reserved. Journal of Clinical Neuroscience (2002) 9(2), 190±192 & 2002, Elsevier Science Ltd. All rights reserved. DOI: 10.1054/jocn.2001.0976, available online at http://www.idealibrary.com on
Keywords: meningoencephalitis, periodic lateralised epileptiform discharges (PLEDs), autoimmune inflammatory disease, corticosteroid therapy Received 1 March 2001 Accepted 31 May 2001 Correspondence to: Akinori Nakamura, Third Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. Tel.: +81-263-37-2673; Fax: +81-263-34-0929; E-mail: [email protected]
INTRODUCTION
admission, neurological examination revealed a comatose state with clonic generalised convulsion, nuchal stiffness, anisocoria, conjugate deviation to the right, and bilateral pyramidal tract signs. Multiple oral stomatitis ulcers were observed, but no uveitis or genital ulcers. The erythrocyte sedimentation rate (ESR) was 40 mm/hr, the white blood cell count 10,300/ml and C-reactive protein (CRP) 8.0 mg/dl (normal: <0.1 mg/dl), but no serum antinuclear antigens were detected. The chemotaxis of polymorphic neutrocytes (PMN) was about two times higher than in a normal control. The cerebrospinal fluid (CSF) showed a pressure of 310 mmH2O, 22 lymphocytes and 134 polynuclear leukocytes/ml, 206 mg/dl of protein (normal range: 10±40 mg/ dl) and 67 mg/dl of glucose (normal range: 50±75 mg/dl). The IgG content was 32.3 mg/dl (normal range: 0.9±2.7 mg/dl). Cultures of the CSF were negative. An enzyme-linked immunosorbent assay (ELISA) for herpes simplex viral infection showed that the titers of HSV1-IgM were not elevated in serum or CSF, and the pair of titers of HSV1-IgG and that of the complement fixing (CF) antibody to HSV-1 examined on the third and 14th hospital day showed no change. Two oligoclonal IgG bands in the CSF were positive. An EEG recorded on the third hospital day showed periodic sharp waves and polyspikes corresponding to PLEDs, predominantly in the right hemisphere (Fig. 1). Plain and enhanced brain computerized tomography did not detect any abnormal lesions, although a brain magnetic resonance imaging (MRI) was not performed. The presence of aseptic meningoencephalitis with PLEDs prompted us to start administration on the third hospital day, 30 mg/kg/day of acyclovir divided into three doses on the basis of a diagnosis of probable HSE, even though HSV-1 titer results were inconclusive. Nuchal stiffness and CSF findings improved over two weeks but the patient remained comatose. On the 17th hospital day, oral stomatitis ulcers, deterioration of mental status and meningeal signs appeared again. After he was given 80 mg/day of oral prednisolone for two weeks, his clinical signs and laboratory data markedly improved. The patient was discharged on the 60th hospital day and the prednisolone dosage was tapered off over six months. Patient 2 was a 41 year old man who was admitted to a local hospital suffering from headaches and a low-grade fever of 37 C. Swelling of the tonsils, oral stomatitis ulcers and nuchal stiffness were seen, and the CSF contained 11 monocytes/ml and 43 mg/dl protein. He was diagnosed as having aseptic meningitis, and he recovered after taking 10 mg of
Periodic lateralised epileptiform discharges (PLEDs) are a characteristic abnormality seen on electroencephalogram (EEG) in herpes simplex virus encephalitis (HSE) and a clue for early diagnosis before virological verification.1 On the other hand, it is known that several brain disorders other than HSE can show PLEDs.2 We present two patients with aseptic meningoencephalitis associated with PLEDs on EEG. No rise in the antibody titer for herpes simplex virus and a dramatic response to corticosteroid therapy suggest a non-herpetic, autoimmune inflammatory pathogenesis. CASE REPORT Patient 1 was a 39 year old man who was admitted to a local hospital for the treatment of meningoencephalitis. He had a low-grade fever of 37 C, and gradually became tight-lipped, followed by abnormal behavior; that is, he left his apartment and spent an entire day in a small automobile. His EEG showed diffuse high amplitude slow waves. Soon after this he developed status epilepticus and was transferred to our hospital. On 190
Fig. 1
EEGs of patient 1 showing PLEDs in the right hemisphere.
