HERPES SIMPLEX VIRUS ENCEPHALITIS: PROBLEMS IN DIAGNOSIS

Six children aged 13 days to nine years with herpes simplex encephalitis (HSE) are presented. Institution of appropriate antiviral treatment was later than six days in three cases; original diagnosis in these cases were post-traumatic epilepsy, bacterial meningitis and febrile convulsion. Initially pyrexia was absent in two cases and cranial CT was normal in two cases. Encephalitic changes were observed on the EEGs of five children. Diagnosis was confirmed by paired serological titres, brain biopsy, vesicle culture and CSF titres. The outcome for all six children was poor. HSE should always be considered in children presenting with focal seizures, even when apyrexial and with normal CT findings. In such situations, saving CSF for antibody titres or antigen identification should be routine practice. Treatment with acyclovir is justified before precise virological diagnosis has been established.     

Epilepsia partialis continua associated with widespread gliomatosis cerebri

We report an uncommon association of intractable epilepsia partialis continua that was the main presentation of widespread gliomatosis cerebri in two females. Both children had a preceding prolonged secondary generalized seizure 2-4 months before the evolution of epilepsia partialis continua, including recurrent clusters of left-sided myoclonic twitching and sensory impairment. During these events, the children remained fully alert. These seizures were corroborated by prolonged focal epileptic spike/wave discharges evident on the electroencephalograms. Cerebral magnetic resonance imaging in the first patient demonstrated a wide area of increasing signals over the right frontocentral regions, along with diffuse cortical-subcortical infiltration impinging on the left hemisphere. In the second patient a cortical lesion was suspected. Evaluation for Rasmussen’s encephalitis, focal cortical dysplasia, or a gliomatous process was conducted; the patients underwent a stereotactic brain biopsy in which the histologic findings were compatible with gliomatosis cerebri with diffuse widespread infiltration of glioma cells with no constitution of a circumscribed tumor mass. The first patient was treated with cranial radiation, chemotherapy, steroids, and combined antiepileptic therapy. The focal seizures gradually but markedly decreased in frequency, and sensory impairment abated within 18 months after establishment of the diagnosis and ensuing therapy. Cognition remains intact. The second female died 2 years after presentation despite massive chemotherapy and antiepileptic medications. Although rare, gliomatosis cerebri should be taken into account in the differential diagnosis of epilepsia partialis continua in children to facilitate a rapid diagnosis and initiation of prompt treatment of this rare disorder that may respond to a concurrent effective combination of cranial radiation, chemotherapy, and antiepileptic medications.     

N-isopropyl-p-[I123] iodoamphetamine single photon emission computed tomography (I123-IMP SPECT) and child neurology]

We studied the clinical usefulness of I123-IMP SPECT in 50 pediatric patients with CNS disorders, which were categorized into the convulsive disorder group (n = 20), the cerebrovascular disorder group (n = 10), the acute encephalopathy or CNS infection group (n = 10), the metabolic or degenerative disorder group (n = 6), the congenital abnormality group (n = 2) and the migraine group (n = 2). The findings obtained were compared with those of cranial CT. I123-IMP SPECT revealed abnormal findings in 45 out of the 50 patients (90%), although cranial CT showed abnormal findings in only 24 patients (48%). This difference was statistically significant (p less than 0.01). In all groups except the migraine, we could find abnormal findings in more than 90% of the patients. Out of 28 patients without focal findings on the initial CT scanning, I123-IMP SPECT showed focal abnormalities in 26 patients (93%). Moreover in many patients with focal neurological abnormalities, we found focal abnormalities of I123-IMP SPECT related with neurological abnormalities of the patients. From these findings, we think I123-IMP SPECT might be better to CT scanning in examining a localized lesion. It was found that in many patients with focal abnormalities in CT scanning, I123-IMP SPECT showed larger abnormalities in CT scanning. By using I123-IMP SPECT we might be able to study the blood perfusional state surrounding the abnormal area shown by CT. In 3 patients with acute cerebrovascular disorders, I123-IMP SPECT revealed abnormal findings 3 to 11 days earlier than cranial CT.I123-IMP SPECT might be useful for early recognition of the pathological state.(ABSTRACT TRUNCATED AT 250 WORDS)     

