scholarly journals Activation of the trigeminal system as a likely target of SARS-CoV-2 may contribute to anosmia in COVID-19

Cephalalgia ◽  
2021 ◽  
pp. 033310242110366
Author(s):  
Karl Messlinger ◽  
Winfried Neuhuber ◽  
Arne May

Clinical publications show consistently that headache is a common symptom in the coronavirus disease of 2019 (COVID-19). Several studies specifically investigated headache symptomatology and associated features in patients with COVID-19. The headache is frequently debilitating with manifold characters including migraine-like characteristics. Studies suggested that COVID-19 patients with headache vs. those without headache are more likely to have anosmia. We present a pathophysiological hypothesis which may explain this phenomenon, discuss current hypotheses about how the coronavirus SARS-CoV-2 enters the central nervous system and suggest that activation of the trigeminal nerve may contribute to both headache and anosmia in COVID-19.

2011 ◽  
Vol 64 (9-10) ◽  
pp. 443-447
Author(s):  
Milan Cvijanovic ◽  
Svetlana Simic ◽  
Sofija Banic-Horvat ◽  
Zita Jovin ◽  
Petar Slankamenac ◽  
...  

Introduction. Neuropathic pain, or pain associated with disease or injury to the peripheral or central nervous system, is a common symptom of a heterogeneous group of conditions, including diabetic neuropathy, trigeminal neuralgia, postherpetic neuralgia and spinal cord injury. Chronic neuropathic pain should not be thought of as a symptom. It should truly be thought of as a disease with a very complicated pathophysiology. Pathophysiology. The mechanisms involved in neuropathic pain are complex and involve both peripheral and central pathophysiologic phenomenon. The underlying dysfunction may involve deafferentation within the peripheral nervous system (e.g. neuropathy), deafferentation within the central nervous system (e.g. post-thalamic stroke) or an imbalance between the two (e.g. phantom limb pain). Clinical characteristics. Neuropathic pain is non-nociceptive, in contrast to acute nociceptive pain, and it can be described as ?burning?, ?electric?, ?tingling?, and ?shooting? in nature. Treatment. Rational polypharmacy is often necessary and actually it is almost always the rule. It would be an exception if a patient was completely satisfied with his treatment. Treatment goals should include understanding that our patients may need to be titrated and managed with more than one agent and one type of treatment. There should be the balance of safety, efficacy, and tolerability. Conclusion. There are many new agents and new applications of the existing agents being currently studied which will most certainly lead to even more improved ways of managing this very complicated set of disorders.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Indra N. Choudhury ◽  
Anu Chacko ◽  
Ali Delbaz ◽  
Mo Chen ◽  
Souptik Basu ◽  
...  

AbstractStaphylococcus aureus infections of the central nervous system are serious and can be fatal. S. aureus is commonly present in the nasal cavity, and after injury to the nasal epithelium it can rapidly invade the brain via the olfactory nerve. The trigeminal nerve constitutes another potential route of brain infection. The glia of these nerves, olfactory ensheathing cells (OECs) and trigeminal nerve Schwann cells (TgSCs), as well as astrocytes populating the glia limitans layer, can phagocytose bacteria. Whilst some glial responses to S. aureus have been studied, the specific responses of different glial types are unknown. Here, we compared how primary mouse OECs, TgSCs, astrocytes and microglia responded to S. aureus. All glial types internalized the bacteria within phagolysosomes, and S. aureus-conjugated BioParticles could be tracked with subtle but significant differences in time-course of phagocytosis between glial types. Live bacteria could be isolated from all glia after 24 h in culture, and microglia, OECs and TgSCs exhibited better protection against intracellular S. aureus survival than astrocytes. All glial types responded to the bacteria by cytokine secretion. Overall, OECs secreted the lowest level of cytokines, suggesting that these cells, despite showing strong capacity for phagocytosis, have immunomodulatory functions that can be relevant for neural repair.


Author(s):  
Gladys Harrison

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.


Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.


Author(s):  
Ezzatollah Keyhani

Acetylcholinesterase (EC 3.1.1.7) (ACHE) has been localized at cholinergic junctions both in the central nervous system and at the periphery and it functions in neurotransmission. ACHE was also found in other tissues without involvement in neurotransmission, but exhibiting the common property of transporting water and ions. This communication describes intracellular ACHE in mammalian bone marrow and its secretion into the extracellular medium.


Author(s):  
S.S. Spicer ◽  
B.A. Schulte

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.


2018 ◽  
Vol 23 (1) ◽  
pp. 10-13
Author(s):  
James B. Talmage ◽  
Jay Blaisdell

Abstract Injuries that affect the central nervous system (CNS) can be catastrophic because they involve the brain or spinal cord, and determining the underlying clinical cause of impairment is essential in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), in part because the AMA Guides addresses neurological impairment in several chapters. Unlike the musculoskeletal chapters, Chapter 13, The Central and Peripheral Nervous System, does not use grades, grade modifiers, and a net adjustment formula; rather the chapter uses an approach that is similar to that in prior editions of the AMA Guides. The following steps can be used to perform a CNS rating: 1) evaluate all four major categories of cerebral impairment, and choose the one that is most severe; 2) rate the single most severe cerebral impairment of the four major categories; 3) rate all other impairments that are due to neurogenic problems; and 4) combine the rating of the single most severe category of cerebral impairment with the ratings of all other impairments. Because some neurological dysfunctions are rated elsewhere in the AMA Guides, Sixth Edition, the evaluator may consult Table 13-1 to verify the appropriate chapter to use.


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