Nerve Recovery Research Articles

Evaluation of the Physical Treatment Success in Patients with Peripheral Nerve Injury Caused by Firearm

Background: All wars bring high incidence of patients with peripheral nerve injuries, and many of today's knowledge about degeneration, regeneration and surgical treatment in this casuistry come from the period of the global world conflict. Such injuries do not endanger life, but the function of the extremities is threatened, which manifests itself in motor and sensory outbursts, as well as negative psychological implications. Objective: The aims of this article were: a) To present the method of monitoring physical treatment in a patient with a peripheral nerve injury; b) To perform a quantitative analysis of nerve lesions caused by firearms (n = 445);; c) To present the effects of physical treatment for this condition;; d) To analyze the time interval from injury to healing (n = 220);; e) Determine the time from injury until the surgery. Results: Anatomical disruption of axons with complete Waler degeneration. The connective tissue network remains intact and the endoneurium can guide the regenerated nerve fibers to their destination. Spontaneous functional recovery can be expected in 12 to 18 months. Clinical evaluation shows a deficit in the innervation area of damaged axons with muscle atrophy and loss of sensitivity. Nerve recovery can be inhibited by scar formations at the site of injury. Complete interruption of the nerve. Functional recovery is not possible without surgical intervention. Paralysis of mm. atrophy, anesthesia and atrophic skin changes are visible. Conclusion: Rehabilitation is a delicate problem and requires long-term treatment and multidisciplinary cooperation, and is carried out in accordance with the principles of peripheral nerve repair. Factors that facilitate successful regeneration are: a) Pre and post-operative physical treatment; b) Younger age; c) Shorter time since injury (<6 months); d) More distal level of the lesion; e) Absence of factors complicating the injury (infection); and f) The first signs of nerve recovery are the return of sweating and pain.

Piezoelectric materials for neuroregeneration: a review.

The purpose of nerve regeneration via tissue engineering strategies is to create a microenvironment that mimics natural nerve growth for achieving functional recovery. Biomaterial scaffolds offer a promising option for the clinical treatment of large nerve gaps due to the rapid advancement of materials science and regenerative medicine. The design of biomimetic scaffolds should take into account the inherent properties of the nerve and its growth environment, such as stiffness, topography, adhesion, conductivity, and chemical functionality. Various advanced techniques have been employed to develop suitable scaffolds for nerve repair. Since neuronal cells have electrical activity, the transmission of bioelectrical signals is crucial for the functional recovery of nerves. Therefore, an ideal peripheral nerve scaffold should have electrical activity properties similar to those of natural nerves, in addition to a delicate structure. Piezoelectric materials can convert stress changes into electrical signals that can activate different intracellular signaling pathways critical for cell activity and function, which makes them potentially useful for nerve tissue regeneration. However, a comprehensive review of piezoelectric materials for neuroregeneration is still lacking. Thus, this review systematically summarizes the development of piezoelectric materials and their application in the field of nerve regeneration. First, the electrical signals and natural piezoelectricity phenomenon in various organisms are briefly introduced. Second, the most commonly used piezoelectric materials in neural tissue engineering, including biocompatible piezoelectric polymers, inorganic piezoelectric materials, and natural piezoelectric materials, are classified and discussed. Finally, the challenges and future research directions of piezoelectric materials for application in nerve regeneration are proposed.

