ECHO 25 focal encephalitis and subacute hemichorea

Square the Circle: Diversity of Viral Pathogens Causing Neuro-Infectious Diseases

Neuroinfections rank among the top ten leading causes of child mortality globally, even in high-income countries. The crucial determinants for successful treatment lie in the timing and swiftness of diagnosis. Although viruses constitute the majority of infectious neuropathologies, diagnosing and treating viral neuroinfections remains challenging. Despite technological advancements, the etiology of the disease remains undetermined in over half of cases. The identification of the pathogen becomes more difficult when the infection is caused by atypical pathogens or multiple pathogens simultaneously. Furthermore, the modern surge in global passenger traffic has led to an increase in cases of infections caused by pathogens not endemic to local areas. This review aims to systematize and summarize information on neuroinvasive viral pathogens, encompassing their geographic distribution and transmission routes. Emphasis is placed on rare pathogens and cases involving atypical pathogens, aiming to offer a comprehensive and structured catalog of viral agents with neurovirulence potential.

Review of Hereditary and Acquired Rare Choreas

Background:

Movement disorders are often a prominent part of the phenotype of many neurologic rare diseases. In order to promote awareness and diagnosis of these rare diseases, the International Parkinson’s and Movement Disorders Society Rare Movement Disorders Study Group provides updates on rare movement disorders.

Methods:

In this narrative review, we discuss the differential diagnosis of the rare disorders that can cause chorea.

Results:

Although the most common causes of chorea are hereditary, it is critical to identify acquired or symptomatic choreas since these are potentially treatable conditions. Disorders of metabolism and mitochondrial cytopathies can also be associated with chorea.

Discussion:

The present review discusses clues to the diagnosis of chorea of various etiologies. Authors propose algorithms to help the clinician in the diagnosis of these rare disorders.

Cerebral vasculitis associated with an Echovirus 6 meningoencephalitis-Case report and review of the literature

When a previously healthy child presents to the hospital with a stroke, generally a Varicella zoster virus vasculopathy seems most likely. However, other causes of a local cerebral vasculitis are possible and need to be explored.

Focal Coxsackie virus B5 encephalitis with synchronous seizure cluster and eruption: Infantile case

Enterovirus focal encephalitis is a rare clinical entity that is characterized by focal neurological signs including seizure, hemiparesis, hemichorea, and headache, which are mainly followed by rapid spontaneous improvement. We herein describe the case of a 9-month-old boy who developed Coxsackie virus B5 (CVB5) focal encephalitis with seizure clusters in the eruption stage of roseola infantum-like illness, which were followed by rapid improvement and benign outcome. Lumbar puncture indicated pleocytosis, and CVB5 infection in the cerebrospinal fluid was subsequently identified on genome sequencing and virus isolation. Magnetic resonance imaging and electroencephalography showed no abnormal findings at the acute stage or on 2 month follow up. Although the pathogenesis of enterovirus focal encephalitis currently remains unclear, the pure synchronism of seizure cluster and eruption in this case suggests the involvement of local vascular impairment as the underlying pathogenesis.

Complete genome sequence of a new recombinant echovirus 25 strain isolated from a neonatal patient with hand, foot, and mouth disease complicated by encephalitis in Beijing, China

Although human echovirus 25 (E-25), a type of the enterovirus B species, is implicated in aseptic meningitis, information on its gene structure, evolution, and virulence are limited. We report here the complete genome sequence of a novel recombinant E-25 strain (E25/2010/CHN/BJ) isolated from a neonate with hand, foot, and mouth disease complicated by encephalitis in Beijing, China in 2010. The complete viral genome consists of 7429 nucleotides (nts), including a 6585-nt open reading frame. Phylogenetic dendrogram based on VP1 gene regions revealed that this strain belonged to subgroup D4, which contains the other E-25 strains isolated from China in recent years. The difference in the amino acid sites (P130S, K/T135I) of the VP1 region may affect its immunogenicity. SimPlot and Bootscan analyses suggested that E25/2010/CHN/BJ is a recombination result of E-25 and Coxsackievirus B3 (CVB-3) strains. Our results would facilitate the study of the origin, evolution, and molecular epidemiology of E-25.

