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Query: UMLS:C0241981 (loss of balance)
 452 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The structured clinical history is the most sensitive test for diagnosing vertigo. Its diagnostic effectiveness on the first visit was analyzed and key signs and symptoms with high predictive value for common causes of vertigo were identified. One hundred outpatients who complained of dizziness or loss of balance were evaluated using a structured clinical interview. Each questionnaire was examined independently by three blinded investigators, who assigned a diagnosis and identified the elements of the history that figured most prominently in the diagnosis. The gold standard was defined as independent selection of the same diagnostic category by all three investigators. A first-visit diagnosis was obtained in 40% of patients (95% confidence interval 30-50%): 38% women and 42% men. Causes included benign positional paroxysmal vertigo (BPPV, 13 patients), headache-associated vertigo (9), Meniere disease (7), cervical vertigo (3), psychiatric dizziness (2), post-traumatic vertigo (2), vertebro-basilar transient ischemic attack (1), vestibular neuritis (1), convulsive seizure (1), and presyncope (1). The best predictors of BPPV were the precipitating mechanism (specificity [SP] 100%), positional nystagmus (sensitivity [SE] 90%, SP 63%), and the Dix-Hallpike test (SE 82%, SP 71%). Elements predictive of headache-associated vertigo were duration of the attack (minutes) and a personal history of headache (both, SP 100%). Other predictors were facial hypoesthesia (SE 92%, SP 47%) and associated neurological disease (SE 82%, SP 58%).
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PMID:[Diagnosis of common causes of vertigo using a structured clinical history]. 1079 28

Cerebellar symptoms at onset are unusual in HTLV-I/II-associated tropical spastic paraparesis (TSP). A prospective study of neurological disorders in Panama (1985-1990) revealed 13 patients with TSP and 3 with HTLV-I/II-associated spinocerebellar syndrome (HSCS) presenting at onset loss of balance, wide-based stance and gait, truncal instability, and mild leg ataxia (vermian cerebellar syndrome), with absent upper limb dysmetria but with postural tremor, downbeat nystagmus, and dysarthria. In 4-5 years, spinal cord manifestations of TSP developed, including spastic paraparesis, pyramidal signs, bladder and sphincter disturbances. Two patients were infected with HTLV-I and another one, a Guaymi Amerindian woman, with HTLV-II. Magnetic resonance imaging (MRI) demonstrated cerebellar atrophy involving predominantly the superior vermis. Mild axonal peripheral neuropathy in the lower limbs, dorsal column involvement and inflammatory myopathy were found by neurophysiology studies. There are 14 similar cases reported in Japan and Canada, but to our knowledge these are the first documented cases of HSCS in the tropics. A cerebellar syndrome constitutes another form of presentation of HTLV-I/II infection of the nervous system.
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PMID:Spinocerebellar syndrome in patients infected with human T-lymphotropic virus types I and II (HTLV-I/HTLV-II): report of 3 cases from Panama. 1087 59

Alpha-mannosidosis is a disease caused by the deficient activity of alpha-mannosidase, a lysosomal hydrolase involved in the degradation of glycoproteins. The disease is characterized by the accumulation of mannose-rich oligosaccharides within lysosomes. The purpose of this study was to characterize the peripheral nervous system (PNS) and central nervous system (CNS) myelin abnormalities in cats from a breeding colony with a uniform mutation in the gene encoding alpha-mannosidase. Three affected cats and 3 normal cats from 2 litters were examined weekly from 4 to 18 wk of age. Progressively worsening neurological signs developed in affected cats that included tremors, loss of balance, and nystagmus. In the PNS, affected cats showed slow motor nerve conduction velocity and increased F-wave latency. Single nerve fiber teasing revealed significant demyelination/remyelination in affected cats. Mean G-ratios of nerves showed a significant increase in affected cats compared to normal cats. Magnetic resonance imaging of the CNS revealed diffuse white matter signal abnormalities throughout the brain of affected cats. Quantitative magnetization transfer imaging showed a 8%-16% decrease in the magnetization transfer ratio in brain white matter of affected cats compared to normal cats, consistent with myelin abnormalities. Histology confirmed myelin loss throughout the cerebrum and cerebellum. Thus, histology, electrodiagnostic testing, and magnetic resonance imaging identified significant myelination abnormalities in both the PNS and CNS that have not been described previously in alpha-mannosidosis.
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PMID:Histopathology, electrodiagnostic testing, and magnetic resonance imaging show significant peripheral and central nervous system myelin abnormalities in the cat model of alpha-mannosidosis. 1148 56