62例病毒性脑炎脑电图与临床及CT分析

为探讨病毒性脑炎（病脑）患者脑电图（EEG）与临床及CT之间的关系,将临床确诊的62例病脑患者进行EEG与CT检查,对其EEG异常的阳性率、异常程度与病程、临床表现、CT之间的关系进行比较分析,并作统计学处理。结果发现,发病10天以内EEG中、重度异常39倒（78%）,与10天以后比较有显著性差异（P＜0．001）。EET可表现为三种形式：以弥漫性异常为主（51.5％）;弥漫性异常伴局灶慢波（32．3%）;局灶性异常（16．2%）。EEG与CT之间无明显相关性（P＞0．05）。提示：EEG检查对病脑的诊断、鉴别诊断,以及动态观察病情、判断预后有重大意义。CT不能取代EEG。     

Utility of Neurodiagnostic Studies in the Diagnosis of Autoimmune Encephalitis in Children

BackgroundAutoimmune encephalitis is currently a clinical diagnosis without widely accepted diagnostic criteria, often leading to a delay in diagnosis. The utility of magnetic resonance imaging (MRI) and electroencephalography (EEG) in this disease is unknown. The objective of this study was to identify disease-specific patterns of neurodiagnostic studies (MRI and EEG) for autoimmune encephalitis in children.MethodsWe completed a retrospective chart review of encephalopathic patients seen at a large pediatric hospital over a four year interval. Clinical presentation, autoantibody status, and MRI and EEG findings were identified and compared. Individuals with autoantibodies were considered “definite” cases, whereas those without antibodies or those with only thyroperoxidase antibodies were characterized as “suspected.”ResultsEighteen patients met the inclusion criteria and autoantibodies were identified in nine of these. The patients with definite autoimmune encephalitis had MRI abnormalities within limbic structures, most notably the anteromedial temporal lobes (56%). Only individuals with suspected disease had nontemporal lobe cortical lesions. Sixteen patients had an EEG and 13 (81%) of these were abnormal. The most common findings were abnormal background rhythm (63%), generalized slowing (50%), focal slowing (43%), and focal epileptiform discharges (31%). Sleep spindle abnormalities occurred in 38% of patients. There were no specific differences in the EEG findings between the definite and suspected cases. Focal EEG findings only correlated with a focal lesion on MRI in a single definite case.ConclusionsPediatric patients with definite autoimmune encephalitis have a narrow spectrum of MRI abnormalities. Conversely, EEG abnormalities are mostly nonspecific. All patients in our cohort had abnormalities on one or both of these neurodiagnostic studies.     

Indications for brain CT scan in patients with minor head injury

OBJECTIVES: Minor head injury is the most common type of head injury. Despite of high incidence and numerous studies performed, there is much controversy about correct evaluation of these patients. The aim of this study was to find clinical signs and symptoms which help to predict the indications for brain CT scan following minor head injury. METHODS: A series of 682 consecutive patients who had been attended at two university hospitals (Alzahra and Kashani) with minor head injury (GCS=15) were prospectively enrolled in this cohort study. In all cases clinical signs and symptoms were collected and a cranial computerized tomography (CT) scan was obtained. The relationship between the occurrence of clinical findings and appearance of intracranial posttraumatic lesions on cranial CT was analyzed by chi-square tests and statistic logistic regression methods, with 95% confidence intervals. RESULTS: Of 682 patients, 46 (6.7%) presented brain injuries on CT scan. All patients with abnormal CT scans had at least one of the following factors (risk factors): posttraumatic amnesia, loss of consciousness, posttraumatic seizure, headache, vomiting, focal neurological deficit, skull fracture, coagulopathy or antecedent of treatment with anticoagulants and patient age older than 60 years. No abnormal CT scans were found among patients without any of those risk factors on admission. Vomiting, skull fracture and age greater than 60 years were risk factors significantly correlated to an abnormal cranial CT after head injury. The presence of several risk factors in a patient increased the probability of posttraumatic lesion on CT scan. CONCLUSION: Some clinical risk factors can be used as a guide to predict the probability of abnormal CT following minor head injury.     

