A case report of recurrent limbic encephalitis caused by an enterovirus infection]

We reported a 28-year-old woman with recurrent focal encephalitis caused by an enterovirus infection. She showed convulsions, abnormal behavior, and consciousness disturbance on the first admission to our hospital in July 1998. A CSF study revealed lymphocyte-dominant pleocytosis (17/microl), and brain MRI revealed high signal intensity in the bilateral limbic system including the hippocampus. We treated her with acyclovir and steroid pulse therapy based on a diagnosis of limbic encephalitis. After that, her symptoms gradually disappeared without any sequelae. She became aware of memory disturbance at the end of April 2001. She was admitted to our hospital because of generalized convulsions on 2 May 2001. Her body temperature was 37.3 degrees C. Her consciousness was disturbed (Japan coma scale 2), but there was no nuchal rigidity. A CSF study failed to reveal pleocytosis (cell count, 2/microl). Brain MRI revealed a bilateral high signal intensity area in the limbic system. Her symptoms gradually improved, but the mild memory disturbance persisted on her discharge. An immunological study revealed no abnormality in either humoral or cell immunity. RT-PCR revealed enterovirus RNA in CSF samples obtained on 1 July 1998, 3 May 2001, and 25 July 2001. We diagnosed her as having recurrent limbic encephalitis caused by an enterovirus infection. This is the first report of recurrent limbic encepalitis caused by enterovirus infection in an host with an undetected defect of immune system.     

30例成人乙型脑炎临床和影像学特点

目的探讨成人乙型脑炎的临床和影像学特点。方法回顾性分析30例成人乙型脑炎患者的临床资料。结果成人乙型脑炎以老年人居多。30例患者起病时均存在高热,意识障碍22例,急性肢体瘫痪4例,头痛6例,恶心、呕吐4例,头晕2例,反应迟钝2例,言语不清1例,癫痫1例。22例行头颅MRI检查,17例异常(77.3%),表现为细胞毒性水肿和(或)血管源性水肿。DWI异常12例,累及中脑7例、丘脑8例、海马2例、基底节1例、侧脑室旁白质1例、胼胝体1例;T2WI Flair异常17例,累及侧脑室旁白质14例、丘脑6例、中脑3例、海马2例、基底节1例。结论成人乙型脑炎多以高热、意识障碍起病,部分以急性肢体瘫痪起病,临床表现和影像学特点与脑梗死相似,鉴别靠血清学和病原学检测。乙型脑炎主要累及中脑、丘脑、基底节、海马、侧脑室旁白质和胼胝体,表现为细胞毒性水肿和(或)血管源性水肿,个别患者治疗后T2WI Flair侧脑室旁白质异常高信号减少。     

Asymptomatic self-limiting white matter lesions in the chronic phase of herpes simplex encephalitis

We report a 9-month-old girl with herpes simplex encephalitis. T(2)-weighted magnetic resonance imaging (MRI) on the 8th day of illness showed increased signal intensity in the gray and white matter of the bilateral lobes, especially the right temporo-parietal lobe. High voltage slow waves were recorded in the right parieto-occipital region on electroencephalography. She was discharged on the 34th day of illness without sequelae. On discharge, the high signal intensity on MRI had improved and the abnormal slow waves on electroencephalography had disappeared. At 4 months after the onset of illness, MRI revealed decreased signal intensities in T(1)-weighted images and increased signal intensities in T(2)-weighted images in the periventricular white matter adjacent to the posterior horns of the lateral ventricles. The white matter lesions had expanded at 9 months after the onset of illness. At 14 months after the onset of illness, the white matter lesions were reduced in size, and at 2 years after the onset of illness, they had completely disappeared. During 2 years follow-up after discharge, however, there were no neurological abnormalities corresponding to the lesions and her psychomotor development was normal. Although the mechanism underlying these white matter lesions had not been elucidated, an immune-mediated complication such as edema or demyelination is suspected. Repeat MRI studies over a long period are necessary to follow up a patient with herpes simplex encephalitis.     

