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PubMedDate not supplied

Rigid flatfoot.

The proper management of the rigid flat-foot requires an accurate diagnosis since the condition is treated on causal or rational basis. Calcaneonavicular coalition best seen on an oblique view of the foot may be treated by resection of the coalition with extensor digitorum brevis interposition. If the diagnosis is made sufficiently early, the resection can lead to an essentially normal foot. Coalition between the talus and the calcaneus may occur in the posterior, middle or anterior facet. The most common coalitions are seen in the middle facet area followed by those in the anterior facet with the posterior facet coalition rarely being seen. Coalitions in the area of the middle facet are usually managed nonoperatively; triple arthrodesis is used only if symptoms are not relieved by nonoperative measures. Resection of a talocalcaneal coalition in the middle facet is rarely indicated but occasionally will give relief when the coalition either presses on the medial plantar nerve or causes a mechanical disturbance of the ankle. Anterior facet coalitions should receive a trial of cast immobilization but frequently require triple arthrodesis. Other conditions such as rheumatoid and post-traumatic arthritis will frequently respond to a period of immobilization in a plaster cast. Triple arthrodesis has not been required in rheumatoid arthritis in the author's series but occasionally is necessary in the post-traumatic rigid flatfoot. Other rare causes of the rigid flatfoot should be kept in mind for a complete diagnostic evaluation since even a neoplasm (fibrosarcoma) has been reported to cause this symptom complex.

Arthrodesis↗
PubMed1993

Micropachometric investigation of rigid contact lens-induced corneal dystrophies.

We evaluated rigid contact lens associated changes in central corneal thickness using an improved method of pachometry. After altering one lens parameter (e.g., lens diameter or base curve) and keeping all other parameters constant, we evaluated 30 rigid lens patients at 4-hour intervals over 20-hour periods. Using micropachometry we were able to detect changes as small as 10-20 microns in the central cornea region. We found that the degree of corneal swelling from rigid contact lens wear can vary from one area to another. Thinning in one area can result from lens compression, while thickening in an adjacent area can result from lens-induced hypoxia. Using micropachometry for the early detection of corneal changes such as thinning may help to avoid problems associated with long-term lens wear.

Adult↗
PubMed1995

Effects of long-term rigid contact lens wear on the endothelium of corneal transplants for keratoconus 10 years after penetrating keratoplasty.

Contact lenses do not appear to cause changes in endothelial cell density in normal individuals. In eyes with abnormal corneal endothelium, however, the effects of contact lens wear may be more severe. We studied eyes with abnormally enlarged endothelial cells resulting from penetrating keratoplasty (PK). We identified 34 patients with phakic corneal transplants for keratoconus that had the following characteristics: first graft, no rejection episodes, no reoperations, and follow-up examinations for at least 5 postoperative years. Fifteen of these patients had been fit with daily wear rigid contact lenses (12 rigid gas permeable, 3 polymethylmethacrylate) postoperatively. Contact lens fitting occurred anywhere from 3 months to 2 years post-PK; 19 control subjects had not been fit with contact lenses. Twenty-one of the patients (nine contact lens wearers and 12 control subjects) were examined 10 years after keratoplasty. The contact lens group developed polymegethism, but there was no significant difference from the controls in endothelial cell density at 5 or 10 years post-PK. The cell density at 10 years was 824 +/- 156 cells/mm2 (mean +/- SD) in the contact lens group and 833 +/- 167 cells/mm2 in the control group (P = 0.90). The endothelial cell loss 10 years after keratoplasty was 73% for both groups. Thus, we found no effect on endothelial cell density from at least 7 years of daily rigid contact lens wear in eyes with corneal transplants for keratoconus.

Adult↗
PubMed1996

[Changes in erythrocyte rigidity and neonatal relative viscosity during the adaptation of the newborn to extrauterine life. Observations on term and premature newborns].

