Correlation between clinical stages and EEG findings of subacute sclerosing panencephalitis

Expanding the Spectrum of EEG Periodic Discharges in Subacute Sclerosing Panencephalitis: A Case Report

Background Atypical electroencephalogram (EEG) abnormalities emerge in patients with subacute sclerosing panencephalitis (SSPE), especially in cases with an atypical clinical presentation that can lead to diagnostic difficulties.

Case Report In this article, we presented a case of SSPE with an atypical onset with epileptic seizures and Parkinson's features. The neurological examination during the initial evaluation of the patient showed extrapyramidal syndrome, hyperreflexia, intention tremor, and dysmetria. Cranial magnetic resonance imaging was normal. Video EEGs were performed in wakefulness and sleep. In wakefulness, multiple brief seizures (1–1.5 seconds were recorded, consisting of gradual bending of the body forward and to the right that lacked the sudden characteristic of myoclonia. During those episodes, we recorded generalized epileptiform activity of 4 or 5 sharp waves, with higher amplitude in the anterior regions, in some of the paroxysms superimposed on a slow wave or followed by a high amplitude slow wave. The paroxysms appeared periodically every 15 to 30 seconds. However, 2 months later, the EEG showed typical periodic generalized activity of biphasic/triphasic slow waves (Radermecker complexes), accompanied by myoclonias.

Conclusion We reported a peculiar EEG pattern in a patient with SSPE that consists of periodic generalized activity of sharp waves. Atypical EEG patterns can appear when the disease progresses, but initially too, before typical periodic complexes and can complicate the diagnostic process.

Immune alterations in subacute sclerosing panencephalitis reflect an incompetent response to eliminate the measles virus

In subacute sclerosing panencephalitis (SSPE) the persistence of measles virus (MeV) may be related to the altered immune response. In this study, cytokine responses of lymphocytes and monocytes were evaluated in SSPE compared to controls with non-inflammatory (NICON) and inflammatory (ICON) diseases. Patients with SSPE (n = 120), 78 patients with ICON and 63 patients with NICON were included in this study. Phenotypes of peripheral blood mononuclear cells (PBMC) have been analyzed by flow cytometry. CD3 and CD28, and S. aureus Cowan strain I (SAC) stimulated and unstimulated cells were cultured and IL-2, IL-10, IFN-γ, IL-12p40, IL-12p70 and IL-23 were detected in supernatants by ELISA. MeV peptides were used for MeV-specific stimulation and IFN-γ secretion of PBMC was measured by ELISPOT. Spontaneous and stimulated secretions of IL-10 were lower in SSPE compared to both control groups. T cell stimulation induced lower IFN-γ production than ICON group, but higher IL-2 than NICON group in SSPE. Stimulated PBMC produced lower IL-12p70 in SSPE and had decreased CD46 on the cell surface, suggesting the interaction with the virus. IFN-γ responses against MeV peptides were not prominent and similar to NICON patients. The immune response did not reveal an inflammatory activity to eliminate the virus in SSPE patients. Even IL-10 production was diminished implicating that the response is self-limited in controlling the disease.

Clinical Electroencephalography Findings and Considerations in Hospitalized Patients With Coronavirus SARS-CoV-2

Background and Purpose

Reports have suggested that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes neurologic manifestations including encephalopathy and seizures. However, there has been relatively limited electrophysiology data to contextualize these specific concerns and to understand their associated clinical factors. Our objective was to identify EEG abnormalities present in patients with SARS-CoV-2, and to determine whether they reflect new or preexisting brain pathology.

Methods

We studied a consecutive series of hospitalized patients with SARS-CoV-2 who received an EEG, obtained using tailored safety protocols. Data from EEG reports and clinical records were analyzed to identify EEG abnormalities and possible clinical associations, including neurologic symptoms, new or preexisting brain pathology, and sedation practices.

