1,720,979 research outputs found
Lateral canal paroxysmal positional vertigo revisited.
No full textThe first reports of an involvement of the lateral canal (LC) in paroxysmal positional vertigo (PPV), were published in 1985, by Luciano Cipparrone et al., from Italy and Joseph McClure from Canada. The increasing interest of otolaryngologists and neurologists has led to a progressive advance in the knowledge of this labyrinthine disorder regarding its epidemiological, physiopathological, clinical, and therapeutic aspects. According to the most recent data, LC-benign PPV accounts for 17% of all PPV patients, regardless of gender and between the two labyrinths. The LC-PPV syndrome is characterized by intense positional vertigo and direction-changing geotropic horizontal nystagmus, both caused by rotation of the head in the supine position. Less frequently, it presents with apogeotropic nystagmus. In some patients nystagmus is also detectable in the sitting position, mimicking a spontaneous nystagmus. In most cases nystagmus is caused by displaced otoconia floating in the semicircular canal. The pathological side, which must be identified for successful treatment, is usually indicated by nystagmus intensity: the more intense positional nystagmus beats toward the affected ear. In a few cases, where there is no difference in nystgmus intensity, other indicators are necessary to determine the pathological side. Vestibular neuritis and posterior fossa lesions should be considered in the differential diagnosis. Treatment of LC-PPV relies on some physical maneuvers, the objective of which is to allow the otoconial debris to exit from the LC by centrifugal inertia and/or by gravitation
Acute Vestibular Neuritis: Prognosis Based upon Bedside Clinical Tests (Trusts and Heaves)
No full textWe compared bedside tests of vestibulo-ocular function (head thrust and head heave signs) with caloric testing results in 68 patients with acute vestibular neuritis seen at onset and in follow-up for one year. The head thrust and head heave signs each were strong predictors of a decreased probability of recovery, and if both were present, there was a trend for a slower recovery and a further decrease in the probability of recovery. If the head thrust sign was absent, recovery was assured. Our results suggest that careful bedside testing of semicircular canal (head thrust maneuver) and otolith (head heave maneuver) function provides useful information for predicting prognosis in patients with acute vestibular neuritis
Aperiodic alternating nystagmus: report of two cases and treatment by baclofen
No full textWe report two cases of non periodic alternating nystagmus, one of vascular origin (ischemia of the vertebrobasilar territory) and a second of traumatic origin (whiplash injury) with otoneurological signs, typical of lesions in posterior cranial fossa and in particular of vestibulum-cerebellum and brainstem: gaze paretic nystagmus, rebound nystagmus, saccadic dysmetria, vestibular hyperreflexia and impaired visual suppression test. In one case it was possible to give baclofen therapy, which yielded positive results. Suspension of drug administration resulted in the worsening of clinical signs. The mechanism of action of the drug will be discussed
Benign Paroxysmal Positional Vertigo and Migraine
No full textBenign paroxysmal positional vertigo (BPPV) is the most frequent cause of vertigo in adults and migraine is the most frequent cause of headache in humans. Females are more commonly affected than males in both diseases. Over the last 15 years, interesting, important relationships between the two disorders have been studied and proposed. Here we review the pathophysiology and diagnosis of BPPV both in its simple and linear presentations and in its more complex forms in which the patterns of nystagmus are less easily understood. We also mention the main therapeutic options for treating posterior and lateral canal BPPV. Possible correlations between BPPV and migraine are described. Finally, since migraine can cause vestibular symptoms, including positional vertigo, suggestions are given for differential diagnosis between the two diseases
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Neuro-ophthalmological involvement in 2 cases of Jejuno-Ileal by-pass surgery and vitamin E deficiency.
No full textImpairment of vertical saccades from an acute pontine lesion in multiple sclerosis
Full text linkA 62-year-old woman with relapsing-remitting multiple sclerosis suddenly complained of diplopia associated with bilateral adduction impairment, nystagmus of the abducting eye bilaterally, and sparing of abduction, convergence, and vertical eye movements, consistent with bilateral internuclear ophthalmoplegia. Within 1 week, she had developed a complete horizontal gaze paralysis even with the oculocephalic maneuver. Vertical saccades were slow and convergence was preserved. There was a right lower motor neuron seventh cranial nerve palsy. Brain MRI showed a new enhancing lesion involving the pontine tegmentum. Clinical and MRI follow-up showed recovery after 6 months. The slowing of vertical saccades may have been due to spread of the demyelinating lesion to the adjacent paramedian pontine reticular formation, which contains omnipause neurons lying in the raphe interpositus nucleus thought to inhibit excitatory burst neurons for horizontal and vertical saccades. Our patient verifies the fact that vertical saccadic abnormalities may occur from a lesion apparently confined to the pons
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