EEG in neonatal herpes simplex encephalitis

The EEGs of 21 newborns with herpes simplex encephalitis were analysed. The diagnosis was based on the demonstration of herpes simplex infection in association with neurological symptoms, other etiological factors being excluded. Sixteen of 21 babies (76%) showed in their EEGs electrical seizures, either focal or unilateral. These paroxysms consisted of sharp waves or slow waves repeating at pseudo-periodic intervals, usually of 0.5-2 sec. Individual paroxysms had a duration of 10-20 sec in 6 babies and 1-2 min in 10 patients. During the same period, 20 other babies displayed the same EEG finding. Of these, 11 had encephalitis of unknown etiology. In our series there appeared to exist a correlation between both the duration of the electrical seizures and the degree of EEG background abnormality and the clinical outcome. Babies with markedly abnormal background and long-lasting paroxysms tended to have a poor prognosis. It is concluded that in newborns with clinical signs of encephalitis who show in their EEGs paroxysms of the type described, the possibility of herpes simplex encephalitis should be considered.     

EEG and pathologic findings in patients undergoing brain biopsy for suspected encephalitis.

Previous studies have suggested that EEG may be helpful in the diagnosis of herpes encephalitis (HE). To further define the value of EEG in an acutely ill, febrile, encephalopathic patient suspected as having encephalitis, we reviewed initial preoperative EEGs with the results of cerebral biopsies in 24 consecutive patients suspected of having encephalitis. Statistical analysis demonstrated that EEG patterns have only limited association with biopsy results. Since diseases which mimic encephalitis may also generate identical EEG changes, this is not an unexpected finding. EEG is useful in the evaluation and management of patients with encephalitis. However, the absence of specific wave forms or focal EEG abnormalities in the proper clinical setting should not deter consideration of HE or delay treatment.     

Periodic EEG complexes in infectious mononucleosis encephalitis.

The presence of periodic EEG complexes in patients with an acute viral encephalitis is generally held to suggest that infection is due to herpes simplex. We now report a patient with clinical and laboratory findings of infectious mononucleosis, and neurologic involvement manifested by lymphocyte meningitis, coma, seizures, aphasia, hemiparesis and hemianopsia. Serial EEGs showed periodic, predominantly left-sided slow wave complexes occurring every 4 to 5 seconds, which disappeared with clinical resolution of the illness. In view of our findings and the similar findings reported previously by others in another case of infectious mononucleosis encephalitis, an EEG showing periodic complexes in the clinical setting of acute viral encephalitis should not be considered pathognomonic of herpes encephalitis, and infectious mononucleosis should be included in the differential diagnosis.     

Recurrent herpes zoster encephalitis: A case report

An 89-year-old lady presented with severe right-sided ophthalmic herpes zoster infection and secondary bacterial infection. Two weeks after admission she became very unwell with confusion and drowsiness and later developed bilateral upgoing plantar reflexes. An EEG was highly suggestive of herpes encephalitis and she made a good recovery with acyclovir. Neuropsychological tests showed pathological signs of impaired left temporal lobe function. After a further three weeks she again developed symptoms and signs of herpes zoster encephalitis and a repeat CT scan showed a right internal capsule infarct had developed. Encephalitis after herpes zoster infection is a rare complication but possibly underreported due to difficulties in diagnosis.     

EEG findings in tick-borne encephalitis.

EEG findings of epidemiologically and serologically confirmed tick-borne encephalitis patients were compared with findings of patients having acute encephalitis of viral or undetermined origins. Tick-borne encephalitis patients had more bilaterally synchronous bursts of slow waves and more focal abnormalities than did controls. Moreover, their EEGs remained mildly pathological, with increased slow and beta activity and intermittent focal abnormalities in some patients, whereas, EEGs in the controls became normal or borderline, usually within two months. EEG can thus reveal differences between individuals' responses to encephalitis and between different types of encephalitis, even though the clinical pictures are rather similar. Finally, the study shows that tick-borne encephalitis causes changes in the EEG that persist long after the clinical disease appears to have resolved.     

A case of herpes zoster encephalitis with Ramsay-Hunt syndrome, herpes zoster generalisatus and acute pancreatitis]

We describe here a 71-year-old man who had herpes zoster encephalitis. He developed high fever, headache and disturbance of consciousness on 1st, May, 1998. On admission, neurological examination revealed disturbance of consciousness with restlessness and meningeal signs. Brain MRI (T 1 and T 2 weighted images) demonstrated high signal lesions in the left temporal lobe and cerebellar vermis. VSV encephalitis was diagnosed based on CSF pleocytosis, high serum and CSF titers of VZV antibody and EEG abnormality. During hospitalization, Ramsay-Hunt syndrome, herpes zoster generalisatus and acute pancreatitis developed. To our knowledge, the characteristic combination of the clinical signs in this case is very rare. We discussed the pathogenic mechanisms of these conditions, and this case was considered to have VZV encephalitis, and to be associated with right facial nerve palsy and pancreatitis, in spite of the absence of immunological deficiency.     

