Chapters authored
The Cutaneous Biopsy for the Diagnosis of Peripheral Neuropathies: Meissner’s Corpuscles and Merkel’s Cells
Cutaneous biopsy is a complementary method, alternative to peripheral nerve biopsy, for the analysis of nerve involvement in peripheral neuropathies, systemic diseases, and several pathologies of the central nervous system. Most of these neuropathological studies were focused on the intraepithelial nerve fibers (thin-myelinated Aδ fibers and unmyelinated C fibers), and few studies investigated the variations in dermal innervation, that is, large myelinated fibers, Merkel’s cell-neurite complexes, and Meissner’s corpuscles. Here, we updated and summarized the current data about the quantitative and qualitative changes that undergo MCs and MkCs in peripheral neuropathies. Moreover, we provide a comprehensive rationale to include MCs in the study of cutaneous biopsies when analyzing the peripheral neuropathies and aim to provide a protocol to study them.
Part of the book: Demystifying Polyneuropathy
The Proprioception in the Muscles Supplied by the Facial Nerve
Proprioception is a quality of somatosensibility that informs the central nervous system about the static and dynamics of muscles and joints. In muscles, the proprioceptive originates in the specialized sensory-organ-denominated muscle spindles. Nevertheless, facial muscles lack muscle spindles, but the facial proprioception plays key roles in the regulation and coordination of facial musculature and diverse reflexes. At the basis of these functional characteristics are the multiple communications between the facial and the trigeminal nerves, and neuroanatomical studies have demonstrated that facial proprioceptive impulses are conveyed via branches of the trigeminal nerve to the central nervous system. Substituting muscle spindles facial muscles contain other kinds of proprioceptors of variable morphology that display immunoreactivity for some putative mechanoproteins known to participate in proprioception (acid-sensing ion channel 2, transient receptor potential vanilloid 4, and Piezo2).
Part of the book: Selected Topics in Facial Nerve Disorders
Nonsurgical Strategies for the Treatment of Temporomandibular Joint Disorders
Temporomandibular disorders are common maxillofacial disturbs of different etiologies (traumatic, inflammatory, degenerative, or congenital) that course with pain and dysfunctions of the temporomandibular joint. The treatment of these disorders includes systematically administered drugs (especially nonsteroid anti-inflammatory drugs and corticoids), physical therapies, and minimally invasive therapies that require intraarticular injections. These techniques are directed to clean or drain the articular cavity, to deliver intraarticularly drugs, biologically active compounds (as platelet-rich plasma), or to enhance lubrication (hyaluronic acid). Moreover, minimally invasive strategies are used in regenerative medicine for to deliver cells and stem cells, and nano- or micro-biomaterials. Surgery of temporomandibular disorders is only used in grave diseases that require arthrodesis or remotion of the temporomandibular joint. This review updates the nonsurgical therapeutic strategies to treat temporomandibular disorders, focusing the attention in the articular delivery or hyaluronic acid and platelet-rich plasma, two minimally invasive widely used at present.
Part of the book: Cartilage Tissue Engineering and Regeneration Techniques
Proprioceptors in Cephalic Muscles
The proprioception from the head is mainly mediated via the trigeminal nerve and originates from special sensitive receptors located within muscles called proprioceptors. Only muscles innervated by the trigeminal nerve, and rarely some muscles supplied by the facial nerve, contain typical proprioceptors, i.e. muscle spindles. In the other cephalic muscles (at the exception of the extrinsic muscles of the eye) the muscle spindles are replaced by sensory nerve formations (of different morphologies and in different densities) and isolated nerve fibers expressing mechanproteins (especially PIEZO2) related to proprioception. This chapter examines the cephalic proprioceptors corresponding to the territories of the trigeminal, facial, glossopharyngeal and hypoglossal nerves.
Part of the book: Proprioception