Non-herpetic fulminant meningoencephalitis with PLEDs 191
dexamethazone daily along with antibiotics. Sixteen months later, the patient was admitted to our hospital in status epilepticus following a period of headaches and fever. On admission, he was intubated in a comatose state, and showed nuchal rigidity, conjugated eye deviation to the left, and repetitive general seizures. He had numerous oral stomatitis ulcers, but no eye inflammation, typical skin lesions or genital ulcers. The ESR was 36 mm/hr, the peripheral white blood cell count was 14,200/ml, CRP was 5.05 mg/dl, but no antinuclear antibodies were detected. The chemotaxis of PMN was twice as high as in normal control. The CSF examination revealed an initial pressure of 170 mmH2O, a cell count of 293/ml, (monocyte 159/ml and poly 134/ml, total protein of 125 mg/dl and IgG of 19 mg/dl. The oligoclonal IgG band was negative. ELISA of HSV-1-IgG titers and CF antibody to HSV-1 were not elevated in either serum or CSF. These titers were still not elevated 16 days after the first examination. The EEG demonstrated PLEDs with a sharp wave train dominating in the frontal portion of the left temporal lobe (Fig. 2). The MRI findings on the fourth hospital day revealed multiple lesions in the bilateral thalami, basal ganglia, the frontal portion of the temporal lobes, the hippocampi and the brainstem (Fig. 3). The patient received intravenous administration of acyclovir (30mg/kg/day, divided into three doses, for 17 days) on the basis of a tentative diagnosis of HSE. Since the patient did not show any improvement, we initiated intravenous dexamethazone (10 mg/day) on the 7th hospital day, followed
Fig. 2
EEGs of patient 2 showing PLEDs in the left hemisphere.
by rapid improvement in neurological manifestations and laboratory data. Oral prednisolone (60 mg) was substituted for dexamethazone on the 21st hospital day, and the dose was tapered off over six months. EEGs on the 24th hospital day showed diffuse slow waves without PLEDs. Three months after onset, the patient was still drowsy, but could communicate. DISCUSSION The remarkable features of the two cases presented here are meningoencephalitis associated with status epilepticus, PLEDs on EEG and a dramatic response to corticosteroid therapy. Although HSE was initially considered to be the causative disease, conventional virological tests failed to confirm this diagnosis, while intravenous administration of acyclovir showed a transient, minor effect on patient 1 and no effect on patient 2. The definite remission obtained with corticosteroid therapy suggests the presence of an underlying autoimmune inflammatory disorder in both patients. Because these patients also had enhanced leukocyte chemotaxis, which is thought to be responsible for positive results on a pathergy test, BehcËet's disease was considered to be the most likely underlying disease causing meningoencephalitis in both patients, but this diagnosis was not definitive for lack of evidence of genital ulceration, typical skin lesions and uveitis. However, some reports have suggested that HSV infection is one of the etiologic or triggering factors in BehcËet's disease.3±5 It has been reported that ICR mice inoculated with HSV-1 showed BehcËet's disease-like symptoms6 and two cases with neuro-BehcËet's disease were reactive to acyclovir, but not to corticosteroid therapy.7,8 HSV infection might thus have been involved in the pathogenesis of patient 1, who partially responded to acyclovir. As to other autoimmune disorders, cerebral vasculitis or acute disseminated encephalomyelitis cannot be excluded. PLEDs are peculiar EEG findings and consist of lateralised complexes usually recurring every 1±2 s, and these complexes often consist of sharp waves or spikes that may be followed by slow waves.2 Involvement of both cortical and subcortical areas may contribute to periodic discharge patterns.2,9 The presence of PLEDs is known to be of diagnostic significance for determining HSE in the acute stage,1 and is helpful for early institution of acyclovir therapy. On the other hand, PLEDs may also be associated with a variety of other disorders, e.g., cerebrovascular disorders, brain tumours, central nervous system infections or anoxia.2 In the literature, four other patients with encephalitis caused by neuro-BehcËet's disease were also reported as showing PLEDs.10±13 In all those, and in our patients with steroid-responsive inflammatory disorders, meningoencephalitis presenting PLEDs was generally severe. To summarize, we presented two cases of fulminant meningoencephalitis presenting PLEDs and showing definite improvement after corticosteroid administration. It is important to be aware that PLEDs on EEG can be associated with disorders other than HSE, and that early administration of corticosteroid therapy is critical for autoimmune inflammatory meningoencephalitis. REFERENCES
Fig. 3 Magnetic resonance imaging (T2-weighted image) in axial section of the brain of patient 2 obtained on the fourth hospital day. Slice at basal ganglia level (A) and one at midbrain level (B). There are multiple lesions in the bilateral thalami, basal ganglia, and frontal portion of the temporal lobes, the hippocampi and the brain stem.
