Peripheral nerve tractography in soft tissue tumors: A preliminary 3‐tesla diffusion tensor magnetic resonance imaging study

Introduction: This diffusion tensor magnetic resonance imaging (DTI) study aimed to clarify the relationship of peripheral nerves and soft tissue tumors (STTs) in 3D to optimize subsequent treatment. Methods: Twenty‐six consecutive STT patients (histologically malignant, n = 10; intermediate, n = 3; and benign, n = 13) underwent 3‐Tesla MRI using an echoplanar DTI sequence. Deterministic tractography was performed. Fractional anisotropy (FA) values were measured within peritumoral and distant regions of interest. Results: Tractography depicted the 3D course of the sciatic (n = 12), femoral (n = 2), tibial (n = 7), fibular (n = 2), median (n = 1), musculocutaneous (n = 1), and ulnar (n = 1) nerves in a regular (n = 8 of 18, 44.4%) or thinned (n = 7 of 18, 38.9%) fashion. The lowest peritumoral FA values, abrupt thinning, and/or complete discontinuity of trajectories were found in 2 cases with histologically proven tumoral nerve infiltration. Conclusions: DTI clarifies the 3D topography between major peripheral nerves and STTs and may be helpful in the assessment of peripheral nerve infiltration by malignant tumors. Muscle Nerve 51: 338–345, 2015     

Nerve conduction changes and fine structural alterations of extra- and intrafusal muscle and nerve fibers in streptozotocin diabetic rats

Streptozotocin-induced diabetes mellitus in known to cause a reduction of both conduction velocity and axon caliber in sciatic nerves and also a decrease in muscle fiber size. The present study investigates whether the distal parts of the peripheral nervous system, including extra- and intrafusal muscle fibers, are more severely affected than the proximal segments in the diabetic state. Proximal and distal sensory nerve conduction velocities were monitored during a period of 3 months in rats rendered diabetic by injection of streptozotocin. Segments of the sciatic and ventral coccygeal nerves, and of the biceps femoris and lumbrical muscles, were studied by light and electron microscopy, including morphometric analysis. In contrast to previous studies, daily suboptimal insulin injections were given to prevent acute metabolic complications. Sensory conduction velocity in the ventral coccygeal nerve was significantly (P > 0.05) decreased in the diabetic rats compared to controls. Proximal and distal nerve segments were equally affected. Mean cross-sectional axon area of the sciatic nerve was moderately, but significantly (P < 0.05), smaller in insulin-treated diabetic rats than in controls. In both the sciatic nerve and the terminal, intrafusal nerve segments, occasional axons showed moderate dystrophic changes. Fibers of the intrafusal nerve segments appeared to be equally affected compared to the fibers in the sciatic nerve, although no quantitative comparison was made. The increase of small caliber skeletal muscle fibers in experimental streptozotocin-induced diabetes was confirmed. These findings indicate that proximal and distal segments of peripheral nerves are affected equally in the early stages of experimental diabetic neuropathy.© 1995 John Wiley &Sons, Inc.     

Chemotherapy‐induced structural changes in cerebral white matter and its correlation with impaired cognitive functioning in breast cancer patients

A subgroup of patients with breast cancer suffers from mild cognitive impairment after chemotherapy. To uncover the neural substrate of these mental complaints, we examined cerebral white matter (WM) integrity after chemotherapy using magnetic resonance diffusion tensor imaging (DTI) in combination with detailed cognitive assessment. Postchemotherapy breast cancer patients (n = 17) and matched healthy controls (n = 18) were recruited for DTI and neuropsychological testing, including the self‐report cognitive failure questionnaire (CFQ). Differences in DTI WM integrity parameters [fractional anisotropy (FA) and mean diffusivity (MD)] between patients and healthy controls were assessed using a voxel‐based two‐sample‐t‐test. In comparison with healthy controls, the patient group demonstrated decreased FA in frontal and temporal WM tracts and increased MD in frontal WM. These differences were also confirmed when comparing this patient group with an additional control group of nonchemotherapy‐treated breast cancer patients (n = 10). To address the heterogeneity observed in cognitive function after chemotherapy, we performed a voxel‐based correlation analysis between FA values and individual neuropsychological test scores. Significant correlations of FA with neuropsychological tests covering the domain of attention and processing/psychomotor speed were found in temporal and parietal WM tracts. Furthermore, CFQ scores correlated negatively in frontal and parietal WM. These studies show that chemotherapy seems to affect WM integrity and that parameters derived from DTI have the required sensitivity to quantify neural changes related to chemotherapy‐induced mild cognitive impairment. Hum Brain Mapp 32:480–493, 2011. © 2010 Wiley‐Liss, Inc.     

