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Open Medicine (Warsaw, Poland) 2022Amyotrophic lateral sclerosis (ALS) is a fatal, multisystem neurodegenerative disease that causes the death of motoneurons (MNs) progressively and eventually leads to... (Review)
Review
Amyotrophic lateral sclerosis (ALS) is a fatal, multisystem neurodegenerative disease that causes the death of motoneurons (MNs) progressively and eventually leads to paralysis. In contrast, delayed onset muscle soreness (DOMS) is defined as delayed onset soreness, muscle stiffness, loss of force-generating capacity, reduced joint range of motion, and decreased proprioceptive function. Sensory deficits and impaired proprioception are common symptoms of both ALS and DOMS, as impairment at the proprioceptive sensory terminals in the muscle spindle is theorized to occur in both. The important clinical distinction is that extraocular muscles (EOM) are relatively spared in ALS, in contrast to limb skeletal muscles; however, the blink reflex goes through a gradual impairment in a later stage of disease progression. Noteworthy is, that, the stretch of EOM induces the blink reflex. The current authors suggest that the impairment of proprioceptive sensory nerve terminals in the EOM muscle spindles are partially responsible for lower blink reflex, beyond central origin, and implies the critical role of Piezo2 ion channels and Wnt-PIP2 signaling in this pathomechanism. The proposed microinjury of Piezo2 on muscle spindle proprioceptive terminals could provide an explanation for the painless dying-back noncontact injury mechanism theory of ALS.
PubMed: 35340618
DOI: 10.1515/med-2022-0444 -
Cureus Dec 2022Leiomyosarcomas are rare malignant mesenchymal neoplasms originating from smooth muscle cells. Although leiomyosarcoma is commonly located in the female reproductive...
Leiomyosarcomas are rare malignant mesenchymal neoplasms originating from smooth muscle cells. Although leiomyosarcoma is commonly located in the female reproductive system, gastrointestinal tract, and subcutaneous tissues, it is a rare entry in the head and neck area, probably due to the scarcity of smooth muscle tissue in this topographical region. Herein we present a histopathological case report of a 60-year-old male with a slow-growing painless mass on the middle third of the right lateral lingual margin, with focal ulceration measuring 1x1.5cm. After gross excision, histopathology revealed pleomorphic spindle cells, some with bizarre nuclei and abundant pathological mitotic activity with a tendency to grow in a fascicular pattern. As the patient had the demographic characteristic and risk factors for oral cavity squamous cell carcinoma, a spindle-shaped variety (sarcomatoid) variety was suspected, and immunohistochemistry with a broad set of antibodies was used to prove the histogenetic group of the tumor. As the tumor was pan-cytokeratin and desmin negative, focally positive for caldesmon, and positive for smooth muscle actin, the diagnosis of pleomorphic leiomyosarcoma of the tongue was established.
PubMed: 36686144
DOI: 10.7759/cureus.32717 -
Advancements in the diagnosis and treatment of renal epithelioid angiomyolipoma: A narrative review.The Kaohsiung Journal of Medical... Oct 2022Renal epithelioid angiomyolipoma (EAML) is a unique subtype of angiomyolipoma that contains a variety of cytoplasmic-rich, eosinophilic cytoplasm epithelioid cells in... (Review)
Review
Renal epithelioid angiomyolipoma (EAML) is a unique subtype of angiomyolipoma that contains a variety of cytoplasmic-rich, eosinophilic cytoplasm epithelioid cells in addition to mature adipocytes, hyaline thick-walled vessels, and smooth muscle-like spindle cells. In recent years, increasing evidence has shown that EAML is a potentially malignant tumor. Due to the lack of typical clinical manifestations and imaging features, it is difficult to diagnose before surgery, and the diagnosis mainly depends on postoperative histopathological examination. With the advancement of pathological diagnostic techniques, more EAML cases has been discovered, but clinicians still lack a comprehensive understanding of EAML. This review comprehensively describes some pathological and clinical features of EAML, with special attention to the pathogenesis and treatment of malignant EAML in order to assist with clinical diagnosis and treatment.