& 2002, Elsevier Science Ltd. All rights reserved.
1. 2.
Schwartz MS, Prior PF, Scott DF. The occurrence and evolution in the EEG of a lateralized periodic phenomenon. Brain 1973; 96: 613±622. Brenner RP, Schaul N. Periodic EEG patterns: classification, clinical correlation, and pathophysiology. J Clin Neurophis 1990; 7: 249±267.
Journal of Clinical Neuroscience (2002) 9(2)
192 Shamoto et al. 3.
4. 5.
6. 7. 8. 9.
10.
11.
12.
13.
Hamaza M, Elleuch M, Slim A, Hamazaoui K, Ayed K. Antibodies to herpes simplex virus in patients with BehcËet's disease. Clin Rheumatol 1990; 9: 498±500. Hamaza M, Slim A. Herpes simplex virus antigens in sera of patients with BehcËet's disease. Clin Rhematol 1991; 10: 456. Studd M, McCance JD, Lehner T. Detection of HSV-1 DNA in patients with BehcËet's syndrome and in patients with recurrent oral ulcers by polymerase chain reaction. J Med Microbiol 1991; 34: 39±43. Sohn S, Lee E-S, Bang D, Lee S. BehcËet's disease-like symptoms induced by the herpes simplex virus in ICR mice. Eur J Dermatol 1998; 8: 21±23. Resegotti L, Pistone M. Acyclovir and BehcËet's syndrome. Ann Intern Med 1984; 100: 319. Prieto J, SuaÂrez M, Civeira P. Acyclovir and BehcËet's disease. Ann Intern Med 1984; 101: 565. Chatrian GE, Shaw C-M, Leffman H. The significance of periodic lateralized epileptiform discharges in EEG: an electrographic, clinical and pathological study. Electroencephalogr Clin Neurophysiol 1964; 17: 177±193. Beneto Pascual A, Blasco Olcina R, Ameave Y. Meningoencephalitis in a case of BehcËet's disease: electroencephalographic findings. Med Clin (Barcelona) 1981; 76: 417±419. Pourmand R, Markand ON, Cook JA. Periodic lateralized EEG abnormality in a case of neuro-BehcËet syndrome. Clin Electroencephalogr 1984; 15: 122±124. Su S-L, Way L-J, Lin R-T, Peng M-J, Wu S-C. Neuro-BehcËet's disease: Report of three cases with a review of the literature. Kaohsiung J Med Sci 1990; 6: 155±162. Kihara M, Takahashi M, Mitsui Y, Tanaka H, Nishikawa S, Nakamura Y. A case of neuro-BehcËet's encephalitis with PLEDs as distinct from herpes simplex encephalitis: a differential diagnosis. Functional Neurol 1996; 11: 99±103.