BACKGROUND: The deformability of the red blood cell is a important factor in the blood viscosity and it is related with the blood viscosity and it is modified by the plasma biochemical characteristics and the composition of hemoglobin in the red blood cell. In this study, we want to compare the rheologic characteristics in the blood of cord umbilical in term and preterm newborns during the first 24 hours of life and we want to evaluate that hemorheologic modifications are explained because of the different gestational age. METHODS: We studied 191 newborns in our maternity from 1989 until 1990. We analyzed four groups: In the first group (n = 40) of preterm newborn (gestational age < 37 weeks); in the second group (n = 72) of term newborns (gestational age > 37 weeks); the samples were obtained from umbilical artery immediately after the umbilical cord clamp; in the third group (n = 38) of preterm newborn and the fourth group of term newborns (n = 41) was studied during 24 hours after delivery. We analyzed the plasma viscosity, the viscosity of red blood cell (RBC) content and the RBC rigidity calculated by Taylor's coefficient. RESULTS: The RBC rigidity is greater during the post-delivery period, which could be in relation with the greater values of plasma viscosity and the RBC content during the postnatal period. The comparisons between umbilical cord of term and preterm newborn they did not show differences for the RBC content viscosity and the relative viscosity. The plasma viscosity of the umbilical cord was discretely greater in the term newborn though in meaning limits statistics. In umbilical cord the hematocrit does not defer significantly between term and preterm newborns. CONCLUSIONS: Following our data we can make firm that the RBC rigidity is increased after the delivery in term and preterm newborns and the greater relative viscosity observed in newborn to term during the first life extrauterine days in related fundamentally to the corporal liquids readjustment that occurs after of delivery.

Adaptation, Physiological↗
PubMed1996

Ocular characteristics associated with rigid gas-permeable lens adherence.

PURPOSE: Rigid gas-permeable (RGP) lens adherence after overnight lens wear is clearly a patient-dependent phenomenon. However, no previous study has attempted to determine whether specific ocular characteristics are associated with an increased frequency of lens adherence. METHOD: In this study, clinically applicable tests were used to measure a range of ocular characteristics, including central and peripheral corneal curvature, tear film status, eyelid characteristics, central corneal thickness, and ocular rigidity in a group of 22 young adult subjects for whom reliable estimates for frequency of overnight RGP lens adherence had been obtained from earlier studies. RESULTS: Linear discriminant analysis revealed that a higher frequency of lens adherence was associated with lower ocular rigidity, thinner central corneas, greater eyelid tension, and lower amounts of corneal astigmatism. CONCLUSIONS: These findings suggest a clinical approach for identifying patients who may develop clinically significant lens adherence during RGP extended wear, and also provide support for the "thin film adherence" theory of RGP lens adherence.

Adhesiveness↗
PubMed1996

Value of rigid bronchoscopy and cytodiagnosis of bronchial washings in detecting bronchial carcinoma in the presence of a carcinoma of the upper aerodigestive tract.

OBJECTIVE: To assess the usefulness of rigid bronchoscopy and bronchial washings in detecting primary lung carcinomas. SETTING: Department of Otolaryngology, University Hospital of Ghent, Belgium. DESIGN: Prospective analysis of patient investigations. METHOD: The results of 127 rigid bronchoscopies with bronchial washings in patients with a new, untreated head and neck tumour and a normal chest radiograph were analyzed for their usefulness in detecting simultaneous primary lung carcinomas. All patients were followed for a minimum of 2 years or till death. RESULTS: We found positive bronchial washings in 19 cases (21%). Unilateral positive bronchial washings were found in 8 patients (9%). In only one patient was a simultaneous primary lung tumour found. One patient was found to have a pulmonary metastasis. The remaining 6 patients with positive unilateral cytology (6/8) had normal chest roentgenograms and/or CT scans, and did not develop a lung tumour in the course of follow up. Of the 19 positive bronchial washings, 10 patients had a carcinoma of the larynx and two had a large hypopharyngeal carcinoma. CONCLUSIONS: Contamination of bronchial washings with tumour cells from head and neck neoplasms limited seriously the usefulness of positive bronchial cytology. The sensitivity and specificity of the rigid bronchoscopy with bronchial washing is too low to justify its cost.

Adult↗
PubMed1997

Rigid lens dynamics: lid effects.