Enterovirus-associated encephalitis in the California encephalitis project, 1998-2005

BACKGROUND

Encephalitis is a relatively rare presentation of enterovirus (EV) infections. Clinical and epidemiologic characteristics of EV encephalitis (EVE) have not been well characterized.

METHODS

Patients with encephalitis enrolled in the California Encephalitis Project from 1998 to 2005 were tested for a range of pathogens, including EV, using a standardized diagnostic algorithm. EVE was categorized as "confirmed" (EV detected in cerebrospinal fluid [CSF] or brain tissue) or "possible" (EV found in respiratory or fecal specimens or serum EV immunoglobulin [Ig] M detected). We compared clinical and epidemiologic characteristics of EVE with those of other infectious encephalitis cases.

RESULTS

EVE was diagnosed in 73 (4.6%) of 1571 patients (45 confirmed cases, 28 possible cases); 11.1% of cases had other infectious causes. Patients with confirmed EVE were younger, although 27% were adults, who presented with significantly less severe symptoms. Serotypes identified in EVE cases correlated with the predominant serotype for the given year reported to the National Enterovirus Surveillance System at the Centers for Disease Control and Prevention. Two of 4 fatal EVE cases were associated with EV71.

CONCLUSION

EVs are an important cause of encephalitis cases requiring hospitalization, in both children and adults. Our data suggest that EVE severity varies by serotype, confirm the importance of CSF/brain tissue polymerase chain reaction, and demonstrate that serum IgM findings are of little value in diagnosing EVE.

Acute infantile bilateral striatal necrosis: single-photon emission computed tomography (SPECT) imaging and review

Acute infantile bilateral striatal necrosis is a rarely described acute neurological syndrome associated with radiological findings. Its etiology and pathogenic mechanisms are unknown. Clinically, the syndrome usually follows respiratory illnesses and presents with an array of neurological findings, including axial ataxia, grimacing, mutism, head nodding, and high-pitched cry. This study follows a child with acute infantile bilateral striatal necrosis both clinically and radiologically. In addition, for the first time, the authors describe the serial findings of single-photon emission computed tomography (SPECT) from onset of illness through 20 months. Their findings indicate an initial insult apparent on both magnetic resonance imaging and SPECT localized to the basal ganglia, which, although improved over time, does not fully regress. The residual lesion on SPECT was clinically associated with only mild attention deficit disorder and no motor pathology. The authors review the published literature concerning acute infantile bilateral striatal necrosis and suggest possible mechanisms of this poorly understood and probably underreported condition.

Acute encephalitis associated with measles: MRI features

We document the MRI features in six patients aged 5-14 years with acute encephalitis following measles. The diagnosis was made on a characteristic morbiliform rash and detection of specific IgM and IgG antibodies. The symptoms of encephalitis occurred 1-11 days after the appearance of the rash. All patients underwent MRI within 1-4 days of the onset of neurological symptoms. Diffusion weighted images (DWI) were obtained in three patients. In all patients, T2-weighted images showed widely distributed, multifocal high signal in both cerebral hemispheres with swelling of the cortex, with bilateral, symmetrical involvement of the putamen and caudate nucleus. The lesions had showed low apparent diffusion coefficients. Three patients showed subacute gyriform haemorrhage, and asymmetrical gyriform contrast enhancement on follow-up MRI.

