Hyperkinetic and Hypokinetic Movement Disorders in SSPE: A Systematic Review of Case Reports and Case Series.

Background: Subacute Sclerosing Panencephalitis (SSPE) typically presents with periodic myoclonus; however, a spectrum of movement disorders including dystonia, chorea, tremor, and parkinsonism have also been described. This review aims to evaluate the array of movement disorders in SSPE, correlating them with neuroimaging findings, disease stages, and patient outcomes. Methods: A comprehensive review of published case reports and case series was conducted on patients with SSPE exhibiting movement disorders other than periodic myoclonus. PRISMA guidelines were followed, and the protocol was registered with PROSPERO (2023 CRD42023434650). A comprehensive search of multiple databases yielded 37 reports detailing 39 patients. Dyken's criteria were used for SSPE diagnosis, and the International Movement Disorders Society definitions were applied to categorize movement disorders. Results: The majority of patients were male, with an average age of 13.8 years. Approximately, 80% lacked a reliable vaccination history, and 39% had prior measles infections. Dystonia was the most common movement disorder (49%), followed by parkinsonism and choreoathetosis. Rapid disease progression was noted in 64% of cases, with a disease duration of ≤6 months in 72%. Neuroimaging showed T2/FLAIR MR hyperintensities, primarily periventricular, with 26% affecting the basal ganglia/thalamus. Brain biopsies revealed inflammatory and neurodegenerative changes. Over half of the patients (56%) reached an akinetic mute state or died. Conclusion: SSPE is associated with diverse movement disorders, predominantly hyperkinetic. The prevalence of dystonia suggests basal ganglia dysfunction.

Adult-onset subacute sclerosing panencephalitis presenting with tonic motor seizures.

PURPOSE/AIM OF THE STUDY: Subacute sclerosing panencephalitis (SSPE) is a degenerative disease of the brain caused by a persistent measles virus infection occurring mostly in childhood or early adolescence. The spectrum of epileptic phenomena associated with SSPE is wide, varying from partial or generalized tonic-clonic seizures and atypical absences to myoclonic-atonic attacks. Tonic seizures are very rare in SSPE. MATERIALS AND METHODS: Herein, we discuss a case of 25 years old male that presented with adult-onset SSPE with tonic seizures accompanying myoclonic seizures. RESULTS: Patient was treated with clonazepam 5 mg/day and an isoprinosine regimen with a dose of 70 mg/kg/day. This is the fourth case of SSPE presenting with myoclonic and tonic seizures and the first case of SSPE with myoclonic and tonic seizures reported in an adult-onset case in the English literature. CONCLUSIONS: Adult-onset SSPE with tonic seizures is rare and may be confusing, thus, it is important to recognize the presence of this type of tonic motor seizures in SSPE patients.

Magnetic resonance imaging patterns of subacute sclerosing panencephalitis may mimic metabolic disorders: clinical, electroencephalographic and imaging features of six cases.

Subacute sclerosing panencephalitis is a rare, devastating neurodegenerative encephalitis whose diagnosis and therapy are still in question. Atypical clinical presentation and heterogeneity of neuroimaging findings that have been initially confused with metabolic disorders have hampered early diagnosis. To describe a series of patients with subacute sclerosing panencephalitis with imaging findings mimicking metabolic disorders. A total of six patients with subacute sclerosing panencephalitis were diagnosed from January 2012 to December 2016 in whom a metabolic disorder was suspected on initial clinical and MRI findings. Detailed laboratory investigation was performed in all patients. All patients presented with atypical neurologic manifestations, including dystonia, syncopal attacks, involuntary limb movements, meaningless speech and ataxia. Magnetic resonance imaging abnormalities included bilateral putaminal, bilateral posterior periventricular white matter and diffuse or splenial corpus callosum involvement which are particularly unusual in SSPE and mostly observed in metabolic disorders. All patients had elevated cerebrospinal fluid Ig G measles antibodies. The diagnosis of subacute sclerosing panencephalitis through clinical and imaging features can be considerably challenging. It is crucial to differentiate it from metabolic disorders, since the management and clinical outcome are different.

Aprepitant in the Treatment of Subacute Sclerosing Panencephalitis: A Randomized, Double-Blind, Placebo-Controlled Study.

