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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transcranial Doppler, electroencephalography, and single photon emission computed tomography were performed in a case of basilar migraine during the different phases of the attack. In the aura phase, the patient had bilateral blindness and ataxia. Doppler ultrasound studies showed a reduction in the mean flow velocity of the posterior cerebral arteries, electroencephalography showed slow activity confined to the posterior regions, and single photon emission computed tomography, an area of hypoperfusion in the right parietal and occipital regions. During the headache phase, when the neurological examination was normal, transcranial Doppler showed an increase in the mean flow velocity of both posterior cerebral arteries and the electroencephalogram revealed an increase in the slow activity over the occipital regions. When the pain subsided, the electroencephalogram showed a progressive reduction of the slow abnormalities and transcranial Doppler was reported as normal. After a week, single photon emission computed tomography and cranial magnetic resonance imaging were normal. After a month, a follow-up electroencephalogram was also normal. All these findings indicated a transient focal reduction of cerebral blood flow during the aura phase.
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PMID:Basilar artery migraine: transcranial Doppler EEG and SPECT from the aura phase to the end. 904 23

Basilar migraine is a complicated headache which the International Headache Society describes as 'migraine with aura symptoms clearly originating from the brainstem or from both occipital lobes'. For years this headache was thought to originate from a transient disturbance in the vertebrobasilar circulation, but more recent studies suggest that a central neuronal disorder may be the source of migraine. Basilar migraines may have certain symptoms which are similar to other neurologic, vascular, psychiatric and metabolic diseases, yet there are specific criteria which can help differentiate it from other diagnoses. It is characterized by a throbbing occipital headache which may be preceded by an aura. The unusual symptoms of basilar migraine, which may precede and continue throughout the duration of the headache and even after it, include bilateral visual symptoms, altered mental status, vertigo, gait ataxia, bilateral paresthesia, bilateral paralysis and dysarthria. We describe a 29-year-old black female whose husband brought her to the emergency department complaining of confusion, headache, and left-sided weakness for 2 h prior to arrival.
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PMID:Basilar migraine. 915 94

Some of the most common diseases in humans occur intermittently in people who are otherwise healthy and active. Such disorders include migraine headache, epilepsy, and cardiac arrhythmias. Because electrical signals are critical to the function of neurons, muscle cells, and heart cells, proteins that regulate electrical signaling in these cells are logical sites where abnormalities might lead to disease. All of these diseases have prominent genetic components. Difficulty in understanding these diseases arises from the complexity of the clinical phenotypes as well as from the genetic heterogeneity that is almost certain to exist. Therefore, early work in may laboratory was aimed at understanding the pathogenesis of rare disorders that are similar in their episodic nature. These disorders of muscle (the periodic paralyses), lead to attacks of weakness that occur intermittently in otherwise normal people. We, and others, have shown that hyperkalemic periodic paralysis (hyperKPP) and paramyotonia congenita (PC) result from mutations in a gene encoding a skeletal muscle sodium channel. We have also shown that hypokalemic periodic paralysis (hypoKPP) is caused by mutations in a gene encoding a voltage-gated calcium channel. The characterization of these diseases as channelopathies has served as a paradigm for other episodic disorders. One example is periodic ataxia, which results from mutations in voltage-gated potassium calcium channels. Long QT syndrome, an episodic cardiac dysrhythmia syndrome, is known to result from mutations in either voltage-gated sodium or potassium channels. We have recently mapped genes that cause a familial paroxysmal dyskinesia (non-kinesiogenic paroxysmal dystonia/choreoathetosis) in humans and a reflex epilepsy in mice. The similarities among all these disorders, including their episodic nature, precipitating factors, and therapeutic responses, are striking. Understanding gained from work in these rare monogenic episodic disorders is not only allowing characterization of the molecular and physiologic basis of these diseases, but may ultimately shed light on our understanding of the pathophysiology of more common and genetically complex disorders of the central nervous system.
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PMID:Channelopathies: ion channel disorders of muscle as a paradigm for paroxysmal disorders of the nervous system. 919 7