富亮氨酸胶质瘤失活1蛋白抗体阳性边缘叶脑炎的临床特点并文献复习

目的 探讨富亮氨酸胶质瘤失活1蛋白(LGI1)抗体阳性边缘叶脑炎的临床特点。方法 对本院收治的1例LGI1抗体阳性的边缘叶脑炎患者的诊治过程进行回顾性分析并复习相关文献。结果 患者为青年女性,亚急性起病,临床主要表现为记忆力下降、癫痫、闭经、情绪障碍。血和脑脊液LGI1抗体阳性; MRI检查T₂及Flair序列可见双侧颞叶内侧、海马高信号病灶; PET-CT示双侧颞叶内侧、海马代谢活性对称性降低。经激素和免疫球蛋白联合治疗,疗效显著。结论 LGI1抗体阳性边缘叶脑炎以记忆力下降、癫痫发作为主要临床表现; 病灶主要累及双侧颞叶内侧、海马; 具有较好的免疫治疗效果,及时的诊断及治疗有助于患者的恢复。     

A case of non-herpetic acute limbic encephalitis associated with a type-2 adenovirus infection]

This is a report of a 31-year-old woman with non-herpetic acute limbic encephalitis following a type-2 adenovirus infection. The patient was admitted to a hospital with high fever, severe liver dysfunction, and thrombocytopenia. Six days after admission, she became afebrile, and her liver dysfunction was normalized by conservative therapy. However, the patient started to experience generalized seizures that developed into status epileptics. The patient was then transferred to a referred hospital. Brain MR images revealed faint high-signal intensity in the bilateral limbic systems on FLAIR images. A CSF examination indicated mild pleocytosis. These findings suggested acute limbic encephalitis, which may have been mediated by an autoimmune reaction following some viral infection. Thus, steroid pulse therapy was started on the day of admission. The patient's condition, including the seizures and disturbances involving consciousness, improved gradually. The patient was discharged from the hospital in one month while still experiencing mild memory disturbances. Three months after onset of the illness, a T1-weighted MR image showed a linear high-signal intensity in the hippocampi, which indicated focal necrosis. Six months after onset, the patient's memory disturbance had been improved (her MMSE score was 28/30 points). We investigated the titers of many viruses that are known to cause liver dysfunction and found that a titer of the type-2 adenovirus was significantly elevated within three weeks. Although the anti-voltage-gated potassium channel (VGKC) antibody was not detected in the patient's serum, it seems that the autoimmune reaction after the type-2 adenovirus infection may have caused the acute limbic encephalitis.     

A case of herpes simplex virus encephalitis characterized by prolonged psychotic symptoms in convalescence--a case report]

A 14-year-old girl was diagnosed as having herpes simplex encephalitis by a polymerase chain reaction examination of the cerebrospinal fluid. MRI showed diffuse high signal areas at the bilateral temporal lobes and right frontal lobe. She was treated with a total of 350 mg/kg of acyclovir for 23 days, and discharged without abnormal neurological findings. On the 90th day after the onset, however, she became excitable and aggressive to her family. She excessively seeked relations with several boy friends. MRI revealed dilation of the bilateral ventricles and atrophy of the temporal lobes. These pathologic changes including the atrophy of hippocampus may be responsible for the character changes in this case.     