Understanding the management of brachial plexus birth palsy and the roles of nerve transfers

Early recognition and management of neonatal brachial plexus injury (NBPP) is key to optimizing outcomes and surgical options. Because up to a third of patients with birth palsy may require surgical intervention, the multidisciplinary team must follow up on the function and recovery of the entire upper extremity, from shoulder to fingertips, within the first few months of life. Options include neuroma resection and primary nerve grafting and/or nerve transfers, which can be intra- or extra-plexal, as adjunctive or standalone procedures. When limited proximal nerve roots are available for nerve grafting, or when too many nerve roots are involved, exceeding the supply of nerve graft, extra-plexal nerve transfers are then indicated. While early intervention is preferred (between 3 and 6 months for most authors), older children presenting late (> 1 year since birth) with partial nerve recovery may still potentially benefit from nerve transfers, which can be offered to late-presenting infants. Here we discuss the anatomy, indications, work-up, options, complications, and outcomes for such nerve transfers for upper, lower, and global plexus palsy in neonates. Nerve transfers are a common procedure done for the treatment of various types of birth plexus palsies. Currently, while there is an abundance of clinical reports and evidence, there is still a lack of clarity regarding best practices or in terms of the type of procedure and technique for the treatment of birth plexus palsy. Our hope is that this chapter provides a concise source after an extensive cumulative review of the evidence of best practices for nerve transfers in the case of birth plexus palsy.

The best of both worlds: mastering nerve regeneration combining biological and nanotechnological tools.

The best of both worlds: mastering nerve regeneration combining biological and nanotechnological tools.

Omega-3 polyunsaturated fatty acids and corneal nerve health: Current evidence and future directions.

Corneal nerves play a key role in maintaining ocular surface integrity. Corneal nerve damage, from local or systemic conditions, can lead to ocular discomfort, pain, and, if poorly managed, neurotrophic keratopathy. Omega-3 polyunsaturated fatty acids (PUFAs) are essential dietary components that play a key role in neural development, maintenance, and function. Their potential application in modulating ocular and systemic inflammation has been widely reported. Omega-3 PUFAs and their metabolites also have neuroprotective properties and can confer benefit in neurodegenerative disease. Several preclinical studies have shown that topical administration of omega-3 PUFA-derived lipid mediators promote corneal nerve recovery following corneal surgery. Dietary omega-3 PUFA supplementation can also reduce corneal epithelial nerve loss and promote corneal nerve regeneration in diabetes. Omega-3 PUFAs and their lipid mediators thus show promise as therapeutic approaches to modulate corneal nerve health in ocular and systemic disease. This review discusses the role of dietary omega-3 PUFAs in maintaining ocular surface health and summarizes the possible applications of omega-3 PUFAs in the management of ocular and systemic conditions that cause corneal nerve damage. In examining the current evidence, this review also highlights relatively underexplored applications of omega-3 PUFAs in conferring neuroprotection and addresses their therapeutic potential in mediating corneal nerve regeneration.

Hypoxic pre-conditioned adipose-derived stem/progenitor cells embedded in fibrin conduits promote peripheral nerve regeneration in a sciatic nerve graft model.

Recent results emphasize the supportive effects of adipose-derived multipotent stem/progenitor cells (ADSPCs) in peripheral nerve recovery. Cultivation under hypoxia is considered to enhance the release of the regenerative potential of ADSPCs. This study aimed to examine whether peripheral nerve regeneration in a rat model of autologous sciatic nerve graft benefits from an additional custom-made fibrin conduit seeded with hypoxic pre-conditioned (2% oxygen for 72 hours) autologous ADSPCs (n = 9). This treatment mode was compared with three others: fibrin conduit seeded with ADSPCs cultivated under normoxic conditions (n = 9); non-cell-carrying conduit (n = 9); and nerve autograft only (n = 9). A 16-week follow-up included functional testing (sciatic functional index and static sciatic index) as well as postmortem muscle mass analyses and morphometric nerve evaluations (histology, g-ratio, axon density, and diameter). At 8 weeks, the hypoxic pre-conditioned group achieved significantly higher sciatic functional index/static sciatic index scores than the other three groups, indicating faster functional regeneration. Furthermore, histologic evaluation showed significantly increased axon outgrowth/branching, axon density, remyelination, and a reduced relative connective tissue area. Hypoxic pre-conditioned ADSPCs seeded in fibrin conduits are a promising adjunct to current nerve autografts. Further studies are needed to understand the underlying cellular mechanism and to investigate a potential application in clinical practice.