Mesial temporal lobe epilepsy with lateral temporal lobe abnormalities in magnetoencephalography and glucose metabolism H. Shamoto1 MD, T. Nakajima2 MD, N. Nakasato1 MD, M. Iwasaki2 MD, R. Shirane2 MD, M. Itoh3 MD, T. Yoshimoto2 MD 1 Department of Neurosurgery, Kohnan Hospital, 2Department of Neurosurgery, Tohoku University School of Medicine, 3 Cyclotron Radioisotope Center, Tohoku University, Sendai, Japan
Summary Magnetoencephalography (MEG) and positron emission tomography (PET) revealed abnormal findings in the lateral temporal lobe of a 22 year old female with mesial temporal lobe epilepsy. Electroencephalography identified the epileptogenic focus in the left mesial temporal lobe and standard anterior temporal lobectomy resulted in a good surgical outcome. These discrepancies can be explained by the presence of anatomical and functional pathways between the mesial and lateral temporal structures, or pathophysiological abnormalities in both the mesial and lateral temporal lobes. Careful evaluation is necessary for analysis of MEG and PET findings in patients with temporal lobe epilepsy. & 2002, Elsevier Science Ltd. All rights reserved.
Received 31 January 2001 Accepted 5 June 2001 Correspondence to: Hiroshi Shamoto, Department of Neurosurgery, Kohnan Hospital, 4-20-1 Nagamachi-minami, Taihaku-ku, Sendai 982-8523, Japan. Tel.: 81-22-248-2131; Fax: 81-22-304-1641.
INTRODUCTION Functional brain imaging with magnetoencephalography (MEG) or positron emission tomography (PET) are becoming important methods of pre-surgical evaluation for the localisation of epileptogenic lesions. However, whether these modalities can identify the mesial or non-mesial type of temporal lobe epilepsy in individual patients remains unclear. We describe a case of mesial temporal lobe epilepsy, in which both preoperative MEG and 18F-fluorodeoxyglucose (FDG)-PET showed abnormalities in the lateral temporal lobe. CASE REPORT A 22 year old female had suffered from complex partial seizures, consisting of motion arrest and manual automatism, since age 16 years. Secondary generalised seizures occurred six months after the first attack. Her seizures did not respond to medical treatment with several anti-convulsants, so she was admitted to our hospital for surgical treatment. She had no neurological deficit. Interictal scalp electroencephalography (EEG) revealed spikes at the left sphenoidal electrode (Sp1) and ictal EEG disclosed rhythmic fast wave at the left temporal region (T3) prior to the appearance of rhythmic theta waves at Sp1. The seizures began with left head turning, followed by motor arrest and left manual automatism. Postictal motor aphasia was notable. Magnetic resonance (MR) imaging found no apparent abnormalities (Fig. 1). MEG was performed with a 122-channel whole head MEG system (Neuromag, Helsinki, Finland1) in a magnetically shielded room. MEG spikes were visually identified, and each spike was analyzed during the period from the early slope to the spike peak using the single dipole model. The relative position of the patient's head to MEG sensors was determined using reference coils attached to the scalp fiduciary points. Anatomical MR images were used to locate the dipole position. Three dimensional spoiled gradient recalled acquisition images with the steady-state sequences were obtained using the following acquisition parameters: TR 40 ms, TE 2 ms, flip angle 45 , section thickness 1.5 mm, FOV 24 cm, and matrix 256 160. The calculated dipole positions were superimposed on the MR images using a graphic workstation linked to the MEG system. PET was performed in the interictal period with a Shimadzu HEADTOME-scanner in three dimensional data acquisition mode 45 minutes after intravenous injection of mean 37 MBq FDG. The subject lay comfortably in the scanner bed and all studies were performed with eyes closed in a darkened room
Journal of Clinical Neuroscience (2002) 9(2), 192±194 & 2002, Elsevier Science Ltd. All rights reserved. DOI: 10.1054/jocn.2001.1005, available online at http://www.idealibrary.com on
Keywords: temporal lobe epilepsy, MEG, FDG-PET, anterior temporal lobectomy Journal of Clinical Neuroscience (2002) 9(2)
Fig. 1
Mesial temporal lobe epilepsy with lateral temporal lobe abnormalities.
& 2002, Elsevier Science Ltd. All rights reserved.
