ABSTRACT
ABSTRACT A 12-year-old boy with Donnai-Barrow syndrome diagnosed intra-uterus presented esotropia, high myopia, nystagmus, and optic disk staphyloma in an ophthalmologic examination. The patient had associated Fanconi syndrome and sensorineural hearing loss as well as facial manifestations as hypertelorism, downward slanting of palpebral fissures and low ear implantation. Magnetic resonance imaging revealed agenesis of the corpus callosum. To our knowledge, this is the first reported case associated with esotropia, nystagmus, and optic disk staphyloma.
RESUMO Paciente do sexo masculino, 12 anos, com diagnóstico intrauterino de síndrome de Donnai-Barrow, apresentava ao exame oftalmológico esotropia, alta miopia, nistagmo e estafiloma de disco óptico. Associado ao quadro, apresentava síndrome de Falconi e perda auditiva neurossensorial, além de alterações faciais, como hipertelorismo, inclinação inferior das fissuras palpebrais e implantação baixa das orelhas. Ressonância magnética revelou agenesia de corpo caloso. Ao nosso conhecimento, este é o primeiro caso relatado associando esotropia, nistagmo e estafiloma de disco óptico.
Subject(s)
Humans , Male , Child , Abnormalities, Multiple , Optic Nerve Diseases/physiopathology , Esotropia/physiopathology , Nystagmus, Pathologic/physiopathology , Myopia/physiopathology , Renal Tubular Transport, Inborn Errors , Syndrome , Acidosis, Renal Tubular , Retinal Detachment , Cryptorchidism , Fanconi Syndrome/physiopathology , Agenesis of Corpus Callosum/physiopathology , Hernias, Diaphragmatic, Congenital , Hearing Loss, Sensorineural , Hypertelorism/physiopathologyABSTRACT
RESUMEN El downbeat nystagmus o nistagmo vertical hacia abajo es el nistagmo de fijación adquirido más frecuente, que en la mayoría de los casos es causado por patología a nivel del sistema nervioso central que genera disrupción del control inhibitorio del flóculo y paraflóculo cerebeloso sobre los núcleos vestibulares. Entre sus causas se encuentran enfermedades neurodegenerativas y vasculares de cerebelo o tronco cerebral, tumores y traumas, pero cerca del 40% de los casos son idiopáticos y hasta la mitad de los pacientes presentan estudio imagenológico negativo. En este artículo presentamos dos casos que consultaron en el Servicio de Otorrinolaringología del Hospital Clínico de la Universidad de Chile.
ABSTRACT Downbeat nystagmus is the most frequent acquired fixation nystagmus and it is generally caused by central pathology disrupting the inhibitory control of the cerebellar flocculus and paraflocculus over the vestibular nuclei. Among its causes are neurodegenerative and vascular diseases of cerebellum or brainstem, tumors and trauma, but nearly 40% of the cases are idiopathic and up to half the patients have negative imaging study. In this article we present two cases that were evaluated in the Otolaryngology Department of the Clinical Hospital of the University of Chile.
Subject(s)
Humans , Male , Female , Aged , Nystagmus, Pathologic/diagnosis , Nystagmus, Pathologic/physiopathology , Nystagmus, Pathologic/therapy , VertigoABSTRACT
ABSTRACT Changes in postural balance and visual complaints are frequent consequences of stroke. We aimed to investigate the symptoms and the vestibular and oculomotor functions of patients with dizziness post ischemic and hemorrhagic stroke and compare the results among them. Methods: Fifty patients with dizziness after stroke were evaluated through a clinical anamnesis and computerized vector electronystagmography: calibration of ocular movements, spontaneous nystagmus, semi-spontaneous nystagmus, pendular tracking, optokinetic nystagmus, rotary chair testing, and the caloric test. Results: All patients complained of dizziness, especially imbalance. Ischemic stroke in the carotid territory was the prevalent type. Visual complaints were reported by 56% of the sample and were related to abnormalities in oculomotor and caloric tests. Conclusion: The occurrence of visual symptoms was related to some abnormalities in the vector electronystagmography tests, being more frequent in cases of stroke in the vertebrobasilar system, and with oscillopsia and reduced visual acuity as symptoms.