Frequency of Infra Orbital Nerve Recovery after Open Reduction Internal Fixation of Zygomatico Maxillary Fracture

Objective: The current research aimed to assess the repossession frequency of infraorbital nerve paresthesia after open reduction internal fixation in the treatment of ZMC fractures. Methodology: Randomized control trial was conducted in department of Oral and Maxillofacial Surgery, Ziauddin hospital and Medical University, Karachi from Jan 2020 to July 2021. Data was collected after ethical approval. Patients with unilateral zygomatico maxillary bone fracture satisfying the exclusion and inclusion criteria, and who were ready to give knowledgeable approval after the given explanation about study procedure, how data taken from their cases will be used for research purpose, and after discussion on risk as well as benefits of the procedure, were involved in our study. Results: Data of 150 patients were collected. Out of these 150, 82 were and females 68 were male. The mean age (SD) was 31.48 (5.67 SD) years. Other socio-demographic characteristics are represented in table 1. 106 (71%) of ZMC patients recovered from infra orbital nerve after Open Reduction Conclusions: On the basis of this study it is recommended that open reduction as chosen mode of management whose outcomes in enhanced recovery of functional nerve amongst paresthesia patients after linked to closed reduction approaches. Keywords: Infra Orbital Nerve, Zygomatico Maxillary Complex (ZMC)

Cerebral Adaptation Associated with Peripheral Nerve Recovery in Neuralgic Amyotrophy: A Randomized Controlled Trial

Background: Neuralgic amyotrophy (NA) is a common peripheral nerve disorder caused by auto-immune inflammation of nerves in the brachial plexus territory, characterized by acute pain and weakness of the shoulder muscles, followed by motor impairment. Recent work has confirmed that NA patients with residual motor dysfunction have abnormal cerebral sensorimotor representations of their affected upper extremity. Objective: To determine whether abnormal cerebral sensorimotor representations associated with NA can be altered by specialized, multidisciplinary outpatient rehabilitation focused on relearning motor control. Methods: 27 NA patients with residual lateralized symptoms in the right upper extremity participated in a randomized controlled trial, comparing 17 weeks of multidisciplinary rehabilitation (n = 16) to usual care (n = 11). We used task-based functional MRI and a hand laterality judgment task, which involves motor imagery and is sensitive to altered cerebral sensorimotor representations of the upper extremity. Results: Change in task performance and related brain activity did not differ significantly between the multidisciplinary rehabilitation and usual care groups, whereas the multidisciplinary rehabilitation group showed significantly greater clinical improvement on the Shoulder Rating Questionnaire. Both groups, however, showed a significant improvement in task performance from baseline to follow-up, and significantly increased activity in visuomotor occipito-parietal brain areas, both specific to their affected upper extremity. Conclusions: Abnormal cerebral sensorimotor representations of the upper extremity after peripheral nerve damage in NA can recover toward normality. As adaptations occurred in visuomotor brain areas, multidisciplinary rehabilitation after peripheral nerve damage may be further optimized by applying visuomotor strategies. This study is registered at ClinicalTrials.gov (NCT03441347).

Exploring the Physicochemical, Electroactive, and Biodelivery Properties of Metal Nanoparticles on Peripheral Nerve Regeneration.

Despite the advances in the regeneration/rehabilitation field of damaged tissues, the functional recovery of peripheral nerves (PNs), especially in a long gap injury, is considered a great medical challenge. Recent progress in nanomedicine has provided great hope for PN regeneration through the strategy of controlling cell behavior by metal nanoparticles individually or loaded on scaffolds/conduits. Despite the confirmed toxicity of metal nanoparticles due to long-term accumulation in nontarget tissues, they play a role in the damaged PN regeneration based on the topography modification of scaffolds/conduits, enhancing neurotrophic factor secretion, the ion flow improvement, and the regulation of electrical signals. Determining the fate of neural progenitor cells would be a major achievement in PN regeneration, which seems to be achievable by metal nanoparticles through altering cell vital approaches and controlling their functions. Therefore, in this literature, an attempt was made to provide an overview of the effective activities of metal nanoparticles on the PN regeneration, until the vital clues of the PN regeneration and how they are changed by metal nanoparticles are revealed to the researcher.

