Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aging is a physiological process that shares many behavioral, biochemical and neuroendocrine phenomena with the pathophysiological situation of unresolved stress, as well as with a pharmacologically induced syndrome resulting from chronic benzodiazepine (BZ) consumption. Behavioral findings include symptoms such as drowsiness, ataxia, fatigue, confusion, weakness, dizziness, vertigo, syncope, reversible dementia, depression, impairment of intellectual, psychomotor and sexual function, agitation, auditory and visual hallucinations, paranoid ideation, panic, delirium, depersonalization, sleepwalking, aggressivity, orthostatic hypotension, and insomnia. Neuroendocrine findings include: central depletion of noradrenaline (NA), dopamine, adrenaline (AD), and serotonin (5-HT); reduction in the ratio of circulating NA/AD as well as platelet 5-HT and increase of AD, plasma free 5-HT and cortisol. These disturbances together with the increased platelet aggregability observed in the three groups are typical of unresolved-stress situations. Immunological findings include significant reduction of peripheral T lymphocytes (CD3, CD4, CD8) and the CD4/CD8 ratio, CD16 and gamma-delta cells. On the other hand, the three groups (elderly subjects, subjects faced with unresolved stress, and BZ consumers) show increase of the CD57 lymphocyte subset as well as natural killer cytotoxicity. Alterations of several biological markers have also been found, specifically in the oral glucose tolerance test, the intramuscular clonidine test, and the supine/orthostasis/exercise test. From a clinical point of view, the three groups appear to be more susceptible to the appearance and progression of many acute and chronic diseases (infectious and malignant diseases). As a result, chronic consumption of BZs should be avoided in both the elderly and subjects in unresolved-stress situations.
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PMID:Benzodiazepines: tolerability in elderly patients. 884 97

Topiramate is a recently licensed and marketed antiepileptic drug in the UK for use as add-on therapy for refractory partial epilepsy. It has multiple modes of action involving voltage-dependent sodium channels, GABA receptors and glutamate receptors. Topiramate has very favourable pharmacokinetics as it is primarily excreted unchanged. Its metabolism is, however, increased by enzyme inducers, and it can inhibit the metabolism of phenytoin in some patients. Its efficacy as adjunctive treatment in refractory partial epilepsy in adults appears good, over 40% of patients have a 50% or greater reduction in seizure frequency when topiramate is added to their regime with up to 7% becoming seizure free. The main adverse events are ataxia, impaired concentration, confusion, dizziness, fatigue, parasthesia, somnolence and "thinking abnormal'. Most of these occurred during rapid titration. During long-term treatment, weight loss also occurred and nephrolithiasis occurred in 1.5% of patients receiving topiramate. Topiramate is a useful and well-tolerated addition to our treatment of refractory epilepsy, but it should be titrated slowly in order to avoid adverse events.
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PMID:Topiramate: a new antiepileptic drug for refractory epilepsy. 890 21

Sensorineural hearing loss, tinnitus, dizziness and ataxia are recognised symptoms associated with Chiari malformations but they are rarely the presenting complaints. Patients with such symptoms are frequently referred to otolaryngologists and audiological physicians. We report a case of a 13-year-old girl who presented complaining of tinnitus and impaired hearing, and was subsequently diagnosed as having a type I Chiari malformation. Pure tone audiogram showed a mild hearing impairment on the left side and the speech audiogram was normal. Auditory brain stem responses and the electronystagmography were abnormal. The patient underwent posterior fossa decompression following which her tinnitus disappeared, the hearing problem recovered and some of the abnormal electrophysiological parameters were corrected.
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PMID:Audio-vestibular manifestations of Chiari malformation and outcome of surgical decompression: a case report. 894 83