Non-herpetic fulminant meningoencephalitis with periodic lateralised epileptiform discharges Akinori Nakamura, Takao Hashimoto, Masayuki Matsuda, Kazuhide Shimada, Nobuo Yanagisawa, Shu-ich Ikeda Third Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
Summary This report concerns two patients with fulminant meningoencephalitis presenting in status epilepticus with periodic lateralised epileptiform discharges (PLEDs) observed on electroencephalogram. The titer of herpes simplex virus type 1 antibody was not elevated in either serum or cerebrospinal fluid, and acyclovir was not effective for either patient. Corticosteroid therapy was dramatically effective, however, suggesting that autoimmune inflammatory diseases were the underlying systemic disorders. PLEDs can thus be associated with steroid-responsive inflammatory meningoencephalitis. & 2002, Elsevier Science Ltd. All rights reserved. Journal of Clinical Neuroscience (2002) 9(2), 190±192 & 2002, Elsevier Science Ltd. All rights reserved. DOI: 10.1054/jocn.2001.0976, available online at http://www.idealibrary.com on
Keywords: meningoencephalitis, periodic lateralised epileptiform discharges (PLEDs), autoimmune inflammatory disease, corticosteroid therapy Received 1 March 2001 Accepted 31 May 2001 Correspondence to: Akinori Nakamura, Third Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan. Tel.: +81-263-37-2673; Fax: +81-263-34-0929; E-mail: [email protected]
INTRODUCTION
admission, neurological examination revealed a comatose state with clonic generalised convulsion, nuchal stiffness, anisocoria, conjugate deviation to the right, and bilateral pyramidal tract signs. Multiple oral stomatitis ulcers were observed, but no uveitis or genital ulcers. The erythrocyte sedimentation rate (ESR) was 40 mm/hr, the white blood cell count 10,300/ml and C-reactive protein (CRP) 8.0 mg/dl (normal: <0.1 mg/dl), but no serum antinuclear antigens were detected. The chemotaxis of polymorphic neutrocytes (PMN) was about two times higher than in a normal control. The cerebrospinal fluid (CSF) showed a pressure of 310 mmH2O, 22 lymphocytes and 134 polynuclear leukocytes/ml, 206 mg/dl of protein (normal range: 10±40 mg/ dl) and 67 mg/dl of glucose (normal range: 50±75 mg/dl). The IgG content was 32.3 mg/dl (normal range: 0.9±2.7 mg/dl). Cultures of the CSF were negative. An enzyme-linked immunosorbent assay (ELISA) for herpes simplex viral infection showed that the titers of HSV1-IgM were not elevated in serum or CSF, and the pair of titers of HSV1-IgG and that of the complement fixing (CF) antibody to HSV-1 examined on the third and 14th hospital day showed no change. Two oligoclonal IgG bands in the CSF were positive. An EEG recorded on the third hospital day showed periodic sharp waves and polyspikes corresponding to PLEDs, predominantly in the right hemisphere (Fig. 1). Plain and enhanced brain computerized tomography did not detect any abnormal lesions, although a brain magnetic resonance imaging (MRI) was not performed. The presence of aseptic meningoencephalitis with PLEDs prompted us to start administration on the third hospital day, 30 mg/kg/day of acyclovir divided into three doses on the basis of a diagnosis of probable HSE, even though HSV-1 titer results were inconclusive. Nuchal stiffness and CSF findings improved over two weeks but the patient remained comatose. On the 17th hospital day, oral stomatitis ulcers, deterioration of mental status and meningeal signs appeared again. After he was given 80 mg/day of oral prednisolone for two weeks, his clinical signs and laboratory data markedly improved. The patient was discharged on the 60th hospital day and the prednisolone dosage was tapered off over six months. Patient 2 was a 41 year old man who was admitted to a local hospital suffering from headaches and a low-grade fever of 37 C. Swelling of the tonsils, oral stomatitis ulcers and nuchal stiffness were seen, and the CSF contained 11 monocytes/ml and 43 mg/dl protein. He was diagnosed as having aseptic meningitis, and he recovered after taking 10 mg of
Periodic lateralised epileptiform discharges (PLEDs) are a characteristic abnormality seen on electroencephalogram (EEG) in herpes simplex virus encephalitis (HSE) and a clue for early diagnosis before virological verification.1 On the other hand, it is known that several brain disorders other than HSE can show PLEDs.2 We present two patients with aseptic meningoencephalitis associated with PLEDs on EEG. No rise in the antibody titer for herpes simplex virus and a dramatic response to corticosteroid therapy suggest a non-herpetic, autoimmune inflammatory pathogenesis. CASE REPORT Patient 1 was a 39 year old man who was admitted to a local hospital for the treatment of meningoencephalitis. He had a low-grade fever of 37 C, and gradually became tight-lipped, followed by abnormal behavior; that is, he left his apartment and spent an entire day in a small automobile. His EEG showed diffuse high amplitude slow waves. Soon after this he developed status epilepticus and was transferred to our hospital. On 190
Fig. 1
EEGs of patient 1 showing PLEDs in the right hemisphere.