A recalcitrant case of encephalitis with voltage-gated potassium channel antibodies

We report the case of a 65-year-old man who had encephalitis with a high titer of voltage-gated potassium channel antibodies (VGKC-Abs). His initial symptoms included memory disturbance, confusion, and seizures. Laboratory tests revealed a low plasma sodium concentration and a strong positive result for VGKC-Abs. A diffusion-weighted magnetic resonance imaging (MRI) scan showed a high intensity lesion within the right basal ganglia, which later showed normal intensity. The patient's initial symptoms resolved without any treatment. During the first relapse, the patient experienced consciousness disturbance and an increased number of seizures than that observed initially. A diffusion weighted MRI scan showed a high intensity lesion within the right hippocampus, and a fluid attenuated inversion recovery (FLAIR) weighted MRI scan showed high intensity lesions within the right hippocampus, right thalamus, and pons. The patient's symptoms and the MRI abnormalities resolved with prednisolone therapy. During the second relapse, he again experienced consciousness disturbance and an increased number of seizures than that observed initially. Diffusion-and FLAIR weighted MRI scans showed high intensity lesions within the right thalamus. However, the array of immunosuppressive treatments used during the first relapse was not as effective during the second relapse. The serum VGKC-Ab titers before steroid therapy during the first relapse and after immunosuppressive treatment during the second relapse were 1,252 pmol/L and 22.4 pmol/L, respectively. Brain MRI revealed signal changes in the basal ganglia at the onset of disease, in the limbic area during the first relapse, and in the thalamus during the second relapse. VGKC-Ab-associated encephalopathy is usually considered a benign autoimmune disorder; however, in our case, the encephalitis gradually became intractable to various immunosuppressive treatments, and unique MRI abnormalities were observed.     

Motor amusia following a right temporal lobe hemorrhage--a case report

A 65-year-old female was admitted to our hospital because of left hemiparesis with sudden onset one week before. She was congenitally right-handed. She had been a teacher of Japanese string instrument (samisen) playing and been able to sing Japanese traditional songs well. A tape on which she had recorded her songs one year before the admission also proved her to be a good singer. Neurological examination on admission revealed almost normal findings except for minimal weakness in her left hand fingers. Right temporal lobe hemorrhage was revealed by CT scan. One month after the admission, she complained that she was unable to sing her songs and to play samisen as she used to do. Her intelligence was normal (WAIS VIQ116, PIQ108) and there were no abnormal findings as follows: aprosodia, aphasia, agraphia, memory disturbance, agnosia and ideational, ideomotor, constructional or limb-kinetic apraxia. She could point out her errors while singing. However, musical receptive function was slightly disturbed with tonal memory in Seashore test. When she was asked to sing a song without any instrumental support, she hummed a melody occasionally with wrong pitch, but rhythmically. After hearing a song she knew well, she reproduced it with slight improvement. With the vocal or the instrumental accompaniment, she could sing fairly well. She had some mistakes of pitch while playing a samisen. MRI was performed one year and a half after the brain hemorrhage. It displayed a thin linear of hematoma in the white matter of the right upper temporal and transverse gyrus. It was proved in our case that motor amusia with minimal musical receptive dysfunction could appear following a cerebral lesion and musical function might be independent of intelligence or verbal function.     

An adult case suspected of recurrent measles encephalitis with psychiatric symptoms]

An adult case of suspected recurrent measles encephalitis with psychiatric symptoms is reported. A 46-year-old woman developed measles encephalitis presenting as schizophreniform disorder and recovered three months after onset. However, approximately two years later, she suffered a relapse of encephalitis presenting with psychiatric symptoms (auditory hallucination, cenesthopathy, insomnia, depressive mood) and became comatose. Following ten days of symptomatic treatment, her clinical symptoms gradually improved. Three months later, she made a remarkable recovery without neurological sequelae. Since then, she has maintained good condition for six years. The diagnosis of suspected recurrent measles encephalitis was made on the basis of the change of anti-measles IgM antibody titers. Acute relapse of disseminated encephalomyelitis (ARDEM) and multiple sclerosis (MS) were ruled out due to no abnormal finding of cerebral white matter on MRI. Six years after the recurrent episode, the titers of anti-measles IgM antibodies (EIA) in the serum were still high, suggesting that she was suffering from a chronic measles virus infection. This patient should be followed up for a longer time because there is a possibility that she might be in the latent period of subacute sclerosing panencephalitis (SSPE).     