Lamotrigine (LTG) inhibits repetitive high frequency firing in depolarised neurones by selectively prolonging slow inactivation of the sodium channel, thereby suppressing the release of excitatory amino acids. It has been shown to be effective in 11 pivotal double-blind add-on trials in patients with refractory partial seizures with or without secondary generalisation. Subsequent anecdotal data support its efficacy for typical and atypical absences, myoclonic jerks, tonic or clonic seizures, Lennox-Gastaut syndrome and infantile spasms. Most recently LTG has been compared with carbamazepine and phenytoin in double-blind trials in patients with newly diagnosed partial and primary and secondary generalised tonic-clonic seizures. At the doses used, its efficacy was similar to the older agents for all seizure types, but LTG was better tolerated than both of the older agents. The commonest side-effects with LTG include headache, nausea, diplopia, dizziness, ataxia and tremor. Rash occurs in fewer than 5% patients. Its incidence can be reduced by starting treatment with a low dose, particularly in patients receiving concomitant sodium valproate which inhibits LTG metabolism. Enzyme inducers, such as carbamazepine, phenytoin and phenobarbital, accelerate its elimination, but LTG itself has no effect on hepatic metabolic processes. A pharmacodynamic interaction with carbamazepine necessitates a dosage reduction in some patients when LTG is introduced. LTG is a new antiepileptic agent with a long elimination half-life, a broad spectrum of activity, and a wide therapeutic ratio.
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PMID:Lamotrigine--an update. 895 Dec 13

Three hundred and forty seven patients with epilepsy from 54 centres across Europe not fully controlled with sodium valproate (VPA, n = 117), carbamazepine (CBZ, n = 129), phenytoin (PHT, n = 92) or phenobarbital (PB, n = 9) monotherapy were recruited into a lamotrigine (LTG) substitution study. If 50% or more seizure reduction occurred (responders) on addition of LTG, an attempt was made to withdraw the original antiepileptic drug (AED). If successful, this was followed by a 12 week period of LTG monotherapy. Overall, 73% patients completed the add-on phase (47% responders), 41% attempted AED withdrawal and 23% achieved LTG monotherapy. In the 60 patients (17%) completing the trial by remaining on LTG monotherapy, median monthly seizure frequency was reduced from 6 during baseline to 1.7. Sixteen percent of patients were withdrawn due to adverse effects, mostly during the add-on phase. Dizziness and diplopia occurred most frequently in the CBZ group, nervousness and ataxia in the PHT group, and rash and tremor in the VPA group. Slower LTG dose escalation resulted in fewer withdrawals due to rash in the VPA-treated patients (38% to 8%, P < 0.01). The responder rate was higher (P < 0.01) in patients with idiopathic tonic-clonic seizures (61%) than in those with partial seizures (43%). The addition of LTG to VPA (64% responders) produced a significantly better response (P < 0.001) than adding it to CBZ (41% responders) or PHT (38% responders). This effect was seen for partial (VPA, 57%; CBZ, 39%; PHT, 39%; P < 0.02) as well as tonic-clonic seizures (VPA, 70%; CBZ, 53%; PHT, 50%; NS). These data lend credence to the suggestion of therapeutic synergy between LTG and VPA.
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PMID:Lamotrigine substitution study: evidence for synergism with sodium valproate? 105 Study Group. 912 23

