Tick paralysis

Cara Ann Pecina1

  • 1Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA. pecinaca@ucmail.uc.edu

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Alterations in Muscle Tone ll01:12

Alterations in Muscle Tone ll

Alterations in muscle tone are common manifestations of neurological disorders and reflect dysfunction within different nervous system regions. Spasticity, paratonia, and dystonia represent distinct forms of hypertonia, each with unique mechanisms, clinical features, and diagnostic importance.CharacteristicsSpasticity happens from upper motor neuron lesions and is characterized by velocity-dependent resistance to passive movement. Clinical features include:Exaggerated deep tendon reflexesClonus...
Alterations in Muscle Tone lll01:11

Alterations in Muscle Tone lll

Rigidity and myotonia are distinct abnormalities of muscle tone that affect resistance and relaxation during movement. Although both involve altered muscle contraction, they arise from different neurological and muscular mechanisms.CharacteristicsRigidity is characterized by uniform resistance to passive movement across the entire range, independent of speed, affecting flexors and extensors equally. It may appear as lead-pipe rigidity (smooth, constant resistance) or cogwheel rigidity...
Depolarizing Blockers: Mechanism of Action01:28

Depolarizing Blockers: Mechanism of Action

Depolarizing blockers act on skeletal muscle fibers' membranes and induce their depolarization. Most depolarizing blockers have two quaternary N+ atoms that bind the nicotinic acetylcholine receptors and cause neuromuscular blockade within minutes.
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
Muscle Stimulation Frequency01:22

Muscle Stimulation Frequency

The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Restless Leg Syndrome and Night Terrors01:27

Restless Leg Syndrome and Night Terrors

Restless Leg Syndrome (RLS), also known as Willis-Ekbom disease, is a neurological disorder characterized by an uncontrollable urge to move the legs due to uncomfortable sensations. These sensations typically occur during periods of rest or inactivity, particularly when lying down or sitting, and can severely disrupt sleep.
The exact cause of RLS is not fully understood, but it is believed to involve dopamine, a neurotransmitter that helps regulate muscle movement. Imbalances in dopamine levels...
Diphtheria01:28

Diphtheria

Diphtheria is an acute, toxin-mediated infectious disease that primarily affects the upper respiratory tract. It is caused by Corynebacterium diphtheriae, a Gram-positive, pleomorphic rod that lacks spore-forming capability and exhibits a characteristic club-shaped morphology under microscopic examination. While C. diphtheriae can asymptomatically colonize mucosal surfaces, clinical disease manifests only when the bacterial strain is lysogenized by a specific β-corynephage. This phage...