Isolated Leptomeningeal Enhancement in Anti-N-Methyl D-Aspartate Receptor Encephalitis: The Diagnostic Value of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Imaging

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a common autoimmune encephalitis that is noted to be a severe but treatable disease entity. Patients with anti-NMDAR encephalitis often develop psychotic symptoms, including delusions, hallucinations, and paranoia, as well as memory impairment and persistent loss of attention. However, MRI findings in such patients show no abnormalities in most cases. Although typical brain abnormality features, known as T2 hyperintensities, involve the brain parenchyma and contrast enhancement at the cerebral cortex or overlying meninges, isolated leptomeningeal enhancement has been rarely reported in anti-NMDAR encephalitis. Herein, we report a patient with anti-NMDAR encephalitis who presented with isolated leptomeningeal enhancement, additionally showing the diagnostic value of contrast-enhanced fluid-attenuated inversion recovery imaging.

Anti-N-methyl-D-aspartate Receptor Encephalitis: a Rare Complication of Ovarian Teratoma

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a potentially life-threatening but reversible autoimmune disorder characterized by psychiatric symptoms, cognitive dysfunction, speech dysfunction, seizures, movement disorder, decreased level of consciousness, and autonomic dysfunction or central hypoventilation. It occurs predominantly in young women and approximately half of them have underlying tumors, mainly ovarian teratoma. A 24-year old woman was admitted because of fever, headache, abnormal movement and decreased mental status. Five cycles of plasmapheresis improved her neurological and mental status. Anti-NMDAR antibodies in her CSF and serum were positive, and computed tomography revealed a 1-cm sized mass suggestive of mature cystic teratoma arising from the right ovary. We promptly performed laparoscopic right ovarian cystectomy. She was discharged after 2 weeks with mild memory deficit. Prompt removal of ovarian teratoma and multidisciplinary care are particularly important for good outcome.

Brain Areas Subserving Torrance Tests of Creative Thinking: An Functional Magnetic Resonance Imaging Study

BACKGROUND AND PURPOSE: Torrance Tests of Creative Thinking (TTCT) is a well-known and commonly used measure of creativity. However, the TTCT-induced creative hemodynamic brain activity is rarely revealed. The purpose of this study is to elucidate the neural correlates of creative thinking in the setting of a modified version of the figural TTCT adapted for an functional magnetic resonance imaging (fMRI) experiment. METHODS: We designed a blocked fMRI experiment. Twenty-five participants (11 males, 14 females, mean age 19.9±1.8) were asked to complete the partially presented line drawing of the figural TTCT (creative drawing imagery; creative). As a control condition, subjects were asked to keep tracking the line on the screen (line tracking; control). RESULTS: Compared to the control condition, creative condition revealed greater activation in the distributed and bilateral brain regions including the left anterior cingulate, bilateral frontal, parietal, temporal and occipital regions as shown in the previous creativity studies. CONCLUSIONS: The present revealed the neural basis underlying the figural TTCT using fMRI, providing an evidence of brain areas encompassing the figural TTCT. Considering the significance of a creativity test for dementia patients, the neural correlates of TTCT elucidated by this study may be valuable to evaluate the brain function of patients in the clinical field.

Neuro-Scientific Studies of Creativity

Creativity has historically been investigated in psychological and educational aspects, and developed by psychologists and educationists. Recent progress of computational and cognitive science has opened new horizons in the neuro-scientific approach, bridging the concept of creativity and specialized brain function. This review discusses the psychological and educational theories of creativity, and focuses on the recent works in neuroscience dealing with creativity in view of divergent thinking. We also summarize the brain areas and their networks found by the neuroimaging studies, especially functional magnetic resonance imaging.