We report a 29-year-old man with diabetes insipidus and cerebellar ataxia who developed spinal cord swelling 15 years after the onset. He was well until 14 years of the age when he noted dizziness. Two years after there was an onset of gait disturbance and slurred speech. He also noted polydipsia and polyuria. He was evaluated at the neurosurgery service of our hospital when he was 17 years of the age. Neurologic examination at that time revealed memory loss, horizontal nystagmus, cerebellar ataxic gait, dysmetria and decomposition more on the left. Cranial CT scan revealed a mass lesion involving the left subthalamic region and the head of the caudate area. Spinal fluid was unremarkable, however, human chorionic gonadotropin was increased to 27 mIU/ml. He was treated by radiation therapy (3,000 rads for total brain area and 5,460 rads for focal region). His CT scan and memory loss improved, however, cerebellar ataxia was unchanged. Three years after the radiation, he started to show choreic movement in his neck and left upper extremity. He was admitted to our service in August 14, 1995 when he was 29 years of the age. On admission, he was alert but disoriented to time; calculation was also poor. Higher cerebral functions were intact. The optic fundi were normal without papilledema. Visual field appeared intact. Gaze nystagmus was observed in all the directions, but more prominent in the horizontal direction. Speech was slurred. Otherwise, cranial nerves were unremarkable. Motor wise, he showed marked truncal and gait ataxia; he was unable to walk because of ataxia. Muscle atrophy and marked weakness was noted in both upper extremities more on the left side. Deep tendon reflexes were diminished in the upper extremities but active in the lower extremities. He was polyuric; urinary specific gravity was low. Spinal fluid contained 6 cells/cmm and 113 mg/ dl of protein; Queckenstedt was positive. MRI revealed swelling of the cervical cord; in addition, the entire cervical region and the medullar oblongata appeared as high signal intensity areas. No mass lesion was noted in the supratentorial structures but the third ventricle was markedly enlarged. Surgical biopsy was performed on the cervical lesion. The patient was discussed in neurologic CPC, and the chief discussant arrived at the conclusion that the patient had germinoma with syncytiotrophoblastic giant cells in the diencephalic region which appeared to have been cured by radiation therapy; he thought that the cervical lesion was the seeding of germinoma. Cerebellar ataxia was ascribed to the remote effect of germinoma. Most of the participants thought that the original tumor was germinoma and the cervical lesion was its spread. Some participants thought that his ataxia was caused by germinoma cells involving the medulla and the inferior cerebellar peduncles. Histologic observation of the biopsied tissue from the spinal cord revealed the typical two cell patterned germinoma. Most of the tumor cells were not stained for an antibody against HCG, but some tumor cells were positively stained. Germinoma is very radio-sensitive; this patient showed T2 high signal lesion involving the medulla oblongata and cervical cord continuously. Probably, tumor cells in the lower brain stem escaped radiation, and gradually spread to the spinal cord over many years. At the time of operation, the surface of the spinal cord was free from tumor cells. Therefore, tumor cells invaded the spinal cord continuously from the medulla oblongata. He was treated with cervical radiation, and his neurologic as well as radiologic findings showed marked improvement.
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PMID:[A 29-year-old man with diabetes insipidus and cerebellar ataxia and development of spinal cord swelling 15 years after the onset]. 916 63

Patients taking anticonvulsant drugs display a broad spectrum of side-effects. Particularly, in the beginning of treatment and with increasing doses of carbamazepine, side effects such as dizziness, ataxia, drowsiness and reduction of alertness occur, which improve some days after the dose has reached a stable level. Our aim was to find objective parameters for grading these side effects and to differentiate between neurophysiological and neuropsychological side effects of carbamazepine in a clinical situation. Twenty-two patients with trigeminal neuralgia were included for a follow-up study with increasing carbamazepine doses (0 mg to 600 mg). The effect of carbamazepine on postural stability was quantified by posturography. Different neuropsychological tests to study cognitive effects of carbamazepine were performed. The composite equilibrium score showed a significant reduction of postural stability with increasing doses of carbamazepine. In sensory analysis the somatosensory ratio was significantly influenced by increased doses of carbamazepine during the study. Mean reaction time of tonic alertness and physical alertness varied significantly with different doses of carbamazepine. There was a significant influence in patients attention during trail making tests and divided attention tests with increase in carbamazepine. In conclusion our observations show that the rate of change of carbamazepine doses is an important determinant of cognitive and motor functions in the phase of increasing doses.
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PMID:Side effects from increased doses of carbamazepine on neuropsychological and posturographic parameters of humans. 921 81

A 55-years-old woman had left neck pain and headache, dizziness, left Horner's sign, left abducens palsy, diplopia, left peripheral facial palsy, left loss of hearing, left tinnitus, left paralysis of vocal cord and soft palate, dysphagia, left limb ataxia, truncal ataxia, disturbance of temperature and pain sensation over Th10 on the right involving the right face. Left vertebral angiography revealed tapering occlusion of the left vertebral artery. Right vertebral angiography showed normal angiogram of the basilar artery and bilateral anterior inferior cerebellar arteries. MRI disclosed infarcts in the left lateral inferior pons, left lateral medulla, and cerebellum of territories in the anterior inferior cerebellar artery and posterior inferior cerebellar artery. T2 weighted image showed septum (intimal flap) in the left vertebral artery. This is the very rare case of lateral inferior pontine syndrome and lateral medullary syndrome due to the vertebral artery dissection.
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PMID:[A case of vertebral artery dissection with lateral inferior pontine syndrome and lateral medullary syndrome]. 921 27

