Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A comprehensive review of the neurotologic manifestations of migraine is presented, focusing on the most recent publications regarding the epidemiology, clinical presentation, pathophysiology, diagnosis, and management of migraine-related vertigo (MV). A strong association exists between vertigo and migraine, with MV being the most common cause of spontaneous (nonpositional) episodic vertigo. Symptoms can be quite variable among patients and within individual patients over time, creating a diagnostic challenge. MV generally presents with attacks of spontaneous or positional vertigo lasting seconds to days with associated migrainous symptoms. Operational diagnostic criteria have been proposed but are not included in the most recent International Headache Society classification of migraine. Better elucidation of the neurologic linkages between the central vestibular pathways and migraine-related pathways and the discovery of ion channel defects underlying some causes of familial migraine, ataxia, and vertigo have furthered the understanding of MV pathophysiology. Treatment of MV currently parallels that of migraine headache, as proper studies of optimal MV management are just beginning.
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PMID:Migraine-related vertigo: diagnosis and treatment. 1652 63

Intracellular calcium ([Ca2+]i) is highly regulated in eukaryotic cells. The free [Ca2+]i is approximately four orders of magnitude less than that in the extracellular environment. It is, therefore, an electrochemical gradient favoring Ca2+ entry, and transient cellular activation increasing Ca2+ permeability will lead to a transient increase in [Ca2+]i. These transient rises of [Ca2+]i trigger or regulate diverse intracellular events, including metabolic processes, muscle contraction, secretion of hormones and neurotransmitters, cell differentiation, and gene expression. Hence, changes in [Ca2+]i act as a second messenger system coordinating modifications in the external environment with intracellular processes. Notably, information on the molecular genetics of the membrane channels responsible for the influx of Ca2+ ions has led to the discovery that mutations in these proteins are linked to human disease. Ca2+ channel dysfunction is now known to be the basis for several neurological and muscle disorders such as migraine, ataxia, and periodic paralysis. In contrast to other types of genetic diseases, Ca2+ channelopathies can be studied with precision by electrophysiological methods, and in some cases, the results have been highly rewarding with a biophysical phenotype that correlates with the ultimate clinical phenotype. This review outlines recent advances in genetic, molecular, and pathophysiological aspects of human Ca2+ channelopathies.
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PMID:Calcium channelopathies. 1677 82

The central nervous system (CNS) is, after the peripheral nervous system, the second most frequently affected organ in mitochondrial disorders (MCDs). CNS involvement in MCDs is clinically heterogeneous, manifesting as epilepsy, stroke-like episodes, migraine, ataxia, spasticity, extrapyramidal abnormalities, bulbar dysfunction, psychiatric abnormalities, neuropsychological deficits, or hypophysial abnormalities. CNS involvement is found in syndromic and non-syndromic MCDs. Syndromic MCDs with CNS involvement include mitochondrial encephalomyopathy, lactacidosis, stroke-like episodes syndrome, myoclonic epilepsy and ragged red fibers syndrome, mitochondrial neuro-gastrointestinal encephalomyopathy syndrome, neurogenic muscle weakness, ataxia, and retinitis pigmentosa syndrome, mitochondrial depletion syndrome, Kearns-Sayre syndrome, and Leigh syndrome, Leber's hereditary optic neuropathy, Friedreich's ataxia, and multiple systemic lipomatosis. As CNS involvement is often subclinical, the CNS including the spinal cord should be investigated even in the absence of overt clinical CNS manifestations. CNS investigations comprise the history, clinical neurological examination, neuropsychological tests, electroencephalogram, cerebral computed tomography scan, and magnetic resonance imaging. A spinal tap is indicated if there is episodic or permanent impaired consciousness or in case of cognitive decline. More sophisticated methods are required if the CNS is solely affected. Treatment of CNS manifestations in MCDs is symptomatic and focused on epilepsy, headache, lactacidosis, impaired consciousness, confusion, spasticity, extrapyramidal abnormalities, or depression. Valproate, carbamazepine, corticosteroids, acetyl salicylic acid, local and volatile anesthetics should be applied with caution. Avoiding certain drugs is often more beneficial than application of established, apparently indicated drugs.
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PMID:Central nervous system manifestations of mitochondrial disorders. 1694 41