BACKGROUND: Aprepitant is a neurokinin-1 receptor antagonist approved for the treatment of chemotherapy-induced nausea. We aimed to investigate the safety and efficacy of aprepitant in patients with subacute sclerosing panencephalitis. METHODS: A randomized, double-blind, placebo-controlled study was conducted in patients with subacute sclerosing panencephalitis assigned to receive two courses of aprepitant 250 mg/day orally or placebo for 15 days with an interval of two months between courses. Primary end points were safety and tolerability, and secondary end point was clinical improvement or stabilization assessed by subacute sclerosing panencephalitis scoring system. Electroencephalography (EEG), brain magnetic resonance imaging, and cerebrospinal fluid measles-specific immunoglobulin G index were evaluated before and after treatment. RESULTS: Sixty-two patients with subacute sclerosing panencephalitis were allocated to aprepitant (n = 31, median age 18 years) or placebo (n = 31, median age 22 years) group. Fifteen patients left the study within the first six months and 12 patients left between six and 12 months. Aprepitant was well tolerated and treatment-associated adverse events were similar to those described in the treatment of nausea. Clinical status at six and 12 months' follow-up did not differ between aprepitant and placebo groups. Post-treatment EEG scores at 12 months were better in the aprepitant group (P = 0.015). Cerebral atrophy on magnetic resonance imaging increased in both groups, whereas measles-specific immunoglobulin G index decreased in the placebo group. CONCLUSIONS: In this first clinical trial of aprepitant treatment in patients with subacute sclerosing panencephalitis, the drug was safe and well tolerated. No clinical effect was observed. A modest improvement in EEG findings might justify trials for longer periods because EEG changes can precede clinical findings in subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis: a rare cause of acute cortical visual impairment in an adult.

Adult onset subacute sclerosing panencephalitis (SSPE) after the third decade of life is rare and the manifestations can mimic disorders such as dysmyelinating and metabolic disorders. This case report presents a patient with acute binocular visual impairment in his fifth decade as the first manifestation of SSPE. This is preventable with immunisation against measles. A prior history of measles infection may not be forthcoming in adult onset SSPE. This should be kept in mind as a differential diagnosis when a patient from endemic area presents with acute visual loss even in the absence of classic features. Periodic generalised discharges on the EEG without myoclonus may be seen in this condition rarely as in this case.

Elevated quinolinic acid levels in cerebrospinal fluid in subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis (SSPE) is a rare neurodegenerative disorder caused by a persistent infection with aberrant measles virus. Indoleamine-2, 3-dioxygenase (IDO) initiates the increased production of kynurenine pathway (KP) metabolites quinolinic acid (QUIN), which has an excitotoxic effect for neurons. We measured serum IDO activity and cerebrospinal fluid (CSF) levels of QUIN. The CSF QUIN levels were significantly higher in SSPE patients than in controls, and increased according as neurological disability in a patient studied. Elevation of CSF QUIN and progression of SSPE indicate a pathological role of KP metabolism in the inflammatory neurodestruction.

Bone matrix hypermineralization associated with low bone turnover in a case of Nasu-Hakola disease.

Analysis of tissue from a 34-years-old male patient from Austrian origin with a history of multiple fractures associated with painful episodes over the carpal, tarsal and at the end of the long bones respectively is presented. Radiographic images and axial 3DCT scans showed widespread defects in trabecular bone architecture and ill-defined cortices over these skeletal sites in the form of discrete cystic-like lesions. Family history indicated two sisters (one half and one full biological sisters) also with a history of fractures. Whole exome sequencing revealed two heterozygous missense mutations in TYROBP (MIM 604142; NM_003332.3) gene encoding for a cell-surface adaptor protein, which is part of a signaling complex triggering activation of immune responses. It is expressed in cells of the ectoderm cell linage such as NK and dendritic cells, macrophages, monocytes, myeloid cells, microglia cells and osteoclasts. The phenotype and genotype of the patient were consistent with the diagnosis of Nasu-Hakola disease (NHD) (OMIM 221770). Investigations at the bone material level of a transiliac bone biopsy sample from the patient using polarized light microscopy and backscatter electron imaging revealed disordered lamellar collagen fibril arrangement and extensively increased matrix mineralization. These findings are the first bone material data in a patient with NHD and point toward an osteoclast defect involvement in this genetic condition.

Senile-Onset Subacute Sclerosing Panencephalitis, Presenting With Peculiar Findings.

Subacute sclerosing panencephalitis (SSPE) is a well-known childhood disease; however, the adult onset of SSPE cases are also widely recognized where the oldest case reported is 52 years old. We report a 61-year-old woman patient presenting with atypical clinical and EEG features, diagnosed with SSPE. Measles and SSPE have decreased dramatically owing to worldwide immunization programs; however, there are still reasons to consider SSPE in differential diagnosis even in patients presenting with atypical clinical findings and older ages. First, there is a generation who missed the immunization era, constituting a latent disease pool. Second, antivaccination movements have led to a decline in MMR (measles, mumps, rubella) vaccination worldwide, leading to measles outbreaks and potential future SSPE cases. Third, most of the vaccination programs start measles immunization at the age of 12 months, leading to a shift in the incidence below the age of 1 year, when the risk of developing SSPE in adult life is higher. Finally, disruption in vaccination programs, in which fast disease transmission due to close contact living, unhygienic conditions of refugee camps, and limited access to health care in displaced populations have also led to measles outbreaks. In conclusion, we believe that neurologists for adults should consider SSPE in differential diagnosis, even in older patients with atypical presentations.