Morphometric analysis of the peripheral neuropathy of AIDS

A morphometric study of the peripheral nervous system at autopsy was undertaken in 11 AIDS patients and 10 controls. The left L4, L5, and S1 dorsal root ganglia (DRG) and samples of the sciatic nerve at the buttock, tibial nerve at the knee, and sural nerve at the ankle were collected. Indices of neuronal/axonal degeneration and of segmental demyelination/remyelination were measured at each level. The small number of cases and evidence of neuropathy in a number of the control cases resulted in statistical significance for only a limited number of comparisons. Nodules of Nageotte in the DRG were increased fivefold in AIDS cases compared with controls, and axonal degeneration in single-teased nerve fibers was increased 9-fold in the sciatic nerve, 28-fold in the tibial nerve, and 12-fold in the sural nerve. The ratios of AIDS to controls for the density of remaining DRG neurons and large myelinated axons were reduced to 0.71 in the DRG, 0.84 in the sciatic nerve, 0.84 in the tibial nerve, and 0.66 in the sural nerve. Axonal regeneration in single-teased nerve fibers was increased threefold at the sciatic nerve level in AIDS, but was markedly reduced at distal levels. Acute segmental demyelination in single-teased nerve fibers was present to a greater extent than in controls at all levels of the peripheral nerves in the AIDS cases. Remyelinating fibers were increased compared with controls only in the proximal sciatic nerve. No case showed the changes of cytomegalovirus infection. In a parallel immunohistochemical study of these AIDS peripheral nerves, T-cell and macrophage infiltration, with cytokine expression, was demonstrated. The pathological process in the neuropathy of terminal AIDS appears to be a multifocal immunologically mediated inflammatory disease, with increased density of macrophages and T cells at all levels of the peripheral nervous system, producing segmental demyelination and axonal degeneration. Reparative processes (axonal regeneration and remyelination) occurred only at the most proximal levels of the nerves. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:1188–1195, 1998.     

Upper leg conduction time distinguishes demyelinating neuropathies

Background: The objective of this study was to determine whether differentiation between demyelinating and axonal neuropathies could be enhanced by comparing conduction time changes in defined segments of the total peripheral nerve pathway. Methods: Compound muscle action potentials (CMAPs) were elicited by cathodal stimulation of the tibial nerve at the ankle and popliteal fossa, and by paravertebral neuromagnetic stimulation at proximal and distal cauda equina while recording from muscles of the foot, shin, and thigh. Segmental conduction times were calculated in normal subjects; in patients with lumbosacral radiculopathy, distal symmetric diabetic neuropathy, amyotrophic lateral sclerosis, acute and chronic inflammatory demyelinating polyneuropathy; and in patients with anti–myelin‐associated glycoprotein, myelomatous, and Charcot–Marie–Tooth type 1a polyneuropathies. Results: Distal cauda equina latency and CMAP duration and segmental conduction times in upper leg and cauda equina facilitated differentiation of demyelinating from axonal neuropathies, even in the presence of a range of reduced amplitude CMAPs. Conclusions: Within the demyelinating neuropathy spectrum, it was further possible to distinguish subtypes. Muscle Nerve, 2011     

Diffusion kurtosis imaging in mild traumatic brain injury and postconcussional syndrome

