Myokymia
Fasciculation
Facial Nerve Diseases
Kv1.1 Potassium Channel
Isaacs Syndrome
Epilepsy, Benign Neonatal
Facial Muscles
KCNQ2 Potassium Channel
Cerebellar Ataxia
Electromyography
Encyclopedias as Topic
Brain Stem Neoplasms
Paraneoplastic Syndromes, Nervous System
Potassium current suppression in patients with peripheral nerve hyperexcitability. (1/12)
Acquired neuromyotonia (Isaac's syndrome) is considered to be an autoimmune disease, and the pathomechanism of nerve hyperexcitability in this syndrome is correlated with anti-voltage-gated K(+) channel (VGKC) antibodies. The patch-clamp technique was used to investigate the effects of immunoglobulins from acquired neuromyotonia patients on VGKCs and voltage-gated Na(+) channels in a human neuroblastoma cell line (NB-1). K(+) currents were suppressed in cells that had been co-cultured with acquired neuromyotonia patients' immunoglobulin for 3 days but not for 1 day. The activation and inactivation kinetics of the outward K(+) currents were not altered by these immunoglobulins, nor did the immunoglobulins significantly affect the Na(+) currents. Myokymia or myokymic discharges, with peripheral nerve hyperexcitability, also occur in various neurological disorders such as Guillain-Barre syndrome and idiopathic generalized myokymia without pseudomyotonia. Immuno-globulins from patients with these diseases suppressed K(+) but not Na(+) currents. In addition, in hKv 1.1- and 1.6-transfected CHO (Chinese hamster ovary)-K1 cells, the expressed VGKCs were suppressed by sera from acquired neuromyotonia patients without a change in gating kinetics. Our findings indicate that nerve hyperexcitability is mainly associated with the suppression of voltage-gated K(+) currents with no change in gating kinetics, and that this suppression occurs not only in acquired neuromyotonia but also in Guillain-Barre syndrome and idiopathic generalized myokymia without pseudomyotonia. (+info)Myokymia and neonatal epilepsy caused by a mutation in the voltage sensor of the KCNQ2 K+ channel. (2/12)
KCNQ2 and KCNQ3 are two homologous K(+) channel subunits that can combine to form heterotetrameric channels with properties of neuronal M channels. Loss-of-function mutations in either subunit can lead to benign familial neonatal convulsions (BFNC), a generalized, idiopathic epilepsy of the newborn. We now describe a syndrome in which BFNC is followed later in life by myokymia, involuntary contractions of skeletal muscles. All affected members of the myokymia/BFNC family carried a mutation (R207W) that neutralized a charged amino acid in the S4 voltage-sensor segment of KCNQ2. This substitution led to a shift of voltage-dependent activation of KCNQ2 and a dramatic slowing of activation upon depolarization. Myokymia is thought to result from hyperexcitability of the lower motoneuron, and indeed both KCNQ2 and KCNQ3 mRNAs were detected in the anterior horn of the spinal cord where the cells of the lower motoneurons arise. We propose that a difference in firing patterns between motoneurons and central neurons, combined with the drastically slowed voltage activation of the R207W mutant, explains why this particular KCNQ2 mutant causes myokymia in addition to BFNC. (+info)Morvan's syndrome: peripheral and central nervous system and cardiac involvement with antibodies to voltage-gated potassium channels. (3/12)
Morvan's 'fibrillary chorea' or Morvan's syndrome is characterized by neuromyotonia (NMT), pain, hyperhydrosis, weight loss, severe insomnia and hallucinations. We describe a man aged 76 years with NMT, dysautonomia, cardiac arrhythmia, lack of slow-wave sleep and abnormal rapid eye movement sleep. He had raised serum antibodies to voltage-gated K(+) channels (VGKC), oligoclonal bands in his CSF, markedly increased serum norepinephrine, increased serum cortisol and reduced levels and absent circadian rhythms of prolactin and melatonin. The neurohormonal findings and many of the clinical features were very similar to those in fatal familial insomnia, a hereditary prion disease that is associated with thalamic degenerative changes. Strikingly, however, all symptoms in our MFC patient improved with plasma exchange. The patient died unexpectedly 11 months later. At autopsy, there was a pulmonary adenocarcinoma, but brain pathology showed only a microinfarct in the hippocampus and no thalamic changes. The NMT and some of the autonomic features are likely to be directly related to the VGKC antibodies acting in the periphery. The central symptoms might also be due to the direct effects of VGKC antibodies, or perhaps of other autoantibodies still to be defined, on the limbic system with secondary effects on neurohormone levels. Alternatively, changes in secretion of neurohormones in the periphery might contribute to the central disturbance. The relationship between VGKC antibodies, neurohormonal levels, autonomic, limbic and sleep disorders requires further study. (+info)X-linked Charcot-Marie-Tooth disease with myokymia: report of a family. (4/12)
