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Biomedical subjects

J Rutka

Publications and source records attributed to J Rutka.

At least 37 records · Page 2Linked to original sources
PubMed1999

Significance of head-shaking nystagmus in the evaluation of the dizzy patient.

In a series of studies, the phenomenon of head-shaking nystagmus (HSN) was assessed in 50 control subjects and 1364 consecutive dizzy patients who underwent formal electronystagmography (ENG) at the Toronto Hospital Center for Advanced Hearing and Balance Testing. HSN was compared in a series of 30 patients who underwent conventional electro-oculography (EOG) vs magnetic (scleral) coil eye movement recordings. Clinical correlation of HSN to other parameters of the ENG test battery was performed in another sub-series of 300 patients with known diagnoses. HSN was identified in 31.7% of dizzy patients vs 24% of control subjects. No significant difference in its manifestation was noted between active vs passive head-shaking tests or on EOG vs magnetic (scleral) coil eye movement recordings. When compared to other aspects of the ENG test battery, HSN was neither specific nor sensitive for vestibular dysfunction. It nevertheless correlated well with the presence of a caloric reduction and with increasing R/L excitability differences on ENG testing. When present, HSN was characteristically monophasic in 76.8%, biphasic in 22.7% and triphasic in 0.5% of subjects. The initial direction of HSN generally obeyed Ewald's second law, but the reverse was noted in 27% with monophasic and 17.6% of patients with biphasic HSN. In the subseries of 300 patients with known diagnoses, the presence of HSN was statistically significant (p < 0.05) in patients with peripheral vestibular dysfunction vs psychogenic dizziness. Its presence was also significant in well-documented peripheral vestibular disorders such as Meniere's disease (p < 0.01), vestibular neuronitis (p < 0.05) and acoustic neuroma (p < 0.05). Localization of the disease involvement based on the initial direction of HSN was especially unpredictable in patients with Meniere's disease. The significance and usefulness of the head-shake test in the otoneurological evaluation of the dizzy patient is further commented on.

Dizziness↗
PubMed1999

Verotoxin induces apoptosis and the complete, rapid, long-term elimination of human astrocytoma xenografts in nude mice.

Verotoxin 1 (VT1) is an E. coli elaborated subunit toxin active only against (tumor) cell lines that express the VT1 receptor, globotriaosyl ceramide-Gb3. Astrocytomas can be highly malignant brain tumors that remain refractory to clinical treatment. Some human astrocytoma cell lines are particularly sensitive to VT1 in vitro. To address whether this represents a feasible approach to the elimination of these tumors in man, human astrocytoma tumor xenografts in nude mice were treated with verotoxin. Following a single low-dose intratumoral injection of VT1, complete regression of a 1-cm-diameter tumor within 10 days was observed in all treated animals, without reoccurrence (up to 60 days). Apoptosis was demonstrated in both tumor and vascular cells within the treated xenograft. Verotoxin binding to tumor cells and blood vessels in sections of primary glioblastoma multiforme was found.

Animals↗
PubMed1999

The risk of hearing loss in nongrowing, conservatively managed acoustic neuromas.

OBJECTIVE: To determine the risk of loss of useful hearing in the absence of tumor growth among patients undergoing conventional management of acoustic neuroma. SETTING: Tertiary referral center. STUDY DESIGN: Retrospective case review. PATIENTS: Ten patients (12 ears) were identified having a period of no tumor growth of at least 6 months (19.0+/-12.8 months), and for whom at least two audiograms were available in this period. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Loss of useful hearing defined using 70% speech discrimination score (SDS) and 30 dB pure tone average (PTA) (70/30), or 50% SD and 50 dB PTA (50/50) criteria. RESULTS: Three of seven (43%) ears with useful hearing using the 70/30 rule and two of eight ears (25%) using the 50/50 rule lost this useful hearing. CONCLUSIONS: There is a significant risk of useful hearing loss with conservative management of nongrowing acoustic neuromas.

Adult↗
PubMed1998

Troy, Mycenae, and the otologic demise of Herr Heinrich Schliemann.