Abnormalities of cerebral blood flow in the acute phase of bacterial meningitis in adults

Summary The frequency, course and clinical significance of changes in regional cerebral blood flow (rCBF) during bacterial meningitis were investigated in 14 adult patients. The results of^99mTc-hexamethylpropylene amine oxime (HMPAO) single photon emission computed tomography (SPECT) were compared with the clinical signs and findings using cerebral angiography and conventional CT. HMPAO SPECT was performed 2–15 days (median 4.5 days) after the onset of neurological disease. Decreased HMPAO accumulation was detected in 13 patients. SPECT studies revealed focal hypoperfusion cor responding to the clinical symptoms in 6 patients suffering from hemiparesis or hemiataxia. Conventional cranial CT disclosed brain infarction in only 1 patient. Focal hypoperfusion was also found in 7 of 8 patients without clinical evidence of focal neurological deficits. In 6 patients, HMPAO SPECT findings were abnormal although cerebral angiography was normal. At follow-up examinations 3–45 weeks after the acute disease, abnormalities revealed by HMPAO SPECT had improved or had even disappeared in all patients studied. Our results indicate that reduced rCBF is a frequent finding in bacterial meningitis in the adult. In most patients it probably represents a functional and reversible disorder without structural lesion detectable on CT.     

Intermittent photic stimulation. Clinical usefulness of non-convulsive responses.

The clinical usefulness of non-convulsive responses induced by intermittent photic stimulation (IPS) was studied in 46 patients whose evaluation included both electroencephalography (EEG) and computerized cranial tomography (CT scan). Three patterns of photic responses were identified and related to background EEG activity and type of lesion seen on CT scan. An asymmetry in photic driving manifested only by a consistent amplitude difference greater than 50% was rarely associated with other EEG changes such as focal slowing or significant asymmetry in the alpha rhythm. In contrast, an asymmetry in development of the photic response correlated well with ipsilateral focal slowing and CT scan evidence of parenchymatous brain disease. Bilateral, symmetrical high amplitude single spikes evoked by individual light flashes were seen only in patients with diffuse encephalopathies. In no patient with structural brain disease as judged by CT scan was an abnormality in IPS the only EEG finding. There was also no apparent relationship between the anatomical site of a focal cerebral lesion and the type of response induced by IPS. Photic stimulation is of limited value in non-epileptic patients. Little clinical significance can be attached to nonconculsive responses in the absence of associated EEG changes which by themselves are generally more informative.     

Intracranial mass lesions associated with late-onset psychosis and depression

Tumors and other mass lesions of the brain may present with symptoms resembling psychosis or depression or with features of delusions, hallucinations, mania, or catatonia. There is an over-representation of tumors affecting the frontal lobe, temporal lobe, and diencephalon in patients with these manifestations. Neurologic symptoms and signs may be helpful in making an early diagnosis of the tumor. Patients with late-onset psychosis, unusual histories of depression, and those with focal neurologic findings associated with psychotic disorders should undergo computerized tomographic (CT) scanning to exclude a focal brain lesion.     

Concomitant administration of sodium dichloroacetate and thiamine in west syndrome caused by thiamine-responsive pyruvate dehydrogenase complex deficiency