The clinical and electrophysiologic profiles of two brothers suffering from Charcot-Marie-Tooth disease are presented. Both had widespread muscle twitching in the legs which showed electrophysiologic features of myokymia. Pedigree analysis suggested an x-linked recessive form of inheritance. This appears to be the first report of an Indian family with x-linked Charcot-Marie-Tooth disease. (+info)KCNQ2 is a nodal K+ channel. (5/12)
Mutations in the gene encoding the K+ channel KCNQ2 cause neonatal epilepsy and myokymia, indicating that KCNQ2 regulates the excitability of CNS neurons and motor axons, respectively. We show here that KCNQ2 channels are functional components of axon initial segments and nodes of Ranvier, colocalizing with ankyrin-G and voltage-dependent Na+ channels throughout the CNS and PNS. Retigabine, which opens KCNQ channels, diminishes axonal excitability. Linopirdine, which blocks KCNQ channels, prolongs the repolarization of the action potential in neonatal nerves. The clustering of KCNQ2 at nodes and initial segments lags that of ankyrin-G during development, and both ankyrin-G and KCNQ2 can be coimmunoprecipitated in the brain. KCNQ3 is also a component of some initial segments and nodes in the brain. The diminished activity of mutant KCNQ2 channels accounts for neonatal epilepsy and myokymia; the cellular locus of these effects may be axonal initial segments and nodes. (+info)Agrypnia excitata in a patient with progeroid short stature and pigmented Nevi (Mulvihill-Smith syndrome). (6/12)
We report the video-polysomnographic sleep characteristics of a 25-year-old woman with the Mulvihill-Smith syndrome, a rare clinical condition characterized by progeria-like aspect, peculiar multiple pigmented nevi, low stature, and cognitive impairment. Among the various exams, two overnight video-polysomnographic recordings were carried out; moreover, cerebral MRI and molecular analysis of the prion protein gene (PRNP) were also performed. The video-polysomnographic recordings showed the absence of clear sleep episodes but the presence of periods during which the patient had poor contact with the environment, stereotyped afinalistic movements of the upper limbs and hands, irregular or periodic breathing (with central apnea episodes), heart rate arrhythmia, and rapid eye movements. Cerebral MRI showed only diffuse mild enlargement of the cortical sulci and the molecular genetics analysis of the PRNP was normal. Our clinical and neurophysiological study seems to indicate that a particular condition of severe sleep disruption, similar to some extent to that reported in the fatal familial insomnia and in the Morvan fibrillary chorea, which has been indicated as Agrypnia Excitata in recent literature, might be associated with the Mulvihill-Smith syndrome. The inclusion of a detailed study on the sleep characteristics of eventual additional patients will certainly help our understanding of this rare condition. (+info)Functional analysis of a novel potassium channel (KCNA1) mutation in hereditary myokymia. (7/12)
Myokymia is characterized by spontaneous, involuntary muscle fiber group contraction visible as vermiform movement of the overlying skin. Myokymia with episodic ataxia is a rare, autosomal dominant trait caused by mutations in KCNA1, encoding a voltage-gated potassium channel. In the present study, we report a family with four members affected with myokymia. Additional clinical features included motor delay initially diagnosed as cerebral palsy, worsening with febrile illness, persistent extensor plantar reflex, and absence of epilepsy or episodic ataxia. Mutation analysis revealed a novel c.676C>A substitution in the potassium channel gene KCNA1, resulting in a T226K nonconservative missense mutation in the Kv1.1 subunit in all affected individuals. Electrophysiological studies of the mutant channel expressed in Xenopus oocytes indicated a loss of function. Co-expression of WT and mutant cRNAs significantly reduced whole-oocyte current compared to expression of WT Kv1.1 alone. (+info)An interesting case report of Morvan's syndrome from the Indian subcontinent. (8/12)