An autopsy case of panencephalopathic type of Creutzfeldt-Jakob disease: an early clinical sign documented by magnetic resonance imaging

We reported an autopsy case of panencephalopathic type of Creutzfeldt-Jakob disease (CJD), one of whose early clinical signs, visual loss, had been documented by magnetic resonance imaging (MRI). The patient was a 59-year-old woman, who showed disturbance of visual acuity, memory and calculation at the early stage. About 2 months later she developed apallic syndrome and revealed myoclonic jerks in her eye balls, face, neck and extremities. Electroencephalography showed periodic synchronous discharge. Three months later after her first symptoms MR showed bilateral occipital atrophy, although we could find no brain atrophy on CT scan. She died of the suffocation caused by bronchopneumonia at the age of 60 years. The total duration of her illness was about 20 months. Neuropathological examination revealed a pronounced diffuse atrophy of the cerebral cortex and white matter. In addition to severe cortical neuronal loss and astrocytosis, spongiform changes were evident. The hippocampus was relatively well preserved. In the cerebral white matter both myelin sheaths and axons disappeared almost completely. The cerebellum showed the severe degeneration of granule cells. These neuropathological findings are consistent with those of panencephalopathic type of CJD. It is important to clarify the abnormalities of MR findings in relation to such early clinical signs of CJD. To the best of our knowledge such reports as ours have not been published previously.     

Postvaccinial encephalomyelitis without cutaneous vaccination reaction

A 5-year-old girl developed a progressive febrile neurological illness consisting of right focal seizures, right hemiparesis, and stupor evolving over a period of six weeks. During the month preceding the onset of her illness she had received two apparently unsuccessful smallpox vaccinations without a skin lesion. Elevation of cerebrospinal fluid gamma globulin and findings on brain biopsy were consistent with postinfectious encephalitis, and a simultaneous increase in serum vacinia antibody titer suggested that the illness was postvaccinial encephalitis. Clinically, the child developed a severe extrapyramidal movement disorder during the acute phase followed by nine months of stuporous unresponsiveness, yet subsequently made a substantial recovery.     

A case of sarcoid myopathy presenting muscle pain and muscle weakness and with muscle MRI abnormality]

We experienced a 70-year-old female diagnosed as sarcoidosis. She complained bilateral femoral pain from 70-year-old. 3 months after the onset, she developed muscle weakness extending to her upper extremities with high fever of 38-39 degrees C. The erythema appeared at the right femoral region 4 months after the onset. She admitted to our hospital because of further evaluation. When she was admitted, she had tenderness on grasping the femoral muscles, proximal limb muscle weakness and Gowers' sign. On laboratory examination, CRP, aldorase, myoglobin, lysozyme were increased mildly. The EMG demonstrated a myogenic pattern. Muscle biopsy performed from the left quadriceps femoris muscle revealed non-caseating granuloma and muscle fiber necrosis. A diagnosis of muscle sarcoidosis was made from the biopsy findings and the clinical features. With oral prednisolone administration, muscle weakness and other clinical features improved gradually. On muscle MRI, multiple small high intensity areas were scattered in the femoral muscles. Muscle MRI is considered to be useful for differential diagnosis of muscle sarcoidosis.     

Acute transverse myelitis after Japanese B encephalitis vaccination in a 4-year-old girl

Fourteen days after Japanese B encephalitis (JBE) vaccination, a 4-year-old girl developed the full clinical manifestation of ATM within 24h. She showed acute ascending flaccid paraplegia with sensory disturbance, bladder dysfunction and meningeal sign. Cerebrospinal fluid examination revealed neutrophil pleocytosis and elevated protein level. Magnetic resonance imaging (MRI) showed diffuse swelling of the cervical and lumbar cord with low signal intensity on T1 and high signal intensity on T2-weighted imaging. These findings suggested that she had developed meningo-radiculomyelopathy.Since sequential MRI studies showed prompt reduction of the cord swelling, the high-dose methylprednisolone therapy employed seemed to have been effective for improvement of inflammation. Even with such potent drug treatment, she still has substantial flaccid diplegia and sphincter disorder 1 year later, and so we are convinced that the pathological change of the cord was as severe as in necrotizing myelopathy. Although the pathological process remains unknown, cellular autoimmune mechanism against the JBE vaccination is suspected.     