Aims of this study were to investigate white matter (WM) and thalamus microstructure 72 hr and 3 months after mild traumatic brain injury (TBI) with diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI), and to relate DKI and DTI findings to postconcussional syndrome (PCS). Twenty-five patients (72 hr = 24; 3 months = 23) and 22 healthy controls were recruited, and DKI and DTI data were analyzed with Tract-Based Spatial Statistics (TBSS) and a region-of-interest (ROI) approach. Patients were categorized into PCS or non-PCS 3 months after injury according to the ICD-10 research criteria for PCS. In TBSS analysis, significant differences between patients and controls were seen in WM, both in the acute stage and 3 months after injury. Fractional anisotropy (FA) reductions were more widespread than kurtosis fractional anisotropy (KFA) reductions in the acute stage, while KFA reductions were more widespread than the FA reductions at 3 months, indicating the complementary roles of DKI and DTI. When comparing patients with PCS (n = 9), without PCS (n = 16), and healthy controls, in the ROI analyses, no differences were found in the acute DKI and DTI metrics. However, near-significant differences were observed for several DKI metrics obtained in WM and thalamus concurrently with symptom assessment (3 months after injury). Our findings indicate a combined utility of DKI and DTI in detecting WM microstructural alterations after mild TBI. Moreover, PCS may be associated with evolving alterations in brain microstructure, and DKI may be a promising tool to detect such changes.     

Effects of extracellular calcium and surgical techniques on restoration of axonal continuity by polyethylene glycol fusion following complete cut or crush severance of rat sciatic nerves

Complete crush or cut severance of sciatic nerve axons in rats and other mammals produces immediate loss of axonal continuity. Loss of locomotor functions subserved by those axons is restored only after months, if ever, by outgrowths regenerating at ～1 mm/day from the proximal stumps of severed axonal segments. The distal stump of a severed axon typically begins to degenerate in 1–3 days. We recently developed a polyethylene glycol (PEG) fusion technology, consisting of sequential exposure of severed axonal ends to hypotonic Ca²⁺‐free saline, methylene blue, PEG in distilled water, and finally Ca²⁺‐containing isotonic saline. This study examines factors that affect the PEG fusion restoration of axonal continuity within minutes, as measured by conduction of action potentials and diffusion of an intracellular fluorescent dye across the lesion site of rat sciatic nerves completely cut or crush severed in the midthigh. Also examined are factors that affect the longer‐term PEG fusion restoration of lost behavioral functions within days to weeks, as measured by the sciatic functional index. We report that exposure of cut‐severed axonal ends to Ca²⁺‐containing saline prior to PEG fusion and stretch/tension of proximal or distal axonal segments of cut‐severed axons decrease PEG fusion success. Conversely, trimming cut‐severed ends in Ca²⁺‐free saline just prior to PEG fusion increases PEG fusion success. PEG fusion prevents or retards the Wallerian degeneration of cut‐severed axons, as assessed by measures of axon diameter and G ratio. PEG fusion may produce a paradigm shift in the treatment of peripheral nerve injuries. © 2016 Wiley Periodicals, Inc.     

Diagnostic utility of somatosensory evoked potentials in chronic polyradiculopathy without electrodiagnostic signs of peripheral demyelination

Introduction: Diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) remains uncertain when nerve conduction studies (NCS) fail to show demyelination. Methods: We conducted a retrospective study of patients who presented with clinical criteria of CIDP in whom electrodiagnostic (EDx) criteria of definite or probable CIDP were missing [axonal sensorimotor neuropathy (n = 23), normal EDx with pure sensory presentation (n = 3)]. All patients received immunomodulatory treatment. Twenty‐six patients were evaluated with somatosensory evoked potentials (SSEPs), MRI of spinal roots, cerebrospinal fluid analysis, and/or nerve biopsy. Diagnosis of CIDP was considered to be confirmed in patients who responded to immunotherapy. Results: Twenty‐two of 26 patients (85%) had SSEPs reflecting abnormal proximal conduction in sensory fibers, including 14 who had only clinical and SSEP data in favor of CIDP. SSEPs were abnormal in 16 of 20 responders (80%) to immunotherapy. Conclusion: SSEP recording contributes to the diagnosis of CIDP when nerve conduction studies fail to detect peripheral demyelination. Muscle Nerve 53 : 78–83, 2016     