The French physician Augustine Marie Morvan first used the term 'la choriotae fibrillare' to describe a syndrome characterized by peripheral nerve hyperexcitability, dysautonomia, insomnia and fluctuating delirium. There are no published reports of the condition from the Indian subcontinent. We report the first such case from the region. Our patient, a 24-year-old male, presented with easy fatigability and stiffness in both the calves for 18 months; continuous twitching of muscles of all four limbs and jaw for two months; hyperhydrosis, palpitations, urinary symptoms, burning dysesthesia in hands, insomnia and abnormal sleep behavior for about a month. Patient had bilateral hyper-reflexia with extensor plantar on the right and equivocal response on the left. Electromyography revealed continuous muscle fiber activity. Thyroid function test, electroencephalography, computerized tomography scan (head) and routine cerebrospinal fluid analysis were normal. The patient showed marked clinical and electrophysiological improvement on prednisolone along with symptomatic therapy over the next two months. (+info)Myokymia is a medical term that refers to the involuntary, fine, worm-like muscle fasciculations or contractions, often described as "bag of worms" movement, seen beneath the skin. These rhythmic, persistent muscle twitches typically occur in small areas of a muscle and can be visible under the skin. Myokymia is generally not painful but can cause cosmetic concerns or discomfort due to the continuous movement.
Myokymia can result from various factors, including nerve injury, nerve compression, metabolic disorders, vitamin deficiencies, or certain medications. In some cases, it may be a symptom of neurological conditions like multiple sclerosis, motor neuron disease, or brainstem tumors. However, isolated myokymia is often idiopathic and not associated with any underlying medical condition.
It's essential to consult a healthcare professional if you experience persistent or worsening myokymia, as they can help determine the cause and recommend appropriate treatment options.
A fasciculation is an involuntary muscle contraction and relaxation that occurs randomly and spontaneously, causing a visible twitching of the muscle. Fasciculations can occur in any skeletal muscle of the body and are often described as feeling like a "mini-charley horse." They are generally harmless and can occur in people without any underlying neurological conditions. However, they can also be a symptom of certain neuromuscular disorders, such as amyotrophic lateral sclerosis (ALS) or motor neuron disease. In these cases, fasciculations are often accompanied by other symptoms, such as muscle weakness, atrophy, and cramping. If you are experiencing persistent or frequent fasciculations, it is important to consult with a healthcare professional for further evaluation and diagnosis.
Facial nerve diseases refer to a group of medical conditions that affect the function of the facial nerve, also known as the seventh cranial nerve. This nerve is responsible for controlling the muscles of facial expression, and it also carries sensory information from the taste buds in the front two-thirds of the tongue, and regulates saliva flow and tear production.
Facial nerve diseases can cause a variety of symptoms, depending on the specific location and extent of the nerve damage. Common symptoms include:
* Facial weakness or paralysis on one or both sides of the face
* Drooping of the eyelid and corner of the mouth
* Difficulty closing the eye or keeping it closed
* Changes in taste sensation or dryness of the mouth and eyes
* Abnormal sensitivity to sound (hyperacusis)
* Twitching or spasms of the facial muscles
Facial nerve diseases can be caused by a variety of factors, including:
* Infections such as Bell's palsy, Ramsay Hunt syndrome, and Lyme disease
* Trauma or injury to the face or skull
* Tumors that compress or invade the facial nerve
* Neurological conditions such as multiple sclerosis or Guillain-Barre syndrome
* Genetic disorders such as Moebius syndrome or hemifacial microsomia
Treatment for facial nerve diseases depends on the underlying cause and severity of the symptoms. In some cases, medication, physical therapy, or surgery may be necessary to restore function and relieve symptoms.