Results

We identified 37 patients with SARS-CoV-2 who underwent EEG, of whom 14 had epileptiform findings (38%). Patients with epileptiform findings were more likely to have preexisting brain pathology (6/14, 43%) than patients without epileptiform findings (2/23, 9%; p = 0.042). There were no clear differences in rates of acute brain pathology. One case of nonconvulsive status epilepticus was captured, but was not clearly a direct consequence of SARS-CoV-2. Abnormalities of background rhythms were common, as may be seen in systemic illness, and in part associated with recent sedation (p = 0.022).

Conclusions

Epileptiform abnormalities were common in patients with SARS-CoV-2 referred for EEG, but particularly in the context of preexisting brain pathology and sedation. These findings suggest that neurologic manifestations during SARS-CoV-2 infection may not solely relate to the infection itself, but rather may also reflect patients' broader, preexisting neurologic vulnerabilities.

Clinical Electroencephalography Findings and Considerations in Hospitalized Patients with Coronavirus SARS-CoV-2

Background and Purpose Reports have suggested that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes neurologic manifestations including encephalopathy and seizures. However, there has been relatively limited electrophysiology data to contextualize these specific concerns and to understand their associated clinical factors. Our objective was to identify EEG abnormalities present in patients with SARS-CoV-2, and to determine whether they reflect new or preexisting brain pathology. Methods We studied a consecutive series of hospitalized patients with SARS-CoV-2 who received an EEG, obtained using tailored safety protocols. Data from EEG reports and clinical records were analyzed to identify EEG abnormalities and possible clinical associations, including neurologic symptoms, new or preexisting brain pathology, and sedation practices. Results We identified 37 patients with SARS-CoV-2 who underwent EEG, of whom 14 had epileptiform findings (38%). Patients with epileptiform findings were more likely to have preexisting brain pathology (6/14, 43%) than patients without epileptiform findings (2/23, 9%; p=0.042). There were no clear differences in rates of acute brain pathology. One case of nonconvulsive status epilepticus was captured, but was not clearly a direct consequence of SARS-CoV-2. Abnormalities of background rhythms were common, and patients recently sedated were more likely to lack a posterior dominant rhythm (p=0.022). Conclusions Epileptiform abnormalities were common in patients with SARS-CoV-2 referred for EEG, but particularly in the context of preexisting brain pathology and sedation. These findings suggest that neurologic manifestations during SARS-CoV-2 infection may not solely relate to the infection itself, but rather may also reflect patients' broader, preexisting neurologic vulnerabilities.

Subacute sclerosing panencephalitis: clinical phenotype, epidemiology, and preventive interventions

Subacute sclerosing panencephalitis (SSPE) is a preventable condition reported in 6.5 to 11 per 100 000 cases of measles, and highest in children who contracted measles infection when they were less than 5 years of age. Children residing in areas with poor vaccination coverage and high prevalence of human immunodeficiency virus are at increased risk of developing SSPE. SSPE is life-threatening in most affected children. This report documents current data relating to the clinical phenotype, epidemiology, and understanding of SSPE, inclusive of preventive interventions. While improvements in disease progression with immunomodulation may occur, overall there is no cure. Most therapies focus on supportive needs. Seizures and abnormal movements may respond to carbamazepine. Many countries advocate policies to enhance vaccination coverage. Effective preventive health care programmes, assurance of parental perceptions, and crisis support for unprecedented events obstructing effective primary health care are needed. Until measles is eradicated worldwide, children in all regions remain at risk. WHAT THIS PAPER ADDS: Measles contracted under 5 years of age has highest risk of developing subacute sclerosing panencephalitis (SSPE). Children with, or exposed to, human immunodeficiency virus infection, who contract measles may be at increased risk of SSPE.

