The role of imaging in focal neuropathies.

Electrodiagnostic testing (EDX) has been the diagnostic tool of choice in peripheral nerve disease for many years, but in recent years, peripheral nerve imaging has been used ever more frequently in daily clinical practice. Nerve ultrasound and magnetic resonance (MR) neurography are able to visualize nerve structures reliably. These techniques can aid in localizing nerve pathology and can reveal significant anatomical abnormalities underlying nerve pathology that may have been otherwise undetected by EDX. As such, nerve ultrasound and MR neurography can significantly improve diagnostic accuracy and can have a significant effect on treatment strategy. In this chapter, the basic principles and recent developments of these techniques will be discussed, as well as their potential application in several types of peripheral nerve disease, such as carpal tunnel syndrome (CTS), ulnar neuropathy at the elbow (UNE), radial neuropathy, brachial and lumbosacral plexopathy, neuralgic amyotrophy (NA), fibular, tibial, sciatic, femoral neuropathy, meralgia paresthetica, peripheral nerve trauma, tumors, and inflammatory neuropathies.

Concurrent transverse myelitis and acute inflammatory demyelinating polyneuropathy.

A woman in her 40s presented with thoracic banding dysaesthesia and lower motor neuron weakness. Spinal imaging revealed a short segment of transverse myelitis and neurophysiology was suggestive of concurrent acute inflammatory demyelinating polyneuropathy. The patient improved with consecutive intravenous immunoglobulin and methylprednisolone treatment. Acute inflammatory demyelinating polyneuropathy is a progressive immune-mediated peripheral neuropathy which responds to intravenous immunoglobulin or plasmapheresis, whereas transverse myelitis is a central inflammatory syndrome usually treated with corticosteroid. We highlight differentiating features of the clinical presentation and the utility of investigations such as neurophysiology and MRI along with a review of treatment and the role for corticosteroid therapy.

Deficiency of adenosine deaminase 2: a genetic autoinflammatory disorder mimicking childhood polyarteritis nodosa.

A girl in the early adolescent age group presented with multisystem manifestations in the form of periodic fever, recurrent abdominal pain, hypertension, seizure, skin lesions over the chest and gangrene over the left ring and middle fingertips. Her condition had remained undiagnosed for 11 years. On evaluation, she had features of polyarteritis nodosa (PAN) (multiple aneurysms, symmetric sensorimotor peripheral neuropathy, superficial ulcers, digital necrosis, myalgia, hypertension and proteinuria). As childhood PAN is a phenocopy of adenosine deaminase 2 with a different management strategy, whole-exome sequencing was performed, which revealed a pathogenic variant in ADA2 gene. The child was treated with TNF alpha inhibitors and showed improvement in the Paediatric Vasculitis Activity Score. The paper highlights the gratifying consequences of correct diagnosis with disease-specific therapy that ended the diagnostic odyssey, providing relief to the patient from debilitating symptoms and to the family from the financial burden of continued out-of-pocket health expenditure.

Sweet syndrome with peripheral neuropathy in a patient with metastatic clear cell renal cell carcinoma.

A female patient in her 70s with a newly diagnosed clear cell renal cell carcinoma (ccRCC) with osseous metastasis presented with sudden onset erythematous painful blistering skin lesions on the dorsum of both hands, with associated intermittent fever episodes. Blood tests showed elevated inflammatory marker levels (C reactive protein 257.8 mg/dL, leucocytes 17.79×109/L, with 94% neutrophils). Histologically, there was predominately neutrophil dermal infiltrate without leucocytoclastic vasculitis. The diagnostic criteria of Sweet syndrome were fulfilled. A week later, the patient developed abrupt left-hand palsy, which was confirmed as a medial and ulnar sensorimotor axonal peripheral neuropathy of paraneoplastic origin. The patient was prescribed a course of oral high-dose steroids, which significantly improved the skin lesions. The peripheral nerve palsy improved after 3 months. This case describes the two very rare concurrent paraneoplastic manifestations of ccRCC occurring simultaneously, which have been rarely reported.

[Analysis of clinical manifestations and imaging features of facial nerve schwannomas].