RESUMO Alterações no equilíbrio postural são consequências frequentes no acidente vascular cerebral (AVC). O objetivo deste estudo foi investigar os sintomas e as funções vestibular e oculomotora de sujeitos com tontura após AVC isquêmico e hemorrágico, comparando seus resultados. Métodos: Foram avaliados 50 sujeitos com tontura após AVC, por meio de anamnese clínica e vectoeletronistagmografia computadorizada (VENG): calibração dos movimentos oculares; nistagmo espontâneo e semi-espontâneo; rastreio pendular; nistagmo optocinético; prova rotatória pendular decrescente e prova calórica com estímulo a ar. Resultados: Todos relataram tontura, principalmente do tipo desequilíbrio. O AVC isquêmico e no sistema carotídeo foi o mais frequente. Sintomas visuais pós-AVC foram referidos por 56% da amostra, os quais tiveram relação com alterações nas provas oculomotoras e calórica da VENG. Conclusão: A ocorrência de sintomas visuais relacionou-se a alterações em alguns testes. Essas alterações foram mais frequentes nos casos de AVC da circulação posterior, naqueles com oscilopsia e diminuição da acuidade visual.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Vestibular Function Tests , Stroke/complications , Stroke/physiopathology , Dizziness/etiology , Dizziness/physiopathology , Oculomotor Nerve/physiopathology , Vision Disorders/etiology , Vision Disorders/physiopathology , Caloric Tests , Visual Acuity/physiology , Nystagmus, Pathologic/etiology , Nystagmus, Pathologic/physiopathology , Vestibule, Labyrinth/physiopathology , Cross-Sectional Studies , Statistics, Nonparametric , Electronystagmography/methodsABSTRACT
ABSTRACT Objective To describe and compare the vestibular findings most evident among the hereditary ataxias, as well as correlate their clinical features with the nervous structures affected in this disease. Methods Seventy-five patients were evaluated and underwent a case history, otorhinolaryngological and vestibular assessments. Results Clinically, the patients commonly had symptoms of gait disturbances (67.1%), dizziness (47.3%), dysarthria (46%) and dysphagia (36.8%). In vestibular testing, alterations were predominantly evident in caloric testing (79%), testing for saccadic dysmetria (51%) and rotational chair testing (47%). The presence of alterations occurred in 87% of these patients. A majority of the alterations were from central vestibular dysfunction (69.3%). Conclusion This underscores the importance of the contribution of topodiagnostic labyrinthine evaluations for neurodegenerative diseases as, in most cases, the initial symptoms are otoneurological; and these evaluations should also be included in the selection of procedures to be performed in clinical and therapeutic monitoring.
RESUMO Objetivo Descrever e comparar os achados vestibulares mais evidentes entre a ataxia hereditária, bem como correlacionar seus aspectos clínicos com o estudo das estruturas nervosas afetadas nesta doença. Métodos 75 pacientes foram avaliados e submetidos aos seguintes procedimentos: anamnese, avaliação otorrinolaringológica e vestibular. Resultados Clinicamente, os pacientes apresentaram sintomas de distúrbios da marcha (67,1%), tonturas (47,3%), disartria (46%) e disfagia (36,8%). No teste vestibular, as alterações foram predominantemente evidentes no teste calórico (79%), dismetria sacádicas (51%) e no teste rotatório (47%). A presença de alterações ocorreu em 87% dos pacientes. A maioria das alterações observadas foram da disfunção vestibular central (69,3%). Conclusão O estudo ressalta a importância da contribuição da avaliação labiríntica no topodiagnóstico para doenças neurodegenerativas, uma vez que, na maioria dos casos, os sintomas iniciais são otoneurológicos, e essas avaliações também devem ser incluídas na seleção de procedimentos a serem realizados no monitoramento clínico e terapêutico.