Topiramate (Topamax), an effective seizure disorder treatment, received additional FDA approval for prevention of migraine headaches in August 2004 and has gained attention for its off-label uses, including psychiatric and eating disorders, neuropathic pain, and alcohol and drug dependency. Side effects of sedation, dizziness, ataxia, speech difficulty, nystagmus, paresthesia, and metabolic acidosis are described. The manufacturer reports that tolerance to the antiseizure properties does not develop. With its established efficacy for epilepsy treatment and its increased use for other disorders, topiramate-positive findings are more common in death-investigation and human-performance casework. To evaluate the role of topiramate, we reviewed all topiramate-positive cases from our laboratory between 1998 and 2004, which constituted 132 cases (63 death investigations, 68 suspected impaired drivers, and 1 sexual assault case). The subjects were predominantly female (69%) with a mean and median age of 42. Blood topiramate concentrations ranged from 1 to 180 mg/L (median 6.4 mg/L, mean 8.4 mg/L), and 94% were positive for at least one additional drug. There was evidence of psychomotor impairment in some drivers with blood concentrations within the normal therapeutic range, and deaths attributed to topiramate alone occurred at concentrations as low as 50 mg/L.
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PMID:Topiramate-positive death-investigation and impaired-driving cases in Washington State. 1713 58

Alternating hemiplegia of childhood (AHC) is a severe brain disorder, mainly characterised by episodes of hemiplegia, progressive mental retardation, and other severe paroxysmal and permanent neurological symptoms. Clinically and genetically, there is some overlap with sporadic (SHM) and familial (FHM) hemiplegic migraine, a severe monogenic subtype of migraine. Although no mutations were detected in the FHM1 CACNA1A and FHM2 ATP1A2 genes in sporadic AHC patients, a mutation was found in the FHM2 ATP1A2 gene in a family with AHC. Recently, a missense mutation was found in the SLC1A3 gene that encodes the glutamate transporter EAAT1, in a patient with alternating hemiplegia, episodic ataxia, seizures, and headache. Because of the remarkable clinical similarities and the potential role of glutamate in AHC, we analysed six sporadic patients with AHC for mutations in the SLC1A3 gene. No mutations were found. The SLC1A3 EAAT1 glutamate transporter gene does not seem to be involved in the pathogenesis of AHC.
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PMID:Alternating hemiplegia of childhood: no mutations in the glutamate transporter EAAT1. 1723 10

Since the first mitochondrial dysfunction was described in the 1960s, the medicine has advanced in its understanding the role mitochondria play in health, disease, and aging. A wide range of seemingly unrelated disorders, such as schizophrenia, bipolar disease, dementia, Alzheimer's disease, epilepsy, migraine headaches, strokes, neuropathic pain, Parkinson's disease, ataxia, transient ischemic attack, cardiomyopathy, coronary artery disease, chronic fatigue syndrome, fibromyalgia, retinitis pigmentosa, diabetes, hepatitis C, and primary biliary cirrhosis, have underlying pathophysiological mechanisms in common, namely reactive oxygen species (ROS) production, the accumulation of mitochondrial DNA (mtDNA) damage, resulting in mitochondrial dysfunction. Antioxidant therapies hold promise for improving mitochondrial performance. Physicians seeking systematic treatments for their patients might consider testing urinary organic acids to determine how best to treat them. If in the next 50 years advances in mitochondrial treatments match the immense increase in knowledge about mitochondrial function that has occurred in the last 50 years, mitochondrial diseases and dysfunction will largely be a medical triumph.
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PMID:Mitochondrial dysfunction and molecular pathways of disease. 1723 70

