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)

We studied cerebral oxygen and glucose metabolism as well as cerebral blood flow using positron emission tomography (PET) in a case with MELAS showing dementia, diabetes mellitus, ataxia and lactic acidosis without any signs of stroke. This case, confirmed to have a point mutation at position 3243 in the transfer RNA gene of mitochondrial DNA, developed a stroke-like episode 8 months after the PET study. Uncoupling was observed between cerebral oxygen metabolism and cerebral blood flow with reduced fractional oxygen extraction ratio, indicating "hyperemia", not ischemia. The "hyperemia" may be closely related to the malfunction of mitochondria in aerobic energy production. A drastic decrease in cerebral oxygen metabolism (CMRO2) was found globally in contrast to preserved cerebral glucose metabolism (CMRglu), resulting in a remarkable decrease in the metabolic ratio (CMRO2/CMRglu). The dissociation between cerebral glucose and oxygen metabolism may be characteristic of MELAS.
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PMID:Cerebral metabolism of oxygen and glucose in a patient with MELAS syndrome. 875 Jan 17

Extracranial-intracranial (EC-IC) bypass grafting procedures were specially designed for treatment of bilateral internal carotid artery occlusion. When performed in an expeditious manner, EC-IC bypass procedures have produced effective and durable results, despite the recent disfavor given to this procedure. This communication reports a 68-year-old white man who developed generalized cerebral ischemia manifested as confusion, incoherence, disorientation, ataxia, and numerous episodes of syncope daily. A cerebral angiogram revealed bilateral external carotid arteries and left solitary vertebral artery critical stenosis. Transcranial Doppler study demonstrated reduction of cerebral and vertebral-basilar perfusion. However, the patient's EC-IC bypass graft had remained patent since 1985. The patient's recurrent symptoms of global ischemia and syncope resolved after carotid endarterectomy, vein patch external carotid artery, and vertebral-to-common carotid artery transposition. This report reiterates the value of the EC-IC bypass procedure and presents the surgical management of symptomatic external carotid and vertebral artery stenosis in patients after EC-IC bypass procedures.
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PMID:Revascularization of cerebral ischemia after previous bilateral extracranial-intracranial bypass procedures. 947 4

NBQX, a specific and potent AMPA receptor antagonist has been found to be neuroprotective in various models of ischemia and to have anticonvulsant properties in different models of epilepsy. In this experiment, the neurobehavioral effects of NBQX were studied. In an open field, an important ataxia was emphasized at a dose of 60 mg/kg. In a swimming task, an increase of the escape latencies was noted on the third day at a dose of 40 mg/kg. In a Morris water maze task, doses devoid of effects on locomotion were used (10, 20, and 30 mg/kg). There was no effect on the acquisition of the task at 10 mg/kg and a slight impairment at 20 mg/kg, but the rats did not learn the task at 30 mg/kg. This impairment was reversible, as shown by the increasing performance of this group without treatment. No impairment was noted in the retention phase of the Morris water maze task. The results are discussed relative to the role of the AMPA receptor in memory processes.
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PMID:Behavioral effects of NBQX, a competitive antagonist of the AMPA receptors. 958 71

A 69-year-old female presented with sudden onset of truncal ataxia, urinary incontinence, mental confusion, and Parinaud's sign. With conservative treatment, her ataxia and urinary incontinence resolved. Magnetic resonance (MR) imaging disclosed a round mass with laminated intramural hemorrhage in the third ventricle. Right vertebral angiography demonstrated a giant aneurysm in the distal basilar artery. Xenon-enhanced computed tomography showed that cerebral blood flow (CBF) was reduced in the thalamus bilaterally and was paradoxically decreased by acetazolamide. Two months later, MR imaging showed that the intramural hemorrhage had shrunk, and the edema in the thalamus was resolving. The CBF reduction and vascular response to acetazolamide had reversed to some extent. A partially thrombosed giant aneurysm can grow acutely as the result of fresh intramural hemorrhage. The edema is secondary to ischemia and loss of vasoresponsivity.
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PMID:Extensive edema in the thalamus caused by thrombosed basilar artery aneurysm. 964 Sep 62

A flock of 15-wk-old tom turkeys experienced an acute onset of paresis and ataxia in 75% of the birds after handling. Cartilaginous emboli were found in the spinal cord vasculature from one of five turkeys at this initial presentation. Most of the flock recovered within 6 days, but 3% remained paretic. Myelomalacia was present in three turkeys that failed to recover. Two of these turkeys had cartilaginous and osseous emboli within the medullary spaces of the vertebral bodies, internal vertebral venous sinuses, and spinal cord. The third turkey had vascular and spinal cord necrosis consistent with thrombosis and resultant ischemia. These changes suggest that turkeys may be susceptible to a syndrome analogous to fibrocartilaginous embolism of the spinal cord in mammals. The articular cartilage of the vertebral body endplate may be the source of the emboli. The turkeys with emboli had articular cartilage defects consisting of matrix eosinophilia, chondrocyte loss, multicellular cluster formation, cartilage detachment, and cartilage clefts. Cartilaginous emboli in the spinal cord should be considered as a potential cause for acute paresis and ataxia, especially in flocks with preexisting abnormalities of the vertebral articular cartilage surfaces.
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PMID:Intravascular cartilaginous emboli in the spinal cord of turkeys. 964 39