PURPOSE: Lid architecture, lid tension, blink action, and blink rate may all influence rigid lens centration and stability. The aims of this study were to assess the nature of the relationship between lid geometry and lens position and to examine the influence of lens-lid interactions on the association between lens position and lens center of gravity and mass. METHODS: Eight subjects (four with high riding lenses and four with low riding lenses) participated in the study. Each subject was fit with 12 lenses-six designs in each of two materials. Lens center of gravity was calculated and lens mass was measured in every case. For each lens, the following four lens dynamics variables were assessed over a five blink cycle for both the vertical and horizontal meridians: 1) initial lens position; 2) settled lens position; 3) amount of lens movement; and 4) rate of lens movement. Lower lid position and palpebral aperture height were measured for each subject. RESULTS: Graphical analysis showed that a low upper lid position and small palpebral aperture promoted superior lens decentration, while a high upper lid position and wide palpebral aperature predisposed an individual to inferior lens decentration. Significant lid-lens overlap was a common finding with high riding lenses in both the initial and settled lens positions. The results also suggested that while a rigid lens tended to become more stable as the lens center of gravity shifted further behind the corneal apex, this gravitational effect was reduced for lenses that interacted with the upper lid. CONCLUSIONS: Lid geometry can influence rigid lens centration and stability by modifying the effects of lens design and lens mass. We recommend that consideration be given to the nature of potential lens-lid interactions prior to lens fitting.

Blinking↗
PubMed1996

[Video-assisted bedside pleuroscopy under local anesthesia: use of a rigid cystoureteroscope in patients with undiagnosed pleural effusion].

Up to 20% of pleural effusions remain undiagnosed despite history-taking, physical examination, thoracentesis, and percutaneous closed pleural biopsy. The next diagnostic procedure used is often thoracoscopy under general anesthesia in an operating room. We report a technique for beside pleuroscopy and pleural biopsy that can be done without assistance of surgeons. We performed video-assisted pleuroscopy with a rigid cysto-ureteroscope in seven patients with pleural effusion that remained undiagnosed despite extensive clinical evaluation. A sterile 19.8 Fr. rigid cysto-ureteroscope was placed into the pleural space under local anesthesia. Pneumothorax was induced to enhance visualization of the surfaces. Forceps-biopsy specimens were taken of suspicious lesions on the parietal pleural. In three patients the pleural surface appeared smooth and in two the parietal pleural surface was studded. A localized coin-like lesion was seen in one patient, and extensive fibrinogenic adhesions and diffuse opacity of the parietal pleura was seen in another. Using this bedside procedure, we diagnosed pleural tuberculosis in three patients and pleural metastases of adenocarcinoma in one. When done under local anesthesia with a rigid cyst-ureteroscopy, video-assisted pleuroscopy can be a safe and useful diagnostic aid in patients with undiagnosed pleural effusion.

Anesthesia, Local↗
PubMedDate not supplied

Clinical experience in airway endoscopy in children: an emphasis on the comparison between flexible and rigid endoscopy.

Congenital and acquired lesions of the pediatric airway frequently pose perplexing problems in children, infants and newborns. Prompt investigation into the etiology and early intervention are essential to decrease the morbidity and to prevent some tragic events. Endoscopy grants access to the lesion sites for either diagnostic or therapeutic purposes. From April 1994 to May 1997, totally 509 endoscopic procedures, including 292 flexible and 217 rigid endoscopic procedures were performed in 296 pediatric patients at National Taiwan University Hospital. For routine diagnostic procedures, the flexible fiberscope is the instrument of choice which should include a detailed examination of entire upper airway, as farther to tracheobronchi as possible. When flexible endoscopy fails to demonstrate the exact airway lesion or certain surgical manipulation is demanded, rigid endoscopy is favored. The indications for endoscopy were: stridor, respiratory distress, follow-up endoscopy or tracheostoma evaluation, feeding difficulty, hoarseness or weak voice, and suspicious airway foreign body. Common airway problems in serial orders were: laryngomalacia, subglottic stenosis, tracheo/bronchomalacia and airway foreign body. Nearly 20% of patients in this series had multiple synchronous airway lesions. There was no major complication in our 292 flexible endoscopic procedures. Two major complications attributed to endoscopic manipulations occurred in 217 rigid endoscopic procedures.

Adolescent↗
PubMed1998

Appropriate use of the day care unit for rigid endoscopy of the upper aerodigestive tract.

