Jennifer Ernst

Dr. Jennifer Ernst

Division of Innovations in Amputee Medicine, Clinic for Trauma Surgery, Hannover Medical School, 30625 Hanover, Germany

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2021 in Pain Reports
Verified
Journal Article
Open access
JEJoachim Erlenwein
Joachim Erlenwein
MDMartin Diers
Martin Diers
Jennifer ErnstJennifer Ernst
Jennifer Ernst
FSFriederike Schulz
Friederike Schulz
FPFrank Petzke
Frank Petzke
Introduction: Most patients with amputation (up to 80%) suffer from phantom limb pain postsurgery. These are often multimorbid patients who also have multiple risk factors for the development of chronic pain from a pain medicine perspective. Surgical removal of the body part and sectioning of peripheral nerves result in a lack of afferent feedback, followed by neuroplastic changes in the sensorimotor cortex. The experience of severe pain, peripheral, spinal, and cortical sensitization mechanisms, and changes in the body scheme contribute to chronic phantom limb pain. Psychosocial factors may also affect the course and the severity of the pain. Modern amputation medicine is an interdisciplinary responsibility. Methods: This review aims to provide an interdisciplinary overview of recent evidence-based and clinical knowledge. Results: The scientific evidence for best practice is weak and contrasted by various clinical reports describing the polypragmatic use of drugs and interventional techniques. Approaches to restore the body scheme and integration of sensorimotor input are of importance. Modern techniques, including apps and virtual reality, offer an exciting supplement to already established approaches based on mirror therapy. Targeted prosthesis care helps to obtain or restore limb function and at the same time plays an important role reshaping the body scheme. Discussion: Consequent prevention and treatment of severe postoperative pain and early integration of pharmacological and nonpharmacological interventions are required to reduce severe phantom limb pain. To obtain or restore body function, foresighted surgical planning and technique as well as an appropriate interdisciplinary management is needed.

5 September 2022 in Cancers
Verified
Journal Article
Open access
PDF file
MHMadelaine Hettler
Madelaine Hettler
JKJulia Kitz
Julia Kitz
AHAli Seif Amir Hosseini
Ali Seif Amir Hosseini
Manuel GuhlichManuel Guhlich
Manuel Guhlich
BPBabak Panahi
Babak Panahi
JJJens Jakob
Jens Jakob
Histological subtype and grading are cornerstones of treatment decisions in soft tissue sarcoma (STS). Due to intratumoral heterogeneity, pretreatment grading assessment is frequently unreliable and may be improved through functional imaging. In this pilot study, 12 patients with histologically confirmed STS were included. Preoperative functional magnetic resonance imaging was fused with a computed tomography scan of the resected specimen after collecting core needle biopsies and placing radiopaque markers at distinct tumor sites. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grading criteria of the biopsies and apparent diffusion coefficients (ADCs) of the biopsy sites were correlated. Concordance in grading between the specimen and at least one biopsy was achieved in 9 of 11 cases (81.8%). In 7 of 12 cases, fusion imaging was feasible without relevant contour deviation. Functional analysis revealed a tendency for high-grade regions (Grade 2/3 (G2/G3)) (median (range) ± standard deviation: 1.13 (0.78–1.70) ± 0.23 × 10−3 mm2/s) to have lower ADC values than low-grade regions (G1; 1.43 (0.64–2.03) ± 0.46 × 10−3 mm2/s). In addition, FNCLCC scoring of multiple tumor biopsies proved intratumoral heterogeneity as expected. The ADC appears to correlate with the FNCLCC grading criteria. Further studies are needed to determine whether functional imaging may supplement histopathological grading.

2 December 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MKMagnus Niklas Kalff
Magnus Niklas Kalff
VHVictor Hoursch
Victor Hoursch
LJLara Anna Jopp
Lara Anna Jopp
VWViktoria Witowski
Viktoria Witowski
MWMeike Wilke
Meike Wilke
Jennifer ErnstJennifer Ernst
Jennifer Ernst
Background: Research on sensory feedback systems for prosthetic devices aims to enhance sensory capabilities to better meet user needs. Feedback systems for lower limb amputees (LLA) have been shown to reduce cognitive efforts, metabolic cost and phantom limb pain. This study evaluated the effect of a non-invasive, gait-synchronized, vibrotactile feedback system (VTFS) on the gait parameters of LLA. Methods: Four stimulators applied vibrotactile stimulation to the thigh of LLA during walking, corresponding to four pressure sensors located at the fore- and hindfoot embedded in a sock worn on the prosthetic foot. Standardized gait tests, such as the Timed “Up and Go” Test (TUG), the Four Square Step Test (FSST), the 10 Meter Walk Test (10 MWT) and the 2 Minute Walk Test (2 MWT), were performed to assess the risk of falling, coordination, walking speed and endurance before and after intervention. Results: After an average of 61.5 days using the VTFS, gait stability (TUG) improved significantly. Coordination (FSST) improved in 36% of subjects, while 45% showed a clinically relevant increase in gait speed (10 MWT). Conclusions: The results suggest an improved gait performance in the cohort. Though FSST lacked statistical significance, a p-value near 0.05 indicates a trend toward meaningful improvement. Notably, the participant with Targeted Sensory Reinnervation demonstrated the most favorable outcomes.