Lurcher (Lc) is a spontaneous, semidominant mouse neurological mutation. Heterozygous lurcher mice (Lc/+) display ataxia due to a selective, cell-autonomous, apoptotic death of 90% of cerebellar Purkinje cells during postnatal development. Homozygous lurcher mice (Lc/Lc) die shortly after birth due to massive loss of mid- and hindbrain neurons during late embryogenesis. We identified the mutations responsible for neurodegeneration in two independent Lc alleles as identical G-to-A transitions that change a highly conserved alanine to a threonine residue in transmembrane domain III of the mouse delta 2 glutamate receptor gene (GluRE2). Lc/+ Purkinje cells displayed a very high membrane conductance and a depolarized resting potential, indicating the presence of a large, constitutive inward current. Expression of the mutant GluR delta 2Lc protein in Xenopus oocytes confirmed these results, demonstrating that lurcher is an inherited neurodegenerative disorder resulting from a gain-of-function mutation in a glutamate receptor gene. Further characterization of GluR delta 2 signaling and the activation of apoptotic death in Lc Purkinje cells have begun to yield mechanistic insights into this neurodegenerative disease, and to highlight its relationship to neuronal loss following ischemia.
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PMID:GluR delta 2 and the development and death of cerebellar Purkinje neurons in lurcher mice. 1041 27

Prothrombin gene G20210A polymorphism has been recently identified as a cause of venous thrombosis. However the association between this mutation and arterial thrombosis remains uncertain. Some authors have suggested that the polymorphism in the 3' region of the prothrombin gene may precipitate cerebral arterial thrombosis in young patients with prothrombotic conditions. We report a case of post-traumatic basilar artery thrombosis in a young patient carrier of the prothrombin gene G20210A polymorphism. Thirty-six hours after sustaining a head injury in the occipital region, a young man developed vomiting, headache, dizziness and truncal ataxia, without signs of focal impairment. Magnetic resonance imaging and selective angiography carried out 2 days later showed an obstruction of the basilar artery, with infarction of the right cerebellar region. A transthoracic echocardiogram showed a patent foramen ovale with little left-to-right shunt and an aneurysm of the interatrial septum. Blood examination showed a heterozygous status for prothrombin gene G20210A polymorphism. We conclude that this prothrombin gene mutation and the coexisting particular head injury and interatrial septal aneurysm could have contributed simultaneously to the development of basilar artery occlusion and cerebellar infarction. We suggest that in selected cases of cerebellar ischemia a prothrombin gene G20210A polymorphism should be considered.
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PMID:Post-traumatic basilar artery thrombosis in a young man with atrial septum aneurysm and prothrombin gene G20210A polymorphism. 1049 21

The study case was a 66-year-old man who had bilateral neurosensory hearing impairment due to brain stem infarctions. He noticed mild hearing loss, frequent vertigo and tinnitus. About one month later, his hearing took a sudden turn for the worse, and he suffered from dysarthria, dysphagea and abasia. Neurological examination revealed pseudobulber palsy, left hemiparesis, cerebeller ataxia, disturbance of pain and temperature sensation on the right face and left side of the body. Brain stem auditory evoked potentials (BAEPs) showed a delayed small wave V with the abscence of previous waves on the right side and no significant waves on the left side. Brain magnetic resonance images (MRI) revealed infarctions in the bilateral middle cerebellar peduncles, including in the right lateral portions of pons, and the right lower pontine base. We believe that not only peripheral, but also central auditory pathways adjacent to infarctions were damaged. Magnetic resonance angiography (MRA) showed severe stenosis or occlusion of left vertebral artery and basilar artery. We concluded that hypoperfusion of the vertebrobasilar artery territories caused ischemia of the cochlear nerve and the auditory tracts in the brain stem, which resulted in bilateral hearing loss.
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PMID:[A case of brain stem infarction with bilateral hearing loss]. 1076 46

Dissecting aneurysms of intracranial posterior circulation have recently been shown to be less uncommon than previously thought. However, those involving the posterior inferior cerebellar artery (PICA) and not vertebral artery at all are extremely rare. We report here a case of a patient with a dissecting aneurysm of the lateral medullary segment of PICA which presented as subarachnoid haemorrhage. The aneurysm was treated by trapping surgery and the distant PICA was anastomosed to the occipital artery. The patient showed a slight ataxia immediately after surgery but recovered fully. Recovery from immediately postoperative cerebellar symptoms due to intra-operative ischemia seemed to be due largely to recovery of flow in the region of cortical branches of PICA.
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PMID:Dissecting aneurysm of the peripheral posterior inferior cerebellar artery. 1112 38

Though the AMPA receptor has been implicated in several neurodegenerative processes (epilepsy, ischemia, spasticity), its role in cognition is yet to be clarified. The aim of this study was to assess in the rat the effects of the AMPA receptor antagonist NBQX (3.5, 7, 10, 20 and 30 mgkg(-1), i.p.) on learning and memory. For this purpose, the object recognition task was chosen. NBQX, at the higher doses used (20 and 30 mgkg(-1)) caused respectively, depression of motility and ataxia, while given at lower doses (3.5, 7 and 10 mgkg(-1)) it did not influence animals performance in the object recognition paradigm. All rats acquired similarly well the task. In conclusion, these results would support and broaden previous observations on the lack of major involvement of AMPA receptors in the rat working memory mechanisms.
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PMID:The non-NMDA receptor antagonist NBQX does not affect rats performance in the object recognition task. 1182 Aug 60


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