Neuroleptic malignant syndrome as a presenting feature of subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis (SSPE) is a slowly progressive degenerative disorder caused by measles virus. It is characterised by typical clinical and electrophysiological features in the form of slow myoclonic jerks, with progressive cognitive impairment, visual symptoms, and periodic complexes on EEG, with raised titres of anti-measles antibodies in CSF and serum. Atypical presentations of SSPE have been reported including brainstem involvement, ADEM-like presentation, acute encephalitis, and cerebellar ataxia. Presentation with predominant extrapyramidal features is uncommon. We describe a case of SSPE presenting with extensive rigidity with highly elevated CPK values, mimicking neuroleptic malignant syndrome (NMS) which was most probably due to central dopaminergic blockade induced by the disease process. To our knowledge, this is the first case of SSPE presenting with a NMS-like syndrome.

[Molecular Pathogenesis of Nasu-Hakola Disease Brain Lesions].

Nasu-Hakola disease (NHD) is a rare intractable autosomal recessive disorder, characterized by pathological bone fractures and progressive dementia owing to multifocal bone cysts and leukoencephalopathy, caused by various genetic mutations of either DAP12 or TREM2. Loss-of-function of TREM2-DAP12, constituting a signaling complex on osteoclasts and microglia, plays a central role in the pathogenesis of NHD. Recently, NHD has been recognized as the disease entity designated "microgliopathy". However, at present, TREM2-specific ligands in microglia and the precise molecular mechanism underlying leukoencephalopathy remain to be investigated in order to establish an effective molecular targeted therapy for NHD.

Epileptic spasms in clusters and associated syndromes other than West syndrome: A study of 48 patients.

OBJECTIVE: To study the different epilepsy syndromes that included epileptic spasms (ES) in clusters without hypsarrhythmia (WoH). METHODS: Between 2/1990 and 7/2013, we registered 48 patients with the electroclinical diagnostic criteria of ES in clusters WoH. RESULTS: We recognized two subgroups. In the first subgroup of 30 patients, ES started at a mean age of 10.6 months (range, 2-40 months). Ictal EEG recordings showed diffuse high-amplitude slow waves in 15 patients, diffuse slow waves followed by voltage attenuation in six patients, diffuse fast rhythms in five, diffuse slow waves with superimposed fast rhythms in three, and diffuse sharp waves in one. In the second subgroup of 18 patients, nine had electroclinical features of Lennox-Gastaut syndrome, four had epilepsy with myoclonic and atonic seizures, two had Dravet syndrome, one 6-year-old boy had a non-convulsive status epilepticus characterized by atypical absences associated with ES, one had epilepsy with migrating seizures of infancy, and one patient had clinical features of subacute sclerosing panencephalitis with ES. ES started at a mean age of 6.3 years (range, 0.5-13 years). The ictal EEG recording during the ES showed diffuse fast rhythms in 10 cases, diffuse slow waves with superimposed fast rhythms in four, and diffuse slow waves in four. CONCLUSION: Our study shows two subgroups of children with ESWoH. The first subgroup had a well-defined electroclinical syndrome predominantly in infancy, and in the second subgroup ES was one more seizure type associated with an epileptic encephalopathy other than West syndrome predominantly occurring in childhood.

A 29-year-old pregnant woman with worsening left hemiparesis, encephalopathy, and hemodynamic instability: a case report of subacute sclerosing panencephalitis.

A 29-year-old pregnant woman developed progressively worsening encephalopathy, left hemiparesis, and hemodynamic instability over a 6-week period. Initial brain MRI and work-up for infectious and autoimmune causes were normal, although elevated IgG and oligoclonal bands were seen on analysis of the cerebrospinal fluid (CSF). After uncomplicated spontaneous delivery of a preterm healthy infant, her condition worsened. Repeat brain MRI demonstrated generalized volume loss and evidence of corticospinal tract degeneration. She underwent a brain biopsy, which showed characteristic viral inclusions of the type seen in subacute sclerosing panencephalitis (SSPE). The diagnosis was confirmed by immunohistochemistry and electron microscopy, and additional CSF analysis also showed markedly elevated IgG titer for measles. Sequence analysis of the nucleoprotein gene N-450 demonstrated a close relationship to the sequences of viruses in genotype D7. This case documents an ~ 6-month progression to death of SSPE in a pregnant woman.