IRDA (intermittent rhythmic delta activity) is an abnormal generalized EEG pattern that is not specific to any single etiology and can occur with diffuse or focal cerebral disturbances. To determine whether different electrographic features of IRDA and associated EEG findings can differentiate underlying focal from diffuse brain disturbances, we performed a blind analysis of 58 consecutive EEGs with an IRDA pattern, recorded from 1993 until 1996, in which we evaluated posterior background activity, focal slowing and IRDA characteristics (frequency, distribution, duration, symmetry and abundance). The clinical diagnosis, state of consciousness and CT brain findings were retrieved from the patients' hospital records. There were 58 patients (33 females; mean age, 58+/-21 years). Twelve (21%) had only focal brain lesions, while 46 (79%) had diffuse brain abnormalities, (15 diffuse structural, 19 metabolic abnormalities, 12 postictal). Normal consciousness and focal EEG slowing were more frequent in patients with focal abnormalities, however, this was not statistically significant. Of the patients with focal abnormality, 11 (92%) had normal posterior background activity either bilaterally (n=4) or contralateral to the focal lesion (n=7). Bilaterally normal posterior background activity was observed in about 30% in both groups. Bilaterally abnormal posterior background activity was apparent in one patient (8%) with focal brain lesion and in 31 patients (67%) with diffuse brain abnormalities (P<0.0001). There were no significant differences in IRDA electrographic features between the focal group and the group with diffuse brain disturbances. We conclude that IRDA morphology cannot distinguish between focal and diffuse brain abnormalities.     

Eastern equine encephalitis in Massachusetts: a report of 16 cases, 1970-1984

We studied the case records of 16 patients with eastern equine encephalitis (EEE) in Massachusetts from 1970 to 1984 and compared their presentations, courses, and outcomes with the data available from previous epidemics. In recent years, there has been a greater frequency of EEE in adults, whereas in the past it was considered a disease of children. Also, prognosis for a good functional recovery seems to be correlated with age over 40 years, a long prodromal course (5 to 7 days) of constitutional symptoms, and the absence of coma. Previous reports did not mention these significant correlations. We also stress the positive and negative diagnostic correlations, in order to distinguish between EEE and herpes simplex encephalitis.     

AIDS-related focal brain lesions in the era of highly active antiretroviral therapy

OBJECTIVE: To compare the years since the introduction of highly active antiretroviral therapy (HAART) with the pre-HAART era for trends in the proportions of HIV-related focal brain lesion-causing disorders. METHODS: A prospective, single-center study of all consecutive HIV-infected patients with a neurologic presentation and focal brain lesions observed between January 1991 and December 1998 was undertaken. RESULTS: The major diagnoses in the 281 patients were toxoplasmic encephalitis (36.4%), primary CNS lymphoma (26.7%), progressive multifocal leukoencephalopathy (18.2%), and focal HIV encephalopathy (5.0%). During the HAART period, patients were less likely to be male, contracted HIV more often through heterosexual exposure, had fewer previous AIDS-defining events, received antiToxoplasma prophylaxis less frequently, had a CD4+ lymphocyte count 2.5 times higher, and had diagnosis based more often on PCR assays from CSF, reducing the need for brain biopsy and enhancing the likelihood of in vivo diagnosis. Using all patients hospitalized per year as reference population, the risk of focal brain lesions strongly increased during the pre-HAART period and declined significantly during the HAART years. In the HAART period a relevant decline of primary CNS lymphoma was found (OR for 1998, 0.25; p for trend = 0.03) and the effect of progressive calendar year was confirmed on multivariable analysis (OR, 0.52; 95% CI, 0.28 to 0.97). The frequency of toxoplasmic encephalitis decreased during the pre-HAART era and was stable afterwards. For progressive multifocal leukoencephalopathy, a slight increase was seen over time. Focal white matter lesions without enhancement or mass effect increased between 1991 and 1998. CONCLUSIONS: During the HAART era, AIDS-related primary CNS lymphoma showed a strong decline, toxoplasmic encephalitis remained stable, and progressive multifocal leukoencephalopathy showed a slight increase. Focal white matter lesions without mass effect or contrast enhancement became the most frequently seen focal brain lesion. For differential diagnosis, PCR-based assays from CSF led to a shift from brain biopsy toward a minimally invasive approach with an augmented likelihood of in vivo diagnosis.     

