Neurological conditions such as traumatic brain injury (TBI) and hydrocephalus may lead to intracranial pressure (ICP) elevation. Current diagnosis methods rely on direct pressure measurement, while CT, MRI and other expensive imaging may be used. However, these invasive or expensive testing methods are often delayed because symptoms of elevated ICP are non-specific. Invasive methods, such as intraventricular catheter, subdural screw, epidural sensor, lumbar puncture, are associated with an increased risk of infection and hemorrhage. On the other hand, noninvasive, low-cost, accurate methods of ICP monitoring can help avoid risks and reduce costs while expediting diagnosis and treatment. The current study proposes and evaluates a novel method for noninvasive ICP monitoring using tympanic membrane pulsation (TMp). These signals are believed to be transmitted from ICP to the auditory system through the cochlear aqueduct. Fifteen healthy subjects were recruited and TMp signals were acquired noninvasively while the subjects performed maneuvers that are known to change ICP. A custom made system utilizing a stethoscope headset and a pressure transducer was used to perform these measurements. Maneuvers included head-up-tilt, head-down-tilt and hyperventilation. When elevated ICP was induced, significant TMp waveform morphological changes were observed in each subject (p < 0.01). These changes include certain waveform slopes and high frequency wave features. The observed changes were reversed by the maneuvers that decreased ICP (p < .01). The study results suggest that TMp waveform measurement and analysis may offer an inexpensive, noninvasive, accurate tool for detection and monitoring of ICP elevations. Further studies are warranted to validate this technique in patients with pathologically elevated ICP.
Introduction Minimally invasive intracranial pressure (ICP) screening has long been desired by neurosurgeons. A novel approach deriving ICP from tympanic membrane (TM) pulsation may offer the solution. The ICP waveform appears to be transmitted to the TM by the cochlear aqueduct. The resulting TM infrasonic pulsations can be measured by certain sensors. Elevated ICP alters brain compliance, which appears to yield slower rise times of the TM pulsation waveform. Measurement of this change may be useful in screening for elevated ICP. This paper investigates one such technique. Methods A stethoscope was modified for airtight external ear canal fit; the dome was exchanged for a magnetic reluctance pressure sensor, allowing measurement of TM pulsations. Analog TM pulsations were analyzed by measuring the pulsation's slope ratio between the waveform’s downslope and upslope. Seventeen normal subjects (ages 18-32 years) underwent hyperventilation and tilt table testing to induce ICP changes. An algorithm processed this data and predicted the subject's ICP status. Results The slope ratio method showed consistent and stable changes with the expected alterations in ICP from the tilt test and hyperventilation maneuvers. The classification algorithm correctly identified subjects with elevated ICP in 60 of 60 independent recordings on 17 subjects. Conclusion This paper has four conclusions. First, the "brain stethoscope" can detect increased ICP from the TM pulsation waveform in healthy subjects. Second, analysis of the TM waveform using slope ratio calculations is capable of distinguishing normal versus elevated ICP. Third, the tilt and hyperventilation maneuvers showed the expected physiologic trends. Last, further studies are needed on patients with pathological ICP before the brain stethoscope can be implemented into clinical practice.
Background: Subacute combined degeneration (SCD) is a rare complication of chronic vitamin B12 deficiency that presents with a variety of neurologic findings, including decreased sensation in the extremities, increased falls, and visual changes. Treatment of SCD involves prompt replacement of vitamin B12 and addressing the underlying conditions that cause the deficiency. Given the prevalence of B12 deficiency in the older adult population, clinicians should remain alert to its possibility in patients who present with progressive neuropathy.Case Presentation: This report presents a case of a patient with progressive SCD secondary to chronic B12 deficiency despite monthly intramuscular B12 injections. Conclusions: Appropriate B12 replacement is aggressive and involves intramuscularB12 1000 mcg every other day for 2 to 3 weeks, followed by additional IM administration every 2 months before transitioning to oral therapy. Failure to adequately replenish B12 can lead to progression or lack of resolution of SCD symptoms.
This report reviews the indications and complications of resuscitative thoracotomy in the trauma patient as seen with the clinical course of a 19-year-old male who experienced postoperative pericardial tamponade after a bilateral resuscitative thoracotomy with pericardiotomy. This patient presented to the hospital in critical condition with 31 gunshot wounds (GSWs) distributed over the chest, abdomen, and extremities. After undergoing an initially successful resuscitative thoracotomy, the patient continued to bleed into his chest at a greater rate than the chest tubes were able to adequately evacuate. Despite the presence of a large pericardial window, clotted blood led to cardiac tamponade. Subsequent bedside reopening of thoracotomy under conscious sedation (ketamine, fentanyl, and midazolam) was required to evacuate the clots and stabilize the patient. This case provides the opportunity to discuss several interesting points for managing the traumatized patient, including indications for resuscitative thoracotomy, use of conscious sedation for bedside major surgery, and complications of clamshell thoracotomy, and ethics of resource allocation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.