25 September 2023 in Medicina
Verified
Journal Article
Open access
PDF file
GPGerfried Peternell
Gerfried Peternell
Harald PenassoHarald Penasso
Harald Penasso
HLHenriette Luttenberger
Henriette Luttenberger
HRHildegard Ronacher
Hildegard Ronacher
RSRoman Schlintner
Roman Schlintner
UKUrsula Kropiunig
Ursula Kropiunig
Background and Objectives: After major upper-limb amputation, people face challenges due to losing tactile information and gripping function in their hands. While vision can confirm the success of an action, relying on it diverts attention from other sensations and tasks. This case report presents a 30-year-old man with traumatic, complete vision loss and transradial left forearm amputation. It emphasizes the importance of restoring tactile abilities when visual compensation is impossible. Materials and Methods: A prototype tactile feedback add-on system was developed, consisting of a sensor glove and upper arm cuff with related vibration actuators. Results: We found a 66% improvement in the Box and Blocks test and an overall functional score increase from 30% to 43% in the Southampton Hand Assessment Procedure with feedback. Qualitative improvements in bimanual activities, ergonomics, and reduced reliance on the unaffected hand were observed. Incorporating the tactile feedback system improved the precision of grasping and the utility of the myoelectric hand prosthesis, freeing the unaffected hand for other tasks. Conclusions: This case demonstrated improvements in prosthetic hand utility achieved by restoring peripheral sensitivity while excluding the possibility of visual compensation. Restoring tactile information from the hand and fingers could benefit individuals with impaired vision and somatosensation, improving acceptance, embodiment, social integration, and pain management.

2 November 2021 in Journal of Wound Care
Verified
Journal Article
Closed access
Jennifer ErnstJennifer Ernst
Jennifer Ernst
MTMurat Tanyeli
Murat Tanyeli
TBThomas Borchardt
Thomas Borchardt
MOMoses Ojugo
Moses Ojugo
AHAndreas Helmke
Andreas Helmke
GFGunther Felmerer
Gunther Felmerer
Objective: The response of different critical acute and hard-to-heal wounds to an innovative wound care modality—direct application of cold atmospheric plasma (CAP)—was investigated in this clinical case series. Method: Over an observation period of two years, acute wounds with at least one risk factor for chronification, as well as hard-to-heal wounds were treated for 180 seconds three times per week with CAP. CAP treatment was additional to standard wound care. Photographs were taken for wound documentation. The wound sizes before the first CAP treatment, after four weeks, after 12 weeks and at wound closure/end of observation time were determined using image processing software, and analysed longitudinally for the development of wound size. Results: A total of 27 wounds (19 hard-to-heal and eight acute wounds) with a mean wound area of 15cm2 and a mean wound age of 49 months were treated with CAP and analysed. All (100%) of the acute wounds and 68% of the hard-to-heal wounds healed after an average treatment duration of 14.2 weeks. At the end of the observation period, 21% of hard-to-heal wounds were not yet closed but were reduced in size by >80%. In 11% of the hard-to-heal wounds (n=2) therapy failed. Conclusion: The results suggested a beneficial effect of additional CAP therapy on wound healing. Declaration of interest: This work was carried out within the research projects ‘Plasma for Life’ (funding reference no. 13FH6I04IA) with financial support from the German Federal Ministry of Education and Research (BMBF). In the past seven years AFS has provided consulting services to Evonik and has received institutional support by Heraeus, Johnson & Johnson and Evonik. There are no royalties to disclose. The Department for Trauma Surgery, Orthopaedics and Plastic Surgery received charitable donations by CINOGY GmbH. CINOGY GmbH released the di_CAP devices and electrodes for the study. WV and AH were involved in the development of the used di_CAP device (Plasmaderm, CINOGY GmbH). WV is shareholder of the outsourced start-up company CINOGY GmbH.

7 December 2023 in Medicina
Verified
Journal Article
Open access
PDF file
Jennifer ErnstJennifer Ernst
Jennifer Ernst
JHJanne M. Hahne
Janne M. Hahne
MMMarko Markovic
Marko Markovic
Arndt SchillingArndt Schilling
Arndt Schilling
LLLisa Lorbeer
Lisa Lorbeer
GFGunther Felmerer
Gunther Felmerer
Adding robotic surgery to bionic reconstruction might open a new dimension. The objective was to evaluate if a robotically harvested rectus abdominis (RA) transplant is a feasible procedure to improve soft-tissue coverage at the residual limb (RL) and serve as a recipient for up to three nerves due to its unique architecture and to allow the generation of additional signals for advanced myoelectric prosthesis control. A transradial amputee with insufficient soft-tissue coverage and painful neuromas underwent the interventions and was observed for 18 months. RA muscle was harvested using robotic-assisted surgery and transplanted to the RL, followed by end-to-end neurroraphy to the recipient nerves of the three muscle segments to reanimate radial, median, and ulnar nerve function. The transplanted muscle healed with partial necrosis of the skin mesh graft. Twelve months later, reliable, and spatially well-defined Hoffmann–Tinel signs were detectable at three segments of the RA muscle flap. No donor-site morbidities were present, and EMG activity could be detected in all three muscle segments. The linear discriminant analysis (LDA) classifier could reliably distinguish three classes within 1% error tolerance using only the three electrodes on the muscle transplant and up to five classes outside the muscle transplant. The combination of these surgical procedure advances with emerging (myo-)control technologies can easily be extended to different amputation levels to reduce RL complications and augment control sites with a limited surface area, thus facilitating the usability of advanced myoelectric prostheses.