Heinrich Schliemann (1822-1890) was a self-made man with a remarkable aptitude for language and an excellent business mind. He was also the founder of Aegean archeology, providing a factual base for the writings of Homer, which until then had been considered merely a collection of mythologic poems. During his life, Schliemann suffered from ear trouble, ultimately dying from an otogenic temporal lobe brain abscess. He consulted many of the most famous 19th century otologists and was eventually operated on by the famous Professor Schwartze. We present the life and death of arguably the most famous man of his day as drawn from a number of biographic sources and speculate on the ear pathology that ultimately lead to his demise.

Archaeology↗
PubMed1998

No therapy: use, abuse, efficacy, and morbidity--the European versus the Third-World experience.

OBJECTIVE: Historical controls documented a marked reduction in complications from acute otitis media (AOM) and chronic suppurative otitis media (CSOM) with the introduction of antibiotic therapy in the period 1930 to 1950s amongst other changes that occurred in North American and Western European society. Today, the natural history of spontaneous remission in AOM in over 80% of children within 24 hours of presentation questions the raison d'etre for the routine prescription of antibiotics for what may essentially be a self-limiting condition. Metaanalyses of numerous antibiotic versus placebo trials in the treatment of AOM have demonstrated little difference in clinical outcome, as have treatment stratagems where antibiotics have been initially withheld. More judicious use of antibiotic therapy in AOM appears to have been associated with a decline in antimicrobial resistance in countries such as the Netherlands and Iceland. It is difficult to know, however, whether the direct savings from decreased antibiotic use will ultimately lead to an actual decrease in the other direct and indirect costs associated with AOM. Unfortunately, children in the third world have not experienced a corresponding decline in ear disease. Significant loss of disability-adjusted life years (DALYs) continues to occur from otitis media. Withholding antibiotic therapy in the treatment of AOM would more than likely impose greater morbidity and mortality on an already disadvantaged population. Nevertheless, the experience of the Thai Rural Ear Nose and Throat Foundation has been seminal in documenting and affecting change in both the morbidity and mortality patterns of AOM and CSOM during Thailand's transition toward developed nation status. This article analyzes these issues and provides a review of the literature available.

Acute Disease↗
PubMed1997

Acute obstructive hydrocephalus and sudden death in children.

STUDY OBJECTIVE: Sudden death from obstructive hydrocephalus related to intracranial neoplasms has rarely been reported in the pediatric literature. We sought to review the presenting signs and symptoms of acute hydrocephalus resulting from intracranial mass lesions to guide clinicians in the early identification of these potentially reversible lesions. METHODS: All cases of sudden unexpected death attributable to obstructive hydrocephalus that occurred from 1990 through 1994 at the Hospital for Sick Children, Toronto, were retrospectively reviewed. RESULTS: During the study period, seven children, ages 10 months to 15 years, died unexpectedly with acute obstructive hydrocephalus. Six children were apparently normal, and none had any known neurologic disease. All patients had a previously undiagnosed intracranial tumor located at a critical site for CSF flow: colloid cyst(n = 2), astrocytoma (n = 2), ependymoma (n = 2), suspected lymphoma (n = 1). Presenting features included vomiting in all cases, vomiting for longer than 2 weeks in three, headache in four, and lethargy in three. Five patients were misdiagnosed with viral illnesses, including three with presumed gastroenteritis who received intravenous rehydration therapy Focal gastrointestinal signs were absent. CONCLUSION: This case series highlights a life-threatening but misleading presentation of intracranial tumors. The diagnosis of gastroenteritis should be made cautiously when headache and vomiting occur in the absence of focal intestinal complaints. A history of vomiting exceeding a few days' duration warrants further investigation. Persistent lethargy should be considered a neurologic rather than a nonspecific clinical sign. Heightened awareness of this neurosurgical emergency may lead to swift intervention and potential reversibility with diversion of CSF.

Brain Neoplasms↗
PubMed1997

Prevalence of head-shaking nystagmus in patients according to their diagnostic classification in a dizziness unit.