Ion channels are part of a large family of macromolecules whose functions include the control and maintenance of electrical potential across cell membranes, secretion and signal transduction. Close inspection of the physiological processes involved in channel function and the secondary structure of various ion channels has served as a basis for subdividing ion channels into a number of superfamilies. The voltage-gated ion channels are one of these superfamilies. Recent work has shown that mutations in various ion channel genes are responsible for a number of neuromuscular and neurological disorders. Correlation of the various mutations with the clinical phenotype is providing us with insight into the pathophysiology of these channel proteins. Interestingly, different mutations within the same gene may cause quite distinct clinical disorders, while mutations in different channel genes may result in very similar phenotypes (genetic heterogeneity). Examples of phenotypic variation and genetic heterogeneity are presented in the context of the periodic paralytic disorders of skeletal muscle, episodic ataxia, migraine, long QT syndrome and paroxysmal dyskinesia. Some of these disorders are known to be caused by mutations in ion channel genes, while in the episodic movement disorders, ion channel genes are considered excellent candidate genes.
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PMID:Phenotype variation and newcomers in ion channel disorders. 930 Jun 59

A gene for familial hemiplegic migraine, a subtype of migraine with aura, was assigned to chromosome 19p13. In this region, we identified a brain-specific P/Q-type calcium-channel alpha 1A-subunit gene, CACNA 1A, with 47 exons covering 300 kb. Sequencing of all exons and their flanking surroundings revealed polymorphic variations, including a (CA)n-repeat and a (CAG)n-repeat in the 3' untranslated region. In patients with familial hemiplegic migraine, we found four different missense mutations in conserved functional domains. One of the mutations has occurred on two different haplotypes in unrelated familial hemiplegic migraine families. Moreover, in episodic ataxia type 2, we found two mutations disrupting the reading frame. Thus, familial hemiplegic migraine and episodic ataxia type 2 can be considered as allelic channelopathies. Involvement of this familial hemiplegic migraine locus in migraine with and without aura was demonstrated by sib-pair analysis. We showed an increase of shared marker alleles of locus D19S394, which is tightly linked to the gene. The association between the alpha 1A calcium channel and familial hemiplegic migraine, and the increase of shared alleles in migraine-affected sib-pairs, have uncovered a new pathway for the pathophysiology of migraine. This finding may provide a rationale for the development of specific prophylactic therapy for migraine and other (paroxysmal) cerebral disorders.
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PMID:Wolff Award 1997. Involvement of a Ca2+ channel gene in familial hemiplegic migraine and migraine with and without aura. Dutch Migraine Genetics Research Group. 932 29

A gene for familial hemiplegic migraine (FHM), a subtype of migraine with aura, has been assigned to chromosome 19p13. In this region we identified a brain-specific P/Q-type calcium channel alpha 1A-subunit gene, CACNL1A4, with 47 exons covering 300 kb. Sequencing of all exons and their flanking surroundings revealed polymorphic variations, including a (CA)n-repeat, and a (CAG)n-repeat in the 3'-UTR. In FHM patients, we found four different missense mutations in conserved functional domains. One of the mutations has occurred on two different haplotypes in unrelated FHM families. Moreover, in episodic ataxia type-2 (EA-2), we found two mutations disrupting the reading frame. Thus, FHM and EA-2 can be considered as allelic channelopathies. Involvement of this FHM locus in migraine with and without aura was demonstrated by sib-pair analysis. We showed an increase of shared marker alleles of locus D19S394, which is tightly linked to the gene. The association between the alpha 1A calcium channel and FHM, and the increase of shared alleles in migraine affected sib-pairs, have uncovered a new pathway for the pathophysiology of migraine. This finding may provide a rationale for the development of specific prophylactic therapy for migraine and other (paroxysmal) cerebral disorders.
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PMID:Familial hemiplegic migraine: involvement of a calcium neuronal channel. 943 52

Neurotologic symptoms are common with migraine, yet relatively little is known about the pathophysiology of such symptoms. Motion sensitivity with bouts of motion sickness occurs in about two thirds of patients with migraine. Episodes of vertigo occur in about one fourth of patients and, in some, vertigo is the only symptom (so-called "migraine equivalent"). Phonophobia is the most common auditory symptom, but fluctuating hearing loss and acute permanent hearing loss occur in a small percentage. Migraine can mimic Meniere's disease and so-called "vestibular Meniere's disease" is usually associated with migraine. The recent discovery of a mutation in a brain calcium-channel gene in families with hemiplegic migraine and in families with episodic vertigo and ataxia suggests a possible mechanism for neurotologic symptoms in patients with more common varieties of migraine. A defective calcium channel, primarily expressed in the brain and inner ear, could lead to reversible hair cell depolarization and auditory and vestibular symptoms. This hypothesis is currently being investigated in other families with migraine headaches and neurotologic symptoms. Hopefully, such studies will lead to improved diagnosis and better treatments in the future.
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PMID:Neurotology of migraine. 943 80

