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Hematopoietic Stem Cell Therapy for Patients with Refractory Myasthenia Gravis
Published in Richard K. Burt, Alberto M. Marmont, Stem Cell Therapy for Autoimmune Disease, 2019
The diagnosis of MG is made by clinical manifestations, improvement to the anticholinesterase edrophonium chloride (Tensilon), and EMG. MG is characterized by weakness, often fluctuating, being worsened by exercise. Fatigue and weakness may occur in ocular, facial, bulbar, and/or limb muscles.9,10 Ocular ptosis, ophthalmoparesis, dysarthria, and dysphagia are common. In severe cases, respiratory muscles are affected. Electrophysiologic studies reveal loss of amplitude with repetitive nerve stimulation. Approximately 85% of patients with MG have anti-AChR antibodies. These patients may have other genetic or autoimmune-mediated problems with the nerve-muscle synapse. Achieving action potential threshold depends on clustering of the AChR at the motor endplate. A neuronal protein, agrin, activates muscle-specific kinase (MuSK) to cluster AChRs via rapsyn, a muscle cytoplasmic synapse protein (Fig. 1).24-26 Some MG patients without anti-AchR antibodies have antibodies to MuSK. Therefore, disruption of AChR clustering by either antibodies to AChR or MuSK results in the same clinical manifestations and EMG findings. MG must also be differentiated from other myasthenic syndromes such as Eaton Lambert syndrome, which is a malignancy-associated disorder with antibodies against PQ-type voltage-gated calcium channels.27 Eaton Lambert syndrome can be distinguished from MG by EMG.
Radiation-induced lung disease
Published in Philippe Camus, Edward C Rosenow, Drug-induced and Iatrogenic Respiratory Disease, 2010
Max M Weder, M Patricia Rivera
Cranial nerve palsy is a rare complication of radiation therapy for head and neck cancer. The latency period with which cranial nerve palsy occurs after completion of radiation treatment varies considerably and can be as long as 10 years.24 The hypoglossal, vagal and recurrent laryngeal nerves seem to be affected most frequently, resulting in hoarseness and dyspnoea due to vocal cord paralysis, dysphagia and dysarthria. Involvement of the other cranial nerves with either single or multiple cranial nerve involvement has also been described. Higher individual fraction size of the radiation dose may increase the risk of developing cranial nerve palsy. Since cranial nerve palsy is a common presentation of tumour recurrence and may also occur as a result of infectious and non-infectious disease processes, a thorough work-up needs to be conducted in these patients and radiation-induced cranial nerve palsy should be considered a diagnosis of exclusion.
Role of Metals in Neurodegeneration
Published in Debasis Bagchi, Manashi Bagchi, Metal Toxicology Handbook, 2020
Abhai Kumar, Smita Singh, Rameshwar Nath Chaurasia
Methylmercury (MeHg) is a xenobiotic toxic organic metal compound derived from inorganic mercury (Hg). The source of release of mercury in environment is through anthropogenic sources such as industrial waste, coal mining, natural sources such as volcanoes and forest fires that release back Hg into the atmosphere (44). Hg, which exudates in water, is readily methylated in MeHg by sulfate-reducing bacteria and a variety of other anerobic bacteria (45). MeHg has a high affinity for sulfur and can cross BBB by binding onto thiol groups of proteins; it can also bind to cysteine, allowing for the possibility of amino acid transporter (45). MeHg can accumulate in brain and was also responsible for epidemics at Minamata Bay and Iraq; children were presented with a variety of central nervous system (CNS) disorders, including ataxia, paralysis, retardation, dysarthria, dysesthesia, and cerebral palsy (46). Studies conducted with the families having high level of MeHg exposure found that their brain have accumulation of inorganic Hg; furthermore, cerebral and occipital lobe atrophy leads to vision and motor issue (46). The exposure of MeHg affects various cellular processes such as dopamine metabolism, neural stem cell differentiation and causes mitochondrial dysfunction by release of ROS and intracellular calcium influx (47). Further, MeHg exposure induces amyloid deposition in the hippocampus and decreases cerebrospinal fluid as hallmark of AD (48).The prevention strategies are more prevalent than treatment of MeHg exposure, government agencies has their own advisories for prevention of their respective population. The major source of entry of MeHg is through sea food, which has many confounding beneficial effect, this limits the understanding of MeHg neurotoxicity on human.
Neural network-based multi-view enhanced multi-learner active learning: theory and experiments
Published in Journal of Experimental & Theoretical Artificial Intelligence, 2022
Dysarthria is known as a neurological disability that affects the ability to control the muscles involved in articulation (Shahamiri & Binti Salim, 2014b) that may result in muscle paralysis and/or poor coordination among them. Dysarthric patients usually have difficulties with phonation and amplitude that compromise the speech signal and reduce its intelligibility (Caballero Morales & Cox, 2009; Selouani et al., 2009). In addition, typically, the patients are physically incapacitated, so that they are unable to use their hands properly to interact with computer-based systems using the typical human-computer interaction methods such as a mouse, keyboard, and/or touchscreen. ASR systems may be employed, instead, to facilitate their computer interactions by enabling dysarthric subjects to articulate their commands to the system through voice-enabled features (Asemi et al., 2018).
Interaction between people with dysarthria and speech recognition systems: A review
Published in Assistive Technology, 2023
Aisha Jaddoh, Fernando Loizides, Omer Rana
Poor articulation or pronunciation is another characteristic of dysarthria. Some studies have examined the correlations between consonants, vowels, and dysarthric speech. Findings on consonants show that pronouncing them is difficult for individuals with dysarthria. For instance, unvoiced consonants were pronounced improperly (Nordberg et al., 2014; Rudzicz, 2013). Similarly, problems with pronouncing vowels were mainly associated with mid-vowels – in which the tongue is positioned midway to the roof of the mouth – and front rounded vowels (Dhanalakshmi et al., 2018).