Human Herpesvirus 6 Encephalitis in Immunocompetent and Immunocompromised Hosts.

OBJECTIVE: The aim of this study was to analyze the clinical, radiologic, and biological features associated with human herpesvirus 6 (HHV-6) encephalitis in immunocompetent and immunocompromised hosts to establish which clinical settings should prompt HHV-6 testing. METHODS: We performed a retrospective research in the virology database of Fondazione IRCCS Policlinico San Matteo (Pavia, Italy) for all patients who tested positive for HHV-6 DNA in the CSF and/or in blood from January 2008 to September 2018 and separately assessed the number of patients meeting the criteria for HHV-6 encephalitis in the group of immunocompetent and immunocompromised hosts. RESULTS: Of the 926 patients tested for HHV-6 during the period of interest, 45 met the study criteria. Among immunocompetent hosts (n = 17), HHV-6 encephalitis was diagnosed to 4 infants or children presenting with seizures or mild encephalopathy during primary HHV-6 infection (CSF/blood replication ratio <<1 in all cases). Among immunocompromised hosts (n = 28), HHV-6 encephalitis was diagnosed to 7 adolescents/adults with hematologic conditions presenting with altered mental status (7/7), seizures (3/7), vigilance impairment (3/7), behavioral changes (2/7), hyponatremia (2/7), and anterograde amnesia (1/7). Initial brain MRI was altered only in 2 patients, but 6 of the 7 had a CSF/blood replication ratio >1. CONCLUSIONS: The detection of a CSF/blood replication ratio >1 represented a specific feature of immunocompromised patients with HHV-6 encephalitis and could be of special help to establish a diagnosis of HHV-6 encephalitis in hematopoietic stem cell transplant recipients lacking radiologic evidence of limbic involvement.

Cerebral Toxocariasis as a Cause of Epilepsy: A Pediatric Case.

Toxocarosis is the consequence of human infection by Toxocara spp. larvae and is one of the most common ascarioses, not only in developing countries, but also in the European region, where its prevalence reaches 14%. Due to their particular behavior, children are at higher risk of this parasitic infection, whose clinical features depend on the localization of the Toxocara larvae. Neurotoxocariasis is very uncommon in children and may take different forms depending on the underlying physiopathologic process: immune reaction against the parasite antigens, vasculitis, treatment complications, or, very rarely, brain localization of Toxocara spp. larvae. The association between neurotoxocariasis and the onset of childhood epilepsy has been postulated but is still debated. Moreover, a Toxocara spp. abscess causing epileptic seizures in children has been rarely described, especially in western countries. Hereby we present a 9-year-old patient with a new diagnosis of epilepsy definitely secondary to brain abscess due to the localization of Toxocara canis larvae. Diagnosis was confirmed by neuroimaging and serological test. The successful treatment with albendazole and steroids was documented with a close and long-term clinical and neuroradiological follow-up. Our experience confirms that every case of cryptogenetic epilepsy in children deserves a neuroimaging study and, in case of cystic images, Toxocara serology is mandatory to avoid further unnecessary invasive diagnostic investigations and to set the specific drug therapy.

Isolated Eustachian Tube Osteoma: Common Lesion in Uncommon Site.

Isolated Eustachian tube osteomata are a very rare entity indeed, with the last case being reported in 1979. We describe a case of the otoscopic finding of a blue-yellowish eardrum and successive identification by computed tomography scan of an osteoma localized in the Eustachian tube. Clinical presentation and diagnostic and therapeutic phases in comparison with the literature will be discussed.

Primary Spinal Epidural Abscesses Not Associated With Pyogenic Infectious Spondylodiscitis: A New Pathogenetic Hypothesis.

Introduction: Spinal epidural abscess (SEA) incidence is rising. However, most series do not differentiate between SEAs associated with pyogenic infectious spondylodiscitis (PS) and SEAs limited to the epidural space. Methods: We retrospectively reviewed the records and radiological images of all patients admitted to our institutions with a diagnosis of SEA not associated with PS between January 2013 and December 2018. Results: We found three males and four females; five of the seven were intravenous drug users. All patients presented with pain: in six, it was associated with acute motor and sensory deficits, while one had only pain and paresthesias. Staphylococcus aureus was cultured from abscesses and/or from multiple blood cultures in four patients. Abscesses were localized to the cervical spine in one patient, thoracic in three, lumbar in one, and in two, the SEAs involved multiple segments. All patients but one underwent urgent open surgery. This patient had a multisegmental abscess and was successfully treated by percutaneous aspiration when pain became intractable. After abscess evacuation, the neurological deficits improved in all patients except one. The patients that were treated without spine instrumentation did not develop delayed kyphosis or instability at follow-up. Conclusion: Patients with SEAs not associated with PS are likely to present with pain and motor deficits, appear to benefit from urgent abscess evacuation, and seem to be less dependent on spine instrumentation to avoid delayed spinal deformities compared to SEA associated with PS. Finally, the lack of initial involvement of bone and intervertebral disks may suggest that at least some of the SEAs without PS originate from infection of epidural lymphatic vessels that are not present inside those structures.

Clinical variability in children with dolichoarteriopathies of the internal carotid artery.

INTRODUCTION: Dolichoarteriopathies of the internal carotid artery (DICA) are frequent non-atheromatous anatomical changes in the general population. The etiology of DICA is still controversial: several hypotheses have been suggested, including an anomaly of embryological development, or a degenerative loss of elasticity of the vessel wall. DICA have been related to a wide spectrum of clinical presentations in adults, varying from asymptomatic forms to acute cerebrovascular events. However, to date, only a few pediatric cases have been reported. METHODS AND RESULTS: We report seven patients with DICA, 6 males and 1 female, aged 3 to 13 years, presenting with variable clinical symptoms. Different imaging techniques, including color Doppler ultrasound and magnetic resonance angiography, were used to show loops and/or kinking of the ICA. Three of these patients received a diagnosis of Ehlers-Danlos syndrome (EDS). DISCUSSION: This study highlights the clinical variability in pediatric patients with DICA. We emphasize the need for close clinical management of pediatric DICA. Finally, considering the long-term prognostic implications of EDS, we recommend specific testing in children with DICA and suspicious clinical signs of this pathology.

Anatomic variations of the round window niche: radiological study and related endoscopic anatomy.

PURPOSE: In the last decades, literature has shown an increasing interest in round windows (RW) anatomy due to its pivotal role in deafness surgery. The high variability of this anatomical region, with particular regard to the round windows niche (RWN), has been studied by several authors through different methods of investigation. The aim of the present research was to radiologically examine the morphological variability of the RWN and to link the imaging findings to the endoscopic view. METHODS: High-resolution CT scans of 300 temporal bones without neuro-otological pathologies were retrospectively reviewed by 2 neuroradiologist and 1 ENT surgeon who independently evaluated the RWN morphological variations. To link the radiological to the endoscopic data, 45 cadaveric human temporal bones were submitted to a radiological evaluation and to an otoendoscopy conducted through a posterior tympanotomy approach. RESULTS: Three variants of the RWN were detected on coronal CT scan reconstructions: 155 "cylindrical-type", 97 "j-type" and 48 "truncated cone-type". For each radiological type the endoscopic findings showed a specific endoscopic position of the RW chamber, which results in different degrees of RW membrane visibility when analysed through a posterior tympanotomy approach. CONCLUSIONS: To the best of our knowledge, this is the first description of the above-mentioned RWN radiological variations supported by endoscopic data. This study suggests an additional anatomical evaluation that could be useful to predict the RW membrane visibility through a posterior tympanotomy approach. Further studies are required to support the clinical implications of our observations.