Spinal charcot‐marie‐tooth disease: A reappraisal

Introduction: Distal hereditary motor neuropathy (dHMN) is characterized by isolated distal muscle atrophy without sensory deficit. Nevertheless, clinical sensory loss has been reported despite preserved sensory nerve conduction in a few patients, thus differentiating these cases from the classical type 2 Charcot‐Marie‐Tooth disease (CMT2). Methods: We report 4 patients who presented with clinical sensory and motor neuropathy and normal peripheral sensory nerve conduction studies and were investigated with complete electrophysiological studies, including somatosensory evoked potentials (SEP). Results: These patients had a clinical presentation of classical CMT with isolated axonal motor neuropathy suggestive of dHMN. Interestingly, tibial nerve SEPs showed abnormalities suggestive of proximal involvement of dorsal roots that may explain the clinical somatosensory disturbances. Conclusions: These cases support the concept of spinal CMT that should be recognized as an intermediate form between dHMN and CMT2. SEP recording was helpful in defining a more precise phenotype of spinal CMT. Muscle Nerve 46: 603–607, 2012     

Clinical and Electrodiagnostic Features Of Nontraumatic Sciatic Neuropathy

Introduction: In this study we sought to characterize etiologies and features of sciatic neuropathy unrelated to penetrating nerve trauma. Methods: This investigation was a retrospective review of 109 patients with electrodiagnostically confirmed sciatic neuropathies. Results: Hip replacement surgery represented the most common (34.9%) etiology, whereas inflammatory sciatic neuropathy was seen in 7.3%. Electrodiagnostic testing revealed an axonal neuropathy in 95.4% and a demyelinating neuropathy in 4.6%. Predominant involvement of the peroneal division was seen in 39.4% and was tibial in 5.5%. Nine of 31 (29.0%) patients who had MRI or neuromuscular ultrasound study showed abnormalities within the sciatic nerve. At the final visit, 46.4% of patients required assistance for ambulation. Young age, lack of severe initial weakness, and presence of tibial compound muscle action potential or sural sensory nerve action potential were predictors of favorable outcome. Discussion: Sciatic neuropathies are usually axonal on electrodiagnostic testing, affect preferentially the peroneal division, and are commonly associated with incomplete recovery. Muscle Nerve 59 :309–314, 2019     

Diffusion tensor imaging to assess axonal regeneration in peripheral nerves

Development of outcome measures to assess ongoing nerve regeneration in the living animal that can be translated to human can provide extremely useful tools for monitoring the effects of therapeutic interventions to promote nerve regeneration. Diffusion tensor imaging (DTI), a magnetic resonance based technique, provides image contrast for nerve tracts and can be applied serially on the same subject with potential to monitor nerve fiber content. In this study, we examined the use of ex vivo high-resolution DTI for imaging intact and regenerating peripheral nerves in mice and correlated the MRI findings with electrophysiology and histology. DTI was done on sciatic nerves with crush, without crush, and after complete transection in different mouse strains. DTI measures, including fractional anisotropy (FA), parallel diffusivity, and perpendicular diffusivity were acquired and compared in segments of uninjured and crushed/transected nerves and correlated with morphometry. A comparison of axon regeneration after sciatic nerve crush showed a comparable pattern of regeneration in different mice strains. FA values were significantly lower in completely denervated nerve segments compared to uninjured sciatic nerve and this signal was restored toward normal in regenerating nerve segments (crushed nerves). Histology data indicate that the FA values and the parallel diffusivity showed a positive correlation with the total number of regenerating axons. These studies suggest that DTI is a sensitive measure of axon regeneration in mouse models and provide basis for further development of imaging technology for application to living animals and humans.     