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged , Young Adult , Spinocerebellar Degenerations/diagnosis , Spinocerebellar Degenerations/epidemiology , Vestibular Diseases/diagnosis , Vestibular Diseases/epidemiology , Vestibular Function Tests/methods , Brazil/epidemiology , Deglutition Disorders/physiopathology , Deglutition Disorders/epidemiology , Spinocerebellar Degenerations/physiopathology , Spinocerebellar Degenerations/genetics , Nystagmus, Pathologic/physiopathology , Nystagmus, Pathologic/epidemiology , Polymerase Chain Reaction , Prevalence , Cross-Sectional Studies , Retrospective Studies , Sex Distribution , Gait Disorders, Neurologic/physiopathology , Gait Disorders, Neurologic/epidemiology , Dizziness/physiopathology , Dizziness/epidemiology , Dysarthria/physiopathology , Dysarthria/epidemiology , MutationABSTRACT
Benign paroxysmal positional vertigo (BPPV), the most frequent cause of vertigo is associated with high morbidity in the elderly population. The most common form is linked to debris in the posterior semicircular canal. However, there has been an increasing number of reported BPPV cases involving the horizontal canals. The purpose of this article is to highlight the clinical features, diagnosis, and treatment in 37 patients with horizontal canal BPPV; twenty-six with geotropic nystagmus, and eleven with the apogeotropic form. Treatment consisted of the Gufoni manoeuver in eighteen patients (48.6%), the barbecue 360° maneuver in twelve patients (32.4%), both manoeuvers in four patients (10.8%), both manoeuvers plus head shaking in one patient (2.7%), and the Gufoni maneuver plus head shaking in two patients. Cupulolithiasis patients were asked to sleep in a forced prolonged position. We obtained a complete resolution of vertigo and nystagmus in 30 patients (81.0%) on the initial visit.
Vertigem posicional paroxística benigna (VPPB) é a causa mais frequente de vertigem e promove alta morbidade na população idosa. A forma mais comum está relacionada com otoconias no canal semicircular posterior. Entretanto, nos últimos anos identifica-se cada vez mais casos de VPPB dos canais horizontais. Os principais objetivos deste artigo são destacar as características clínicas, diagnóstico e tratamentos aplicados em 37 pacientes com VPPB do canal horizontal; vinte e seis com nistagmo geotrópico, e onze com nistagmo apogeotrópico. O tratamento consistiu na manobra de Gufoni em dezoito pacientes (48,6%) manobra do churrasco 360° em doze pacientes (32,4%) ambas as manobras em quatro pacientes (10,8%) ambas as manobras mais a manobra de sacudir a cabeça (MSC) em um paciente (2,7%), e manobra de Gufoni mais MSC em dois pacientes (2,7%). Pacientes com cupulolitíase dormiram uma noite na posição forçada prolongada. Em 30 pacientes (81,0%) o sucesso terapêutico ocorreu na primeira consulta.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Benign Paroxysmal Positional Vertigo/diagnosis , Benign Paroxysmal Positional Vertigo/therapy , Exercise Therapy/methods , Patient Positioning/methods , Benign Paroxysmal Positional Vertigo/physiopathology , Head Movements/physiology , Nystagmus, Pathologic/physiopathology , Nystagmus, Pathologic/therapy , Semicircular Canals/physiopathology , Supine Position/physiology , Time Factors , Treatment OutcomeABSTRACT
Purpose: Evaluate the relationship between the postural alignment of the head and possible interference in the view of children. Methods: We evaluated 11 children between 2 and 7 years of age of both sexes, with the visually impaired, who had nystagmus and head lock position. The test Lea Grating Acuity Test® was used to collect measurements of visual acuity. This applied on two occasions: with and without postural alignment of the head. For reliability of the postural alignment of the head, the slopes were measured by Fisiologic® software. Results: The children had a poorer performance after physiological postural alignment. This poor performance is possible due to loss of position lock nystagmus to gain postural alignment, said to be ideal. Postural compensations were observed, and sharply increased eyestrain. Conclusion: The pursuit of traditional postural alignment affect the visual response of children with visual impairments. .