Comparison of Electroencephalography and Diffusion-Weighted MR Findings in Transient Global Amnesia Patients

BACKGROUND: The etiology of transient global amnesia (TGA) is uncertain. Recent studies have demonstrated a high signal intensity on diffusion MRI in TGA patients. In this study we reviewed and compared the use of electroencephalography (EEG) and diffusion-weighted imaging (DWI) in TGA in order to determine their sensitivity and to reveal clues about the etiology of this condition. METHODS: Twenty patients (7 males and 13 females; aged 58.0+/-12.1 years, mean+/-SD) who had been diagnosed with TGA at Dongguk University International Hospital within a 2-year period (2007 and 2008) were included in the study. All patients underwent EEG and DWI. RESULTS: The EEG of 12 of the 20 patients (60.0%) exhibited abnormalities; all 12 exhibited slowing on either the left side (n=6) or bilaterally (n=6). Spikes or sharp waves were detected in two patients. DWI revealed unilateral high signal intensities in the hippocampus of eight patients; five of these patients had left hippocampal lesions, and the other three had right hippocampal lesions. Four patients with a unilateral DWI lesion exhibited bilateral EEG abnormalities, and six patients exhibited only EEG abnormalities (without DWI abnormalities). Three patients had a high-signal-intensity lesion on DWI without EEG abnormalities. Five patients had normal EEG and DWI results. Interestingly, no patient had EEG abnormalities confined to the right temporal area. CONCLUSIONS: These findings suggest that left temporal dysfunction is important for the development of TGA. EEG might be complementary to DWI in TGA investigations, and may be superior at illustrating the associated memory dysfunction.

Clinical practice guideline for dementia by Clinical Research Center for Dementia of South Korea

The Clinical Research Center for Dementia of South Korea (CREDOS), a nation-wide clinical dementia research group, has prepared clinical practice guidelines (CPG) for dementia tailored to the Korean population. In this article, a summary of the CREDOS CPG is presented with the Korean and English version of full report included in the appendix. The CREDOS CPG in intended not only for psychiatrists and neurologists, but also internists, family physicians, and other primary care physicians involved in the prevention and early diagnosis of dementia. While our CPG for dementia mainly covers Alzheimer's disease (AD) and vascular dementia (VaD), it also includes mild cognitive impairment (MCI) and vascular MCI, which are currently known to be the preclinical stages of AD or VaD, respectively, with emphasis placed on early diagnosis. The CREDOS CPG aims to achieve the following goals by developing CPG for dementia: to establish evidence-based, objective and clear clinical standards for dementia; to improve the clinical decision-making process for patients with dementia; to provide scientific and systematic scales to aid in the work of dementia specialists; to suggest comprehensive and systematic healthcare services tailored to each dementia subtype. The CREDOS CPG focuses on diagnosis and evaluation of clinical practice available domestically, and provides useful concepts of dementia. Its emphasis is on etiologies and epidemiology, diagnostic criteria and evaluation, neuropsychological tests, behavioral and psychological symptoms, the activities of daily living, laboratory tests, and brain imaging.

Primary Central Nervous System Lymphoma Diagnosed by Biopsy of Skin and Sural Nerve

Primary central nervous system lymphoma (PCNSL) is a rare tumor that accounts for less than 2% of all cerebral neoplasms. A 72-year-old man had been suffering from recurrent cranial nerve palsies for several years. His condition improved with steroid treatment, but then eventually worsened; he developed encephalopathic symptoms, quadriparesis, axonal neuropathy, and skin lesions. He was eventually diagnosed with PCNSL following an examination of skin and sural nerve biopsy samples. Biopsy of skin lesions or nerves should be considered for the accurate and early diagnosis of PCNSL.

A Case of Gemcitabine and Cisplatin Associated Posterior Reversible Encephalopathy Syndrome / Journal of the Korean Cancer Association, 대한암학회지

A 58-year-old female receiving gemcitabine and cisplatin chemotherapy for stage IV gallbladder cancer developed the clinicoradiologic syndrome, posterior reversible encephalopathy syndrome (PRES). Just before the 4th gemcitabine chemotherapy cycle, she was admitted to the hospital with complaints of headache, dizziness, and generalized tonic-clonic seizures. A MRI was performed on the day when the seizure developed, and the findings showed patchy cortical and subcortical T2 hyperintensity without enhancement that involved both occipital and parietal lobes. Phenytoin loading and maintenance was started for prevention of recurrent seizures, which was successful. The follow-up brain MRI obtained 10 days after the seizure attack showed completely resolved radiologic findings. After the MRI findings revealed complete resolution, phenytoin maintenance was stopped. Even with discontinuation of phenytoin, she had no seizures or other clinical manifestations.