Governing role of primary afferent drive in increased excitation of spinal nociceptive neurons in a model of sciatic neuropathy

Previously we reported that the cuff model of peripheral neuropathy, in which a 2 mm polyethylene tube is implanted around the sciatic nerve, exhibits aspects of neuropathic pain behavior in rats similar to those in humans and causes robust hyperexcitation of spinal nociceptive dorsal horn neurons. The mechanisms mediating this increased excitation are not known and remain a key unresolved question in models of peripheral neuropathy. In anesthetized adult male Sprague–Dawley rats 2–6 weeks after cuff implantation we found that elevated discharge rate of single lumbar (L_3–4) wide dynamic range (WDR) neurons persists despite acute spinal transection (T9) but is reversed by local conduction block of the cuff-implanted sciatic nerve; lidocaine applied distal to the cuff (i.e. between the cuff and the cutaneous receptive field) decreased spontaneous baseline discharge of WDR dorsal horn neurons  40% (n = 18) and when applied subsequently proximal to the cuff, i.e. between the cuff and the spinal cord, it further reduced spontaneous discharge by  60% (n = 19; P < 0.05 proximal vs. distal) to a level that was not significantly different from that of naive rats. Furthermore, in cuff-implanted rats WDR neurons (n = 5) responded to mechanical cutaneous stimulation with an exaggerated afterdischarge which was reversed entirely by proximal nerve conduction block. These results demonstrate that the hyperexcited state of spinal dorsal horn neurons observed in this model of peripheral neuropathy is not maintained by tonic descending facilitatory mechanisms. Rather, on-going afferent discharges originating from the sciatic nerve distal to, at, and proximal to the cuff maintain the synaptically-mediated gain in discharge of spinal dorsal horn WDR neurons and hyperresponsiveness of these neurons to cutaneous stimulation. Our findings reveal that ectopic afferent activity from multiple regions along peripheral nerves may drive CNS changes and the symptoms of pain associated with peripheral neuropathy.     

Sonography of the median nerve in CMT1A,CMT2A,CMTX, and HNPP

Introduction: In this study we compare the ultrasound features in the median nerve in patients with different types of Charcot–Marie–Tooth (CMT) disease and hereditary neuropathies with liability to pressure palsies (HNPP) as a typical entrapment neuropathy. Methods: Median nerve ultrasound and conduction studies were performed in patients with CMT1A (n = 12), MFN2‐associated CMT2A (n = 7), CMTX (n = 5), and HNPP (n = 5), and in controls (n = 28). Results: Median nerve cross‐sectional area (CSA) was significantly increased in CMT1A, whereas, in axonal CMT2A, fascicle diameter (FD) was enlarged. CSA correlated with nerve conduction slowing in CMT1A and with axonal loss, as shown by motor and sensory nerve amplitudes in both CMT1A and CMT2A. A relatively low wrist‐to‐forearm‐ratio (WFR <0.8) or a relatively high WFR (>1.8) appeared to be unlikely in MFN2 and Cx32 mutations of CMT2A and CMTX, respectively. Conclusion: Differences in CSA, FD, and WFR of the median nerve can be helpful in defining subtypes of hereditary neuropathies. Muscle Nerve 47:385‐395, 2013     

Traumatic axonal injury: Relationships between lesions in the early phase and diffusion tensor imaging parameters in the chronic phase of traumatic brain injury