Topics: Angiomyolipoma; Epithelioid Cells; Humans; Kidney Neoplasms
PubMed: 36056704
DOI: 10.1002/kjm2.12586 -
Journal of Manipulative and... Jun 2021The purpose of this study was to characterize trunk muscle spindle responses immediately after high-velocity, low-amplitude spinal manipulation (HVLA-SM) delivered at...
OBJECTIVE
The purpose of this study was to characterize trunk muscle spindle responses immediately after high-velocity, low-amplitude spinal manipulation (HVLA-SM) delivered at various thrust magnitudes and thrust durations.
METHODS
Secondary analysis from multiple studies involving anesthetized adult cats (N = 70; 2.3-6.0 kg) receiving L6 HVLA-SM. Muscle spindle afferent recordings were obtained from L6 dorsal rootlets before, during, and immediately after HVLA-SM. L6 HVLA-SM was delivered posteriorly-to-anteriorly using a feedback motor with peak thrust magnitudes of 25%, 55%, and 85% of cat body weight (BW) and thrust durations of 25, 50, 75, 100, 150, 200, and 250 ms. Time to the first action potential and muscle spindle discharge frequency at 1 and 2 seconds post-HVLA-SM were determined.
RESULTS
A significant association between HVLA-SM thrust magnitude and immediate (≤2 s) muscle spindle response was found (P < .001). For non-control thrust magnitude, pairwise comparisons (25%, 55%, 85% BW), 55% BW thrust magnitude had the most consistent effect on immediate post-HVLA-SM discharge outcomes (false discovery rate < 0.05). No significant association was found between thrust duration and immediate post-HVLA-SM muscle spindle response (P > .05).
CONCLUSION
The present study found that HVLA-SM thrust magnitudes delivered at 55% BW were more likely to affect immediate (≤2 s) post-HVLA-SM muscle spindle response.
Topics: Animals; Cats; Manipulation, Spinal; Muscle Spindles; Muscle, Skeletal; Spinal Nerve Roots; Torso
PubMed: 34103172
DOI: 10.1016/j.jmpt.2021.03.004 -
Acta Neuropathologica Communications Dec 2022Oculopharyngodistal myopathy (OPDM) and oculopharyngeal muscular dystrophy (OPMD) are similar and even believed to be indistinguishable in terms of their myopathological...
Oculopharyngodistal myopathy (OPDM) and oculopharyngeal muscular dystrophy (OPMD) are similar and even believed to be indistinguishable in terms of their myopathological features. To address the diagnostic gap, we evaluated the muscle biopsy samples for p62 expression by immunohistochemistry and compared the occurrence and the frequency of intranuclear inclusions among the individuals with OPDM (harboring CGG repeat expansion in LRP12 (n = 19), GIPC1 (n = 6), or NOTCH2NLC (n = 7)), OPMD (n = 15), and other rimmed vacuolar myopathies. We found that myonuclei with p62-positive intra-nuclear inclusions (myo-INIs) were significantly more frequent in OPMD (11.9 ± 1.1%, range 5.9-18.6%) than in OPDM and other rimmed vacuolar myopathies (RVMs) (0.9-1.5% on average, range 0.0-2.8%, p < 0.0001). In contrast, INIs in non-muscle cells such as blood vessels, peripheral nerve bundles, and muscle spindles (non-muscle-INIs) were present in OPDM, but absent in OPMD. These results indicate that OPMD can be differentiated from OPDM and other RVMs by the frequent presence of myo-INIs; and in OPDM, the presence of non-muscle-INIs in muscle pathology should be a diagnostic hallmark.
Topics: Humans; Muscular Dystrophy, Oculopharyngeal; Intranuclear Inclusion Bodies
PubMed: 36476314
DOI: 10.1186/s40478-022-01482-w -
Ear, Nose, & Throat Journal Jan 2024Solitary myofibroma or infantile myofibroma is a rare spindle cell neoplasm that generally affects infants before the age of 2 years but cases in young children and...