Objetivo: Avaliar a relação entre o alinhamento postural da cabeça e a possível interferência na visão de crianças. Métodos: Foram avaliadas 11 crianças, entre 2 e 7 anos de idade de ambos os sexos, com o diagnóstico de deficiência visual, que apresentavam nistagmo e posição de bloqueio de cabeça. O teste Lea Grating Acuity Test® foi utilizado para coletar medidas de acuidade visual. Este aplicado em dois momentos: sem e com o alinhamento postural da cabeça. Para confiabilidade do alinhamento postural da cabeça, as inclinações foram medidas pelo software Fisiologic®. Resultados: As crianças apresentaram pior desempenho após o alinhamento postural fisiológico. Este pior desempenho é possível devido à perda da posição de bloqueio do nistagmo para ganho do alinhamento postural, dito como ideal. Foram observadas compensações posturais e maior esforço visual. Conclusão: A busca do alinhamento postural tradicional prejudica a resposta visual de criança com deficiência visual. .
Subject(s)
Child , Child, Preschool , Female , Humans , Male , Head , Nystagmus, Pathologic/physiopathology , Posture/physiology , Visual Acuity/physiology , Cross-Sectional Studies , Nystagmus, Physiologic/physiology , Prospective StudiesABSTRACT
Recientes estudios clínicos han revelado la utilidad del test del nistagmus inducido por la hiperventilación aguda, en la investigación de patologías vestibulares retrolaberínticas, neurales y de origen central, con la aparición de nistagmus paréticos o bien excitatorios. El propósito de este estudio ha sido: primero, conocer la sensibilidad de este examen según el análisis de los estudios de diferentes autores; segundo, entender la fisiopatología de este nistagmus inducido por la hiperventilación y tercero, efectuar una interpretación y análisis de este examen que permita obtener conclusiones sólidas del mejor nivel de medicina basada en evidencias. Para efectuar este estudio y análisis se procedió a una investigación exhaustiva de las publicaciones sobre el tema en los últimos 25 años, recurriendo para ello como fuentes de información a las principales bases de datos biomédicos y a la revisión en texto completo de estas publicaciones. Llamó la atención la escasez de trabajos clínicos publicados sobre el tema que no superan los 40, y también la escasez de trabajos sobre la fisiopatología del nistagmus inducido por la hiperventilación aguda. La metódica del test es muy simple por lo que su utilización resulta muy atractiva, con un escaso número de falsos positivos. La mayor parte de los estudios publicados, se focaliza en su utilización en el schwanoma vestibularyen la neuronitis vestibular. Respecto al schwanoma vestibular de un total de 107 pacientes estudiados el test fue positivo en el 80 por ciento de los casos, con aparición de nistagmus ipsilesional o contralesional. En la neuronitis vestibular la positividad del test alcanzó a 60 por ciento de un total de 272 pacientes estudiados y que estaba en relación directa con el tiempo de evolución de la enfermedad. En la esclerosis múltiple, en pacientes con síntomas vestibulares, la positividad del test fue de 75 por ciento, en cambio en aquellos pacientes sin síntomas vestibulares...
Recent clinical studies have revealed the usefulness of the hyperventilation-induced nystagmus in retrolabyrinthine and central vestibular diseases with the appearance either excitatory (ipsilateral) or paretic (contralateral) nystagmus. The objectives of this study have been: 1) to get to know the sensitivity of the exam, according to the best literature available; 2) to get to know the physiopathology of this hyperventilation-induced nystagmus, and 3) to carry out an analysis and interpretation of this exam in order to reach solid conclusions of the highest level in evidence based medicine. An exhaustive research of literature published on this topic in the last 25 years was carried out. The main source of information being the most important medical data-based publications and also a thorough revision of these texts. The scarce number of publications on this topic (not more than 40) is what strikes the attention most, as well as the very few studies of the physiopathology of the hyperventilation-induced nystagmus. The method of the test is a simple one; this fact makes its application an attractive one, with a low number of false positive. Most of the studies published are focused on its application in the vestibular schwannoma and in the vestibular neuritis. As to what the Vestibular schwannoma is concerned, ofa group of 107 patients studied, the test was positive in 80 percent of the cases, with the appearance of ipsilesional or contralesional nystagmus. In vestibular neuritis the test was positive in 68 percent of a number of 272 patients; this amount was in direct correlation with the time of evolution of the disease. In multiple sclerosis, in patients with vestibular symptoms, the test gave positive in 75 percent, whereas in those patients without vestibular symptoms it was positive only in 7 percent. In patients with cerebellar diseases, particularly degenerative ones this test was positive in 78 percent of the cases...