This prospective study of traumatic brain injury (TBI) patients investigates fractional anisotropy (FA) from chronic diffusion tensor imaging (DTI) in areas corresponding to persistent and transient traumatic axonal injury (TAI) lesions detected in clinical MRI from the early phase. Thirty‐eight patients (mean 24.7 [range 13–63] years of age) with moderate‐to‐severe TBI and 42 age‐ and sex‐matched healthy controls were included. Patients underwent 1.5‐T clinical MRI in the early phase (median 7 days), including fluid‐attenuated inversion recovery (FLAIR) and T2* gradient echo (T2*GRE) sequences. TAI lesions from the early phase were characterized as nonhemorrhagic or microhemorrhagic. In the chronic phase (median 3 years), patients and controls were imaged at 3 T with FLAIR, T2*GRE, T1, and DTI sequences. TAI lesions were classified as transient or persistent. The FLAIR/T2*GRE images from the early phase were linearly registered to the FA images from the chronic phase and lesions manually segmented on the FA‐registered FLAIR/T2*GRE images. For regions of interest (ROIs) from both nonhemorrhagic and microhemorrhagic lesion, we found a significant linear trend of lower mean FA from ROIs in healthy controls to ROIs in patients without either nonhemorrhagic or microhemorrhagic lesions and further to transient and finally persistent lesion ROIs (P < 0.001). Histogram analyses showed lower FA in persistent compared with transient nonhemorrhagic lesion ROIs (P < 0.001), but this was not found in microhemorrhagic lesion ROIs (P = 0.08–0.55). The demonstrated linear trend of lower FA values from healthy controls to persistent lesion ROIs was found in both nonhemorrhagic and microhemorrhagic lesions and indicates a gradual increasing disruption of the microstructure. Lower FA values in persistent compared with transient lesions were found only in nonhemorrhagic lesions. Thus, clinical MRI techniques are able to depict important aspects of white matter pathology across the stages of TBI. © 2016 Wiley Periodicals, Inc.     

Triple‐stimulation technique improves the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy

Introduction: A difficult clinical situation occurs when a chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patient does not fulfill any of the diagnostic criteria. Moreover, nerve conduction studies (NCS) can be consistent with axonal neuropathy and lead to misdiagnosis. Methods: We aimed to assess the usefulness of the triple‐stimulation technique (TST) for detection of proximal conduction blocks (CBs) in patients with axonal‐like CIDP. Four patients with axonal‐like CIDP were studied and compared with 10 typical CIDP patients. In the axonal‐like group, NCS showed a decrease in compound muscle action potential amplitude without features of demyelination, but nerve biopsy showed features of demyelination in all 4. Results: Twelve nerves were tested with TST, and 8 CBs were detected between the root emergence and the Erb point in the 4 patients, all of whom improved after treatment with intravenous immunoglobulin. Conclusion: TST can identify very proximal CBs in CIDP. The sensitivity of nerve conduction studies may be improved by TST in CIDP. Muscle Nerve 51: 541–548, 2015     

Sciatic neuropathy due to popliteal fossa nerve block

Introduction: Sciatic neuropathy after popliteal nerve block (PNB) for regional anesthesia is considered uncommon but has been increasingly recognized in the literature. We identified a case of sciatic neuropathy that occurred after bunionectomy during which a PNB had been performed. Methods: To understand the frequency of PNB‐related sciatic neuropathy, we performed a retrospective review of sciatic neuropathies at our center over a 5‐year period. Results: Forty‐five cases of sciatic neuropathy were reviewed. Similar to earlier reports, common etiologies of sciatic neuropathy, including compression, trauma, fractures, and hip arthroplasty, were noted in the majority of our cases (60%, n = 27). Unexpectedly, PNB was the third most common etiology (16%, n = 7). Conclusions: Our results suggest PNB is a relatively common etiology of sciatic neuropathy and is an important consideration in the differential diagnosis. These findings should urge electromyographers to assess history of PNB in sciatic neuropathies, particularly with onset after surgery. Muscle Nerve 56 : 822–824, 2017     

Ultrasound differentiation of axonal and demyelinating neuropathies

Introduction: Ultrasound can be used to visualize peripheral nerve abnormality. Our objective in this study was to prove whether nerve ultrasound can differentiate between axonal and demyelinating polyneuropathies (PNPs). Methods: Systematic ultrasound measurements of peripheral nerves were performed in 53 patients (25 with demyelinating, 20 with axonal, 8 with mixed neuropathy) and 8 healthy controls. Nerve conduction studies of corresponding nerves were undertaken. Results: Analysis of variance revealed significant differences between the groups with regard to motor conduction velocity, compound muscle action potential amplitude, and cross‐sectional area (CSA) of different nerves at different locations. Receiver operating characteristic curve analysis revealed CSA measurements to be well suited for detection of demyelinating neuropathies, and boundary values of peripheral nerve CSA could be defined. Conclusions: Systematic ultrasound CSA measurement in different nerves helped detect demyelination, which is an additional cue in the etiological diagnosis of PNP, along with nerve conduction studies and nerve biopsy. Muscle Nerve 50: 976–983, 2014     