Solitary myofibroma or infantile myofibroma is a rare spindle cell neoplasm that generally affects infants before the age of 2 years but cases in young children and adults have been described. Although the location of infantile myofibroma in the oral and maxillofacial region has been described, the intramasseteric location of the lesion is very uncommon. A thorough assessment of histopathological and immunohistochemical characteristics is necessary to have a correct diagnosis. Treatment relies on surgical resection. In this article, we present a rare clinical case of a 15-year-old patient with a myofibroma of the masseteric muscle and its management.
PubMed: 38284156
DOI: 10.1177/01455613231223378 -
Turkish Journal of Physical Medicine... Mar 2023The aim of this research was to examine whether high-frequency whole-body vibration activates the tonic vibration reflex (TVR).
OBJECTIVES
The aim of this research was to examine whether high-frequency whole-body vibration activates the tonic vibration reflex (TVR).
PATIENTS AND METHODS
The experimental study was conducted with seven volunteers (mean age: 30.8±3.3 years; range, 26 to 35 years) between December 2021 and January 2022. To elicit soleus TVR, high-frequency (100-150 Hz) vibration was applied to the Achilles tendon. High-frequency (100-150 Hz) whole-body vibration and low-frequency (30-40 Hz) whole-body vibration were applied in quiet standing. Whole-body vibration-induced reflexes were recorded from the soleus muscle using surface electromyography. The cumulative average method was used to determine the reflex latencies.
RESULTS
Soleus TVR latency was 35.6±5.9 msec, the latency of the reflex activated by high-frequency whole-body vibration was 34.8±6.2 msec, and the latency of the reflex activated by low-frequency whole-body vibration was 42.8±3.4 msec (F=40.07, p=0.0001, ƞ =0.87). The low-frequency whole-body vibration-induced reflex latency was significantly longer than high-frequency whole-body vibration-induced reflex latency and TVR latency (p=0.002 and p=0.001, respectively). High-frequency whole-body vibration-induced reflex latency and TVR latency were found to be similar (p=0.526).
CONCLUSION
This study showed that high-frequency whole-body vibration activates TVR.
PubMed: 37201009
DOI: 10.5606/tftrd.2023.10854 -
Experimental Brain Research Apr 2022Muscle spindle afferent feedback is modulated during different phases of locomotor tasks in a way that facilitates task goals. However, only a few studies have studied...
Muscle spindle afferent feedback is modulated during different phases of locomotor tasks in a way that facilitates task goals. However, only a few studies have studied H-reflex modulation during landing. This study aimed to characterize soleus (SOL) H-reflex modulation during the flight and early landing period of drop landings. Since landing presumably involves a massive increase in spindle afferent firing due to rapid SOL muscle stretching, we hypothesized H-reflex size would decrease near landing reflecting neural modulation to prevent excessive motoneuron excitation. The soleus H-reflex was recorded during drop landings from a 30 cm height in nine healthy adults. Electromyography (SOL, tibialis anterior (TA), medial gastrocnemius, and vastus lateralis), ankle and knee joint motion and ground reaction force were recorded during landings. Tibial nerve stimulation was timed to elicit H-reflexes during the flight and early ground contact period (five 30 ms Bins from 90 ms before to 60 ms after landing). The H-reflexes recorded after landing (0-30 and 30-60 ms) were significantly smaller (21-36% less) than that recorded during the flight periods (90-0 ms before ground contact; P ≤ 0.004). The decrease in H-reflex size not occurring until after ground contact indicates a time-critical modulation of reflex gain during the last 30 ms of flight (i.e., time of tibial nerve stimulation). H-reflex size reduction after ground contact supports a probable neural strategy to prevent excessive reflex-mediated muscle activation and thereby facilitates appropriate musculotendon and joint stiffness.
Topics: Adult; Ankle Joint; Electromyography; H-Reflex; Humans; Muscle Spindles; Muscle, Skeletal
PubMed: 35122483
DOI: 10.1007/s00221-022-06316-8 -
The Journal of Physiology Apr 2020Muscular dystrophy patients suffer from progressive degeneration of skeletal muscle fibres, sudden spontaneous falls, balance problems, as well as gait and posture...