SPECT in focal enterovirus encephalitis: evidence for local cerebral vasculitis

We report a 4-year-old, left-handed male with focal coxsackievirus A3 encephalitis who presented with seizures and acquired aphasia. Electroencephalography exhibited focal spike discharges over the right frontal regions, but cranial magnetic resonance imaging did not reveal any structural abnormalities. However, brain single-photon emission computed tomography performed during the acute phase disclosed focal hypoperfusion in the right frontal lobe, consistent with decreased regional cerebral blood flow in the territory of some branches of the right cerebral anterior artery. Without specific treatment, the patient recovered completely within 1 month, when brain single-photon emission computed tomography images returned to normal and cranial magnetic resonance imaging still demonstrated no abnormalities. The present case suggests the possible role of transient local cerebral vasculitis in the pathogenesis of focal enterovirus encephalitis.

Infantile bilateral striatal necrosis following measles

A previously healthy 4-year-old boy presented with typical measles and demonstrated lesions confined to basal ganglia. The clinical symptoms were an abrupt onset, impaired consciousness and mutism, extrapyramidal signs and severe neurovegetative dysfunction. No modification of the cerebrospinal fluid was observed; laboratory tests were all normal with the exception of a positive serologic test for measles. Cranial magnetic resonance imaging showed abnormal signals in the striatum, affecting the putamen and the caudate nuclei bilaterally. Neurologic improvement occurred within 2 months, with regression of lesions on cranial imaging, suggesting that edema played an important role in the initial stage of the disease.

Dystonia and chorea in acquired systemic disorders

Dystonia and chorea are uncommon accompaniments, but sometimes the presenting features of certain acquired systemic disorders that presumably alter basal ganglia function. Hypoxia-ischaemia may injure the basal ganglia through hypoperfusion of subcortical vascular watershed regions and by altering striatal neurotransmitter systems. Toxins interfere with striatal mitochondrial function, resulting in cellular hypoxia. Infections may affect the basal ganglia by causing vasculitic ischaemia, through the development of antibodies to basal ganglia epitopes, by direct invasion of the basal ganglia by the organism, or through cytotoxins causing neuronal injury. Autoimmune disorders alter striatal function by causing a vasculopathy, by direct reaction of antibodies with basal ganglia epitopes, or by stimulating the generation of a cytotoxic or inflammatory reaction. Endocrine and electrolyte abnormalities influence neurotransmitter balance or affect ion channel function and signalling in the basal ganglia. In general, the production of chorea involves dysfunction of the indirect pathway from the caudate and putamen to the internal globus pallidus, whereas dystonia is generated by dysfunction of the direct pathway. The time of the onset of the movement disorder relative to the primary disease process, and course vary with the age of the patient and the underlying pathology. Treatment of dystonia or chorea associated with a systemic medical disorder must initially consider the systemic disorder.

Clinical and neuroradiographic manifestations of eastern equine encephalitis

BACKGROUND

Eastern equine encephalitis occurs principally along the east and Gulf coasts of the United States. Recognition of the neuroradiographic manifestations of eastern equine encephalitis could hasten the diagnosis of the illness and speed the response to index cases.

METHODS

We reviewed all cases of eastern equine encephalitis reported in the United States between 1988 and 1994. The records of 36 patients were studied, along with 57 computed tomographic (CT) scans and 23 magnetic resonance imaging (MRI) scans from 33 patients.

RESULTS

The mortality rate was 36 percent, and 35 percent of the survivors were moderately or severely disabled. Neuroradiographic abnormalities were common and best visualized by MRI. Among the patients for whom MRI scans were available, the results were abnormal for all eight comatose patients as well as for all three noncomatose patients who subsequently became comatose. The CT results were abnormal in 21 of 32 patients with readable scans. The abnormal findings included focal lesions in the basal ganglia (found in 71 percent of patients on MRI, and in 56 percent on CT), thalami (found in 71 percent on MRI and in 25 percent on CT), and brain stem (found in 43 percent on MRI and in 9 percent on CT). Cortical lesions, meningeal enhancement, and periventricular white-matter changes were less common. The presence of large radiographic lesions did not predict a poor outcome, but either high cerebrospinal fluid white-cell counts or severe hyponatremia did.