Non-herpetic fulminant meningoencephalitis with PLEDs 191
dexamethazone daily along with antibiotics. Sixteen months later, the patient was admitted to our hospital in status epilepticus following a period of headaches and fever. On admission, he was intubated in a comatose state, and showed nuchal rigidity, conjugated eye deviation to the left, and repetitive general seizures. He had numerous oral stomatitis ulcers, but no eye inflammation, typical skin lesions or genital ulcers. The ESR was 36 mm/hr, the peripheral white blood cell count was 14,200/ml, CRP was 5.05 mg/dl, but no antinuclear antibodies were detected. The chemotaxis of PMN was twice as high as in normal control. The CSF examination revealed an initial pressure of 170 mmH2O, a cell count of 293/ml, (monocyte 159/ml and poly 134/ml, total protein of 125 mg/dl and IgG of 19 mg/dl. The oligoclonal IgG band was negative. ELISA of HSV-1-IgG titers and CF antibody to HSV-1 were not elevated in either serum or CSF. These titers were still not elevated 16 days after the first examination. The EEG demonstrated PLEDs with a sharp wave train dominating in the frontal portion of the left temporal lobe (Fig. 2). The MRI findings on the fourth hospital day revealed multiple lesions in the bilateral thalami, basal ganglia, the frontal portion of the temporal lobes, the hippocampi and the brainstem (Fig. 3). The patient received intravenous administration of acyclovir (30mg/kg/day, divided into three doses, for 17 days) on the basis of a tentative diagnosis of HSE. Since the patient did not show any improvement, we initiated intravenous dexamethazone (10 mg/day) on the 7th hospital day, followed
Fig. 2
EEGs of patient 2 showing PLEDs in the left hemisphere.
by rapid improvement in neurological manifestations and laboratory data. Oral prednisolone (60 mg) was substituted for dexamethazone on the 21st hospital day, and the dose was tapered off over six months. EEGs on the 24th hospital day showed diffuse slow waves without PLEDs. Three months after onset, the patient was still drowsy, but could communicate. DISCUSSION The remarkable features of the two cases presented here are meningoencephalitis associated with status epilepticus, PLEDs on EEG and a dramatic response to corticosteroid therapy. Although HSE was initially considered to be the causative disease, conventional virological tests failed to confirm this diagnosis, while intravenous administration of acyclovir showed a transient, minor effect on patient 1 and no effect on patient 2. The definite remission obtained with corticosteroid therapy suggests the presence of an underlying autoimmune inflammatory disorder in both patients. Because these patients also had enhanced leukocyte chemotaxis, which is thought to be responsible for positive results on a pathergy test, BehcËet's disease was considered to be the most likely underlying disease causing meningoencephalitis in both patients, but this diagnosis was not definitive for lack of evidence of genital ulceration, typical skin lesions and uveitis. However, some reports have suggested that HSV infection is one of the etiologic or triggering factors in BehcËet's disease.3±5 It has been reported that ICR mice inoculated with HSV-1 showed BehcËet's disease-like symptoms6 and two cases with neuro-BehcËet's disease were reactive to acyclovir, but not to corticosteroid therapy.7,8 HSV infection might thus have been involved in the pathogenesis of patient 1, who partially responded to acyclovir. As to other autoimmune disorders, cerebral vasculitis or acute disseminated encephalomyelitis cannot be excluded. PLEDs are peculiar EEG findings and consist of lateralised complexes usually recurring every 1±2 s, and these complexes often consist of sharp waves or spikes that may be followed by slow waves.2 Involvement of both cortical and subcortical areas may contribute to periodic discharge patterns.2,9 The presence of PLEDs is known to be of diagnostic significance for determining HSE in the acute stage,1 and is helpful for early institution of acyclovir therapy. On the other hand, PLEDs may also be associated with a variety of other disorders, e.g., cerebrovascular disorders, brain tumours, central nervous system infections or anoxia.2 In the literature, four other patients with encephalitis caused by neuro-BehcËet's disease were also reported as showing PLEDs.10±13 In all those, and in our patients with steroid-responsive inflammatory disorders, meningoencephalitis presenting PLEDs was generally severe. To summarize, we presented two cases of fulminant meningoencephalitis presenting PLEDs and showing definite improvement after corticosteroid administration. It is important to be aware that PLEDs on EEG can be associated with disorders other than HSE, and that early administration of corticosteroid therapy is critical for autoimmune inflammatory meningoencephalitis. REFERENCES
Fig. 3 Magnetic resonance imaging (T2-weighted image) in axial section of the brain of patient 2 obtained on the fourth hospital day. Slice at basal ganglia level (A) and one at midbrain level (B). There are multiple lesions in the bilateral thalami, basal ganglia, and frontal portion of the temporal lobes, the hippocampi and the brain stem.