Axonal excitability in primary amyloidotic neuropathy

Introduction: Acquired and hereditary amyloidosis can cause peripheral neuropathy, but the mechanisms by which this occurs have not been established. Threshold tracking techniques allow in vivo assessment of the properties of the axonal membrane and may shed light on pathogenetic mechanisms underlying neuropathic disorders. Methods: We studied 10 subjects with primary amyloidosis using conventional nerve conduction studies and quantitative sensory, autonomic, and axonal excitability testing of median motor and sensory fibers. Results: As expected, subjects with amyloidosis had evidence of small‐ and large‐fiber neuropathy on conventional testing. There was no significant difference in axonal excitability between subjects and controls apart from the stimulus required to activate sensory fibers. Conclusions: Amyloid‐related neuropathy does not produce a change in membrane potential as either a primary or secondary event. This suggests that ischemia and axonal compression are unlikely mechanisms for the neuropathy. Muscle Nerve 51: 443–445, 2015     

Miconazole enhances nerve regeneration and functional recovery after sciatic nerve crush injury

Introduction: Improving axonal outgrowth and remyelination is crucial for peripheral nerve regeneration. Miconazole appears to enhance remyelination in the central nervous system. In this study we assess the effect of miconazole on axonal regeneration using a sciatic nerve crush injury model in rats. Methods: Fifty Sprague‐Dawley rats were divided into control and miconazole groups. Nerve regeneration and myelination were determined using histological and electrophysiological assessment. Evaluation of sensory and motor recovery was performed using the pinprick assay and sciatic functional index. The Cell Counting Kit‐8 assay and Western blotting were used to assess the proliferation and neurotrophic expression of RSC 96 Schwann cells. Results: Miconazole promoted axonal regrowth, increased myelinated nerve fibers, improved sensory recovery and walking behavior, enhanced stimulated amplitude and nerve conduction velocity, and elevated proliferation and neurotrophic expression of RSC 96 Schwann cells. Discussion: Miconazole was beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Muscle Nerve 57 : 821–828, 2018     

In vivo demonstration of microstructural brain pathology in progressive supranuclear palsy: A DTI study using TBSS

We investigated DTI changes, potentially indicating alterations of microstructure and brain tissue integrity in 13 patients with probable progressive supranuclear palsy (PSP, Richardson syndrome) at stage III or less and 10 age‐matched controls using a whole brain analysis of diffusion tensor imaging (DTI) data. DTI images were analyzed using tract‐based spatial statistics, a hypothesis‐free technique. Fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) were determined. In patients with PSP, significant increases in FA (P < 0.0001), an unspecific measure of microstructural tissue integrity, were found in the cerebellum and in the superior cerebellar peduncle bilaterally, in the fornix, the body of the corpus callosum and the olfactory region, when compared with age‐matched healthy controls. Further, regional reductions in AD (P < 0.0001), an indicator of altered axonal integrity, were observed in the pons, the right substantia nigra and the cerebellar white matter bilaterally. Significant increases in RD (P < 0.0001), a potential measure of altered myelin integrity, occurred bilaterally in the superior cerebellar peduncle, the cerebellar white matter, the vermis of the cerebellum, the fornix, the body of the corpus callosum, and the olfactory region. RD values in the superior cerebellar peduncle discriminated patients with PSP and controls with high sensitivity (0.92) and specificity (1.0). The findings are supported by neuropathological studies. Our data suggest the usefulness of this clinically available new technique as a possible tool for differential diagnosis. © 2010 Movement Disorder Society