There is increasing pressure for more day surgery to be undertaken in the health service. In this retrospective study of 325 rigid upper aerodigestive tract endoscopies performed in the Day Care Unit of The Royal National Throat Nose and Ear Hospital, London, there were no post-discharge complications and only four patients required admission, none were, in our opinion, the direct result of day case rigid endoscopy. In our unit, the day case rate for microlaryngeal surgery is 44.8%, showing that rates significantly higher than published national rates of 17.1% (1993/1994) are achievable. We conclude that day case microlaryngeal surgery and diagnostic rigid endoscopy of the upper aerodigestive tract is safe if performed by suitably qualified staff in dedicated specialist units with patients selected according to existing day case criteria.

Adolescent↗
PubMed2004

Behavioral disorder, dementia, ataxia, and rigidity in a large family with TATA box-binding protein mutation.

BACKGROUND: Spinocerebellar ataxia type 17 is an autosomal dominant cerebellar ataxia caused by a CAG repeat expansion in the TATA box-binding protein gene. Ataxia is typically the first sign whereas behavioral symptoms occur later. OBJECTIVE: To characterize the unusual phenotypic expression of a large spinocerebellar ataxia type 17 kindred. DESIGN: Clinical, neuropathological, and molecular genetic characterization of a 4-generation family with 16 affected patients. RESULTS: Behavioral symptoms and frontal impairment dominated the early stages preceding ataxia, rigidity, and dystonic movements. Neuropathological examination showed cortical, subcortical, and cerebellar atrophy. Purkinje cell loss and gliosis, pseudohypertrophic degeneration of the inferior olive, marked neuronal loss and gliosis in the caudate nucleus, and in the medial thalamic nuclei were salient features together with neuronal intranuclear inclusions stained with anti-TATA box-binding protein and antipolyglutamine antibodies. The disease was caused by a stable 52 CAG repeat expansion of the TATA box-binding protein gene, although there was apparent variability in the age of onset. CONCLUSION: The characteristics of this family broaden the clinical picture of spinocerebellar ataxia type 17: initial presenile dementia with behavioral symptoms should be added to ataxia, rigidity, and dystonic movements, which are more commonly encountered.

Adult↗
PubMed2002

Encephalomyelitis with rigidity complicating human immunodeficiency virus infection.

A 34-year-old man with human immunodeficiency virus type 1 (HIV-1) presented with axial rigidity, painful spasms, and delayed hemiparesis and dementia. Cerebrospinal fluid analysis showed no antiglutamic acid dehydrogenase antibodies but viral genome from Epstein-Barr virus was detected by polymerase chain reaction. Clinical features and possible viral aetiology of progressive encephalomyelitis with rigidity are briefly discussed.

Adult↗
PubMed1993

Akinetic-rigid syndrome in a 13-year-old girl with HIV-related progressive multifocal leukoencephalopathy.

A 13-year-old HIV-infected girl presented with a rapidly progressive akinetic-rigid syndrome. Cranial magnetic resonance imaging revealed bilateral centrum semiovale lesions extending into the basal ganglia. Detailed histopathological study of a biopsy specimen from the involved regions resulted in a diagnosis of progressive multifocal leukoencephalopathy (PML). This case illustrates that an akinetic-rigid syndrome may be a rare presentation of PML. HIV-related PML may have unusual radiological features. Brain biopsy may be necessary to confirm PML in cases associated with atypical clinical and radiological presentations.

AIDS-Related Opportunistic Infections↗
PubMed1985

Rigidity and catalepsy after injections of muscimol into the ventromedial thalamic nucleus: an electromyographic study in the rat.

The cataleptic state induced by injection of the GABAmimetic drug muscimol into the rat's ventromedial thalamic nucleus (VM) was examined using an electromyographic (EMG) approach. Muscimol in doses up to 50 ng/0.5 microliter injected into the VM induced a tonic EMG activity in the gastrocnemius muscle which is considered to be a measure of limb rigidity. This tonic EMG activity was found to be dose-dependent, GABA specific and locus specific. By recording EMG signals from chronically implanted electrodes in awake, unrestrained rats it was shown that muscular reactions serving to maintain the animal's static equilibrium were intact in the state of VM induced catalepsy. However, animals were unable to initiate movements or locomotion even when they were forced by strong external stimuli. It was found that the animals' immobility was due to an inability to induce a phasic activation of their muscles whereas tonic activation still occurred. It is concluded that the rat's VM is part of a neuronal chain conducting information relevant for the expression of limb rigidity, the VM is involved in the central mechanisms responsible for the phasic activation of a set of muscles.