Kv1.1 potassium channel, also known as KCNA1, is a type of voltage-gated potassium channel that plays a crucial role in the regulation of electrical excitability in neurons and other excitable cells. It is encoded by the KCNA1 gene located on chromosome 12p13.
The Kv1.1 channel is composed of four α-subunits, each containing six transmembrane domains with a pore-forming region between the fifth and sixth domains. These channels are responsible for the rapid repolarization of action potentials in neurons, which helps to control the frequency and pattern of neural activity.
Mutations in the KCNA1 gene have been associated with various neurological disorders, including episodic ataxia type 1 (EA1) and familial hemiplegic migraine (FHM). EA1 is characterized by brief episodes of cerebellar ataxia, myokymia, and neuromyotonia, while FHM is a severe form of migraine with aura that can cause temporary paralysis on one side of the body.
Overall, Kv1.1 potassium channels play an essential role in maintaining normal neural excitability and are critical for proper neurological function.
Isaac's syndrome, also known as neuromyotonia, is a rare neurological disorder characterized by continuous muscle fiber activity leading to stiffness, cramps, and delayed relaxation after contraction. This condition results from hyperexcitability of the peripheral nerves due to dysfunction of voltage-gated potassium channels.
The symptoms may include:
1. Muscle stiffness (rigidity)
2. Muscle twitching or cramping (myokymia)
3. Delayed relaxation after contraction (percussion myotonia)
4. Involuntary muscle activity (neuromyotonia)
5. Hyperhidrosis (excessive sweating)
6. Paresthesias (abnormal sensations)
Isaac's syndrome can be associated with other conditions, such as autoimmune disorders, paraneoplastic syndromes, or genetic factors. The diagnosis typically involves clinical examination, electromyography (EMG), and nerve conduction studies. Treatment options may include medications that reduce neuronal excitability, such as anticonvulsants, plasma exchange, or intravenous immunoglobulin therapy.
Benign neonatal epilepsy is a rare and specific type of epilepsy that affects newborns within the first few days of life. The term "benign" in this context refers to the relatively favorable prognosis compared to other forms of neonatal epilepsy, rather than the severity of the seizures themselves.
The condition is typically characterized by the presence of brief, recurrent seizures that may appear as repetitive jerking movements, staring spells, or subtle changes in muscle tone or behavior. These seizures are often triggered by routine handling or stimulation and can be difficult to distinguish from normal newborn behaviors, making diagnosis challenging.
Benign neonatal epilepsy is typically associated with specific genetic mutations that affect the electrical activity of brain cells. The most common form of this condition, known as Benign Familial Neonatal Epilepsy (BFNE), is caused by mutations in genes such as KCNQ2 or KCNQ3, which encode potassium channels in neurons.
While the seizures associated with benign neonatal epilepsy can be alarming, they are generally not harmful to the developing brain and tend to resolve on their own within a few months. Treatment is often focused on managing the seizures with antiepileptic medications to reduce their frequency and severity, although some infants may require no treatment at all.
Overall, while benign neonatal epilepsy can be a concerning condition for parents and caregivers, its favorable prognosis and relatively mild impact on long-term neurological development make it one of the more manageable forms of neonatal epilepsy.