OBJECTIVE: In a previous publication, the authors documented the prevalence and characteristics of head-shaking nystagmus (HSN) in over 1300 consecutive dizzy patients during formal electronystagmography (ENG) at the combined Otologic Function Unit (OFU) of the Toronto and Mount Sinai Hospitals. This companion study was done to prospectively analyze a subgroup of 300 patients with known clinical diagnoses belonging to the senior author (J.R.). METHODS: The prevalence of HSN in this series of patients with a known diagnosis is prospectively compared to the presence of HSN in a series of normal controls. RESULTS: Results indicate that HSN is seen significantly (p < .05) in those patients with peripheral vestibular dysfunction and that the more globally the peripheral vestibular disorder involves end-organ (i.e., Meniere's) or primary afferent-neuron function (i.e., vestibular neuronitis), the more likely HSN will be present. CONCLUSION: We further comment on the usefulness of the head-shake test and its clinical relevance in the bedside examination of the dizzy patient.

Adolescent↗
PubMed1997

Rescued from the sands of time: interesting otologic and rhinologic findings in two ancient Egyptian mummies from the Royal Ontario Museum.

OBJECTIVE: Two mummified specimens from the Royal Ontario Museum both approximately 3500 years old were recently examined in the Ear Pathology Research Laboratory (EPRL) of the University of Toronto. High-resolution computed tomography (CT) scanning of the ancient Egyptian mummified heads was undertaken with special reference to the nasal cavities, paranasal sinuses, anterior cranial fossae, and temporal bones. The elaborate ritual for the dead that was required to prepare for the after life and our knowledge concerning the status of ear and nasal pathology in ancient Egypt is reviewed. CONCLUSION: As a result of this preliminary study, we believe we may have discovered a hitherto unrecognized step in the formal process of mummificiation.

Egypt, Ancient↗
PubMed1996

Results of labyrinthectomy in the treatment of Menière's disease and delayed endolymphatic hydrops.

Transmastoid total osseous labyrinthectomy for incapacitating unilateral Meniére's disease and the related clinical phenomenon of delayed endolymphatic hydrops (DEH) is a generally accepted treatment modality when hearing preservation is not an issue. Over the past 8 years, 25 patients (13 Meniére's and 12 DEH) underwent labyrinthectomy by the senior author (J.R.) at the Toronto Hospital. This retrospective study compares and contrasts these two clinical groups preoperatively and subsequently analyzes the results of labyrinthectomy. The patients' own responses to a specially designed questionnaire provided valuable insight into the efficacy of labyrinthectomy and into some of the long-term problems they experienced following surgery.

Adult↗
PubMed1995

Prenatal diagnosis of retinal nonattachment in the Walker-Warburg syndrome.

We report on the prenatal ultrasonographic diagnosis of Walker-Warburg syndrome based on cerebral and ocular findings. The ultrasound study done at 37 weeks gestation documented hydrocephalus and retinal nonattachment consistent with this syndrome. The ability to detect retinal nonattachment prenatally may have implications for the prenatal diagnosis of other conditions which have early retinal nonattachment as one of their findings. However, it is uncertain how early in pregnancy this defect can be detected.

Abnormalities, Multiple↗
PubMed1994

Pediatric malignant glioma with tubuloreticular inclusions and MYCN amplification. Report of a case with immunohistochemical, ultrastructural, flow cytometric, karyotypic, and Southern blot analysis.