CONCLUSIONS

Eastern equine encephalitis produces focal radiographic signs. The characteristic early involvement of the basal ganglia and thalami distinguish this illness from herpes simplex encephalitis. MRI is a sensitive technique to identify the characteristic early radiographic manifestations of this viral encephalitis.

Bilateral basal ganglia lucencies following acute febrile illness

Bilateral striatal necrosis in children without damage elsewhere in the brain can present as an acute neurological disorder or as a progressive disorder. Three children of 6, 7 and 12 years age developed dystonic posture of limbs without any cranial nerve involvement or alteration of sensorium soon after recovery from acute high grade febrile illness of 3-4 days duration. Computerized tomographic scan of head showed bilateral necrosis of basal ganglia. We think that these patients probably constitute a clinically and radiologically distinct subgroup of disorder that produce bilateral striatal necrosis in children. The cause of the syndrome is unknown.

A special case of congenital adrenal hypoplasia and acute bilateral infantile striatal necrosis

Isolated mineralocorticoid deficiency is described in a 5-week-old boy. The deficiency progressed to general adrenal insufficiency during the boy's first year of life. The family history suggested X-linked inheritance. At 18 months of age the patient developed acute bilateral infantile striatal necrosis, which might suggest a possible relationship between both entities.

Infarction of basal ganglia associated with California encephalitis virus

A child developed acute hemiparesis due to infarction of basal ganglia and internal capsule. Pleocytosis of cerebrospinal fluid and elevated immunoglobulin M antibodies suggest that California encephalitis virus infection caused the stroke.

Q fever meningoencephalitis in five patients

Within the last four years, we have observed five patients with epidemiological, clinical, and serological features that were consistent with Q fever meningoencephalitis. Attempts to isolate Coxiella burnetii from the cerebrospinal fluid of two patients were unsuccessful. Neurological features ranged from coma, general seizures, confusion, to palsy and meningitis. All patients were febrile. These patients were neuroradiologicaly investigated. Since 1984, four other cases have been reported in the literature. Antibiotics with good penetration into the cerebrospinal fluid, such as new quinolones, may be useful for treatment of confirmed cases. Q fever should be considered as a possible etiology of meningitis in endemic areas, and diagnosis should be confirmed by serology.

Brain perfusion in acute encephalitis: relationship to prognosis studied using SPECT

Single photon emission computed tomography (SPECT) and cranial computed tomography were sequentially examined in 2 patients with acute encephalitis. Radiographic computed tomography revealed focal low-density areas within a few days of the onset of symptoms in both patients. In SPECT, 1 patient exhibited hyperperfusion in the corresponding area, while the other had a normal scan. The outcome of the former was poor, while the latter recovered fully. Abnormal brain perfusion, thus, coincided with a poor prognosis. SPECT may be used to promptly evaluate the focal change of acute encephalitis.

Combined HIV-CMV encephalitis presenting with brainstem signs

Two cases of combined HIV-CMV encephalitis are described. One presented with a sixth nerve palsy and a tetraparesis, the other with an internuclear ophthalmoplegia. Pathologically brain stem involvement was predominantly due to CMV.

Ischaemic stroke in the basal ganglia and internal capsule in childhood

Ischaemic stroke in childhood is rare. In particular, there have only been a few reports of lacunar infarcts in children. In this study, four children with true lacunar infarcts and four with larger subcortical infarcts are described. We compare the clinical features and the possible pathogenesis of ischaemic strokes in the basal ganglia and internal capsule in childhood with those in adults, and discuss diagnostic and therapeutic management.

Acute measles encephalitis of the delayed type in an immunosuppressed child

The authors described a case of an immunosuppressed child with acute measles encephalitis of the delayed type (AMED). The authors also discussed the relationship between the AMED, epilepsia partialis continua and the neuroradiological picture, in which bilateral putaminal lucency was evident.

Symmetrical low density areas in bilateral thalami in an infant with measles encephalitis

Symmetrical low density areas in the thalami at CT were found in an 11-month-old boy with measles encephalitis. The focal lesions on CT appeared to be localized inflammation, necrosis or edema. The cause of these lesions is unknown.