Mccune Albright Syndrome/Craniofacial Fibrous Dysplasia and Postcraniectomy Syndrome: Case Report and Literature Review

Introduction: McCune Albright syndrome (MAS) is a rare pathology caused by a genetic mutation of the GNAS1 gene that causes fibrous dysplasia (FD) among other endocrinological and metabolic manifestations (1). Here is presented a case report, in which craniofacial dysplasia (CFFD) produces functional alteration, its treatment, and the management of underlying complications. Case report: A 10-year-old female patient who presented with CFD with progressive involvement of the orbital cavity, compression of the optic nerve and right oculomotor cranial nerves, associated with precocious puberty and the appearance of ‘’café-au-lait’’ spots on the skin and finally, the diagnosis of MAS is made. Right front-parieto-temporal craniectomy and intracanalicular decompression of the optic nerve was performed getting partial improvement of functional alteration. Subsequently, cranioplasty is performed to manage postcraniectomy/trephined syndrome. Discussion: MAS is a genetic postzygotic disease that occurs in early stages of embryonic development, which explains its mosaicism. Among its manifestation is FD, which is explained by the hyperfunctioning nature of the mutation. In the case of DCF, continuous surveillance is required by a multidisciplinary team that includes a neurosurgeon, whose intervention is reserved for cases in which functional alterations occur, following the recommendations given by medical literature regarding the approach and type of surgery. Decompressive craniectomy can be associated with complications such as postcraniectomy/trephined syndrome, which shows improvement or resolution with cranioplasty. Conclusion: The diagnosis of MAS is clinical, and its mosaicism is explained by its early presentation in embryonic development. In the case of FCD with functional compromise, neurosurgical intervention is required, seeking the recovery and preservation of the compromised cranial nerves, avoiding prophylactic decompressions. In case of complications such as postcraniectomy/trephination syndrome, timely cranioplasty should be performed as it turns out to be highly effective as a treatment, however, the need for studies aimed at its characterization and diagnosis arises.

Ultrasound and elastography role in pre- and post-operative evaluation of median neuropathy in patients with carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is a common compression neuropathy of the median nerve in the wrist. Early diagnosis of CTS is essential for selecting treatment options and assessing prognosis. The current diagnosis of CTS is based on the patient's clinical symptoms, signs, and an electromyography (EMG) test. However, they have some limitations. Recently, ultrasound has been adopted as an adjunct diagnostic tool for electromyography (EMG). Ultrasound is a non-invasive and cost-effective technique. It provides a dynamic display of morphological changes in the median nerve and an assessment of CTS etiology such as tenosynovitis, mass compression, and tendon disease. This study aimed to investigate the value of conventional ultrasound and real-time shear wave elastography (SWE) in evaluation of median neuropathy in patients with carpal tunnel syndrome (CTS) before and after surgery. First, the Boston Carpal Tunnel Questionnaire (BCTQ) was administered to patients with CTS. All subjects were measured at three levels: the distal 1/3 of the forearm, the carpal tunnel inlet, and the distal carpal tunnel using conventional ultrasound and SWE. Median nerve parameters were examined in patients with CTS 1 week after surgery. The cross-sectional area (CSA) and stiffness of the median nerve at the carpal tunnel inlet and distal carpal tunnel were significantly higher in patients with CTS than in healthy controls (p < 0.001). The CSA and stiffness of the median nerve at the carpal tunnel inlet were statistically significantly significantly between pre- and postoperative patients with CTS (p < 0.001). The CSA and stiffness of the nerve in patients with CTS had a positive correlation with electrophysiology severity. Conventional ultrasound and elastography are valuable in the diagnosis of CTS and are useful in the clinical assessment of patient's nerve recovery after operation.

