Twelve clinical pearls to help distinguish essential tremor from other tremors

Elan D Louis1

  • 1GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.

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Alterations in Muscle Tone lll01:11

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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...
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Alterations in Muscle Tone ll01:12

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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...
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Seizures: Classification

Epilepsy is primarily characterized by unpredictable seizures, either provoked by an identifiable factor, such as injury or illness, or unprovoked, occurring spontaneously without apparent cause.
Seizures are typically classified into two main categories: focal and generalized seizures.
Focal Seizures
Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types:
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Seizures are sudden bursts of abnormal electrical discharge in the brain that interfere with normal function. They are commonly divided into three groups: focal seizures, generalized seizures, and other types that do not fit neatly into either category.Focal SeizuresFocal seizures begin in a single brain region. When awareness is preserved, they are called focal aware seizures and may cause sensations such as tingling, unusual smells, or flashing lights. When awareness is impaired, they are...
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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...
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Myasthenia gravis is an autoimmune condition affecting neuromuscular transmission, causing generalized weakness in skeletal muscles. Initial diagnoses rely on patients' signs, symptoms, and medical history. The challenge lies in distinguishing myasthenia from other muscular dystrophies. An important diagnostic feature is the significant improvement of symptoms after administering anticholinesterase inhibitors.
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