BACKGROUND: The authors described unusual pathologic features in a left frontal lobe malignant glioma in a 31/2-year-old boy. The pathology was similar in the initial excision and two subsequent recurrences at 9 and 11 months and at autopsy, when extensive subarachnoid spread was noted. METHODS: The tumor was studied by conventional histology, immunohistochemistry, flow cytometry, transmission electron microscopy (TEM), immune electron microscopy (IEM), and cytogenetic and Southern blot analysis. RESULTS: The tumor revealed two different histologic patterns. One component showed large cells with eosinophilic cytoplasm, vesicular nuclei with prominent nucleoli, eosinophilic perinuclear inclusions, and immunoreactivity for glial fibrillary acidic protein (GFAP) and vimentin. The other component consisted of undifferentiated cells with hyperchromatic nuclei and scanty cytoplasm. By TEM, the perinuclear aggregates were composed of tubuloreticular inclusions, which were also observed in endothelial cells within the tumor vasculature. By IEM, the intermediate filaments in the tumor cell cytoplasm were decorated with GFAP. Flow cytometric results revealed a marked increase in the S-phase (48%), whereas cytogenetic analysis of short-term cultures showed an abnormal karyotype containing marker chromosomes and double minutes. In the second resection, additional karyotypic abnormalities were noted, including 1p- and several additional markers. The first and second resections showed MYCN amplification by Southern Blot analysis in the 60- to 80-fold range. CONCLUSIONS: This tumor presents unique histologic, ultrastructural, and cytogenetic findings as well as MYCN amplification that is notable for a pediatric malignant glioma. Tubuloreticular inclusions were a prominent feature in this tumor, which again is unique for a glioma.

Blotting, Southern↗
PubMed1994

Computer generated three-dimensional reconstruction of the bony labyrinth in Mondini's dysplasia.

The bony labyrinth obtained at necropsy in four cases was studied by a new computer-generated three-dimensional (3-D) system. One case was normal (control) and the other three were histopathologically confirmed cases of Mondini's dysplasia. In case 1, the cochlea had only 2 turns and the lateral semicircular canal did not make a circle but appeared as a spherical mass projecting from the utricle even though the posterior semicircular canal made a normal circle. In case 2, there were no turns in the cochlea even though the semicircular canals and the vestibule appeared normal. In case 3, the cochlea showed 1 to 1 and 1/2 turns and the semicircular canals were premature showing only bud-like projections. This 3-D imaging system, which utilizes the toggling method, provides a way of obtaining satisfactory images without markers, and the time required to obtain these 3-D images was reduced by using a video camera instead of a digitizer. One of the problems associated with the use of 3-D imaging is the long processing time. We resolved this by inputting the section images with a video camera and by picking up structures using density segmentation instead of tracing with a digitizer.

Child, Preschool↗
PubMed1993

Brain tumor protocols in North America.

A list of active investigative brain tumor protocols in North America is presented. The fact that there are 138 protocols (and certainly some have been missed) indicates the diversity and intensity of research into this difficult problem. The geographic diversity of institutions involved in brain tumor clinical trials also underscores the opportunity available to a large number of clinicians caring for patients with brain tumors to refer them for participation in such a study.

Brain Neoplasms↗
PubMed1993

A study into the phenomenon of head-shaking nystagmus: its presence in a dizzy population.

In this paper we have prospectively analyzed results from approximately 1,500 patients who underwent a head-shaking test during routine electronystagmography (ENG). The incidence of head-shaking nystagmus (HSN) in a dizzy population was relatively high (31.7%) when compared to other so-called abnormalities in the routine ENG test battery. Its presence was also similar in both active vs. passive head-shake tests. When present, different types of HSN were identified (monophasic (76.8%), biphasic (22.7%) and triphasic (0.5%)). In some cases, reversals of the expected "normal" pattern occurred. A high correlation was found to exist between a positive head-shake test and the presence of spontaneous nystagmus, positional nystagmus and caloric test abnormalities.

Adolescent↗
PubMed1992

The incidence and distribution of cupular deposits in the labyrinth.

Findings of large basophilic staining deposits on the cupula of the posterior semicircular canal ampulla have been used in part to explain the clinical phenomenon of benign positional vertigo (BPV). Although it is generally agreed that cupulolithiasis may involve other canal ampullae, the precise nature, distribution, and origin of these deposits remains unclear. In order to provide a better understanding of this finding, a series of 566 temporal bone specimens from the Ear Pathology Research Laboratory at the University of Toronto were reviewed. The results from this survey and speculations concerning the nature and formation of these deposits are discussed.

Calculi↗