KEY POINTS
Muscular dystrophy patients suffer from progressive degeneration of skeletal muscle fibres, sudden spontaneous falls, balance problems, as well as gait and posture abnormalities. Dystrophin- and dysferlin-deficient mice, models for different types of muscular dystrophy with different aetiology and molecular basis, were characterized to investigate if muscle spindle structure and function are impaired. The number and morphology of muscle spindles were unaltered in both dystrophic mouse lines but muscle spindle resting discharge and their responses to stretch were altered. In dystrophin-deficient muscle spindles, the expression of the paralogue utrophin was substantially upregulated, potentially compensating for the dystrophin deficiency. The results suggest that muscle spindles might contribute to the motor problems observed in patients with muscular dystrophy.
ABSTRACT
Muscular dystrophies comprise a heterogeneous group of hereditary diseases characterized by progressive degeneration of extrafusal muscle fibres as well as unstable gait and frequent falls. To investigate if muscle spindle function is impaired, we analysed their number, morphology and function in wildtype mice and in murine model systems for two distinct types of muscular dystrophy with very different disease aetiology, i.e. dystrophin- and dysferlin-deficient mice. The total number and the overall structure of muscle spindles in soleus muscles of both dystrophic mouse mutants appeared unchanged. Immunohistochemical analyses of wildtype muscle spindles revealed a concentration of dystrophin and β-dystroglycan in intrafusal fibres outside the region of contact with the sensory neuron. While utrophin was absent from the central part of intrafusal fibres of wildtype mice, it was substantially upregulated in dystrophin-deficient mice. Single-unit extracellular recordings of sensory afferents from muscle spindles of the extensor digitorum longus muscle revealed that muscle spindles from both dystrophic mouse strains have an increased resting discharge and a higher action potential firing rate during sinusoidal vibrations, particularly at low frequencies. The response to ramp-and-hold stretches appeared unaltered compared to the respective wildtype mice. We observed no exacerbated functional changes in dystrophin and dysferlin double mutant mice compared to the single mutant animals. These results show alterations in muscle spindle afferent responses in both dystrophic mouse lines, which might cause an increased muscle tone, and might contribute to the unstable gait and frequent falls observed in patients with muscular dystrophy.
Topics: Animals; Disease Models, Animal; Dystrophin; Humans; Mice; Mice, Inbred mdx; Muscle Spindles; Muscle, Skeletal; Muscular Dystrophies; Muscular Dystrophy, Animal; Utrophin
PubMed: 32003874
DOI: 10.1113/JP278563 -
International Journal of Oral Science Sep 2023Dental primary afferent (DPA) neurons and proprioceptive mesencephalic trigeminal nucleus (MTN) neurons, located in the trigeminal ganglion and the brainstem,...
Dental primary afferent (DPA) neurons and proprioceptive mesencephalic trigeminal nucleus (MTN) neurons, located in the trigeminal ganglion and the brainstem, respectively, are essential for controlling masticatory functions. Despite extensive transcriptomic studies on various somatosensory neurons, there is still a lack of knowledge about the molecular identities of these populations due to technical challenges in their circuit-validated isolation. Here, we employed high-depth single-cell RNA sequencing (scRNA-seq) in combination with retrograde tracing in mice to identify intrinsic transcriptional features of DPA and MTN neurons. Our transcriptome analysis revealed five major types of DPA neurons with cell type-specific gene enrichment, some of which exhibit unique mechano-nociceptive properties capable of transmitting nociception in response to innocuous mechanical stimuli in the teeth. Furthermore, we discovered cellular heterogeneity within MTN neurons that potentially contribute to their responsiveness to mechanical stretch in the masseter muscle spindles. Additionally, DPA and MTN neurons represented sensory compartments with distinct molecular profiles characterized by various ion channels, receptors, neuropeptides, and mechanoreceptors. Together, our study provides new biological insights regarding the highly specialized mechanosensory functions of DPA and MTN neurons in pain and proprioception.
Topics: Animals; Mice; Neurons; Proprioception; Gene Expression Profiling; Pain; Sequence Analysis, RNA
PubMed: 37749100
DOI: 10.1038/s41368-023-00246-z