& 2002, Elsevier Science Ltd. All rights reserved.
1. 2.
Schwartz MS, Prior PF, Scott DF. The occurrence and evolution in the EEG of a lateralized periodic phenomenon. Brain 1973; 96: 613±622. Brenner RP, Schaul N. Periodic EEG patterns: classification, clinical correlation, and pathophysiology. J Clin Neurophis 1990; 7: 249±267.
Journal of Clinical Neuroscience (2002) 9(2)
192 Shamoto et al. 3.
4. 5.
6. 7. 8. 9.
10.
11.
12.
13.
Hamaza M, Elleuch M, Slim A, Hamazaoui K, Ayed K. Antibodies to herpes simplex virus in patients with BehcËet's disease. Clin Rheumatol 1990; 9: 498±500. Hamaza M, Slim A. Herpes simplex virus antigens in sera of patients with BehcËet's disease. Clin Rhematol 1991; 10: 456. Studd M, McCance JD, Lehner T. Detection of HSV-1 DNA in patients with BehcËet's syndrome and in patients with recurrent oral ulcers by polymerase chain reaction. J Med Microbiol 1991; 34: 39±43. Sohn S, Lee E-S, Bang D, Lee S. BehcËet's disease-like symptoms induced by the herpes simplex virus in ICR mice. Eur J Dermatol 1998; 8: 21±23. Resegotti L, Pistone M. Acyclovir and BehcËet's syndrome. Ann Intern Med 1984; 100: 319. Prieto J, SuaÂrez M, Civeira P. Acyclovir and BehcËet's disease. Ann Intern Med 1984; 101: 565. Chatrian GE, Shaw C-M, Leffman H. The significance of periodic lateralized epileptiform discharges in EEG: an electrographic, clinical and pathological study. Electroencephalogr Clin Neurophysiol 1964; 17: 177±193. Beneto Pascual A, Blasco Olcina R, Ameave Y. Meningoencephalitis in a case of BehcËet's disease: electroencephalographic findings. Med Clin (Barcelona) 1981; 76: 417±419. Pourmand R, Markand ON, Cook JA. Periodic lateralized EEG abnormality in a case of neuro-BehcËet syndrome. Clin Electroencephalogr 1984; 15: 122±124. Su S-L, Way L-J, Lin R-T, Peng M-J, Wu S-C. Neuro-BehcËet's disease: Report of three cases with a review of the literature. Kaohsiung J Med Sci 1990; 6: 155±162. Kihara M, Takahashi M, Mitsui Y, Tanaka H, Nishikawa S, Nakamura Y. A case of neuro-BehcËet's encephalitis with PLEDs as distinct from herpes simplex encephalitis: a differential diagnosis. Functional Neurol 1996; 11: 99±103.