A case report of infantile striatal necrosis with an acute onset

We report here an autopsy case, an 8-year-old boy diagnosed as having infantile striatal necrosis, characterized by a preceding febrile illness followed by acute encephalopathy with abrupt obtundation, seizures and dystonia, with remarkable improvement of the disturbed consciousness and intelligence after TRH-T therapy. These clinical symptoms were linked with bilateral necrosis of the striata on CT scanning. The presented case belonged to a newly described subgroup of the heredogenous disorders that produce necrosis of the putamina in children.

Computed tomographic brain scan findings in Q fever encephalitis

Neurological involvement in Q Fever is unusual. We present a case of encephalitis due to Coxiella Burnetii with neuroradiologic findings on CT not described previously, consisting in areas of decreased absorption coefficient in the subcortical white matter of both hemispheres, predominantly in the right. Differential diagnosis must be established from viral encephalitis, of similar clinical presentation, which may show similar CT lesions to those in this case.

Focal convulsions associated with subclinical measles infection

A patient with focal convulsions of sudden onset had cerebrospinal pleocytosis and electroencephalographic evidence of a focal lesion in the right hemisphere. Except for fever, there was no clinical evidence of a viral infection. Measles antibodies were detected in the serum and CSF. The CSF abnormalities resolved, and the patient has been well for 4 years. This case is unusual because of the focal CNS involvement and the lack of any other clinical features of measles infection.

Computed tomography in postinfluenzal encephalitis

A 2-year-old girl developed encephalitis following influenza A virus infection. Brain computed tomography (CT) showed symmetrical hypodense areas in the putamina. Contrast enhancement was noted surrounding the hypodense areas 2 days after the onset of encephalitis. These localized lesions demonstrated on CT have not been reported in the literature of postinfluenzal encephalitis.

Acute neurological dysfunction associated with destructive lesions of the basal ganglia in children

Three children ranging in age from 1 to 4 1/2 years suffered an acute illness with disturbance of consciousness followed by motor rigidity, loss of spontaneous movements and language, axial hypotonia, and a stereotyped response to any kind of stimulus. In two cases, images on computerized tomography were consistent with necrosis of the lenticular and caudate nuclei. The acute onset was followed by later improvement and stabilization. One child died, probably not as a direct consequence of the neurological disorder, autopsy showed bilateral necrosis of the putamina. We suggest that these three patients, together with two previously reported cases, constitute a clinically and radiologically recognizable subgroup among the heterogeneous disorder that produce bilateral striatal necrosis in children. The cause of the syndrome is unknown.

Non-pyogenic focal encephalitis diagnosis and follow-up by computed tomography and nuclear brain scanning

A localized brain affection in a 10-year-old girl was closely followed for 2 1/2 years by means of EEG, nuclear brain scans, angiography and computed tomography. Owing to the absence of angiographic evidence of an arterial occlusion, the possibility of an infarct was abandoned and a tentative diagnosis of focal encephalitis, probably viral in origin, was made. The necessity of arriving at such a diagnosis by exclusion of other possibilities rather than by the positive demonstration of the causative agent is discussed. The importance of neuroradiological methods in stressed.

Central nervous system complications of Mycoplasma pneumoniae

Three cases of central nervous system complications of Mycoplasma pneumoniae infections are reported. There were several atypical findings: the first patient presented with an acute disseminated encephalitis with normal cerebrospinal fluid and hypogammaglobulinaemia. The second patient presented with a left sixth nerve palsy followed six weeks later by choreoathetoid movements and an acute psychosis. The third patient presented with an acute encephalitis associated with acute renal failure secondary to rhabdomyolysis and was the only patient who did not completely recover; he was discharged akinetic and mute, but with normal renal function. The diagnosis of complications of Mycoplasma pneumoniae may be difficult. In two of the three cases a raised red blood cell volume secondary to a high titre of cold agglutinins rapidly led to the correct diagnosis.