Viral encephalitis. Experiences with 53 patients in Middle Hessia

Clinical symptoms, course of disease, cerebrospinal fluid (CSF) and cranial CT of 53 patients suffering from acute or subacute encephalitis were evaluated retrospectively. The virus could be identified in 21 (39%) patients. Nine of them had herpes simplex virus-encephalitis. 16 patients, eight with herpes simplex virus-encephalitis, died due to the disease. Complete restitution could be observed in 73% of survivors. Disturbance of consciousness and severe focal neurological deficit worsened prognosis towards letality and functional recovery. Most patients had initially elevated number of cellular elements and/or pathological protein concentration in CSF. CSF protein profile showed disturbance of blood-CSF-barrier function in a great number of patients during the first week of the disease whereas autochthonous production of immunoglobulin G was observed predominantly during the second and third week. Elevated concentration of CSF-lactate was seen in herpes simplex virus-encephalitis and in letal cases. 28 (53%) patients had pathological CT-findings. Generalized brain edema, focal hypodensities, focal and cortical contrast enhancement and hemorrhagic imbibation were observed. With one exception patients with herpes simplex virus-encephalitis had hypodense lesions in the temporal lobe. Besides this CT-findings did not allow conclusions regarding the etiology of encephalitis. Prognosis of encephalitis caused by other than herpes simplex virus was worse in case of pathological CT.     

Hemorrhagic encephalitis associated with Epstein-Barr virus infection

Epstein-Barr virus (EBV) encephalitis is a rare neurological complication, usually only reported in pediatric patients. We present a 20-year-old, previously healthy male who developed hemorrhagic encephalitis caused by EBV. He was admitted to our hospital with a 1-week history of fever, diarrhea, headache, and confusion. Brain T2-weighted MRI showed a focal area of increased signal in the right temporal lobe. Brain MRI and CT scans on day 2 revealed progression of the lesion, with partial hemorrhagic change, acute brain swelling, and severe midline shift. The patient underwent external decompression and external ventricular drainage. EBV DNA was identified in brain biopsy specimens by polymerase chain reaction. The postoperative course was uneventful. To our knowledge, this is the second report of hemorrhagic EBV encephalitis in an adult.     

Chagasic Granulomatous Encephalitis in Immunosuppressed Patients; Computed Tomography and Magnetic Resonance Imaging Findings

American trypanosomiasis (Chagas' disease), a zoonosis caused by Trypanosoma cruzi with a high incidence in Latin America, may induce an uncommon form of localized encephalitis termed “chagoma,” found in few immunocompromised patients. The computed tomography (CT) and magnetic resonance imaging (MRI) findings of brain chagoma are reported for 3 males (ages 32, 32, and 9 yr), the first 2 infected with human immunodeficiency virus (HIV) and the third with acute lymphoblastic leukemia. Diagnosis was confirmed by biopsy. CT disclosed a single, supratentorial, nodular-shaped lesion that substantially enhanced with contrast material, localized in parietal or frontal lobes. T1-weighted MRI showed hypointense lesions that enhanced with gadolinium-diethylenetriaminepentaacetic acid, corresponding to extensive hyperintense areas on T2-weighted images, producing mass effect. The imaging pattern of brain chagoma presented here is similar to that of cerebral toxoplasmosis and should be considered in the differential diagnosis of an intracerebral mass lesion in immunocompromised patients.     

Comparison of CT scan and MRI findings in the diagnosis of Japanese encephalitis

Japanese encephalitis (JE) is the commonest endemic encephalitis but there are very few studies on the radiological changes and these are based on relatively small number of patients. The present study aims at comparing the CT scan and MRI findings in JE and correlate these with the reported histopathological findings. Forty two patients with JE were subjected to detailed neurological examination. Cranial CT scan was carried out in 38 and MRI scan in 31 patients. Haemagglutination inhibition test was carried out in the acute and convalescent sera. The CT scan and MRI findings have been compared. Both CT scan and MRI were available in 28 patients. In 21 patients, CT scans were abnormal and changes included thalamic hypodensity in 15, midbrain and basal ganglia hypodensity in 1 patient each, cerebral oedema in 4 and cortical atrophy with ventricular dilatation in 2 patients. MRI however was abnormal in all 31 patients including 17 with normal CT scan. Cranial MRI revealed either mixed intensity or hypointense lesion on T(1) and hyperintense or mixed intensity lesion on T(2) in thalami in all except two patients. The MRI lesions were also noted in basal ganglia in 11, midbrain in 18, pons in 8, cerebellum and cerebral cortex in 6 patients each and subcortical white matter in 2 patients. MRI was more sensitive than CT scan in revealing thalamic and extrathalamic abnormalities. Thalamic changes may be helpful in the diagnosis of JE especially in endemic area.     