Topiramate is a new antiepileptic drug which has recently become available in the United States and in a number of European countries. Pharmacological studies suggest that its mode of action is multifactorial and involves blockade of voltage-dependent sodium channels, potentiation of GABAergic transmission and inhibition of excitatory pathways through an action at AMPA receptor sites. Carbonic anhydrase inhibiting properties have also been demonstrated but they are considered not to be relevant to anticonvulsant activity. Topiramate is well absorbed from the gastrointestinal tract, peak plasma levels being usually attained in 2-3 hours. The drug is negligibly (9-17%) bound to plasma proteins and is eliminated partly by renal excretion in unchanged form and partly by oxidation and hydrolysis. In healthy volunteers, the half-life is about 20-30 hours, but elimination rate is accelerated in patients taking concomitant enzyme inducing drugs such as phenytoin, carbamazepine and barbiturates. Topiramate has no major effects on plasma levels of concurrent anticonvulsants, except for a rise in plasma phenytoin in occasional patients. In double-blind add-on trials in refractory partial epilepsy, a significant reduction in seizure frequency has been demonstrated in over 40% of topiramate-treated patients (vs about 10% of those treated with placebo), a response rate which compares favourably with that observed with other new antiepileptic drugs. Dosages found to be effective in add-on controlled trials range between 200 and 1000 mg day-1, although most patients are likely to benefit from receiving 400 mg day-1 or less. Preliminary data suggest that topiramate may be effective also in generalized epilepsies, but this needs to be confirmed in prospective studies. The most common adverse effects of topiramate are CNS-related and include dizziness, fatigue, visual disturbances, ataxia, mental slowing and impaired concentration. Paresthesias, anorexia, weight loss and increased risk of nephrolithiasis have been also reported. Many of these effects are related to dose and/or to rate of dose titration. Based on these data, topiramate appears to be a valuable new drug, whose main current indication is in the add-on management of refractory partial and secondarily generalized seizures. Studies on its potential-value as monotherapy are in progress.
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PMID:A pharmacological and clinical review on topiramate, a new antiepileptic drug. 926 38

The introduction on the French market of vigabatrin, gabapentin and lamotrigine has considerably diversified our conventional therapeutical schemes in epilepsies, as will be as amplified by the arrivals of topiramate, tiagabine and oxcarbazepine. Compared to the conventional drugs, these new products present more favorable pharmacokinetics, no or very weak interactions and a better tolerability, specially regarding the cognitive field. They should be used according to their spectrum of activity, function of their modes of action. In add-on trials on partial epilepsy patients all these new products have shown efficacy on partial and secondarily generalized seizures. Seizure frequency is reduced by at least 50 p. 100 in 30 to 50 p. 100 of the patients. A substantial number of patients can be rendered seizure-free with vigabatrin. Lamotrigine has a broader spectrum, as it is also efficacious on the different seizure types of generalized, symptomatic or idiopathic epilepsies. Main adverse events are non-specific central nervous system disturbances such as dizziness, drowsiness, ataxia, tremor or diplopia. More specifically, vigabatrin may induce weight gain and requires closer supervision in case of psychiatric history; lamotrigine which has also probable antidepressant properties, may induce skin rashs, rarely severe. Further data are needed for gabapentin which is now used at daily dosages which are two to three times those used in the initial studies. Gabamimetic agents may be worsening in some cases of generalized epilepsies, more specially on absence and myoclonic seizures. The most obvious benefits, some patients becoming seizure-free, are obtained in cases of intermediate severity, with a bitherapy including one of these new drugs. Developments in children are often delayed. Nevertheless the prognosis, including cognitive outcome, is considerably improved in infantile spasms with vigabatrin and in Lennox-Gastaut syndrome with lamotrigine and felbamate, the latter being highly toxic. For the moment in France, authorities have limited the use of all these new antiepileptic drugs to adjunctive therapy in epilepsies resisting to conventional drugs. But recent monotherapy data show similar efficacy with better tolerability. Once the pivotal, controlled studies have enabled to obtain regulatory approval, all these compounds must undergo a large-scale evaluation phase in order to better define dosages, long-term tolerability, indications and eventual contra-indications in the various epileptic syndromes, including children.
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PMID:[Therapeutic options provided by new antiepileptic drugs]. 929 53


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