Subject(s)
Humans , Vestibular Diseases/physiopathology , Hyperventilation/complications , Nystagmus, Pathologic/etiology , Nystagmus, Pathologic/physiopathologyABSTRACT
Benign paroxysmal positioning vertigo (BPPV) is considered as the most common vestibular disease. AIM: to evaluate the age, gender, type and site of the lesion, association with other vestibular diseases, progression, and recurrence in these patients. MATERIAL AND METHOD: A retrospective series study. Data from medical reports of BPPV patients examined in series during the past six years were analyzed. RESULTS: prevalences of BPPV were: at age 41-60 years (42.2 percent); in females (62.8 percent), wit nystagmus and positioning vertigo (81.3 percent); affecting the posterior canal (87 percent), unilateral (91.8 percent), the right labyrinth (60.2 percent) - p<0.001). Due to canalithiasis (97.5 percent), idiopathic (74.8 percent), association with Menière's disease compared to other affections (55.4 percent); healing or recovery by means of the particle repositioning maneuver (77.9 percent); and possible recurrence (21.8 percent in a one-year follow-up period). CONCLUSION: BPPV is characterized by its prevalence at age 41 to 60 years, in females, with nystagmus and positioning vertigo, involving mostly the posterior canal of the right labyrinth, associated with canalithiasis or idiopathic, associated with Menière's disease compared to other affections, healing or recovery by means of particle repositioning maneuver, and possible recurrence.
A vertigem posicional paroxística benigna (VPPB) é considerada a mais comum das vestibulopatias. OBJETIVO: Avaliar pacientes com VPPB quanto à idade, gênero, tipo e localização da lesão, associação com outras vestibulopatias, dados evolutivos e recorrência. MATERIAL E MÉTODO: Estudo de séries retrospectivo. Foram analisados os prontuários de 1271 pacientes consecutivos examinados nos últimos seis anos com VPPB. RESULTADOS: A VPPB apresentou prevalência de faixa etária entre 41 e 60 anos (42,2 por cento), gênero feminino (62,8 por cento), presença de nistagmo e vertigem de posicionamento (81,3 por cento), comprometimento do canal posterior (87,0 por cento; p<0,001), unilateral (91,8 por cento), do labirinto direito (60,2 por cento; p<0,001), por ductolitíase (97,5 por cento), forma idiopática (74,8 por cento), associação com a doença de Ménière em relação a outras afecções (55,4 por cento; p<0,001), cura ou melhora por meio de manobra de reposicionamento de partículas (77,9 por cento); e pela possibilidade de recorrência (21,8 por cento, em um ano de acompanhamento). CONCLUSÃO: A VPPB é caracterizada pela prevalência de faixa etária entre 41 e 60 anos, gênero feminino, presença de nistagmo e vertigem de posicionamento, comprometimento do canal posterior unilateral do labirinto direito por ductolitíase, forma idiopática, associação com a doença de Ménière em relação a outras afecções, cura ou melhora por meio de manobra de reposicionamento de partículas; e pela possibilidade de recorrência.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Nystagmus, Pathologic/diagnosis , Vertigo/diagnosis , Disease Progression , Nystagmus, Pathologic/physiopathology , Recurrence , Retrospective Studies , Vertigo/physiopathology , Young AdultABSTRACT
A Síndrome de Deiscência de Canal Semicircular Superior (SDCSS), primeiramente descrita em 1998 por Minor et al., caracteriza-se por vertigem associada à presença de nistagmo, relacionados à exposição a estímulos sonoros intensos ou a modificações de pressão dentro da orelha média ou intracraniana. Disacusia, em sua maioria de padrão condutivo à audiometria tonal, também pode estar presente. Nesta revisão da literatura objetivou-se abordar a SDCSS, com seus principais sinais e sintomas, achados diagnósticos e tratamento, assim como enfatizar a importância de sua inclusão dentre as causas de vertigem, visto tratar-se de acometimento ainda pouco conhecido até mesmo entre especialistas. O diagnóstico correto, além de possibilitar seu tratamento, impede que abordagens diagnósticas e terapêuticas inapropriadas sejam realizadas.
