Cerebral blood flow threshold of ischemic penumbra and infarct core in acute ischemic stroke: a systematic review.
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Brain Ischemia↗
Biomedical subjects
Donald H Lee
Publications and source records attributed to Donald H Lee.
Ultrasound appearance of knuckle pads.
OBJECTIVE: We describe the ultrasound appearance of knuckle pads. DESIGN AND PATIENTS: Retrospective analysis of imaging in a series of five patients initially referred for evaluation of periarticular soft-tissue swelling of the hands involving the dorsum of the PIP and MP joints. Two patients had associated Dupuytren's contractures. Ultrasound and radiographs of the hands in all patients were reviewed and correlated with clinical history and physical exams. RESULTS: Radiographs in four patients demonstrated dorsal soft-tissue thickening. Ultrasound exams showed increased dorsal subcutaneous thickening, with either diffuse or focal hypoechoic areas corresponding to the areas of soft-tissue fullness identified on physical exam. No erosions or synovial proliferation were identified either by radiographs or ultrasound of the underlying joints. CONCLUSIONS: Knuckle pads can sometimes be difficult to distinguish from synovitis on physical examination. Musculoskeletal ultrasound can quickly identify these superficial lesions and exclude underlying synovial proliferation.
Adult↗
Magnetic resonance imaging sequences for detection of lesions in refractory epilepsy.
Typical sequences in MR imaging of epilepsy been described, in addition to a brief overview of imaging abnormalities that may be seen. The interested reader is referred to a recent publication, Neuroimaging Clinics of North America on Epilepsy, which goes into considerable detail on imaging, including MRI and other modalities.
Brain↗
High-resolution magnetic resonance imaging (MRI), surface coil MRI, and magnetoencephalography.
The high-resolution, phased array, or surface coil techniques offer promise of improvements in diagnosis of cortical abnormalities. Further prospective studies in larger numbers of patients will be needed to determine the exact improvement, which might be expected from experienced image interpreters. Combining high-resolution imaging with MEG would seem to be the best noninvasive way of accurately localizing seizure foci, and any potential anatomic derangements, currently available to us.
Brain↗
Investigations: how the data affect management.
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Age Factors↗
Novel surgical approach to the carpal tunnel: cadaveric feasibility study.
Carpal tunnel syndrome is the most common entrapment neuropathy dealt with by the clinician. Multiple techniques have been used to surgically treat this pathological condition and all of these approach the carpal tunnel from the palmar surface of the hand or wrist. We have developed a novel endoscopic approach to the carpal tunnel utilizing a dorsal approach that necessitates a good appreciation of the anatomy of this region. This approach was carried out in 10 hands. Through a single dorsal incision we were able to transect the flexor retinaculum in all specimens without obvious damage to neural or vascular tissues. The microscissors used in our study were found to be too delicate for transection of the flexor retinaculum thus another cutting tool should be considered. Our dorsal approach with visualization of the internal aspect of the flexor retinaculum may obviate many of the complications that are seen with the current techniques used to surgically treat carpal tunnel syndrome such as injury to the median nerve and its branches. Clinical trials are now necessary with prospective randomized studies that will determine which techniques are most efficacious and minimize complications most effectively.
Aged↗
Intra-arterial thrombolysis of embolic middle cerebral artery using collateral pathways.
BACKGROUND AND PURPOSE: Cervical internal carotid artery (ICA) occlusion associated with middle cerebral artery (MCA) embolic occlusion requires prompt revascularization to prevent devastating stroke. With the advent of endovascular techniques for chemical and mechanical thrombolysis, the clinical outcome of patients with major arterial occlusions will improve. Finding the most expedient pathway to the site of end organ occlusion for thrombolysis is important. METHODS: We present two cases of acute stroke secondary to thrombotic occlusion of the cervical ICA associated with MCA embolic occlusion treated with intra-arterial thrombolysis via catheter navigation through the posterior communicating artery to the site of MCA arterial occlusion. No attempt was made to transverse the occluded ICA. RESULTS: Near complete restoration of flow was achieved in one patient and minimal vessel reopening was observed in the other patient. Both patients had good outcomes. CONCLUSION: Intra-arterial thrombolysis via Circle of Willis collaterals such as the posterior communicating artery for the treatment of acute thrombotic occlusion of the cervical internal carotid artery associated with embolic occlusion of the middle cerebral artery is a therapeutic option. This treatment option avoids the potential complications of navigating through an occluded proximal internal carotid artery and may expedite reopening of the MCA.