Syndrome of inappropriate secretion of anti-diuretic hormone associated with limbic encephalitis due to herpes simplex virus infection--a case report]

We report a case of syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) associated with limbic encephalitis. A 79-year-old woman was admitted with a complaint of fever, disturbance of consciousness and generalized seizure. Her conscious level was E1V2M4 by Glasgow coma scale. Physical examination showed generalized seizure, neck stiffness, hyperreflexia and flaccid paralysis in her all extremities, and pathological reflexes. Blood analysis revealed hyponatremia, decrease of plasma osmolarity, spared secretion of urine sodium and increase of ADH, leading to the diagnosis of SIADH. Cerebrosponal fluid examination showed mild pleocytosis, elevated protein, and normal glucose level. Although herpes simplex virus (HSV) DNA was not detected by the polymerase chain reaction method, titers of anti-HSV IgG antibody elevated chronologically. Brain MRI revealed abnormal T2 and FLAIR high intensities in the cingulate gyrus and hippocampus bilaterally. An EEG revealed periodic synchronous discharges predominantly in the frontal areas. Based on the clinical course, laboratory data, MRI and EEG findings, we diagnosed as SIADH associated with acute limbic encephalitis caused by HSV infection. After the fluid restriction and sodium supply, plasma sodium was normalized. Administration of acyclovir and steroid was not so effective, however her condition improved gradually. Several cases of SIADH associated with limbic encephalitis have been reported; however, the pathophysiology is to be clarified. We thought that in the presented case, SIADH was caused by disturbance of the hormonal control at the hypothalamus on the pituitary gland due to the spreading of inflammation from limbic system to these areas.     

CT perfusion abnormalities in a case of non-herpetic acute limbic encephalitis]

We report a 42-year-old woman of non-herpetic acute limbic encephalitis (NHALE) whose CT perfusion (CTP) images revealed abnormalities of the limbic system at the early stage. The patient had high fever, convulsion and memory disturbance soon after having caught a common cold, and was admitted to a hospital where she developed progressive disturbance of consciousness. She was then transferred to our hospital 7 days after the initial manifestations. Although enhanced CT images of the brain failed to find any lesion, CTP images revealed a focal increase in the cerebral blood flow and shortening of mean transit time in the bilateral hippocampi and amygdalae. MRI of the subsequent day showed high signal intensity lesions on diffusion, T2-weighted and FLAIR images at the same area. Her consciousness improved by intravenous administration of high-dose methylprednisolone together with other combination therapies. Her CTP images apparently improved by 5 weeks after the onset, but she was left with mild memory disturbance, amenorrhea secondary to hypothalamic failure, hyperosmia, and hypogeusia. In conclusion, CTP is sensitive enough to detect the lesions of the limbic system even in the early stage of NHALE.     

A case of probable cytomegalovirus encephalitis who restored from persistant disturbance of consciousness

A 50-year-old woman presented with confusion, fever and drowsiness following an episode of headache and dizziness. On admission, neurological examination found positive pyramidal tract signs, meningeal irritation, and bilateral myoclonus in her arms. Laboratory tests revealed liver dysfunction, positive inflammatory reaction, elevated serum IgM antibody against cytomegalovirus, and increased cerebrospinal fluid protein of 67 mg/dl. MRI of brain by diffusion weighted imaging showed a wide spread hyperintense lesion in white matter and limbic areas. We administered aciclovir, ganciclovir and steroid pulse therapy that showed a limited effect in the initial stage. In spite of all these therapies, she suffered from status epilepticus, followed by persistent disturbance of consciousness for about 2 months. However, her level of consciousness and motor deficit were gradually improved by continuous administration of ganciclovir. The present case indicates that prolonged disturbance of consciousness due to cytomegalovirus encephalitis could be restored with continuous ganciclovir administration.     