Facial muscles, also known as facial nerves or cranial nerve VII, are a group of muscles responsible for various expressions and movements of the face. These muscles include:
1. Orbicularis oculi: muscle that closes the eyelid and raises the upper eyelid
2. Corrugator supercilii: muscle that pulls the eyebrows down and inward, forming wrinkles on the forehead
3. Frontalis: muscle that raises the eyebrows and forms horizontal wrinkles on the forehead
4. Procerus: muscle that pulls the medial ends of the eyebrows downward, forming vertical wrinkles between the eyebrows
5. Nasalis: muscle that compresses or dilates the nostrils
6. Depressor septi: muscle that pulls down the tip of the nose
7. Levator labii superioris alaeque nasi: muscle that raises the upper lip and flares the nostrils
8. Levator labii superioris: muscle that raises the upper lip
9. Zygomaticus major: muscle that raises the corner of the mouth, producing a smile
10. Zygomaticus minor: muscle that raises the nasolabial fold and corner of the mouth
11. Risorius: muscle that pulls the angle of the mouth laterally, producing a smile
12. Depressor anguli oris: muscle that pulls down the angle of the mouth
13. Mentalis: muscle that raises the lower lip and forms wrinkles on the chin
14. Buccinator: muscle that retracts the cheek and helps with chewing
15. Platysma: muscle that depresses the corner of the mouth and wrinkles the skin of the neck.
These muscles are innervated by the facial nerve, which arises from the brainstem and exits the skull through the stylomastoid foramen. Damage to the facial nerve can result in facial paralysis or weakness on one or both sides of the face.
KCNQ2 potassium channel, also known as Kv7.2 channel, is a type of voltage-gated potassium channel that plays a crucial role in regulating the electrical excitability of neurons. The channel is composed of four KCNQ2 subunits and can form heteromeric complexes with KCNQ3 subunits to form the M-current, which helps to set the resting membrane potential and control the firing frequency of action potentials in neurons.
Mutations in the KCNQ2 gene have been associated with a variety of neurological disorders, including benign familial neonatal seizures (BFNS), epileptic encephalopathy, and intellectual disability. These mutations can alter the function or expression of the KCNQ2 channel, leading to abnormal neuronal excitability and seizure activity.
In summary, KCNQ2 potassium channel is a type of voltage-gated potassium channel that helps regulate the electrical excitability of neurons and has been implicated in several neurological disorders when its function is altered due to genetic mutations.
Cerebellar ataxia is a type of ataxia, which refers to a group of disorders that cause difficulties with coordination and movement. Cerebellar ataxia specifically involves the cerebellum, which is the part of the brain responsible for maintaining balance, coordinating muscle movements, and regulating speech and eye movements.
The symptoms of cerebellar ataxia may include:
* Unsteady gait or difficulty walking
* Poor coordination of limb movements
* Tremors or shakiness, especially in the hands
* Slurred or irregular speech
* Abnormal eye movements, such as nystagmus (rapid, involuntary movement of the eyes)
* Difficulty with fine motor tasks, such as writing or buttoning a shirt
Cerebellar ataxia can be caused by a variety of underlying conditions, including:
* Genetic disorders, such as spinocerebellar ataxia or Friedreich's ataxia
* Brain injury or trauma
* Stroke or brain hemorrhage
* Infections, such as meningitis or encephalitis
* Exposure to toxins, such as alcohol or certain medications
* Tumors or other growths in the brain
Treatment for cerebellar ataxia depends on the underlying cause. In some cases, there may be no cure, and treatment is focused on managing symptoms and improving quality of life. Physical therapy, occupational therapy, and speech therapy can help improve coordination, balance, and communication skills. Medications may also be used to treat specific symptoms, such as tremors or muscle spasticity. In some cases, surgery may be recommended to remove tumors or repair damage to the brain.
Electromyography (EMG) is a medical diagnostic procedure that measures the electrical activity of skeletal muscles during contraction and at rest. It involves inserting a thin needle electrode into the muscle to record the electrical signals generated by the muscle fibers. These signals are then displayed on an oscilloscope and may be heard through a speaker.
EMG can help diagnose various neuromuscular disorders, such as muscle weakness, numbness, or pain, and can distinguish between muscle and nerve disorders. It is often used in conjunction with other diagnostic tests, such as nerve conduction studies, to provide a comprehensive evaluation of the nervous system.
EMG is typically performed by a neurologist or a physiatrist, and the procedure may cause some discomfort or pain, although this is usually minimal. The results of an EMG can help guide treatment decisions and monitor the progression of neuromuscular conditions over time.