Aged↗
The association between restraint system and upper extremity injury after motor vehicle collisions.
OBJECTIVES: This study was designed to investigate the relationship between upper extremity (UE) injuries and occupant restraint systems among front seat occupants who were involved in frontal motor vehicle collisions (MVCs). DESIGN: Case-control. SETTING: The 1995 through 2002 National Automotive Sampling System (NASS) Crashworthiness Data System (CDS). PARTICIPANTS: Subjects were identified from the NASS-CDS. All cases sustained an UE injury with a > or = 2 Abbreviated Injury Scale Score. OUTCOMES: Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated comparing risk of UE in 3 mutually exclusive restraint system groups (seatbelt-only, airbag-only, seatbelt-airbag-combined) to the unrestrained group. Data analysis was adjusted for significant occupant, vehicle, and collision characteristics. RESULTS: Seatbelt-only occupants had a reduced UE injury risk (OR, 0.41; 95% CI, 0.22-0.76). Near null associations were found for airbag-only (OR, 1.1; 95% CI, 0.68-1.76) and seatbelt-airbag-combined (OR, 0.97; 95% CI, 0.56-1.69). CONCLUSION: The results of this study suggest that UE injuries may become more common as a result of MVCs as the proportion of airbags in motor vehicles increases.
Abbreviated Injury Scale↗
Endovascular coil embolization of intracranial aneurysms: important factors related to rates and outcomes of incomplete occlusion.
OBJECT: The authors report on important factors that influenced clinical and angiographically demonstrated outcomes in patients treated using coil embolization. METHODS: This study included 160 consecutive patients who underwent endovascular coil embolization for treatment of intracranial aneurysms. Univariate and multivariate logistic regression analyses were performed to assess factors that influenced the immediate posttreatment angiographic result. Cox regression analysis was used to establish factors related to the occurrence of negative events as well as a curve indicating the time to a negative event. Negative events were defined as aneurysm remnant increase, repeated treatment, rebleeding, or death during periprocedural hospitalization. Seventy-three percent of the patients treated in this study were independent or demonstrated no deficit (Glasgow Outcome Scale [GOS] Score 4 or 5) at a mean follow up of 18.2 months. The annual delayed rebleeding rate was 0.45%. Fifty percent of patients (65 of 131) suffered a negative event within 13 +/- 14 months (standard deviation). Statistically significant factors associated with the occurrence of negative events were rupture status (p = 0.0128) and immediate posttreatment angiographic result (p < 0.001). Overall clinical outcome assessed using the GOS was significantly related to the immediate posttreatment angiographic result (chi2 = 4.788, p = 0.029). The immediate post-treatment angiographic results were significantly influenced by catheter stability (p = 0.0012), aneurysm geometry (that is, simple or complex, p = 0.0053), and aneurysm neck diameter (p = 0.0205). CONCLUSIONS: A good or excellent clinical outcome can be obtained in most patients treated using endovascular coil embolization of intracranial aneurysms. Note, however, that a significant number of patients treated using traditional platinum coils will harbor unstable aneurysm remnants or require repeated treatment.
Adult↗
Efficacy of treatment of severe carotid bifurcation stenosis by using self-expanding stents without deliberate use of angioplasty balloons.