The Superior Canal Dehiscence Syndrome (SCDS) was first reported by Minor at. Al. (1998), and has been characterized by vertigo and vertical-torsional eye movements related to loud sounds or stimuli that change middle ear or intracranial pressure. Hearing loss, for the most part with conductive patterns on audiometry, may be present in this syndrome. We performed a literature survey in order to to present symptoms, signs, diagnostic and therapeutic approaches to the SCDS, also aiming at stressing the great importance of including this syndrome among the tractable cause of vertigo. We should emphasize that this is a recent issue, still unknown by some specialists. The Correct SCDS diagnosis, besides enabling patient treatment, precludes misdiagnosis and inadequate therapeutic approaches.
Subject(s)
Humans , Semicircular Canals/abnormalities , Acoustic Stimulation/adverse effects , Nystagmus, Pathologic/physiopathology , Temporal Bone/abnormalities , Vertigo/physiopathology , Audiometry, Pure-Tone , Bone Conduction/physiology , Nystagmus, Pathologic/etiology , Syndrome , Tomography, X-Ray Computed , Vertigo/etiologyABSTRACT
OBJETIVO: Avaliar o número de manobras necessárias para abolir o nistagmo posicional em pacientes com Vertigem Posicional Paroxística Benigna e verificar possíveis influências do substrato fisiopatológico e/ou canal semicircular acometido. FORMA DE ESTUDO: clínico prospectivo com coorte transversal. MATERIAL E MÉTODO: Sessenta pacientes com Vertigem Posicional Paroxística Benigna foram tratados por meio das manobras de reposicionamento de estatocônios, repetidas semanalmente até a abolição do nistagmo. A Análise de Variância foi aplicada para verificar diferenças entre as variáveis dos fatores "substrato fisiopatológico" e "canal semicircular acometido". RESULTADOS: Foram necessárias de 1 a 8 manobras, em média 2,13 para abolir o nistagmo posicional. A cupulolitíase necessitou de um número maior de manobras que a ductolitíase (p=0,0002*) e não houve diferença entre os canais semicirculares (p=0,5213). Nos canais anterior e posterior, a ductolitíase precisou em média de uma a duas manobras e a cupulolitíase precisou em média de três manobras. No canal lateral, tanto a ductolitíase quanto a cupulolitíase precisaram de duas manobras, em média. CONCLUSÕES: São necessárias de uma a oito manobras semanais de reposicionamento de estatocônios, em média duas, para eliminar o nistagmo posicional na Vertigem Posicional Paroxística Benigna. A cupulolitíase necessita de maior número de manobras que a ductolitíase. O canal semicircular acometido não influencia o número de manobras terapêuticas.