Subacute Sclerosing Panencephalitis Presenting with Unilateral Periodic Myoclonic Jerks

Background:

Subacute sclerosing panencephalitis (SSPE) is a rare complication of measles virus infection. The disease is characterized by behavioural abnormalities, intellectual deterioration, motor weakness, and generalized myoclonic jerks progressing to coma and death in one to two years in 80% of the cases. The myoclonic jerks are associated with characteristic generalized slow periodic complexes on electroencephalography (EEG). The symptoms and signs of SSPE are frequently quite variable. The clinical course is equally variable and difficult to predict. The characteristic periodic myoclonus can rarely occur unilaterally particularly in the early stages of the disease. As well, the periodic EEG complexes have been reported unilaterally in up to 3% of cases.

Case Report:

A 12-year-old boy, who was seen at a later stage with atypical manifestation of myoclonic body jerks confined entirely unilaterally, combined with contralateral periodic EEG complexes. One could assume clinically that the more diseased hemisphere was responsible for generating the jerks. However, brain magnetic resonance imaging revealed asymmetric hemispheric changes suggesting that the less neurologically damaged hemisphere is responsible for generating the unilateral myoclonic jerks. This has led to the interpretation that the more severely damaged hemisphere has lost the neuronal connectivity required to generate these periodic myoclonic jerks.

Conclusion:

Subacute sclerosing panencephalitis may have asymmetric hemispheric involvement, not only early, but also in the advanced stages of the disease, which can result in unilateral periodic myoclonic jerks.

A close look at EEG in subacute sclerosing panencephalitis

PURPOSE

To define atypical clinical and EEG features of patients with subacute sclerosing panencephalitis that may require an overview of differential diagnosis.

METHODS

A total of 66 EEGs belonging to 53 (17 females and 36 males) consecutive patients with serologically confirmed subacute sclerosing panencephalitis were included in this study. Patient files and EEG data were evaluated retrospectively. EEGs included in the study were sleep-waking EEGs and/or sleep-waking video-EEG records with at least 2 hours duration. Cranial MRIs of the patients taken 2 months before or after the EEG records were included.

RESULTS

Age range at the onset of the disease was 15 to 192 months (mean age: 80.02 months). Epilepsy was diagnosed in 21 (43%) patients. Among epileptic seizures excluding myoclonic jerks, generalized tonic-clonic type constituted the majority (58%). Tonic seizures were documented during the video-EEG recordings in four patients. Epileptogenic activities were found in 56 (83%) EEG recordings. They were localized mainly in frontal (58%), posterior temporal, parietal, occipital (26%), and centrotemporal (8%) regions. Multiple foci were detected in 26 recordings (39%). Epileptiform activities in the 39 (59%) EEGs appeared as unilateral or bilateral diffuse paroxysmal discharges.

CONCLUSIONS

Recognition of uncommon clinical and EEG findings of subacute sclerosing panencephalitis, especially in countries where subacute sclerosing panencephalitis has not been eliminated yet, could be helpful in prevention of misdiagnosis and delay in the management of improvable conditions.

Epilepsia partialis continua in children with fulminant subacute sclerosing panencephalitis

Various inflammatory diseases of central nervous system, including subacute sclerosing panencephalitis, could cause epilepsia partialis continua. Two boys with epilepsia partialis continua with onset in terminal phase of atypical subacute sclerosing panencephalitis have been reported. Children were not vaccinated against measles, and the second case had history of measles at an early age. In both cases, the onset of subacute sclerosing panencephalitis was characterized by altered behavior and cognitive decline with very fast mental and neurological deterioration. One boy was suffering from complex partial seizures and myoclonic jerks synchronous with periodic electroencephalographic pattern. Diagnosis was proved by increased titers of antimeasles antibodies in both serum and cerebrospinal fluid. In terminal phase of the disease, epilepsia partialis continua of localized group of the muscles was diagnosed, with good response to intravenous infusion of midazolam. Surface electroencephalographic recordings during epilepsia partialis continua did not show the epileptic discharges. During the terminal phase of the disease, no other type of seizures and movement disorders were recognized, except epilepsia partialis continua. In spite of the treatment, period from the onset of disease to death lasted less than 3 months, suggesting very fulminant course of subacute sclerosing panencephalitis.

