Neurol Sci (2015) 36:1743–1745 DOI 10.1007/s10072-015-2268-0
LETTER TO THE EDITOR
Occult dual pathology in mesial temporal lobe epilepsy Shin-ichiro Osawa1 • Masaki Iwasaki1 • Hiroyoshi Suzuki2 • Nobukazu Nakasato3 Teiji Tominaga1
•
Received: 9 March 2015 / Accepted: 23 May 2015 / Published online: 30 May 2015 Ó Springer-Verlag Italia 2015
Keywords Dual pathology Temporal lobe epilepsy Ganglioglioma Negative magnetic resonance imaging Dear Sir, Hippocampal sclerosis (HS) can appear secondary to neocortical epileptogenic lesion in medically refractory epilepsy, called dual pathology. In the dual pathology, removal of both the primary lesion and HS is necessary to achieve better seizure outcome. However, if the primary lesion is not apparent in pre-operative imaging studies, selective surgery to hippocampus may be performed and followed by inadequate seizure control. Here, we report a case of dual pathology which was not diagnosed preoperatively. A 50-year-old man with drug-resistant temporal lobe epilepsy (TLE) was referred to our department for evaluation of surgical treatment. Seizures had started at age 10 years and had become intractable to multiple
& Masaki Iwasaki [email protected] 1
Departments of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan
2
Department of Pathology and Laboratory Medicine, National Hospital Organization, Sendai Medical Center, Sendai, Japan
3
Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Japan
medications at age 22 years. He had aura of fear or de´ja`vu followed by complex partial seizures 2–3 times a month despite antiepileptic medications including carbamazepine and lamotrigine. Previously, he was treated with valproic acid, levetiracetam and zonisamide. Comprehensive presurgical evaluation including video-electroencephalography (EEG), ‘‘epilepsy protocol’’ high-field magnetic resonance imaging (MRI), fluoro-deoxy-glucose positron emission tomography (FDG-PET), neuropsychological testing, was performed. 3.0-T MRI revealed increased T2 signal intensity and volume loss of the right hippocampus (Fig. 1). No cystic lesions or other neocortical abnormalities were observed by neuroradiologists. Gadolinium enhancement was not performed. No calcifying lesions were seen in computed tomography scans. Video-EEG monitoring revealed that complex partial seizures with automatisms were associated with rhythmic EEG changes in the right anterior temporal region. FDG-PET showed glucose hypometabolism in the right antero-basal temporal region. Neuropsychologically, mild impairment of verbal memory function was noted. Under a diagnosis of right TLE with hippocampal sclerosis, trans-sylvian selective amygdalo-hippocampectomy was performed. Histological examination revealed both Type 1b HS (Fig. 2a) and ganglioglioma in the subiculum (Fig. 2b, c) [1]. He has suffered no additional neurological deficits post-operatively. The patient was seizure free for 2 years with continuing medication. Follow-up MRI at 1 year showed no evidence for recurrence of tumor. Neocortical epileptogenic lesion occasionally coexists with HS, and is called ‘‘dual pathology.’’ Surgical removal of both neocortical lesion and hippocampus is better for the achievement of seizure freedom [2]. In the present case, the subicular tumor was not identified pre-
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1744 Fig. 1 a Pre-operative coronal short-tau inversion recovery magnetic resonance images revealing volume loss and increased signal intensity of the right hippocampus. b Preoperative coronal fluid attenuated inversion recovery images showing increased signal intensity of the right hippocampus. c Axial T2weighted images showing marked atrophy of the right hippocampus. No neocortical lesion is observed. d Manual hippocampal volumetry revealing significant volume loss of the right hippocampus
Neurol Sci (2015) 36:1743–1745
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operatively, but was fortunately included in the specimen. Although not performed in the present case, gadoliniumenhanced MRI is worth considering for epilepsy patients with ‘‘typical’’ hippocampal sclerosis to detect occult tumors. Occult dual pathology has been reported as the cause of failed seizure control after selective amygdalohippocampectomy in patients with TLE [3]. If the removal was not adequate, selective hippocampectomy may have left the parahippocampal epileptogenic lesion
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behind. Occult dual pathology might explain the marginally better post-operative seizure outcome after standard rather than selective anterior temporal resection for mesial TLE in a recent meta-analysis [4], because the larger neocortical resection is more likely to include any neocortical lesion in the removed tissue. The present case suggests that careful pre-operative evaluation of the possibility of concurrent neocortical lesion is important in the presence of HS.