Encephalitis associated with herpes zoster: a case report and review.

This paper describes the case of a patient with a history of affective disorder who developed encephalitis associated with herpes zoster which presented as a delirium with prominent manic symptoms. Published reports of encephalitis following herpes zoster infections are reviewed. The diagnosis of herpes zoster-associated encephalitis should be suspected in individuals with changes in his or her mental state, an abnormal electroencephalogram and an abnormal cerebrospinal fluid examination which closely follow a cutaneous herpes zoster lesion.     

Characteristic early electroencephalographic changes in herpes simplex encephalitis.

We review electroencephalograms taken from 17 patients with severe meningoencephalitis within seven days of onset of CNS symptoms and prior to cortical brain biopsies. All patients had CNS disease clinically compatible with the diagnosis of herpes simplex encephalitis (HSE). The diagnosis was demonstrated by the isolation of virus from the brain in five patients (group 1) but considered highly unlikely in the other 12 patients (group 2) by negative immunofluorescent studies and failure of viral isolation from the brain tissue. Abnormal but nonspecific EEGs with diffuse or focal slowing were found in all patients. Distinctive high-voltage, 1-cycle-per-2-to-3 seconds periodic sharp waves from unilateral temporal lobes were seen only in three of the five patients with virologically proved HSE but in none of the 12 patients without viral isolation. This EEG pattern is strikingly similar in all three patients, regardless of their age, and may be specific for the early diagnosis of HSE prior to brain biopsy. The EEGs of the other two patients with proved HSE did not contain such abnormalities. Athough periodic EEGs with some resemblance to those previously described may occur in other CNS disorders, their presence strongly suggests the diagnosis of HSE when recorded from patients with viral meningoencephalitis. Moreover, EEGs may help locate the best site for cerebral biopsy since maximal yield of the virus in this study was from unilateral temperoal lobes corresponding with the site of local EEG changes.     

Fine specificities of antibodies in sera and cerebrospinal fluid in herpes virus infections of the central nervous system as detected by the antigen variable immunoblot technique

Applying the immunoblot technique a sensitive and specific method was developed for the detection of intrathecally synthesized antibodies against individual specific proteins that are antigens of various infectious agents causing encephalitis. Paired serum and cerebrospinal fluid (CSF) samples from five patients with herpes virus infections of the central nervous system (CNS) (three herpes simplex virus encephalitis, one varicella zoster virus encephalitis, one zoster ganglionitis) were investigated for the presence of locally produced IgG against the electrophoretically separated antigens of herpes simplex virus (HSV), varicella zoster virus (VZV) and human cytomegalovirus (HCMV), as well as for IgM antibodies in one case of HSV encephalitis. In two cases (HSV encephalitis and VZV encephalitis) four and one antibody, respectively, were found that were synthesized intrathecally only. In the other cases the patterns of sera and CSF antibodies were similar, the CSF antibodies showing an all-over stronger reaction, at identical IgG concentrations. In contrast to the conception of a 'limited heterogeneity' of intrathecal antibody synthesis in encephalitis, we thus found an 'expanded heterogeneity' of the intrathecally synthesized antibodies in comparison to the corresponding serum antibodies.     

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。     

Clinical characteristics and prognostic factors of postencephalitic epilepsy in children

The goal of this study was to clarify the clinical characteristics and prognostic factors of childhood postencephalitic epilepsy. Forty-four patients (20 boys and 24 girls; age range 21 months to 17 years, mean age 8.1 +/- 4.6 years) with postencephalitic epilepsy were selected from the 798 epileptic children treated and followed up at our hospital between 1993 and 2003. The clinical data included clinical features, electroencephalograms (EEGs), and neuroimages, all reviewed and analyzed retrospectively. Based on their post-treatment seizure outcomes, the children were divided into favorable (n = 20) and poor outcome groups (n = 24). Between the two groups, the age at encephalitis, cerebrospinal fluid findings, and seizure type were comparable. Factors indicating a poor prognosis for these patients during the acute phase of encephalitis were (1) status epilepticus occurring as the first seizure (P < .005), (2) slow background activity (P < .001) and multifocal spike discharges on EEGs (P < .01), and (3) herpes simplex viral encephalitis (P < .01). Our findings indicated that patients with status epilepticus and multifocal spikes on EEG during acute encephalitis have an increased risk of developing intractable epilepsy. To improve the outcome of postencephalitic epilepsy, intervention must occur earlier in the encephalitis stage.     