Nonconvulsive status epilepticus on electroencephalography in a case with subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis is a neurodegenerative disease with a poor prognosis. We report a case of a 5 1/2-year-old boy who had emotional lability, cognitive difficulties, and myoclonia after a mild closed head injury. The magnetic resonance image of the brain and computed tomographic scan of the head were normal. His electroencephalogram (EEG) showed continuous nonconvulsive status epilepticus activity, which could not be suppressed with intravenous diazepam. After treatment with phenytoin for 2 days, an EEG showed periodic high-amplitude sharp-and-slow-wave complexes, which were also not suppressed with intravenous diazepam. Since the patient had measles at 5 months of age, subacute sclerosing panencephalitis was considered, and the diagnosis was confirmed by the presence of measles antibodies in cerebrospinal fluid.

Atypical EEG findings in subacute sclerosing panencephalitis

OBJECTIVE

To evaluate atypical electroencephalographic features in subacute sclerosing panencephalitis (SSPE) and to detect its relation to clinical features.

METHODS

Twenty-two patients aged 2-17 years (mean 9.4 years) with definite diagnosis of SSPE were studied. Their clinical data and EEG records were reviewed retrospectively. All EEG records were analysed for features of periodic complexes (PCs) in relation to age, age at onset, clinical stage and the rate of progression as well as duration of the disease.

RESULTS

Classical periodic complexes of SSPE were found in EEGs of 13 patients (group I). Atypical patterns were observed in EEGs of nine patients (group II). Two new atypical findings were identified: prolonged discharges which include sharp waves and slow waves for 4-7 s followed by suppression for 1-4s; and periodic complexes which consist of four or five sharp waves in every 2 s. We observed atypical EEG patterns were more frequently in Stage III, acute form, and the disease duration was longer than in the typical group.

CONCLUSIONS

Atypical EEG patterns in SSPE might be related to the progression of the disease, but this theory needs further longitudinal studies.

SIGNIFICANCE

We suggest atypical EEG patterns might be observed more frequently in patients with severe neurologic disability, more rapidly progressive disease and longer duration of disease.

Fulminant subacute sclerosing panencephalitis:two cases with atypical presentation

From 1972 to 2002, we diagnosed and treated 22 cases of subacute sclerosing panencephalitis. We report on two pediatric patients with fulminant subacute sclerosing panencephalitis who had atypical clinical manifestations. In both patients diagnosis was confirmed by elevated titers of CSF and serum antimeasles antibodies. Patient 1 presented with behavioral disorder, dysarthria, and drop attacks, while Patient 2 presented with partial complex seizures. Mental difficulties, personality changes, or myoclonus were not noticed in Patient 2. In both our patients stage I was not prominent, and stage II was of shortened duration. In spite of treatment with isoprinosine and interferon-alpha, both our patients deteriorated rapidly and died 2.5 and 4 months, respectively, after the onset of neurologic symptoms. Both atypical presentation and rapid clinical course observed in our patients could cause problems in making final diagnosis of subacute sclerosing panencephalitis. Therefore, subacute sclerosing panencephalitis should be included in differential diagnosis of acute unexplained encephalopathic diseases.

A case of subacute sclerosing panencephalitis preceded by epileptic seizures: evolutional EEG changes

We reported a patient with subacute sclerosing panencephalitis (SSPE) in whom EEG had been serially performed before the onset. She was referred to our hospital due to epileptic seizures at 2 years of age. Focal spikes were seen on EEG at the time of her first seizure (2 years 4 months). At the time of the second unprovoked seizure (9 years 8 months), EEG showed poorly organized background activity associated with focal spikes and a few diffuse spike-and-waves. Then, diffuse paroxysms became predominant, followed by periodic synchronous discharges. In our case, EEG abnormalities were recognized before mental deterioration. Unexpected EEG changes in a patient with epilepsy could be a clue as to the diagnosis of SSPE.