Animals↗
PubMed1990

An autopsy case of peroneal muscular atrophy with rigidity and tremor. Ultrastructural and systematic morphometrical studies on peripheral nerves.

An autopsy case of hereditary peroneal muscular atrophy (PMA) with rigidity and static tremor is presented. The patient developed slowly progressive distal muscular atrophy of the legs at the age of 15 years. By the age of 52 years, PMA became marked associated with pes cavus, and tremor and rigidity of the extremities were noted. Motor and sensory conduction velocities gradually depressed and lost near the end of his life. At autopsy, the major neuropathological abnormalities involved the peripheral nervous systems, and were characterized by axonal atrophy and loss of myelinated fibers. These changes involved both the proximal and distal nerves, being more severely affected in the distal. The pathological changes in other regions of the nervous systems were mainly confined to the spinal cord, dorsal ganglia and spinal nerve roots, and pigmented neurons in the brain stem. Morphometrically, the total fascicular area was much smaller than in control, but the total number of myelinated fibers greatly outnumbered that of control 75,200 to 48,200 at the proximal sciatic nerve and then gradually decreased towards the periphery; however, even in the distal sural nerve, the total number of myelinated fibers exceeded that of control (6820 to 5469). Thus, the density of myelinated fibers were much higher, being 1.5 to 2 times greater, than in control. Its abrupt decline at the distal nerve might account for neurogenic atrophy of the distal musculature. Unmyelinated fibers were slightly increased in density and not atrophic. This case is unique in its clinicopathology and does not belong to any subtypes of PMA including "neuronal plus".

Adult↗
PubMed1984

Acute polyneuropathy with severe generalized rigidity in a child aged 16 months. Preliminary report.

A case of acute severe generalized muscle rigidity in a 16-month-old child is described. The arm flexors and leg extensors were the most severely involved, with all stretch reflexes absent. Motor conduction velocities on the arms and legs were very slow and nerve potentials were not elicited. The rigidity and electromyographically recorded spontaneous activity almost disappeared on carbamazepine treatment, with nerve conduction velocities remaining unchanged.

Acute Disease↗
PubMed1979

The effect of decerebrate rigidity on the intracranial pressure: an experimental study.

The mechanical effect of acute decerebrate rigidity upon the ICP and the mechanisms underlying the relationship between them have been investigated with experiments performed on 26 cats. It has been shown that: a) Extreme rigidity of the peripheral musculature with or without partial activation of the trunkal muscles produces no change in ICP, b) the simultaneous elevation of the intra-thoracic and intra-abdominal pressures is the factor primarily operative in raising and maintaining the elevated ICP, c) when cerebrovascular homeostasis is already defective a subsidiary but not unimportant role is played by the elevation of the systemic arterial pressure, d) under conditions of normal brain elastance mild and short-lasting spasms produce no effect on the ICP. In an animal, however, in which the brain elastance had been increased by inflating a small air-filled balloon, similar spasms produced a marked increase in ICP.

Animals↗
PubMed1981

Decerebrate rigidity produced in cats by focal stereotactic radiofrequency lesions.

A method of producing decerebrate rigidity in cats by means of a radio frequency current was developed. Adequate control of the extent an shape of the lesions necessitated a preliminary investigation of the relationship between the intensity and duration of current, the size of the lesion, and the tissue impedance before and after destruction; this was performed on guinea pigs. The mesencephalic reticulum in cats was identified by depth microelectrode recording and electrical stimulation. Unilateral, midline, and combined stereotactic radiofrequency lesions were made. The anatomical location, the pathological characteristics, and the physiological significance of the lesions with regard to the production of decerebrate rigidity and of the other clinical reactions of the animals are discussed.

Animals↗