Longitudinal Extensive Transverse Myelitis in an Immunocompetent Older Individual-A Rare Complication of Varicella-Zoster Virus Reactivation.

Varicella-zoster virus (VZV) is a human neurotropic herpes virus that causes chickenpox in children. After becoming latent in dorsal root ganglia, it can reactivate to cause dermatological manifestations, the most common one being shingles or herpes zoster. Severe neurologic dysfunctions can occur in immunocompromised patients such as encephalitis, meningitis, myelitis and neuropathy. Longitudinal extensive transverse myelitis (LETM) is an unusual neurological complication mainly described in immunocompromised patients, with very few cases described in immunocompetent ones. We hereby report a case of VZV-induced LETM in an immunocompetent older adult-a situation rarely described in the literature. LETM is a rare complication of VZV and its pathogenesis; therapeutic interventions and prognosis are far from being fully clarified. However, a prompt diagnosis is needed to allow a rapid initialization of treatment and ensure a better outcome. Although the therapeutic lines are not clear, immunosuppressive agents may have their place in cases of unsuccessful results and/or relapses following acyclovir coupled with a well conducted methylprednisolone therapy. Further studies are highly needed to improve the current understanding of the disease course and mechanisms, and to optimize therapeutic strategies.

The Effects of the COVID-19 Confinement on Screen Time, Headaches, Stress and Sleep Disorders among Adolescents: A Cross Sectional Study.

Background: Headache is a common symptom affecting children and adolescents. The medical literature over the last three decades reveals a variable prevalence and triggers in different countries, regions, circumstances and times. This study aims to assess the prevalence, frequency and quality of headaches in the Lebanese adolescent population under the COVID-19 confinement and study its triggers and relationship to screen time, self-reported anxiety, and sleep. Methods: A cross sectional design was used to collect two survey results by snowball distribution using social media targeting adolescents aged 15 to 17 years of age. The first survey included 13 questions with a single best answer about screen time, feeling anxious, sleep time, schedule and consistency, and headaches. The second survey included 3 questions about the quality of the headaches, anxiety and its triggers. Results: Among 433 responders to the first survey, the prevalence of headaches, especially pressure points and band-like pressure was higher than any previously reported among adolescents in the literature, reaching 93.4%. Screen time was also higher than any previous reports with 95.6% spending 9 hours or more on screen while 64% of adolescents spending at least 12 hours a day on screen. In addition, the majority (82%) don't have consistent sleep habits and 41.8% consider themselves anxious. School was considered the main source of stress by 82.8% of the responders. The frequency of headache correlated significantly with increased screen time, self-reported anxiety and inconsistent sleep habits. Conclusions: Headaches among adolescents are associated with increased screen use, sleep disorders, and self-reported anxiety. It is one of the primary somatization symptoms in this group expressing their extreme stress under the current economic, political, and health crisis. The present trends are likely to have major long term implications on adolescents' health and academic achievements and should alarm educators and health officials to intervene in this situation.

Small nerve fiber selectivity of laser and intraepidermal electrical stimulation: A comparative study between glabrous and hairy skin.

OBJECTIVES: In clinical neurophysiology practice, various methods of stimulation can be used to activate small-diameter nociceptive cutaneous afferents located in the epidermis. These methods include different types of laser and intraepidermal electrical stimulation techniques. The diffusion of the stimulation in the skin, inside or under the epidermis, depends on laser wavelength and electrode design, in particular. The aim of this study was to compare several of these techniques in their ability to selectively stimulate small nerve fibers. METHODS: In 8 healthy subjects, laser stimulation (using a CO2 or Nd:YAP laser) and intraepidermal electrical stimulation (using a micropatterned, concentric planar, or concentric needle electrode), were applied at increasing energy or intensity on the dorsal or volar aspect of the right hand or foot. The subjects were asked to define the perceived sensation (warm, pinprick, or electric shock sensation, corresponding to the activation of C fibers, Aδ fibers, or Aß fibers, respectively) after each stimulation. Depending on the difference in the sensations perceived between dorsal (hairy skin with thin stratum corneum) and volar (glabrous skin with thick stratum corneum) stimulations, the diffusion of the stimulation inside or under the epidermis and the nature of the activated afferents were determined. RESULTS: Regarding laser stimulation, the perceived sensations turned from warm to pinprick with increasing energies of stimulation, in particular with the Nd:YAP laser, of which pulse could penetrate deep in the skin according to its short wavelength. In contrast, CO2 laser stimulation produced only warm sensations and no pricking sensation when applied to the glabrous skin, perhaps due to a thicker stratum corneum and the shallow penetration of the CO2 laser pulse. Regarding intraepidermal electrical stimulation using concentric electrodes, the perceived sensations turned from pinprick to a combination of pinprick and electrical shocks with increasing intensities. Using the concentric planar electrode, the sensations perceived at high stimulation intensity even consisted of electric shocks without concomitant pinprick. In contrast, using the micropatterned electrode, only pinprick sensations were produced by the stimulation of the hairy skin, while the stimulation of the glabrous skin produced no sensation at all within the limits of stimulation intensities used in this study. CONCLUSIONS: Using the CO2 laser or the micropatterned electrode, pinprick sensations were selectively produced by the stimulation of hairy skin, while only warm sensation or no sensation at all were produced by the stimulation of glabrous skin. These two techniques appear to be more selective with a limited diffusion of the stimulation into the skin, restricting the activation of sensory afferents to the most superficial and smallest intraepidermal nerve fibers.

Isolated Mammillary Bodies Damage-An Atypical Presentation of Wernicke Syndrome.

We report atypical magnetic resonance imaging (MRI) lesions in a case of Wernicke encephalopathy. The patient presented with isolated anterograde amnesia following a partial colectomy complicated by peritonitis. Fluid-attenuated inversion recovery and T2 MRI sequences were normal. However, bilateral contrast enhancement of mammillary bodies was shown on T1 gadolinium-enhanced sequences. Blood tests revealed thiamine deficiency. The diagnosis of Wernicke encephalopathy was made and thiamine supplementation was given, resulting in complete recovery of the memory functions.