Types of Vascular Response to Direct Intraoperative Electrical Stimulation of the Sciatic Nerve after Autoneuroplasty and Their Effect on Limb Function Recovery.

We studied different types of the vascular response to direct intraoperative low-frequency electrical stimulation of the sciatic nerve after autoneuroplasty of its tibial portion and analyzed their effects on the limb function recovery. Rats (n=20) underwent 40-min intraoperative electrical stimulation, and hemodynamics in the leg was recorded by photoplethysmography. Functional recovery of the tibial nerve was assessed using a walking path analysis within 12 weeks after surgery. Three types of the vascular response to electrical stimulation were identified: the absence of pronounced hemodynamic changes during the electrostimulation session, hyperkinetic type of hemodynamics, and venous outflow disturbances. In rats demonstrating vascular responses of types I and II during the postoperative period, the functional index of the tibial nerve partially recovered within 12 weeks; in type III, no recovery was observed. It was concluded that the type of hemodynamics during intraoperative electrical stimulation of the damaged nerve subjected to autoneuroplasty affects further restoration of the motor function of the limb.

Electrical stimulation or tacrolimus (FK506) alone enhances nerve regeneration and recovery after nerve surgery, while dual use reduces variance and combines strengths of each in promoting enhanced outcomes.

Repaired nerve injuries can fail to achieve functional recovery. Therapeutic options beyond surgery, such as systemic tacrolimus (FK506) and electrical stimulation (E-stim), can improve recovery. We tested whether dual administration of FK506 and E-stim enhances regeneration and recovery more than either therapeutic alone. Rats were randomized to four groups: E-stim, FK506, FK506 + E-stim, and repair alone. All groups underwent tibial nerve transection and repair. Two sets of animals were created to measure outcomes of early nerve regeneration using nerve histology (n=36) and functional recovery (n=42) (21- and 42-day endpoints, respectively). Functional recovery was measured by behavioral analyses (walking track and grid walk) and, at the endpoint, muscle mass and force. Dual E-stim and FK506 administration produced histomorphometric measurements of nerve regeneration no different than either therapeutic alone. All treatments were superior to repair alone (FK506, P < .0001; E-stim, P < .05; FK506 + E-stim, P < .05). The E-stim and FK506 + E-stim groups had improved behavioral recovery compared with repair alone (at 6 weeks: E-stim, P < .05; FK506 + E-stim, P < .01). The FK506 group had improved recovery based on walking-track analysis (at 6 weeks: P < .001) and muscle force and mass (P < .05). The concurrent use of both therapies ensured earlier functional recovery and decreased variability in functional outcomes compared with either therapy alone, suggesting a moderate benefit. Dual administration of FK506 and E-stim showed minimal additive effects to further improve regeneration or recovery compared with either therapy alone. The data suggest the combination of FK506 and E-stim appears to combine the relative strengths of each therapeutic.

Abstract 15176: Development of Femoral Artery Denervation Models for Vascular Remodeling