An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.
Brain stem neoplasms refer to tumors that originate in the brainstem, which is the lower part of the brain that connects to the spinal cord. These tumors can be benign or malignant and can arise from various types of cells within the brainstem, such as nerve cells, glial cells (which support and protect nerve cells), or cells that make up blood vessels.
Brain stem neoplasms are relatively rare, accounting for about 2% of all primary brain tumors. They can cause a variety of symptoms depending on their size and location, including headache, vomiting, double vision, difficulty swallowing, facial weakness, and problems with balance and coordination. Treatment options may include surgery, radiation therapy, and chemotherapy, depending on the type, location, and extent of the tumor.
Paraneoplastic syndromes of the nervous system are a group of rare disorders that occur in some individuals with cancer. These syndromes are caused by an immune system response to the cancer tumor, which can lead to the damage or destruction of nerve cells. The immune system produces antibodies and/or activated immune cells that attack the neural tissue, leading to neurological symptoms.
Paraneoplastic syndromes can affect any part of the nervous system, including the brain, spinal cord, peripheral nerves, and muscles. Symptoms vary depending on the specific syndrome and the location of the affected nerve tissue. Some common neurological symptoms include muscle weakness, numbness or tingling, seizures, memory loss, confusion, difficulty speaking or swallowing, visual disturbances, and coordination problems.
Paraneoplastic syndromes are often associated with specific types of cancer, such as small cell lung cancer, breast cancer, ovarian cancer, and lymphoma. Diagnosis can be challenging because the symptoms may precede the discovery of the underlying cancer. A combination of clinical evaluation, imaging studies, laboratory tests, and sometimes a brain biopsy may be necessary to confirm the diagnosis.
Treatment typically involves addressing the underlying cancer with surgery, chemotherapy, or radiation therapy. Immunosuppressive therapies may also be used to manage the immune response that is causing the neurological symptoms. While treatment can help alleviate symptoms and improve quality of life, paraneoplastic syndromes are often difficult to cure completely.
Eyelid diseases refer to a variety of medical conditions that affect the function and/or appearance of the eyelids. These can include structural abnormalities, such as entropion (inward turning of the eyelid) or ectropion (outward turning of the eyelid), as well as functional issues like ptosis (drooping of the upper eyelid). Other common eyelid diseases include blepharitis (inflammation of the eyelid margin), chalazion (a blocked oil gland in the eyelid), and cancerous or benign growths on the eyelid. Symptoms of eyelid diseases can vary widely, but often include redness, swelling, pain, itching, tearing, and sensitivity to light. Treatment for these conditions depends on the specific diagnosis and may range from self-care measures and medications to surgical intervention.
Myokymia - Wikipedia
Myokymia: Background, Pathophysiology, Epidemiology
Neuropathies with prolonged conduction block, single and grouped fasciculations, localized limb myokymia
FreiDok plus - Superior Oblique Myokymia An Electromyographical Analysis
No Proof Chemicals Caused Pasir Gudang Boy's Myokymia - CodeBlue
Eyelid twitch: MedlinePlus Medical Encyclopedia
Blown Pupil - All About Vision
SOM Archives - Genetic Support Network Victoria (GSNV)
Around the Eye in 365 Days - SLACK Books
Eyelid Conditions - Optometrists.org
Wisdom Panel™ Premium dog DNA test | Most accurate breed detection
Eyes Twitches? Your Lids May Just Need Some Shut Eye.
Everything About Eye Twitching: Causes Of The Condition And Precautions
Neurol India: Table of Contents
What is the Effect of Alcohol on the Eye? | CooperVision
The AMEDEO Literature Guide
Patricia
-
Patricia - Maxyboy: Vinyl LP
- Recordstore
KV1.1 (KCNA1) Polyclonal Antibody (PA5-95168)
Eyelid Spasms
European Journal of Neuroscience
Natural Remedies for Bell's Palsy, Ayurvedic Medicine, Herbal Cure
Why's My Eyelid Twitching?