A case of acute measles encephalitis with periodic synchronous discharge on electroencephalography]

A 18-year-old man was diagnosed as having measles on the basis of cutaneous and mucosal eruption and high grade fever on May 10, 2001. Six days after the skin eruption, the patient developed general convulsion (day1). He was admitted to our hospital because of status epilepticus. We made a diagnosis of acute measles encephalitis, based on the clinical features and pleocytosis with an increase in protein in the cerebrospinal fluid. Under artificial ventilation and sedation, he received intravenous immunoglobulin and dexamethasone. Electroencephalography (EEG) on day 4 revealed periodic synchronous discharge (PSD). Significant elevation of antibody titer for measles virus was found in the serum, but not in the cerebrospinal fluid. Polymerase chain reaction method did not show viral genes of measles virus, herpes simplex virus and herpes zoster virus. Serial EEG studies demonstrated a decrease in PSD, followed by irregular spike-wave complexes within 20 days. He recovered completely one month after the onset. It should be kept in mind that PSD can emerge on EEG in the early stage of acute measles encephalitis.     

Neonatal herpes simplex meningoencephalitis: EEG investigations and clinical correlates

We studied the sequential EEGs of 15 neonatal herpes simplex virus meningoencephalitis (NHSV-ME) patients and correlated them with corresponding clinical and laboratory findings. During days 1 to 4 of the illness, 8 had EEGs. All but 1 had abnormal tracings and 3 (38%) showed the multifocal periodic pattern (MPP). Three had an early abnormal EEG at a time when their cranial CT/ultrasound studies were normal. During days 5 to 11, 13 had EEGs: all were abnormal and 3 showed the MPP. After day 11, EEGs (available on 10) showed a very low voltage background in 9, and only 1 had normal EEG and development. During 1 year in which 1 patient with NHSV-ME was observed, we noted that 9/324 (2.8%) of neonates with other CNS conditions manifested the MPP. All, however, had CSF findings that distinguished them from herpes cases. We conclude that: (1) In patients with suspected NHSV-ME, EEG is a sensitive test that is superior to radiologic procedures in detecting early cerebral involvement. Most of the early EEGs show nonspecific background and paroxysmal abnormalities. (2) In the presence of inflammatory CSF, the MPP, an otherwise nonspecific finding, is highly suggestive of NHSV-ME. (3) Sequential EEGs may be important in the follow-up of neonates with NHSV-ME.     

Unusual manifestations of herpes zoster. A clinical and electrophysiological study.

The literature on complicated herpes zoster is summarized in this paper. The case histories of 18 patients with herpes zoster are presented. Two patients had encephalitis, 2 had myelitis and the other 14 patients had various types of lower motor neurone disturbance. Both patients with encephalitis--one of who developed choreo-athetosis during the illness--recovered fully. Only 1 of the 2 patients with myelitis recovered fully; the other remains severely paraparetic and the reason for her incomplete recovery may be related to the presence of generalized arteriolar disease associated with seronegative rheumatoid disease. One patient developed a Guillain-Barre syndrome 3 weeks after the onset of herpes zoster. Recovery in the 15 patients with lower motor neurone involvement has been slow butcomplete--or almost complete--in all but 1, a patient with persistent facial weakness as part of the Ramsay Hunt syndrome and who also had weakness of one upper limb. Seven other patients had lower limb weakness. In 2 patients the weakness was confined to abdominal myotomes and 2 other patients had urinary retention. Electromyographic abnormalities were found in the muscles which were weak and frequently also in muscles which appeared strong. It is emphasized that neurological disturbances other than sensory abnormalities may be found in patients with herpes zoster. Motor complications of various types are not uncommon.     

Intrathecal production of specific IgA antibodies in CNS infections

Cerebrospinal fluid (CSF) and serum from subjects with herpes simplex encephalitis, herpes zoster, mumps meningitis and neuroborreliosis were analysed for the presence of immunoglobulin A (IgA) and G (IgG) antibodies to the corresponding four antigens. Specific intrathecal IgA antibody synthesis as manifested by an elevated index was a frequent finding. Higher IgA index values than the corresponding IgG was seen in one third of the samples from subjects with herpes simplex encephalitis and herpes zoster. Correlation between specific IgG and IgA index was most pronounced for varicella-zoster virus (r =0.66,P < 0.001). In subjects with mumps meningitis a strong intrathecal IgA and IgG antibody response toBorrelia burgdorferi was demonstrated. Specific herpes simplex and varicella-zoster virus IgA was not found to contain secretory component, thus contradicting an active secretion into the CNS compartment. In conclusion, our data indicate that specific IgA is intrathecally produced in herpes simplex encephalitis, herpes zoster and mumps meningitis but is a rare finding in neuroborreliosis.     