Clinical details are given of different types of episodic ataxia: type 1, with myokymia, and attacks which usually last a few minutes, and may occur several times a day, and treatment with acetazolamide can reduce the number of attacks; type 2, with interictal nystagmus, and attacks which last for several hours to a day or more, and treatment with acetazolamide is very effective; paroxysmal choreoathetosis with episodic ataxia, with attacks lasting for about 20 min and occurring at varying intervals; and familial hemiplegic migraine, with transient hemiplegia presenting during the aura of a migraine headache, the symptoms improving on treatment with acetazolamide. Their inheritance is of dominant type; and the gene for type 1 is mapped to chromosome 12p near to a cluster of potassium channel genes, and that for type 2 and for familial hemiplegic migraine to chromosome 19p near to calcium channel genes. The differential diagnosis from other conditions with a periodic symptomatology is discussed, especially from a number of metabolic disorders. Treatment is effective for many of these, and the treatment of the episodic ataxias with acetazolamide can sometimes have a dramatic effect. The possible role of the channelopathies in the causation of some periodic neurological disorders is considered; with the expectation that further research will improve the identification of specific diseases, and lead to more effective treatment.
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PMID:Episodic ataxia and channelopathies. 953 53

Familial hemiplegic migraine (FHM) is an autosomal dominant subtype of migraine with aura, with half of the families being assigned to chromosome 19p13. We identified missense mutations in a brain-specific calcium channel alpha1A-subunit (CACNA1A) gene on 19p13 segregating with FHM and truncating mutations in families with episodic ataxia type 2 (EA-2). Expansions of an intragenic CAG repeat have been shown in autosomal dominant cerebellar ataxia (SCA6). Hence, FHM, EA-2, and SCA6 are allelic ion channel disorders. We analyzed the phenotype-genotype relation in three unrelated FHM families with the calcium channel alpha1A-subunit gene mutations I1811L (two families) and V714A (one family). We found mutations in all but three patients with FHM (i.e., three phenocopies). In addition, the I1811L mutation occurred in two patients with "nonhemiplegic" migraine and in one subject without migraine. Cerebellar ataxia was found in both families with the I1811L mutation but not in the family with the V714A mutation. We failed to find expansions of the intragenic CAG repeat in FHM patients with cerebellar ataxia. We conclude that the I1811L mutation causes both FHM and cerebellar ataxia independent of the number of CAG repeats. The I1811L mutation may also occur in "normal" migraine patients, supporting the hypothesis that FHM is part of the migraine spectrum.
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PMID:Variable clinical expression of mutations in the P/Q-type calcium channel gene in familial hemiplegic migraine. Dutch Migraine Genetics Research Group. 956 2

Acute infarcts of the anterior inferior cerebellar artery (AICA) are unusual. We report 15 cases of AICA infarcts and their correlation with the topography of the lesion by brain MRI. During 2 years we prospectively identified 7 cases of AICA infarcts among 770 acute strokes (0.9% of the acute strokes seen in our department). We studied these cases and also another 8 that we found retrospectively. Most patients (8/15) had a unilateral affectation of both middle cerebellar peduncle (MCP) and inferior lateral pontine area (ILP), in these cases the main symptoms were vertigo, ataxia, peripheral facial palsy and hypoacusia. Two other patients had isolated MCP infarcts and were characterized by peripheral vertigo and ataxia, without hypoacusia or facial palsy. Another 2 patients had isolated ILP territory infarct characterized by vertigo, left peripheral facial palsy without hypoacusia and mild or no ataxia. One patient had a Gasperini syndrome. Finally 3 patients had bilateral AICA infarcts due to basilar thrombosis. The etiology was atherosclerosis in 9 patients, lacunar due to hypertension in 1, cardiac embolism in 1, migraine in 1 and unknown in 3. Among the 15 patients only 2 died, both with AICA plus infarcts. In the remaining patients a follow-up during a mean of 31 months (3 months to 12 years) showed no recurrences.
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PMID:The anterior inferior cerebellar artery infarcts: a clinical-magnetic resonance imaging study. 957 36


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