Myotonia is delayed muscle relaxation after forceful contraction. It is due to hyperexcitability of the skeletal muscle membrane. It can arise from primary skeletal muscle ion channel dysfunction, involving chloride or sodium channels, but is also a prominent clinical feature in myotonic dystrophies where altered RNA splicing leads to secondary ion channel dysregulation amongst other systemic manifestations. Clinically, myotonia can range from delayed eye opening to a disabling symptom causing impaired mobility, functional difficulty and sometimes pain. It can also be a "hidden disability" with many patients feeling socially embarrassed by "looking healthy", yet being unable to do everyday physical tasks or to do them as effortlessly as their peers. It is a symptom that almost always indicates a genetic diagnosis, although it can occur in acquired conditions, including metabolic and drug-induced causes. To experience myotonia without knowing what it is can be baffling. To receive a genetic diagnosis associated with it can be life changing. Although there is no cure, there are many effective and available symptomatic treatments for myotonia and currently we are in an exciting era of clinical trials for new molecular disease-modifying therapies for myotonic dystrophy type 1. In this review, we consider recent developments in the treatment of myotonic disorders and how they may change clinical practice.

Falls, delirium and functional decline are commonly treated as distinct geriatric outcomes despite sharing vulnerabilities in sensory integration, gait regulation, attention and physiological reserve. We propose silent neurovestibular frailty as a conceptual model describing a latent ageing phenotype in which vestibular dysfunction, dual-task gait deterioration and sensitivity to cognitive load interact before overt disability becomes apparent. This construct is presented as a hypothesis-generating framework rather than a validated diagnostic entity, intended to integrate currently separate lines of evidence into a testable model. Vestibular impairment in later life is associated with balance deficits, mobility limitation and reduced functional reserve, whilst dual-task gait assessment may reveal cognitive-motor interference that remains undetected during routine walking evaluation, although dual-task cost may reflect impairment, strategic task prioritisation, or both. Delirium introduces additional clinical urgency because acute cognitive deterioration frequently develops in older adults with sensory impairment, immobility, multimorbidity, medication exposure and diminished adaptive reserve. We argue that vestibular function, dual-task mobility and cognition deserve coordinated assessment as a candidate translational risk triad for older adults vulnerable to falls, hospital-acquired delirium and accelerated functional decline, whilst recognising that prospective evidence validating this integrated phenotype is currently lacking. The model extends rather than replaces multifactorial fall prevention and provides an empirical agenda for operationalisation, validation and intervention testing across community, perioperative, inpatient and rehabilitation settings.

Inclusion body myopathy associated with Paget disease of bone (PDB) and/or frontotemporal dementia (IBMPFD) is characterized by adult-onset proximal and distal muscle weakness (clinically resembling a limb-girdle muscular dystrophy syndrome), early-onset PDB, and premature frontotemporal dementia (FTD). Muscle weakness progresses to involve other limb and respiratory muscles. PDB involves focal areas of increased bone turnover that typically lead to spine and/or hip pain and localized enlargement and deformity of the long bones; pathologic fractures occur on occasion. Early stages of FTD are characterized by dysnomia, dyscalculia, comprehension deficits, and paraphasic errors, with minimal impairment of episodic memory; later stages are characterized by inability to speak, auditory comprehension deficits for even one-step commands, alexia, and agraphia. Mean age at diagnosis for muscle disease and PDB is 42 years; for FTD, 56 years. Dilated cardiomyopathy, amyotrophic lateral sclerosis, and Parkinson disease are now known to be part of the spectrum of findings associated with IBMPFD.

PurposeThis study aimed to evaluate differences in diaphragm and deep abdominal muscle function between patients with ankylosing spondylitis (AS) and healthy controls and to examine their relationships with clinical parameters, including spinal mobility, quality of life, and balance performance.Materials and MethodsPatients with AS and healthy controls were included. Diaphragm and deep abdominal muscles were evaluated using two-dimensional ultrasonography. The clinical status of AS patients was assessed using ASDAS, BASDAI, BASFI, BASMI, and ASQoL. Static and dynamic balance were assessed with the NeuroCom Balance Master, including limits of stability (LOS) and sit-to-stand (STS) tests.Results30 AS patients (27 male, 3 female) and 33 healthy controls (27 male, 6 female) were assessed. Ultrasound measurements showed significant between-group differences in diaphragm thickness at end-expiration (p = 0.021), transversus abdominis (TrA) thickness at rest (p = 0.009), and TrA thickening fraction during the abdominal drawing-in maneuver (p = 0.010). AS patients demonstrated lower scores in several LOS and STS parameters compared with controls (p < 0.05). A significant negative correlation was found between the thickening fraction of the internal oblique muscle (TFIO) and ASQoL (r = -0.371, p < 0.05). TFIO showed positive correlations with BASMI (r = 0.439, p < 0.05) and tragus-to-wall distance (r = 0.461, p < 0.05). For the internal oblique muscle, resting thickness correlated positively with cervical rotation (r = 0.464, p < 0.01), while TFIO correlated negatively with cervical rotation (r = -0.571, p < 0.01).ConclusionAS patients exhibit greater diaphragm end-expiratory thickness and resting TrA thickness than controls; however, reduced TrA thickening fraction indicates functional impairment despite these structural changes.

ObjectiveSustained postural loading is a common contributor to neck-shoulder pain, yet its effects on muscle microvascular function and cervical segmental motion are not fully understood. This study investigated changes in muscle microcirculation and cervical intervertebral mobility in individuals with postural neck-shoulder pain and examined the effects of therapeutic stretching.MethodsThirty asymptomatic participants and thirty with neck-shoulder pain were assessed using laser-Doppler flowmetry and videofluoroscopy to measure blood flow in the sternocleidomastoid (SCM), upper trapezius (UT), and masseter (MA) muscles and spinal motion, respectively. The patient group participated in an 8-week supervised stretching intervention.ResultsCompared to asymptomatic controls, patients with neck-shoulder pain showed 7.3%-11.2% lower blood volume and 5.8%-13.6% lower blood speed in target muscles. Post-intervention, significant improvements were observed in blood volume (SCM: 71.26 ± 9.00, UT: 75.80 ± 27.22, MA: 83.78 ± 19.26 au) and speed (SCM: 16.09 ± 4.75, UT: 17.65 ± 6.83, MA: 24.55 ± 10.58 au; all p < 0.05). Intervertebral flexion/extension mobility from C2/3 to C6/7 also significantly improved.ConclusionsAlterations in muscle microcirculation may be associated with impaired cervical biomechanics in postural neck-shoulder pain. Combined assessment of local blood perfusion and intervertebral mobility may provide valuable insights into the underlying mechanisms and support the development of targeted rehabilitation strategies to patients experiencing postural neck-shoulder pain.