Hypoglycemic Encephalopathy With Delayed Lesion on Magnetic Resonance Imaging

We report on delayed emergence of restricted diffusion on MRI after hypoglycemia. A 56-year-old man with type 2 diabetes was admitted with mental change. Initial serum glucose was 19 mg/dl. Fifteen hours after presumed symptom onset, brain imaging did not show any definite abnormality. However, areas of restricted diffusion emerged evident in both basal ganglia 9 days later. Hypoglycemia can cause delayed cytotoxic edema even after normalization of the serum glucose.

Early Onset Hemiparesis with Epilepsy: Pattern of Surgical Outcome according to Ictal Onset Zone / 대한간질학회지

PURPOSE: To reveal the pattern of surgical outcome according to the location of ictal onset zone in the patients who had a history of early onset (less than two years old) hemiparesis and delayed epilepsy. Many children with acute infantile hemiplegia (AIH) develop delayed epilepsy. This can lead to HHE (Hemiplegia, hemiconvulsion, and epilepsy) syndrome. Epilepsy patients associated with AIH or HHE syndrome generally have been thought to be medically intractable and difficult to treat surgically. METHODS: Patients with a history of early onset hemiparesis with epilepsy who had undergone surgical treatment from November 1995 to May 2002 at Seoul National University Comprehensive Epilepsy Center were recruited. Diagnostic criteria include convulsions, followed by a flaccid hemiplegia, and later epilepsy with partial seizures. Multidisciplinary presurgical evaluations were performed which include a complete neurological examination, brain MRI, long-term video-EEG monitoring, FDG-PET, intracarotid amobarbital test, and ictal and interictal SPECT if possible. Patients with epileptogenic zone outside the hippocampus underwent implantation of intracranial electrodes. The surgical side was localized by the clinical, neuroimaging, and electrophysiological results includeing results of invasive studies. Anterior temporal lobectomy (ATL), cortical resection, functional hemispherectomy, and callosotomy were performed according to the results of presurgical evaluation. RESULTS: Twenty-five patients were included. Mean age was 29.8 ranging from 19 to 60 years old. Fifteen were male and 10 were female. All had a previous history of febrile convulsions. The onset age of febrile convulsion and hemiplegia was one to 48 months (mean=18.0+/-13.2) and the onset age of epileptic seizures were 0.5 to 40 years (mean=9.9+/-8.2). Seventeen of them were right-handed, eight were left-handed and one was bilateral-handed. Follow-up periods after surgery were one to eleven years (mean=5.6+/-2.2). Twelve patients were diagnosed as medial TLE and underwent ATL. The other thirteen patients were diagnosed as neocortical or multifocal epilepsy. Eleven of medial TLE patients were seizure free after ATL and only one had aura. However, only four patients with neocortical epilepsy were seizure free and nine were not. Surgical outcome was significantly different between ATL only and other surgical procedures (p=0.004). CONCLUSION: In patients of early onset hemiparesis with epilepsy, various ictal onset zones can be possible. The medial TLE patients diagnosed by comprehensive presurgical evaluation, in spite of hemiatrophy on brain MRI, showed a good surgical outcome. Surgical treatment should be considered for the selected patients.

Clinico-electrical Characteristics of Lateral Temporal Lobe Epilepsy; Anterior and Posterior Lateral Temporal Lobe Epilepsy

BACKGROUND AND PURPOSE: This study aimed to determine whether there are clinicoelectrical differences between anterior lateral temporal lobe epilepsy (ALTLE) and posterior lateral temporal lobe epilepsy (PLTLE), taking medial temporal lobe epilepsy (MTLE) as a reference. METHODS: We analyzed the historical information, ictal semiologies, and ictal EEGs of temporal lobe epilepsy patients with a documented favorable surgical outcome (Engel class I or II) at follow-up after more than one year. LTLE was defined when a discrete lesion on MRI or an ictal onset zone in invasive study was located outside the collateral sulcus. LTLE was further divided into ALTLE and PLTLE by reference to the line across the cerebral peduncle. Total 107 seizures of 13 ALTLE, 8 PLTLE and 21 MTLE patients were reviewed. RESULTS: Initial hypomotor symptom was frequently observed in PLTLE (P<0.001). Oroalimentary automatism (OAA) was not observed initially in PLTLE. Generalized tonic-clonic seizures occurred significantly earlier in PLTLE than in ALTLE or MTLE (P< 0.001). Ictal scalp EEG was not helpful in differentiating between ALTLE and PLTLE. CONCLUSIONS: Frequent hypomotor onset, the absence of initial oroalimentary automatism, and early generalization are characteristic findings of PLTLE, although they are insufficient to differentiate it from ALTLE or MTLE.