BACKGROUND AND PURPOSE: One of the limitations of carotid artery angioplasty is the potential for embolic stroke. Our purpose was to assess whether the force of a self-expanding stent alone is usually sufficient to dilate severely stenotic atherosclerotic plaques without the deliberate use of an angioplasty balloon. If so, the procedural stroke risk might be reduced. METHODS: Over a 30-month period, 21 consecutive patients were prospectively identified with severe symptomatic carotid artery stenosis (>70% NASCET [North American Symptomatic Carotid Endarterectomy Trial]) and relative indications for endovascular treatment. All underwent treatment with the aim of deploying a self-expanding stent across the stenosis without the use of angioplasty balloons or distal protection devices. RESULTS: Stent deployment was successful in 20/21 patients. In one patient, the stent could not be deployed without balloon predilatation and a stroke occurred. In the other 20 patients, angiography before and immediately after stent deployment showed a reduction in the mean stenosis from 83% to 49%. A second periprocedural stroke occurred as a result of early stent thrombosis at 4 days in a patient who stopped Acetylsalicylic acid while undergoing bowel preparation for colon surgery. He made a good recovery. Average duration of follow-up imaging was 19 months (range, 1-44 months). During the follow-up period there were four deaths, all unrelated to the carotid disease, and no major strokes. At 5-11 months, the average residual stenosis was 21%, which remained stable in 16 of the 18 patients studied between 12 and 44 months (average, 24 months). At last follow-up, in these 16 the mean peak systolic velocity was 123 cm/s (range, 60-238 cm/s) and the mean internal-to-common carotid ratio was 1.8. The other two patients were long-term failures of the "stent-only" approach. In one patient, a heavily calcified plaque prevented stent expansion and the artery occluded at 18 months with a minor stroke. In the second patient, a recurrent stenosis developed at 16 months with one episode of transient ischemic attack. CONCLUSION: Deployment of a self-expanding stent alone resulted in a favorable and more gradual reduction of severe symptomatic carotid stenosis. Improvements in stent profile and chronic outward force may widen the indications for simple stent placement without the use of balloons or adjunctive protection devices.
Aged↗
Imaging correlates of molecular signatures in oligodendrogliomas.
Molecular subsets of oligodendroglioma behave in biologically distinct ways. Their locations in the brain, rates of growth, and responses to therapy differ with their genotypes. Retrospectively, we inquired whether allelic loss of chromosomal arms 1p and 19q, an early molecular event and favorable prognostic marker in oligodendrogliomas, were reflected in their appearance on magnetic resonance imaging. Loss of 1p and 19q was associated with an indistinct border on T(1) images and mixed intensity signal on T(1) and T(2). Loss of 1p and 19q was also associated with paramagnetic susceptibility effect and with calcification, a common histopathological finding in oligodendrogliomas. These data encourage prospective evaluation of molecular alterations and magnetic resonance imaging characteristics of glial neoplasms.
Adult↗
MRI compatible EEG electrode system for routine use in the epilepsy monitoring unit and intensive care unit.
OBJECTIVE: We report on the development of an electroencephalographic (EEG) recording system that is Magnetic Resonance Imaging (MRI) compatible and can safely be left on the scalp during anatomical imaging or used to obtain simultaneous EEG and metabolic or hemodynamic data using functional imaging techniques such as functional MRI or MR spectroscopy. METHODS: We assembled a versatile EEG recording set-up with medically acceptable materials that contained no ferromagnetic components. It was tested for absence of excess heating and distortion of the image quality in a spherical phantom similar in size to average adult human head in a clinical 1.5 T GE scanner. After testing its safety in four volunteers, 100 consecutive patients from our epilepsy long-term monitoring unit were studied. RESULTS: There was no change in the temperature of the EEG electrode discs during the various anatomical MRI sequences used in our routine clinical studies (maximum temperature change was -0.45 degrees C with average head SAR<==1.6 W/Kg in the selected subjects) nor were there any reported complications in the others. The brain images were not distorted by the susceptibility artifact of the EEG electrodes. CONCLUSIONS: Our MRI compatible EEG set-up allows safe and artifact free brain imaging in 1.5T MR scanner with average SAR<==1.6 W/Kg. This EEG system can be used for EEG recording during anatomical MRI studies as well as functional imaging studies in patients requiring continuous EEG recordings.
Artifacts↗
The incidence of wrist interosseous ligament and triangular fibrocartilage articular disc disruptions: a cadaveric study.