Neurol Sci (2015) 36:1743–1745
1745 Conflict of interest of interest.
A
The authors declare that they have no conflict
Informed consent Informed consent was obtained from the participant.
References 1. Blumcke I, Pauli E, Clusmann H, Schramm J, Becker A, Elger C, Merschhemke M, Meencke HJ, Lehmann T, von Deimling A, Scheiwe C, Zentner J, Volk B, Romstock J, Stefan H, Hildebrandt M (2007) A new clinico-pathological classification system for mesial temporal sclerosis. Acta Neuropathol 113(3):235–244 2. Li LM, Cendes F, Andermann F, Watson C, Fish DR, Cook MJ, Dubeau F, Duncan JS, Shorvon SD, Berkovic SF, Free S, Olivier A, Harkness W, Arnold DL (1999) Surgical outcome in patients with epilepsy and dual pathology. Brain 122(Pt 5):799–805 3. Plowey ED, Vogel H, Salmi D, Shuer LM (2013) Occult pigmented ganglioglioma in an adult male with chronic posttraumatic epilepsy. Clin Neuropathol 32(3):192–195 4. Josephson CB, Dykeman J, Fiest KM, Liu X, Sadler RM, Jette N, Wiebe S (2013) Systematic review and meta-analysis of standard vs selective temporal lobe epilepsy surgery. Neurology 80(18):1669–1676
B
C
Fig. 2 a Low-magnification view of the histological specimen of the cornus ammonis and subiculum showing extensive loss of pyramidal neurons in CA1, CA3, and CA4 areas together with granular cell depletion. (Nissl staining, original magnification 95.) b Photomicrograph of the resected specimen of the subiculum showing the border of the tumor vaguely demarcated (arrowheads). (Hematoxylin–eosin staining, original magnification 940.) c Higher magnification photomicrograph showing the tumor consisted of spindle-shaped glial cells and dysplastic neurons with cytomegaly and irregularshaped nucleus (arrowheads). (Hematoxylin–eosin staining, original magnification 9200.) Immunohistochemistry showed glial cells are positive for glial fibrillary acidic protein and vimentin, and the dysplastic neurons positive for NeuN (data not shown)
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LETTER TO THE EDITOR
Occult dual pathology in mesial temporal lobe epilepsy Shin-ichiro Osawa1 • Masaki Iwasaki1 • Hiroyoshi Suzuki2 • Nobukazu Nakasato3 Teiji Tominaga1
•
Received: 9 March 2015 / Accepted: 23 May 2015 / Published online: 30 May 2015 Ó Springer-Verlag Italia 2015
Keywords Dual pathology Temporal lobe epilepsy Ganglioglioma Negative magnetic resonance imaging Dear Sir, Hippocampal sclerosis (HS) can appear secondary to neocortical epileptogenic lesion in medically refractory epilepsy, called dual pathology. In the dual pathology, removal of both the primary lesion and HS is necessary to achieve better seizure outcome. However, if the primary lesion is not apparent in pre-operative imaging studies, selective surgery to hippocampus may be performed and followed by inadequate seizure control. Here, we report a case of dual pathology which was not diagnosed preoperatively. A 50-year-old man with drug-resistant temporal lobe epilepsy (TLE) was referred to our department for evaluation of surgical treatment. Seizures had started at age 10 years and had become intractable to multiple
& Masaki Iwasaki [email protected] 1
Departments of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan
2
Department of Pathology and Laboratory Medicine, National Hospital Organization, Sendai Medical Center, Sendai, Japan
3
Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Japan
medications at age 22 years. He had aura of fear or de´ja`vu followed by complex partial seizures 2–3 times a month despite antiepileptic medications including carbamazepine and lamotrigine. Previously, he was treated with valproic acid, levetiracetam and zonisamide. Comprehensive presurgical evaluation including video-electroencephalography (EEG), ‘‘epilepsy protocol’’ high-field magnetic resonance imaging (MRI), fluoro-deoxy-glucose positron emission tomography (FDG-PET), neuropsychological testing, was performed. 