Introduction: Restenosis is a common cause of vascular device failure. An important contributor is the transdifferentiation of vascular smooth muscle cells (VSMCs) from a contractile to synthetic phenotype. Healthy arteries are innervated by sympathetic nerves to regulate VSMC contractility and phenotype, yet this interaction has been overlooked in pathological vascular remodeling such as restenosis. Hypothesis: Sympathetic denervation of the femoral artery will lead to transdifferentiation of arterial VSMC and pathological remodeling of the arterial structure. Methods: The femoral arteries of male BALB/c mice were surgically exposed and treated with specific dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) or vehicle for 5 minutes. In the model of long-term denervation, the mice were subcutaneously injected with 6-OHDA or vehicle weekly for 4 weeks. Femoral arteries and peri-adventitial tissue were harvested for histology. Innervation density was calculated as the number of sympathetic nerve fibers (tyrosine hydroxylase-positive) normalized to the medial layer area (α-smooth muscle actin-positive). Extracellular matrix (ECM) composition was visualized with Masson’s trichrome and Verhoeff's elastic staining. Results: One week after surgery, 6-OHDA-treated arteries had a notable reduction in sympathetic nerve density compared to controls (2.9 vs. 11.7 fibers/10,000 μm 2 [P=.22, n=2]). This difference decreased at 2 weeks (6.8 vs. 8.0 fibers/10,000 μm 2 [P=0.50, n=3]) and at 4 weeks (4.4 vs. 5.0 fibers/10,000 μm 2 [P=0.83, n=3]), suggesting nerve recovery. No difference was observed in ECM composition. Tissues harvested at 1 and 4 weeks in the 6-OHDA injection model demonstrate qualitative denervation of the treated limb compared to control. Conclusions: Sympathetic denervation of murine femoral arteries can be achieved by direct surgical application or subcutaneous injection of 6-OHDA. Future work will characterize vascular remodeling after long-term denervation and combine denervation with vascular injury. If a causal relationship can be identified between sympathetic denervation and VSMC pathology, engineering reinnervation could be a viable approach for future graft design.

A Dual-network Nerve Adhesive with Enhanced Adhesion Strength Promotes Transected Peripheral Nerve Repair.

Peripheral nerve transection has a high prevalence and results in functional loss of affected limbs. The current clinical treatment using suture anastomosis significantly limits nerve recovery due to severe inflammation, secondary damage, and fibrosis. Fibrin glue, a commercial nerve adhesive as an alternative, avoids secondary damage but suffers from poor adhesion strength. To address their limitations, a highly efficacious nerve adhesive based on dual-crosslinking of dopamine-isothiocyanate modified hyaluronic acid and decellularized nerve matrix is reported in this paper. This dual-network nerve adhesive (DNNA) shows controllable gelation behaviors feasible for surgical applications, robust adhesion strength, and promoted axonal outgrowth in vitro. The in vivo therapeutic efficacy is tested using a rat-based sciatic nerve transection model. The DNNA decreases fibrosis and accelerates axon/myelin debris clearance at 10 days post-surgery, compared to suture and commercial fibrin glue treatments. At 10 weeks post-surgery, the strong adhesion and bioactivity allow DNNA to significantly decrease intraneural inflammation and fibrosis, enhance axon connection and remyelination, aid motor and sensory function recovery, as well as improve muscle contraction, compared to suture and fibrin treatments. Overall, this dual-network hydrogel with robust adhesion provides a rapid and highly efficacious nerve transection treatment to facilitate nerve repair and neuromuscular function recovery.

Stimulating peripheral nerve regrowth to preserve muscle tissue

Fat stem cell treatment helps speed up nerve recovery after injury.

GelMA-MXene hydrogel nerve conduits with microgrooves for spinal cord injury repair

Repair of spinal cord injury (SCI) depends on microenvironment improvement and the reconnection between injured axons and regenerated neurons. Here, we fabricate a GelMA-MXene hydrogel nerve conduit with electrical conductivity and internal-facing longitudinal grooves and explore its function in SCI repair. It is found that the resultant grooved GelMA-MXene hydrogel could effectively promote the neural stem cells (NSCs) adhesion, directed proliferation and differentiation in vitro. Additionally, when the GelMA-MXene conduit loaded with NSCs (GMN) is implanted into the injured spinal cord site, effective repair capability for the complete transection of SCI was demonstrated. The GMN group shows remarkable nerve recovery and significantly higher BBB scores in comparison to the other groups. Therefore, GMN with the microgroove structure and loaded with NSCs is a promising strategy in treating SCI.

Exploration of radial nerve in patients with humerus shaft fracture with radial nerve palsy, is it necessary?