病毒性脑炎患者Borna病病毒P24基因片段的检测

目的探讨Borna病病毒(BDV)感染与人类病毒性脑炎的关系。方法采用荧光定量套式逆转录酶聚合酶链反应(FQ nRT PCR)检测了59例临床诊断的原因未明的病毒性脑炎及112名健康人外周血单个核细胞(PBMC)中BDVP24基因片段。结果59例原因未明的病毒性脑炎患者中有3例PBMC中检出BDVP24基因片段,而112名健康对照均未检出。病毒性脑炎患者BDV阳性率(5.08%)高于健康对照,差异有统计学意义(P<0.05),且BDVP24基因片段检测阳性病例的脑脊液中其他常见致脑炎病毒(单纯疱疹病毒、带状疱疹病毒、腮腺炎病毒、柯萨奇病毒和巨细胞病毒)检查均为阴性。结论中国的部分病毒性脑炎患者中存在BDV感染,BDV感染与病毒性脑炎的发病可能有关。     

Segmental myoclonus preceding herpes zoster radiculitis.

Segmental myoclonus arising in the spinal cord occurs with several viral infections, including herpes zoster radiculitis. Usually, abnormal movements follow the rash and require drug treatment to suppress. We report a patient with AIDS in whom arm and shoulder myoclonus preceded herpes zoster involving the same segments contralaterally on two occasions. Myoclonus remitted promptly with antiviral treatment. Unlike in other immunosuppressed patients, encephalitis did not occur after the second episode.     

Value of sphenoidal electrodes in the EEG diagnosis of herpes encephalitis

EEG features in acute necrotizing encephalitis show periodic activity, localized in the temporal area with a slow background activity. Nevertheless, this periodic activity is transient and may lack. Sphenoidal electrodes study of the internal face of the temporal lobe could record such activity in herpes encephalitis. Sphenoidal electrodes were inserted in 4 patients known to have herpes encephalitis. In 2 cases, periodic discharges were observed both on the surface and sphenoidal electrodes, while in 2 cases, periodic discharge was observed under only sphenoidal electrodes. Faced with uncertain diagnosis of herpes encephalitis, it may be useful to insert sphenoidal electrodes to record deep periodic discharges, not seen on surface electrodes, in order to confirm the diagnosis.     

Computerized transverse axial tomography (CTAT) in the diagnosis of epilepsy.

99 patients with late epilepsy were investigated in our EEG laboratory. In intervals of maximal 100 days (averaged 23 days) a waking EEG recording and a CTAT were carried out. The average age was 43. 62.5% of the pathological CTATs were found in partial seizures with elementary symptomatology. In patients with generalized seizures the diagnosis of symptomatic epilepsy could be made in 20 cases (34%) with the help of computerized tomography. Generalized seizures were related to tumors only in 8.5% in our case material. In 20 of 99 EEGs in our patients there was a continuous delta wave focus, 12 of these with epileptogenic activity. Of these 20 patients, 18 showed a pathological result in computerized tomography. Eight tumors or metastases, 8 cases of atrophy (7 local and 1 diffuse) as well as 1 case of encephalitis could be diagnosed. 12 EEGs showed continuous or intermittent theta wave foci. Computerized tomography never gave a pathological finding in these patients. If one compares the results of CTAT and EEG in cases of tumor, the agreement between positive tomography and the pathological EEG is very high (97%): 33 positive CTATs comapred with 31 positive EEGs. Our investigations with computerized tomography show organic findings in 34 of 99 epilepsies, that is about 34%.     

脑电图对小儿病毒性脑炎诊断和转归的评价

目的探讨病毒性脑炎儿童脑电图异常与病情及预后关系。方法对96例病毒性脑炎的脑电图结果进行回顾性分析。结果脑电图异常率为94.8%。轻型、普通型多表现为弥漫性中波幅或高波幅慢波改变,预后好。重症组以局限性、低波幅慢波多见,预后差。脑电图出现癫样放电者,应警惕继发癫的可能。结论脑电图对小儿病毒性脑炎诊断和转归评估中有较高的价值。