PURPOSE: The purpose of this cadaveric wrist study was to determine the incidence and size of defects of the scapholunate interosseous ligament (SLIL), lunotriquetral interosseous ligament (LTIL), and triangular fibrocartilage (TFC) articular disc, and to determine their relationship to wrist arthrosis. METHODS: The status of the SLIL, LTIL, and the TFC articular disc was determined in 96 cadaveric wrists with an average age of 75 years (range, 61-92 y). The location and length of the SLIL and LTIL ligament disruptions and the site of ligament detachment were noted. Ligament disruptions were classified into 1 of 3 grades based on the size of the ligament disruption and the absence (grade 1 and 2 disruptions) or presence (grade 3 disruption) of wrist arthrosis. The location, size, and configuration of the TFC articular disc disruptions also were noted. RESULTS: Disruptions of the SLIL were noted in 34 wrists (35%). There were 20 grade 1, 4 grade 2, and 10 grade 3 ligament disruptions. The average length of ligament disruption was 10.9 mm, or 40% of the length of the ligament. Twenty-four of 34 SLIL disruptions occurred without wrist arthrosis. Disruptions of the LTIL were noted in 47 wrists (49%). There were 23 grade 1, 10 grade 2, and 14 grade 3 ligament disruptions. The average length of ligament disruption was 7.6 mm, or 52% of the ligament length. Thirty-three of 47 LTIL disruptions occurred without wrist arthrosis. Disruptions of the TFC articular disc were noted in 58 wrists (60%). The most common patterns of disruption were either a linear defect at the radial attachment of the articular disc or a centrally located oval defect. Thirty-seven of the 58 TFC articular disc disruptions were noted in wrists without distal radioulnar joint (DRUJ) arthrosis. CONCLUSIONS: There is a high incidence of SLIL, LTIL, and TFC articular disc disruptions in the cadaveric model. Large ligament and TFC articular disc disruptions without wrist arthrosis are very common.
Aged↗
Contralateral motor automatisms in neocortical temporal lobe epilepsy.
BACKGROUND: The lateralizing value of the motor automatisms is generally doubted in most patients with temporal lobe epilepsy. However, subgroup analysis of the seizures of temporal lobe origin suggests a role for motor automatisms in discriminating seizures of neocortical versus mesial temporal lobe origin. METHODS: Video-EEG of a patient with well-defined neocortical temporal lobe epilepsy was reviewed to assess the localizing value of motor automatisms. RESULTS: We report a patient with left upper extremity motor automatisms and clonic movements of the proximal left lower extremity with altered awareness as the sole manifestations of right temporal neocortical seizures. CONCLUSION: Early onset unilateral motor automatisms without dystonic posturing can localize the seizure origin to the contralateral temporal lobe neocortex.
Automatism↗
Infiltrating spinal angiolipoma: a case report and review of the literature.
Angiolipomas are rarely encountered in the spine. We report the case of a 47-year-old man with a thoracic angiolipoma involving the T9 vertebral body. A preoperative spinal angiogram confirmed a highly vascular neoplasm. The lesion was treated with endovascular embolization prior to a T9 corpectomy and resection of the epidural component of the tumor. At time of surgery, minimal blood loss occurred during resection of the vertebral body and the epidural mass. Pathologic examination demonstrated features consistent with spinal angiolipoma. This report emphasizes the clinical, radiographic, and pathologic features of infiltrating spinal angiolipoma and discusses therapeutic management options.
Angiolipoma↗
Indices of resective surgery effectiveness for intractable nonlesional focal epilepsy.