Amnesia following herpes simplex encephalitis]

We describe three patients presenting themselves with amnesia following herpes simplex encephalitis. All three patients showed anterograde amnesia. Moreover, one patient showed retrograde amnesia extending about fifty years prior to the onset of the illness. Two patients revealed semantic memory disorder, disinhibitory behaviors and confabulations, which suggested the existence of frontal lobe dysfunction. MRI of all three patients disclosed uni- or bilateral temporal lesions. SPECT images showed decreased uptake not only in the temporal lobes but also in the frontal lobes. Amnesia following herpes simplex encephalitis has been thought to be caused by the temporal lobe disorder. However, we postulate that the frontal lobe dysfunction might contribute to the appearance of amnesia.     

Hemiplegia: an initial manifestation of Japanese encephalitis

A 7-year-old boy from an area endemic to Japanese encephalitis (JE) manifested with acute febrile illness, left hemiplegia and preserved consciousness during the prodromal phase of illness. The child developed features of encephalitis 48 hours after the onset of hemiplegia. IgM MAC ELISA for JE virus revealed high titers in the serum and cerebrospinal fluid suggestive of JE. MRI of the brain showed asymmetrical bilateral thalamic hyperintense lesions on T2 weighted image, considered diagnostic of JE. Hemiplegia during the prodromal phase or as an initial symptom of JE is rather unusual.     

A case of multiple sclerosis with hypothalamic amenorrhea]

We present a 31-year-old woman of multiple sclerosis. At age 28, she was admitted with complaints of echolalia and a gradual onset of weakness affecting the right upper and bilateral lower limbs. Brain MRI showed high intensity areas in the bilateral frontal gyri, lobuli paracentralis, and left anterior thalamus. Although she had been in remission for 3 years, she developed dysesthesia of left upper and lower limbs. Cervical T2 weighted MRI showed a new high signal intensity lesion in the spinal cord from the C2 to C3 level. The combination of the cerebral, thalamic and spinal cord lesions with remission and excerbations allowed the diagnosis of clinically MS to be made. She suffered amenorrhea from the onset of her illness. Serum prolactin was within the normal range. The LH and FSH basal secretions were decreased and there were low delayed secretions of LH and FSH after intravenous injection of 100 micrograms LHRH. We consider that her amenorrhea was caused by the hypothalamic lesion, supported by MR findings of dilatation of the third ventricle.     

Reversible MRI findings of posterior column of the spinal cord in a patient with acute autonomic and sensory neuropathy]

We report serial spinal MRI T2 findings in a patient with acute autonomic and sensory neuropathy (AASN). A 20-year-old woman was admitted to our hospital with progressive sensory disturbance in her extremities and orthostatic syncope after her symptoms of upper respiratory infection. Neurological examination demonstrated reduced tendon reflexes, hypalgesia, paresthesia, reduced position sensation in distal dominant extremities (predominant in lower legs) and wide variety of autonomic dysfunction (severe orthostatic hypotension, anhidrosis, urinary disturbance, coughing attack, constipation and appetite loss). She was diagnosed as having AASN. Although high dose intravenous immunoglobulin therapy successfully prevented the symptom progression, her sensory disturbance and autonomic dysfunction were prolonged and showed only slow improvement. Spinal MRI on acute phase was normal. On chronic phase (11 month after the onset), spinal MRI T2 weighted images demonstrated high intensity lesion in the posterior column successive from upper cervical to lower thoracic spinal cord. Those abnormal findings were attenuated in concordance with her symptom improvement and finally disappeared when she became to walk stably without assist.