Ion channelopathies are inherited diseases in which alterations in control of ion conductance through the central pore of ion channels impair cell function, leading to periodic paralysis, cardiac arrhythmia, renal failure, epilepsy, migraine and ataxia. Here we show that, in contrast with this well-established paradigm, three mutations in gating-charge-carrying arginine residues in an S4 segment that cause hypokalaemic periodic paralysis induce a hyperpolarization-activated cationic leak through the voltage sensor of the skeletal muscle Na(V)1.4 channel. This 'gating pore current' is active at the resting membrane potential and closed by depolarizations that activate the voltage sensor. It has similar permeability to Na+, K+ and Cs+, but the organic monovalent cations tetraethylammonium and N-methyl-D-glucamine are much less permeant. The inorganic divalent cations Ba2+, Ca2+ and Zn2+ are not detectably permeant and block the gating pore at millimolar concentrations. Our results reveal gating pore current in naturally occurring disease mutations of an ion channel and show a clear correlation between mutations that cause gating pore current and hypokalaemic periodic paralysis. This gain-of-function gating pore current would contribute in an important way to the dominantly inherited membrane depolarization, action potential failure, flaccid paralysis and cytopathology that are characteristic of hypokalaemic periodic paralysis. A survey of other ion channelopathies reveals numerous examples of mutations that would be expected to cause gating pore current, raising the possibility of a broader impact of gating pore current in ion channelopathies.
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PMID:Gating pore current in an inherited ion channelopathy. 1733 30

There are multiple reports in the literature of serious and at times fatal complications after cervical spine manipulation therapy (CSMT), even though CSMT is considered by some health providers to be an effective and safe therapeutic procedure for head and neck pain syndromes. We report a case of a young female with cervicalgia and headache with fatal posterior circulation cerebrovascular accident after CSMT. Serious complications are infrequent, with a reported incidence between one per 100,000 to one in 2 million manipulations. The most frequent injuries involve artery dissection or spasm. Stroke as a complication of cervical manipulation and dissection of the vertebral arteries (VAD) is a rare but well recognized problem. Neck pain, headache, vertigo, vomiting and ataxia are typical symptoms of VAD, but this vascular injury also can be asymptomatic. The most common risk factors are migraine, hypertension, oral contraceptive pills and smoking. Stroke following CSMT is more common than the literature reports. The best values derive from retrospective surveys. The lack of identifiable risk factors place those who undergo CSMT at risk of neurologic damage. Accurate patient information and early recognition of the symptoms are important to avoid catastrophic consequences.
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PMID:Cervical spine manipulation: an alternative medical procedure with potentially fatal complications. 1845 37

Episodic ataxia type 1 is a paroxysmal neurological disorder characterized by short-lived attacks of recurrent midline cerebellar dysfunction and continuous motor activity. Mutations in KCN1A, the gene encoding Kv1.1, a voltage-gated neuronal potassium channel, are associated with the disorder. Although rare, the syndrome highlights the fundamental features of genetic ion-channel diseases and serves as a useful model for understanding more common paroxysmal disorders, such as epilepsy and migraine. This review examines our current understanding of episodic ataxia type 1, focusing on its clinical and genetic features, pathophysiology, and treatment.
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PMID:Episodic ataxia type 1: a neuronal potassium channelopathy. 1739 36

Familial hemiplegic migraine (FHM) is a severe subtype of migraine with hemiparesis during attacks. We scanned 10 families with FHM without mutations in the CACNA1A (FHM1) and ATP1A2 (FHM2) genes. We identified the novel p.L1649Q mutation (c.4946T>A) in Na(v)1.1 sodium channel gene SCN1A (FHM3) in a North American kindred with FHM without associated ataxia or epilepsy. Functional analysis of the mutation, introduced in the highly homologous human SCN5A, revealed markedly slowed inactivation and a two-fold faster recovery from fast inactivation predicting enhanced neuronal excitation. Our findings establish the role of neuronal Na(v)1.1 sodium channels in FHM and reinforce the involvement of ion channel dysfunction in the pathogenesis of this episodic brain disorder.
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PMID:The novel p.L1649Q mutation in the SCN1A epilepsy gene is associated with familial hemiplegic migraine: genetic and functional studies. Mutation in brief #957. Online. 1739 47


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