Brain Areas Involved in Tactile Letter Recognition (graphesthesia)

BACKGROUND: Graphesthesia is the ability to recognize letters or symbols via somatic sensation. We employed functional MRI to determine neurological substrates underlying this ability. We also designed a behavioral experiment to examine the relationship between graphesthesia and working memory. METHODS: Images were acquired in a 1.5T scanner from ten right-handed normal subjects while tactile stimulation was applied for either graphesthesia or simple sensation. Additional eight right-handed normal observers participated in the behavioral experiment where they performed a visuo-spatial or a verbal working memory task, simultaneously with graphesthesia. Overall performance times were measured to detect interference in the dual-task situations. RESULTS: Comparison between graphesthesia and simple sensory stimulation revealed activations at bilateral prefrontal, parietal and superior temporal cortices, regardless of the hand stimulated. The right parietal operculum was activated for both hand conditions, while the corresponding area in the left hemisphere was activated by right-hand stimulation only, suggesting a right-hemisphere dominance for graphesthesia. From the behavioral experiments, we observed that the visuo-spatial task, but not the verbal task, interfered with graphaesthesia. CONCLUSIONS: Taken together, these results suggest that the brain areas underlying the visuo-spatial sub-system of working memory are involved in graphesthesia and that some cognitive processes underlying graphesthesia are right-lateralized.

Voluntary Nystagmus

PURPOSE: We evaluated the clinical manifestations of voluntary nystagmus in three patients and verified the efficacy of video-oculography as a diagnostic tool to differentiate voluntary nystagmus from congenital or latent nystagmus. METHODS: Meticulous history taking and neuro-ophthalmologic examination were performed for three patients with voluntary nystagmus. Video-oculography was also performed in one patient. RESULTS: All of the three patients were young men in military service. Neuro-ophthalmologic examination was normal in all three patients, except for shaking of the eyes. Video-oculography in one patient showed 5~6 Hz pendular oscillation with an amplitude of 7~15 degrees and a peak velocity of 345.4 deg/sec, verifying that the oscillatory eye movement was composed of saccades and was not a nystagmus. CONCLUSIONS: In differentiating between voluntary and congenital nystagmus, video-oculography as well as history taking and neuro-ophthalmologic examination were very helpful.

Neurological Manifestations and Image Findings in Patients with Exercise-induced Heat Stroke

BACKGROUND: Heat stroke is a thermal insult to the cerebral thermo-regulatory system that controls heat production and heat dissipation. Heat stroke occurs in all age groups and in different parts of the world. In the Korean army heat stroke can occur during marching or any other military training. This study was intended to reveal the pattern of neurological manifestations and brain images of heat stroke. METHODS: All patients who were transferred to one army hospital from March 2000 to September 2002 were included in this study and their neurological manifestations were recorded. A brain MRI was taken in 13 patients. PET images were taken in 6 patients. RESULTS: A total of nineteen patients were included in the study. The mean age was 20.2 (19~23) years. In the acute stage, all patients showed altered mentality and 11 patients showed seizure. During the subacute to chronic stage, the patients showed various neurological statuses ranging from normal to severe neurologic deficits such as abulia, cerebellar ataxia and so on. Brain MRI also showed various findings from normal to severe cerebellar atrophy. In one patient who showed persistent severe cerebellar dysfunction, the MRI showed progressive cerebellar atrophy. A PET image showed cerebellar hypometabolism in 5 patients and frontal hypometabolism in one patient. CONCLUSIONS: Heat stroke can cause various neurological deficits. Brain images can also vary. In the acute stage, the MRI may not correlate with clinical findings and may need a follow-up study. Additionally, a PET may explain neurological findings better in some cases.