An epileptic syndrome in patients with the sequelae of gunshot craniocerebral wounds

To study the specific features of the epileptic syndrome after present-day gunshot cranial wounds (GCW), as well as risk factors of its occurrence, 56 victims were examined prospectively (within at least a year after their admission). The epileptic syndrome developed in 18 (32.1%) patients within 1 to 15 months following GCW; there were prevalent generalized convulsive (in 13 of the 18 patients) and focal (in 12 of the 18 ones) seizures. One type of seizures was noted in 7 patients, two or three ones were in 11. The polymorphism of seizures and a disparity of their psychopathological structure to the side of brain lesion were typical for left-handers. As compared to other patients, epileptics were more commonly found to have: 1) frontoparietal lesion; 2) multiple bony defects of the vault of the skull; 3) enlargement of the lateral ventricle of the brain on CT scans; 4) primary coma for > 2 hours and other depressed consciousness syndromes for > 1 day; 5) signs of left-handedness. The findings suggest that there is a need for studies of the functional asymmetry of the brain to gain a better insight into the problem.     

Novel FDG-PET findings in anti-NMDA receptor encephalitis: a case based report

The clinical manifestation and nuclear imaging findings in a 15-year-old boy with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis are described in this case report. The previously healthy patient presented with new onset hallucinations, seizure, and within a week, his mental status rapidly deteriorated to nonverbal with oro-lingual-facial dyskinesias. An extensive laboratory work-up for encephalopathy was negative. Repeated brain magnetic resonance imaging (MRI) studies were normal. On day 26 of admission, nuclear imaging using fluorodeoxyglucose positron emission tomography (FDG-PET) showed global hypometobolism with a prominent focally intense hypermetabolic lesion in the right cerebellar cortex. Diagnosis of anti-NMDAR encephalitis was confirmed with quantitative serology. The patient showed clinical signs of improvement after 2 courses of intravenous immunoglobulin therapy over 4 weeks. On day 46, repeat brain FDG-PET showed overall improvement but in contrast to the previous, the right cerebellar cortex showed focal hypometabolism. This is the first reported case of such findings using FDG-PET in anti-NMDAR encephalitis.     

脑血吸虫病的影像学特点及诊断治疗

目的分析脑血吸虫病的影像学特点，提出诊断要点和治疗方法选择。方法回顾性分析大坪医院1998年11月至2007年7月诊治21例脑血吸虫病的临床资料，全部行了CT和MRI检查，免疫学检查确诊20例，病理确诊1例。结果病灶位于皮层或皮层下，周围指套样水肿及占位效应，MPd增强表现为：脑皮质或皮层下线状强化影，多发或单发大小不等强化结节，呈簇状聚集围绕成团，部分邻近脑膜呈炎性改变。全部经吡喹酮及糖皮质激素治疗治愈，包括手术切除1例。结论头颅CT和MPd检查见成簇状堆积的结节状强化伴脑膜炎性改变，提示颅内寄生虫感染，需行免疫学确诊，大多可经吡喹酮化疗和糖皮质激素治愈。     

Seizure-induced transient brain edema in the medial temporal lobe]

We reported a patient with sudden onset seizure resulting in prolonged amnesia. MRI revealed a T2 high signal lesion with swelling in the right medial temporal lobe. Because the MRI lesion remained to be the same in size for two months, biopsy specimens were obtained under informed consent to rule out the brain tumor. Based on histological findings showing brain edema without specific abnormal findings (malignancy, inflammation etc), we concluded that the temporal lesion was the edema induced by the seizure attack. In Japan, many papers on non-herpetic acute limbic encephalitis (NHALE) have recently been published. In their reports, seizures were frequently observed as a preceding symptom; moreover, clinical courses and MRI findings are similar to those of seizure-induced brain edema. The secondary brain edema induced by the seizure must be considered in patients with NHALE and other CNS disorders, especially if the patient has a history of the recent seizure.