Among 70 patients with intractable focal epilepsy and no specific lesion, as determined by both MRI (magnetic resonance imaging) and histopathology, outcome after resective surgery was polarized: 26 (37%) became seizure free (SF), and 27 (39%) were not helped. Eighteen (42%) of 43 standard temporal resections rendered patients SF, somewhat more than eight (30%) of 27 other procedures. To seek reliable prognostic factors, the subsequent correlative data compared features of the 26 SF patients with those of the 27 not helped. Although ictal semiology guided the site of surgical resection, it and other aspects of seizure and neurologic history failed to predict surgical outcome. However, two aspects of preoperative scalp EEGs correlated with SF outcomes: (a) among 25 patients in whom >50% of clinical seizures arose from the later resected lobe and no other origins, 18 (72%) became SF compared with seven (28%) of 25 with other ictal profiles; (b) 13 (93%) of 14 temporal lobe patients whose interictal and ictal EEGs lacked features indicative of multifocal epileptogenesis became SF compared with five (33%) of 15 with such components. The considered need for subdural (SD) EEG reduced SF outcome from 18 (90%) of 20 patients without SD to eight (24%) of 33 with SD; this likely reflected an insufficient congruity of ictal semiology and interictal and ictal scalp EEG for localizing epileptogenesis. Within this SD group, >50% of clinical seizure origins from a later resected lobe increased SF outcome somewhat: from two (14%) of 14 without this attribute to six (40%) of 15 with it; 100% of such origins increased SF outcome from two (12%) of 16 to six (46%) of 13.
Adolescent↗
The double-density sign: a radiographic finding suggestive of an os acromiale.
BACKGROUND: An os acromiale results from the failure of fusion of the acromial secondary centers of ossification. It is most easily seen radiographically on an axillary lateral view. The purpose of the present study was to describe two simple radiographic findings, the double-density sign on a standard anteroposterior view of the shoulder and a cortical irregularity found on a supraspinatus outlet view, that are highly suggestive of an os acromiale. METHODS: Anteroposterior, axillary lateral, and supraspinatus outlet radiographs of thirty-four shoulders in thirty adult patients with an os acromiale were reviewed by two independent observers and were compared with those of a control group of thirty-one shoulders in twenty-nine patients without an os acromiale. Statistical analysis was performed with use of a generalized logistic regression model to determine if an os acromiale could be detected on all three radiographic views. A kappa analysis was performed to determine interobserver reliability. RESULTS: In the group with an os acromiale, twenty-eight shoulders had a meso-acromion and six had a pre-acromion. A double-density sign was noted on the anteroposterior radiograph of 82.4% of the shoulders, an os acromiale was noted on the axillary lateral radiograph of 95.6% of the shoulders, and a cortical irregularity was noted on the supraspinatus outlet radiograph of 75.8% of the shoulders. In the control group, a double-density sign was noted on the anteroposterior radiograph of 4.8% of the shoulders, no os acromiale was seen on the axillary lateral radiograph of any of the shoulders, and a cortical irregularity was noted on the supraspinatus outlet radiograph of one shoulder. These differences between the os acromiale and control groups were significant (p < 0.0001). The overall sensitivities of the anteroposterior, axillary, and supraspinatus outlet views for the detection of an os acromiale were 82.4%, 94.1%, and 73.5%, respectively. The overall specificities of the three views were 95.2%, 100%, and 98.4%, respectively. The interobserver reliabilities of the three views were 0.66, 0.88, and 0.7, respectively (p < 0.0001). CONCLUSIONS: The double-density sign on a standard anteroposterior radiograph of the shoulder and a cortical irregularity on the supraspinatus outlet view are highly suggestive of an os acromiale. An os acromiale should be suspected in a patient with these radiographic findings. LEVEL OF EVIDENCE: Diagnostic study, Level IV-1 (case-control study). See Instructions to Authors for a complete description of levels of evidence.
Acromion↗
Boxer knuckle (injury of the extensor hood with extensor tendon subluxation): diagnosis with dynamic US--report of three cases.
The use of dynamic ultrasonography (US) in diagnosing traumatic and nontraumatic extensor tendon dislocations in fingers of three subjects is reported. Dynamic US of the clenched fist in two patients with traumatic injury revealed dislocated but grossly intact tendons surrounded by soft-tissue edema; magnetic resonance (MR) imaging in one patient indicated similar findings. Rupture in the sagittal band of the extensor hood mechanism in the two patients was confirmed at surgery. The third subject, an asymptomatic volunteer, had a congenital tendency toward dislocation. Dynamic US of the clenched fist is useful in diagnosing injuries of the extensor hood mechanism.
Adult↗