AIM: To evaluate the number of weekly canalith repositioning procedures needed to eliminate positioning nystagmus in patients with benign paroxysmal positional vertigo and to verify influences of canalithiasis or cupulolithiasis and/or semicircular canal involvement. STUDY DESIGN: clinical prospective with transversal cohort. MATERIAL AND METHOD: Sixty patients with benign paroxysmal positional vertigo were consecutively selected according to each combination of canalithiasis or cupulolithiasis with semicircular canal involvement. Patients were treated by means of canalith repositioning procedures repeated weekly until the elimination of the positioning nystagmus. Analysis of Variance was used to verify differences between the variables. RESULTS: An average of 2.13 procedures (from 1 to 8) was needed to eliminate the positioning nystagmus. Canalithiasis required an average of 1.53 procedures, while cupulolithiasis needed 2.92 procedures (p=0.0002). An average of two procedures was needed to eliminate the positioning nystagmus in cases with posterior canal involvement, 2.39 procedures in cases with anterior canal involvement and 2.07 procedures in cases with lateral canal involvement (p=0.5213). CONCLUSIONS: From one to eight weekly canalith repositioning procedures were needed, with an average of two, to eliminate positioning nystagmus in benign paroxysmal positional vertigo. Cupulolithiasis requires a greater number of procedures than canalithiasis to eliminate positioning nystagmus. Semicircular canal involvement didn't influence the number of therapeutic maneuvers.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged, 80 and over , Nystagmus, Pathologic/therapy , Otolithic Membrane/physiopathology , Physical Therapy Modalities , Semicircular Canals/physiopathology , Vertigo/therapy , Cohort Studies , Cross-Sectional Studies , Nystagmus, Pathologic/etiology , Nystagmus, Pathologic/physiopathology , Prospective Studies , Vertigo/complications , Vertigo/physiopathologyABSTRACT
A pesquisa do nistagmo de posicionamento com óculos de Frenzel foi conduzida em 340 pacientes com hipótese diagnóstica de Vertigem Posicional Paroxística Benigna (VPPB). Houve comprometimento, em ordem decrescente de prevalência, dos canais semicirculares posteriores em 285 casos, posteriores ou anterioresem 44 casos, anteriores de canal semicircular posterior é comum, enquanto que o canal anterior é pouico freqüente e o de canal lateral é mais raro; o envolvimento labiríntico unilateral é mais freqüente do que o bilateral; o substrato fisiopatológico presumido de ductolitíase é mais comum do que o de cupulolitíase.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Nystagmus, Pathologic/physiopathology , Vertigo/diagnosis , Aged, 80 and over , Diagnostic Techniques, Otological , Electronystagmography , Eyeglasses , Vertigo/physiopathologyABSTRACT
To examine HSN, horizontal HST should be performed routinely, supplemented by vertical HST when a central lesion is suspected. HSN with more than four distinct consecutive beats is generally pathological, especially when observed using Frenzel's glasses in a dark room. However, HSN may be physiologial only when the patient's vision is completely blocked, such if the patient's eyes are closed. Horizontal HSN suggests the exsistence of an imbalance between right and left in the vestibular system, and it may have either a peripheral or a central origin. On the other hand, a distinct vertical (usualy down beating) HSN strongly suggests the existence of a central lesion. HSN usually appears in a monophasic or biphasic pattern. The pattern which appears in case of peripheral vestibular disorder (PVD) depends mainly on the stage of recovery. PII nystagmus of biphasic HSN is usually weaker in terms of nystagmus intensity, but tends to lost longer than PI in PVD. PII that is a strong or stronger than PI may suggest a central origin. In long-lasting PVD, HSN beats toward the normal ear in about 75 per cent of monophasic cases and in more than 85 per cent of biphasic cases in PI. Usually, a patient with biphasic HSN of this type is already in the recovery stage. In many cases with long-lastins PVD, both spontaneous nystagmus (SPN) and HSN reverse their nystagmus directions during the course recovery in the following order: SPN toward the impaired ear (irritative nystagmus), SPN toward the normal ear, (paretic nystagmus) monophasic HSN toward the normal ear, biphasic HSN in PI toward the normal ear, monophasic HSN toward the impaired ear, and finally SPN toward the impaired ear (recovery nystagmus). In patients with long-lasting PVD, who show monophasic nystagmus toward the impaired side, the function of the impaired labyrinth is usually recovering (reverse-type monophasic HSN). This type of HSN can also be observed in cases of Meniere's disease. Biphasic HSN in which the nystagmus in PI beats toward the impaired ear (reverse-type biphasic HSN) is rarely encoutered in cases of long-lasting PVD. In cases of Meneire's discase, on the other hand, this type of biphasic HSN is relative ly common and amounts, when added to cases of monophasic HSN toward the impaired ear, to about 30 per cent of all cases. The monoexistence of CP is highly probale (95 per cent), when HSN is not present. On the other hand, whether CP is present cannot be determined when HSN is positive.