&lt;p&gt;Fractures in the distal third of the humerus shaft usually are associated with complete or incomplete radial nerve lesions which may be caused due to traction, entrapment or compression between bony fragments. We managed these patients by bridge plating using minimally invasive percutaneous plate osteosynthesis. A total of 5 patients were operated on and all showed full functional recovery of radial nerve. Fracture united in all cases and no patient developed any complication.&lt;/p&gt;

Transcriptional Control of Peripheral Nerve Regeneration.

Transcription factors are master regulators of various cellular processes under diverse physiological and pathological conditions. Many transcription factors that are differentially expressed after injury to peripheral nerves play important roles in nerve regeneration. Considering that rapid and timely regrowth of injured axons is a prerequisite for successful target reinnervation, here, we compile transcription factors that mediates axon elongation, including axon growth suppressor Klf4 and axon growth promoters c-Myc, Sox11, STAT3, Atf3, c-Jun, Smad1, C/EBPδ, and p53. Besides neuronal changes, Schwann cell phenotype modulation is also critical for nerve regeneration. The activation of Schwann cells at early time points post injury provides a permissive microenvironment whereas the re-differentiation of Schwann cells at later time points supports myelin sheath formation. Hence, c-Jun and Sox2, two critical drivers for Schwann cell reprogramming, as well as Krox-20 and Sox10, two essential regulators of Schwann cell myelination, are reviewed. These transcription factors may serve as promising targets for promoting the functional recovery of injured peripheral nerves.

Postlingually Deafened Adult Cochlear Implant Users With Prolonged Recovery From Neural Adaptation at the Level of the Auditory Nerve Tend to Have Poorer Speech Perception Performance.

This study investigated the effects of two temporal response properties of the auditory nerve (i.e., neural adaptation and recovery from neural adaptation) on speech perception performance in postlingually deafened adult cochlear implant (CI) users. Study participants included 18 postlingually deafened adults who were Cochlear Nucleus device users with a full electrode array insertion in the test ear(s). Neural adaptation and adaptation recovery of the auditory nerve (AN) were evaluated using electrophysiological measures of the electrically evoked compound action potential (eCAP). The amount of neural adaptation was quantified by the adaptation index within three time windows: 0 to 8.89 (window 1), 44.44 to 50.00 (window 2), and 94.44 to 100.00 ms (window 3). The speed of neural adaptation was estimated using a two-parameter power law function. To evaluate adaptation recovery of the AN, eCAPs to the last pulse of the 100-ms pulse train were recorded at masker-probe-intervals ranging from 1.054 to 256 ms in logarithmic steps. The amount of adaptation recovery was quantified by the adaptation recovery ratio. The time-constant of adaptation recovery was estimated using an exponential function with up to three components. Speech perception performance was evaluated by measuring consonant-nucleus-consonant (CNC) word scores presented in quiet and in speech-shaped noise at a signal-to-noise ratio (SNR) of +10 dB. One-tailed Pearson Product Moment correlation tests were used (1) to assess the associations among parameters of neural adaptation and adaptation recovery and (2) to evaluate the strength of association between these parameters and CNC word scores measured in quiet and in noise. The contributions of different parameters quantifying neural adaptation and adaptation recovery on speech perception scores were evaluated using multivariable linear regression analyses. The Pearson Product Moment correlation coefficient demonstrated a moderate, negative correlation between the speed of adaptation recovery and CNC word scores measured in quiet and in noise. The speed of adaptation recovery accounted for 14.1% of variability in CNC word scores measured in quiet and 16.7% of variability in CNC word scores measured in noise. The correlation strengths between CNC word scores and the adaptation index, the adaptation recovery ratio and the speed of neural adaptation ranged from negligible to weak. The speed of adaptation recovery plays a more important role than other features of neural adaptation and adaptation recovery of the AN in speech perception in postlingually deafened adult CI users. Patients with prolonged adaptation recovery tend to show poorer speech perception performance.