Mesial temporal lobe epilepsy with lateral temporal lobe abnormalities in magnetoencephalography and glucose metabolism H. Shamoto1 MD, T. Nakajima2 MD, N. Nakasato1 MD, M. Iwasaki2 MD, R. Shirane2 MD, M. Itoh3 MD, T. Yoshimoto2 MD 1 Department of Neurosurgery, Kohnan Hospital, 2Department of Neurosurgery, Tohoku University School of Medicine, 3 Cyclotron Radioisotope Center, Tohoku University, Sendai, Japan
Summary Magnetoencephalography (MEG) and positron emission tomography (PET) revealed abnormal findings in the lateral temporal lobe of a 22 year old female with mesial temporal lobe epilepsy. Electroencephalography identified the epileptogenic focus in the left mesial temporal lobe and standard anterior temporal lobectomy resulted in a good surgical outcome. These discrepancies can be explained by the presence of anatomical and functional pathways between the mesial and lateral temporal structures, or pathophysiological abnormalities in both the mesial and lateral temporal lobes. Careful evaluation is necessary for analysis of MEG and PET findings in patients with temporal lobe epilepsy. & 2002, Elsevier Science Ltd. All rights reserved.
Received 31 January 2001 Accepted 5 June 2001 Correspondence to: Hiroshi Shamoto, Department of Neurosurgery, Kohnan Hospital, 4-20-1 Nagamachi-minami, Taihaku-ku, Sendai 982-8523, Japan. Tel.: 81-22-248-2131; Fax: 81-22-304-1641.
INTRODUCTION Functional brain imaging with magnetoencephalography (MEG) or positron emission tomography (PET) are becoming important methods of pre-surgical evaluation for the localisation of epileptogenic lesions. However, whether these modalities can identify the mesial or non-mesial type of temporal lobe epilepsy in individual patients remains unclear. We describe a case of mesial temporal lobe epilepsy, in which both preoperative MEG and 18F-fluorodeoxyglucose (FDG)-PET showed abnormalities in the lateral temporal lobe. CASE REPORT A 22 year old female had suffered from complex partial seizures, consisting of motion arrest and manual automatism, since age 16 years. Secondary generalised seizures occurred six months after the first attack. Her seizures did not respond to medical treatment with several anti-convulsants, so she was admitted to our hospital for surgical treatment. She had no neurological deficit. Interictal scalp electroencephalography (EEG) revealed spikes at the left sphenoidal electrode (Sp1) and ictal EEG disclosed rhythmic fast wave at the left temporal region (T3) prior to the appearance of rhythmic theta waves at Sp1. The seizures began with left head turning, followed by motor arrest and left manual automatism. Postictal motor aphasia was notable. Magnetic resonance (MR) imaging found no apparent abnormalities (Fig. 1). MEG was performed with a 122-channel whole head MEG system (Neuromag, Helsinki, Finland1) in a magnetically shielded room. MEG spikes were visually identified, and each spike was analyzed during the period from the early slope to the spike peak using the single dipole model. The relative position of the patient's head to MEG sensors was determined using reference coils attached to the scalp fiduciary points. Anatomical MR images were used to locate the dipole position. Three dimensional spoiled gradient recalled acquisition images with the steady-state sequences were obtained using the following acquisition parameters: TR 40 ms, TE 2 ms, flip angle 45 , section thickness 1.5 mm, FOV 24 cm, and matrix 256 160. The calculated dipole positions were superimposed on the MR images using a graphic workstation linked to the MEG system. PET was performed in the interictal period with a Shimadzu HEADTOME-scanner in three dimensional data acquisition mode 45 minutes after intravenous injection of mean 37 MBq FDG. The subject lay comfortably in the scanner bed and all studies were performed with eyes closed in a darkened room
Journal of Clinical Neuroscience (2002) 9(2), 192±194 & 2002, Elsevier Science Ltd. All rights reserved. DOI: 10.1054/jocn.2001.1005, available online at http://www.idealibrary.com on
Keywords: temporal lobe epilepsy, MEG, FDG-PET, anterior temporal lobectomy Journal of Clinical Neuroscience (2002) 9(2)
Fig. 1
Mesial temporal lobe epilepsy with lateral temporal lobe abnormalities.
& 2002, Elsevier Science Ltd. All rights reserved.