Subacute sclerosing panencephalitis presenting with hemiparesis in childhood: case report

Subacute sclerosing panencephalitis is a chronic and fatal disease of the central nervous system. Most patients present with progressive psychointellectual disturbances. A 14-month-old girl was admitted to our hospital because of left-sided hemiparesis. During hospitalization, focal and generalized seizures occurred. The electroencephalogram (EEG) revealed that periodic lateralized discharges consisted of polyspike and high-voltage slow waves in the left hemisphere. The clinical and EEG findings and positive serology of measles in the cerebrospinal fluid were consistent with subacute sclerosing panencephalitis. In conclusion, we suggest that subacute sclerosing panencephalitis be considered in the differential diagnosis of focal neurologic signs in infants.

EEG-mediated diagnosis of an unusual presentation of SSPE

OBJECTIVE

To highlight the role of EEG in the diagnosis of SSPE.

METHODS

EEG was performed in an 18 month old girl who had a 1 week history of repeated episodes of sudden flexion of the head and trunk and frequent falls.

RESULTS

EEG abnormalities consisted of stereotyped, generalized and synchronous high amplitude periodic complexes. These abnormalities correlated with brief episodes of axial and upper limb atonia on electromyogram examination. They persisted during sleep although abnormal movements disappeared. Biological results and cerebral MRI confirmed the diagnosis of subacute sclerosing panencephalitis.

CONCLUSIONS

This case is exceptional because of the age of the patient, the clinical presentation and the mode of contamination and it highlights the role of EEG in this diagnosis.

[Pseudoperiodic and paroxysmal electroencephalographic activities]

Periodic and paroxysmal EEG patterns are frequent and easily recognized. They often correlate with particular neurological or systemic conditions. We propose a reclassification and critical examination of these periodic EEG patterns by reviewing the original work presented by J. Gaches in this journal some thirty years ago. Periodic EEG activity is still classified by its localisation--generalised or focal--and by its periodicity--long or short. Periodic long-interval diffuse paroxysmal patterns are reported with rare pathologies such as SSPE, trypanosomiasis or intoxication with phencyclidine. Suppression bursts (SB) may be found in two main situations post-anoxic encephalopathies and drug-induced comas. Ohtahara syndrome is a very rare childhood epileptic syndrome with SB. Periodic short-interval diffuse pattern have been reported in Creutzfeldt-Jakob disease but also in toxic encephalopathies, such as lithium intoxication or as recently reported in acute Cefepime intoxication as well as with metabolic encephalopathies and rarely during AIDS. Periodic lateralized epileptiform discharges (PLEDs) have been classified according to their morphology and the associated condition (epileptic seizures, subtle status, "vascular" seizure). The principal etiology is cerebro-vascular disease and herpes encephalitis but it has also been reported in several other neurological diseases.

Subacute sclerosing panencephalitis: clinical and magnetic resonance imaging evaluation of 36 patients

We studied 36 patients (24 males, 12 females), all of whom had definite subacute sclerosing panencephalitis with typical periodic complexes in their electroencephalograms and increased titers of measles antibody in serum and cerebrospinal fluid. Their clinical and laboratory findings on admission were reviewed retrospectively. The age at onset of symptoms varied from 4 to 23 years. The average age at onset of disease was 13.1 +/- 4.18 years. The mean of the duration from the infection to the onset of subacute sclerosing panencephalitis was 9 years. Unusual symptoms, especially in the early periods of disease, included hemiparesis (7 patients), headache (3), generalized tonic-clonic seizures (6), absence seizure (1), nausea (3), and vomiting (3). Twenty-six cranial magnetic resonance imaging (MRI) and 12 computed tomography examinations were performed. Nine patients had normal MRI. In the early stages, lesions usually involved parieto-occipital corticosubcortical regions asymmetrically. In time, symmetric periventricular white-matter changes became more prominent. In addition to the common clinical findings in cases of subacute sclerosing panencephalitis reported in the literature, there were some different clinical features of the disease. Eventually, we concluded that there seems to be no correlation between the clinical stages and either the duration from the onset of subacute sclerosing panencephalitis or the MRI findings.