A 4-year-old, neutered male domestic shorthair cat presented for evaluation of ataxia and visual deficits. Neurological examination revealed severe cerebellar ataxia with symmetrical hypermetria and spasticity, a coarse whole-body tremor, positional vertical nystagmus, and frequent loss of balance. A menace response was absent bilaterally, and the pupils were widely dilated in room light. A funduscopic examination revealed markedly attenuated to absent retinal vessels and pronounced tapetal hyperreflectivity, findings consistent with end-stage retinal degeneration. Blood work evaluation included retroviral testing, a complete blood count, serum biochemistry analysis, taurine levels, and toxoplasma immunoglobulin G and immunoglobulin M titers. All were within reference ranges. The patient was euthanized, and a necropsy was performed. Microscopically, lesions of the nervous system were confined to the cerebellum and were consistent with cerebellar cortical abiotrophy. Selective photoreceptor degeneration was seen on histopathological examination of the retina with a reduction in the number of rods and cones. The combination of clinical findings and histopathological lesions seen here has not been previously reported in the cat.
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PMID:Adult-onset cerebellar cortical abiotrophy and retinal degeneration in a domestic shorthair cat. 1180 15

Three American Staffordshire Terriers were presented with gait abnormalities and loss of balance at the age of 4.5 (female) and 6 years (2 males). The onset varied between 3 and 5 years of age and the clinical signs were slowly progressive. The neurological examination revealed symmetrical generalized cerebellar ataxia with hypermetria, stiffness, and loss of balance with no evidence of paresis. The menace reflex was decreased in one dog and absent in another. A positional nystagmus was found in two dogs. The dogs were euthanized and a histopathological examination of each brain was performed. Pathological changes were confined to the cerebellum. The main finding was loss of Purkinje cells, as well as depletion of granular cell bodies and shrinkage of the granular and molecular cell layer. These findings are consistent with cerebellar cortical abiotrophy. A genetic basis is supposed, but the mode of inheritance is not determined yet. In contrast to some spinocerebellar ataxias in humans, the cause of Purkinje cell degeneration in cerebellar cortical abiotrophy of dogs is not known.
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PMID:[Cerebellar cortical abiotrophy in American Staffordshire terriers: clinical and pathological description of 3 cases]. 1295 8

The investigation of stability under bilateral acoustic stimulation was undertaken in an attempt to mimic the real-life conditions of noisy environment (e.g., industry, aviation). The Tullio phenomenon evaluated by computed dynamic posturography (CDP) under acoustic stimulation is reflected in postural unsteadiness, rather than in the classic nystagmus. With such a method, the dangerous effects of noise-induced instability can be assessed and prevented. Three groups of subjects were submitted. The first (group A) included 20 patients who complained of sonovestibular symptoms (i.e., Tullio phenomenon) on the background of an inner-ear disease. The second group (B) included 20 neurootological patients without a history of Tullio phenomenon. Group C consisted of 20 patients with normal hearing, as controls. A pure-tone stimulus of 1,000 Hz at 110 dB was delivered binaurally for 20 seconds during condition 5 and condition 6 of the CDP sensory organization test. The sequence of six sensory organization conditions was performed three times with two intermissions of 15-20 minutes between the trials. The first was performed in the regular mode (quiet stance). This was followed 20 minutes by a trial carried out in quiet stance in sensory organizations tests (SOTs) 1 through 4, and with acoustic stimulation in SOT 5 and SOT 6. The last test was performed in quiet stance throughout (identical to the first trial). A significant drop in the composite equilibrium score was witnessed in group A patients upon acoustic stimulation (p < .0001). This imbalance did not disappear completely until 20 minutes later when the third sensory organization trial was performed. In fact, the composite score obtained on the last SOT was still significantly worse than the baseline. Group B and the normal subjects (group C) showed no significant change in composite score. As regards the vestibular ratio score, again, group A marked a drop on stimulation with sound (p < .004). This decrease contrasted once more with the other two groups. The leading sensory organization pattern was vestibular dysfunction (i.e., 40%, 10%, and 0% before acoustic stimulation in groups A, B, and C, respectively). The initial proportion of vestibular dysfunction increased on acoustic stimulation to 55% in group A, but this subsequently decreased in the third trial. The percentages of vestibular dysfunction remained constant during repeated trials in the other two groups. The positive medical history of sonovestibular symptoms was confirmed objectively by CDP with sound stimulation with a high statistical significance. This establishes the described method as a sensitive testing technique for validating the existence of the Tullio phenomenon in patients with a variety of disorders of the inner ear, especially chronic noise-induced hearing loss and acute acoustic trauma. All patients who suffered phonic trauma, chronic exposure to noise (e.g., aviation employees, industry and army personnel), or other neurootological disorders and who complain of sonovestibular symptoms should be tested for the presence of the Tullio phenomenon. This should be carried out preferably by means of CDP with acoustic stimulation for an objective corroboration of their complaint before continuing activity in a noisy environment, thus preventing dangerous loss of balance when exposed to noise.
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PMID:Sonovestibular symptoms evaluated by computed dynamic posturography. 1468 33