3.0-T MRI revealed increased T2 signal intensity and volume loss of the right hippocampus (Fig. 1). No cystic lesions or other neocortical abnormalities were observed by neuroradiologists. Gadolinium enhancement was not performed. No calcifying lesions were seen in computed tomography scans. Video-EEG monitoring revealed that complex partial seizures with automatisms were associated with rhythmic EEG changes in the right anterior temporal region. FDG-PET showed glucose hypometabolism in the right antero-basal temporal region. Neuropsychologically, mild impairment of verbal memory function was noted. Under a diagnosis of right TLE with hippocampal sclerosis, trans-sylvian selective amygdalo-hippocampectomy was performed. Histological examination revealed both Type 1b HS (Fig. 2a) and ganglioglioma in the subiculum (Fig. 2b, c) [1]. He has suffered no additional neurological deficits post-operatively. The patient was seizure free for 2 years with continuing medication. Follow-up MRI at 1 year showed no evidence for recurrence of tumor. Neocortical epileptogenic lesion occasionally coexists with HS, and is called ‘‘dual pathology.’’ Surgical removal of both neocortical lesion and hippocampus is better for the achievement of seizure freedom [2]. In the present case, the subicular tumor was not identified pre-
123
1744 Fig. 1 a Pre-operative coronal short-tau inversion recovery magnetic resonance images revealing volume loss and increased signal intensity of the right hippocampus. b Preoperative coronal fluid attenuated inversion recovery images showing increased signal intensity of the right hippocampus. c Axial T2weighted images showing marked atrophy of the right hippocampus. No neocortical lesion is observed. d Manual hippocampal volumetry revealing significant volume loss of the right hippocampus
Neurol Sci (2015) 36:1743–1745
A
B
C
D
operatively, but was fortunately included in the specimen. Although not performed in the present case, gadoliniumenhanced MRI is worth considering for epilepsy patients with ‘‘typical’’ hippocampal sclerosis to detect occult tumors. Occult dual pathology has been reported as the cause of failed seizure control after selective amygdalohippocampectomy in patients with TLE [3]. If the removal was not adequate, selective hippocampectomy may have left the parahippocampal epileptogenic lesion
123
behind. Occult dual pathology might explain the marginally better post-operative seizure outcome after standard rather than selective anterior temporal resection for mesial TLE in a recent meta-analysis [4], because the larger neocortical resection is more likely to include any neocortical lesion in the removed tissue. The present case suggests that careful pre-operative evaluation of the possibility of concurrent neocortical lesion is important in the presence of HS.
Neurol Sci (2015) 36:1743–1745
1745 Conflict of interest of interest.
A
The authors declare that they have no conflict
Informed consent Informed consent was obtained from the participant.
References 1. Blumcke I, Pauli E, Clusmann H, Schramm J, Becker A, Elger C, Merschhemke M, Meencke HJ, Lehmann T, von Deimling A, Scheiwe C, Zentner J, Volk B, Romstock J, Stefan H, Hildebrandt M (2007) A new clinico-pathological classification system for mesial temporal sclerosis. Acta Neuropathol 113(3):235–244 2. Li LM, Cendes F, Andermann F, Watson C, Fish DR, Cook MJ, Dubeau F, Duncan JS, Shorvon SD, Berkovic SF, Free S, Olivier A, Harkness W, Arnold DL (1999) Surgical outcome in patients with epilepsy and dual pathology. Brain 122(Pt 5):799–805 3. Plowey ED, Vogel H, Salmi D, Shuer LM (2013) Occult pigmented ganglioglioma in an adult male with chronic posttraumatic epilepsy. Clin Neuropathol 32(3):192–195 4. Josephson CB, Dykeman J, Fiest KM, Liu X, Sadler RM, Jette N, Wiebe S (2013) Systematic review and meta-analysis of standard vs selective temporal lobe epilepsy surgery. Neurology 80(18):1669–1676
B
C
Fig. 2 a Low-magnification view of the histological specimen of the cornus ammonis and subiculum showing extensive loss of pyramidal neurons in CA1, CA3, and CA4 areas together with granular cell depletion. (Nissl staining, original magnification 95.) b Photomicrograph of the resected specimen of the subiculum showing the border of the tumor vaguely demarcated (arrowheads). (Hematoxylin–eosin staining, original magnification 940.) c Higher magnification photomicrograph showing the tumor consisted of spindle-shaped glial cells and dysplastic neurons with cytomegaly and irregularshaped nucleus (arrowheads). (Hematoxylin–eosin staining, original magnification 9200.) Immunohistochemistry showed glial cells are positive for glial fibrillary acidic protein and vimentin, and the dysplastic neurons positive for NeuN (data not shown)
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