Reliability of Semiology Descriptions by Frequent Observers

BACKGROUND: Semiology of epileptic seizure is very important for diagnosis and treatment. However, little is known about the reliability of the observers' description. This study aims to determine the description reliability of seizures in the aspects of classification and lateralization. METHODS: We recorded 72 patients with habitual seizures during video-EEG monitorings. We, then, compared the ictal behaviors described by frequency observers and those recorded on the videotape to compare the accuracy of the observers' descriptions. Finally, we reviewed which aspects of the informants affected the reliability of the data. RESULTS: The classification of seizures based only on the observer-description was somewhat discordant from the videotape (correct classification: 82%) especially in dividing simple partial from complex partial seizures. Description of many ictal behaviors in presumed complex partial seizure such as oroalimentary automatism, motionless staring, tonic/clonic posture and version was accurate except for the hand automatism. A specified direction by the observer has a very high true positive rate. The accuracy of the description was related to the educational status of the observer. CONCLUSIONS: Semiology description by well-educated observers is may be reliable, but every physician should keep its limitation in mind and judge accordingly.

Differentiation between Idiopathic Acute Transverse Myelitis and Myelopathic Multiple Sclerosis by MRI

BACKGROUND: Idiopathic acute transverse myelitis (ATM) is an inflammatory or demyelinating illness of unknown etiology. It is usually monophasic, though recurrences at the same spinal level of the initial attack have been reported. In Korea, the spinal cord is the most commonly affected site of multiple sclerosis (MS) and its clinical features often resemble those of ATM. As the prognoses of these two conditions are different, it is important to distinguish them from each other. The purpose of this study was to evaluate spinal MRI findings that could help differentiate ATM from myelopathic MS. METHODS: A total of 50 MRIs obtained less than four weeks after the onset of symptoms in 13 patients with ATM and 24 patients with clinically definite MS were reviewed retrospectively. The diagnostic criterion for ATM was a rapid onset of spinal motor and sensory dysfunction referable to a distinct spinal cord level with sphincter dysfunction, reaching its peak within 4 weeks, in the absence of pre-existing neurological diseases and spinal cord compression. For MS, Poser's criteria were used. We analyzed the lesion length, location, cross-sectional area, cord morphology, and contrast enhancement patterns in each of the groups. RESULTS: Characteristic MRI findings of ATM included; 1) centrally located hyperintensity (86%) occupying more than half of the cross-sectional area of the cord (100%), 2) thoracic preponderance in lesion location (thoracic: 7, cervicothoracic:3, cervical: 1), 3) lesion length of more than 3 vertebral segments (100%), 4) cord swelling (73%), and 5) focal or diffuse enhancement (90%). Most MRI findings of myelopathic MS (MMS) were not different from those of ATM, especially in Asian-type MS. Different MRI features of MMS from those of ATM included: 1) peripherally located hyperintensity occupying less than half of the cross-sectional area of the cord (20.8%), 2) lesion length less than two vertebral segments (33.3%), 3) normal cord morphology (25%), 4) no enhancement (36.1%), and 5) multifocality (22.2%), which were more commonly found in Western-type MS. CONCLUSIONS: Although there were some differences of spinal MRI features between ATM and MMS, it was not easy to differentiate them by MRI findings alone. The findings suggest that Asian-type MS has unique MRI characteristics similar to those of ATM and different from those of Western-type MS.

Disconnection Syndrome in Acute Hydrocephalus due to Intraventricular Hemorrhage

The right and left hemispheres of the brain play somewhat different roles but help each other perform higher cortical functions. A 43 year-old right-handed woman was admitted due to a intraventricular hemorrhage followed by hydro-cephalus. A brain MRI revealed an intraventricular hemorrhage in the lateral, 3rd, and 4th ventricle and the hemorrhage in the lateral ventricle was compressing the genu of the corpus callosum. When asked to draw the face of a clock, she placed the numbers in reverse order (counter clockwise) when performing the task with her right hand, whereas the same task performed by the left hand was normal. In addition, when she wrote out simultaneously with right and left hands , she wrote Korean words in their mirror image with her left hand . When she wrote Chinese characters, she performed better with her right hand. These findings revealed some aspects of interhemispheric interaction in processing the images of a clock, and the orthographic lexicon of Korean and Chinese characters.