Two ultrashort-acting hypnotics, triazolam 0.25 mg and zolpidem 10 mg, were studied for their effects on equilibrium function in humans. Eight healthy male subjects participated in a double-blind, placebo-controlled study after informed consent. They subjected to static equilibrium tests, oculomotor tests and an assay of drug concentrations in the blood. Zolpidem was statistically significant in postural sway in tandem stance test, as defined by parametric values of tracing sum length and polygonal area of foot pressure center measured by a gait analysis system. In the tandem stance test, triazolam was statistically significant in postural sway only as defined by the polygonal area. However, in the Romberg test, the only statistically significant difference in zolpidem use was observed in polygonal area values. Blood concentrations of triazolam and zolpidem were found to closely correlate with the extent of postural sway in both tandem stance and Romberg tests. In this study, zolpidem with minimal muscle-relaxant effect incurred imbalance more extensively than triazolam, which is known for its effect of muscle relaxation. In addition, gaze deviation nystagmus was observed only in zolpidem use in 5 of 8 subjects (62.5%). From these results, it is suggested that in the use of hypnotics, sway derives from the suppression of the central nervous system relevant to awakening rather than from muscle relaxation. The prior reference to blood concentrations of hypnotics should help improve safety care in minimizing loss of balance control and possible fall.
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PMID:Temporal changes in postural sway caused by ultrashort-acting hypnotics: triazolam and zolpidem. 1582 54

The present work reports cerebellar degeneration in cattle associated with the ingestion of Solanum subinerme in northern Brazil. The main clinical signs were periodic crises with loss of balance, falls, opisthotonus, and nystagmus. The histological lesions consisted of diffuse vacuolation of the perikaryon of the Purkinje neurons, followed by the loss of these cells and their substitution by Bergman glia. It is concluded that S. subinerme is another species of Solanum that causes cerebellar degeneration in cattle.
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PMID:Spontaneous poisoning by Solanum subinerme Jack as a cause of cerebellar cortical degeneration in cattle. 2456 Nov 22

Recently there is increased regulatory interest in the assessment of physical dependence and withdrawal as part of the safety assessment for novel therapeutic entities. Choosing appropriate and sensitive parameters to detect withdrawal syndromes, and relevant positive control comparator drugs that can be administered in the same manner as the test agent, are critical study design elements. Pilot studies to determine the effects of oral ketamine in cynomolgus monkeys during, and following cessation of treatment, were explored. Detailed behavioral observations (both remote and interactive), food consumption, and body weight and temperature, were assessed during the dose-ranging, repeat dose (5 or 14 days), and withdrawal phases (3 or 5 days). Doses explored during dose-ranging included 20, 40, 100, or 200 mg/kg ketamine; subsequent withdrawal assessments were conducted following repeat dosing of 150 mg/kg. In the 14-day dosing study, exposure to ketamine and norketamine was assessed following 8 days of dosing. Administration of 150 mg/kg ketamine produced decreased activity, loss of balance, ataxia, hunched posture, nystagmus, lateral recumbence, and changes in alertness levels during dosing phases. When ketamine was withdrawn, increased reactivity, increased activity, and stereotypic behaviors were demonstrated that were absent during baseline or the dosing phase of the studies.
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PMID:Withdrawal assessment following subchronic oral ketamine administration in Cynomolgus macaques. 2464 80