Objective:To explore the clinical manifestations and imaging characteristics, and to clarify the imaging value in the diagnosis of facial nerve schwannomas. Methods:Retrospectively analyze the data of 23 patients with facial nerve schwannomas confirmed by surgery and pathology in the Department of Otorhinolaryngology of the First Affiliated Hospital of the Air Force Military Medical University from September 2020 to September 2022, including 8 males and 15 females, aged 18-66 years old. Summarize and analyze their clinical symptoms, specialized examinations, and imaging findings. Results:The clinical manifestations were facial nerve paralysis in 15 cases（2 cases of HB Ⅳ, 6 cases of HB Ⅴ, 7 cases of HB Ⅵ）, hearing loss in 14 cases（5 cases of conductive deafness, 2 cases of mixed deafness, and 7 cases of severe sensorineural hearing loss）, 8 cases tinnitus, 7 cases ear pain, 4 cases dizziness, 4 cases headache, 2 cases ear pus, and parotid gland tumors in 6 cases presenting as local masses. Endoscopic examination revealed 8 cases of external ear canal tumors and 3 cases of intratympanic tumors. Combining temporal bone HRCT, MRI enhanced scanning, and CPR imaging techniques, 1 case involved the internal auditory canal segment, 2 cases in the tympanic segment, 6 cases in the parotid gland area. A total of 14 cases involved two or more segments of the internal auditory canal segment, the labyrinthine segment, geniculate ganglion, the tympanic segment, and the mastoid segment. When the tumors were large, adjacent structures were involved. It was found that 8 cases invaded the external auditory canal and tympanic cavity, ossicles were displaced or bony destruction; 3 cases invaded the jugular foramen area, and 1 case grew to the middle cranial fossa region with temporal lobe brain parenchymal compression. Conclusion:The clinical manifestations of facial nerve schwannomas are diverse. The combination of various imaging techniques will be conducive to topical and qualitative diagnosis and provide an important basis for treatment strategies.

Severe papilloedema with vision loss secondary to Guillain-Barré syndrome.

We discuss a patient who presented with bilateral VI and VII cranial nerve palsies, symmetric upper and lower limb weakness and areflexia, 2 weeks following an flu-like illness. At presentation, there was no papilloedema, and her visual function was normal. Cerebrospinal fluid analysis and electrophysiology supported the diagnosis of Guillain-Barré Syndrome (GBS). She received intravenous immunoglobulins. She subsequently developed headaches and vision loss. Funduscopy demonstrated severe papilloedema with visual acuity of 6/18 right eye, 6/12 left eye with bitemporal visual field depression. Lumbar puncture revealed elevated opening pressure with high protein and normal cell count. She received acetazolamide. There was resolution of papilloedema and normal visual function at 3 months. Of note, the patient's body mass index was 17 kg/m2Our case highlights the rare occurrence of papilloedema in GBS, reiterating the importance of performing funduscopy on patients with any neurological diagnosis. Early detection and prompt management of papilloedema can prevent permanent vision loss.

Analyzing the Effect of Intraoperative Stimulation Voltage on Facial Numbness Following Radiofrequency Thermocoagulation in the Treatment of Idiopathic Trigeminal Neuralgia.

INTRODUCTION: Radiofrequency thermocoagulation (RFT) effectively alleviates idiopathic trigeminal neuralgia (ITN); however, postoperative facial numbness poses a significant challenge. This issue arises due to the close proximity of high-temperature thermocoagulation, which not only ablates pain-related nociceptive fibers but also affects tactile fibers. Intraoperative sensory stimulation voltage (SV), which reflects the distance between the RFT cannula and the target nerve, potentially possesses the ability to prevent tactile fiber injury. This study aimed to investigate the influence of SV on postoperative facial numbness and provide valuable insights to mitigate its occurrence. METHODS: A retrospective analysis was performed on 72 ITN patients with maxillary division (V2) pain who underwent RFT between 2020 and 2022. Among them, 13 patients with SV ≤ 0.2 V constituted the low SV group. Subsequently, a matched-cohort analysis was conducted on the remaining 59 patients. The patients paired with the low SV patients were subsequently enrolled in the high SV group, adhering to a 1:1 match ratio. The primary outcome was the facial numbness scale assessment at 3 days, 3 months and 6 months post-surgery. The pain intensity and medication burden served as the secondary outcomes. RESULTS: We successfully matched a cohort consisting of 12 patients in the low SV group and 12 patients in the high SV group. Each patient experienced various degrees of facial numbness at 3 days post-RFT. Notably, the low SV group exhibited a higher incidence of moderate numbness (66.7% vs. 16.67%, P = 0.036), whereas the high SV group had more cases of mild numbness at the 6-month follow-up (25% vs. 83.3%, P = 0.012). Both groups demonstrated significant decreases in pain intensity and medication burden compared to before the operation. CONCLUSIONS: SV proved to be a reliable parameter for mitigating the degree of postoperative facial numbness in RFT treatment for ITN. A relatively high sensory SV ranging from 0.3 to 0.6 V during the RFT procedure results in less facial numbness in the treatment of ITN.

Task force of the Brazilian Society of Otology - evaluation and management of peripheral facial palsy.

OBJECTIVE: To review key evidence-based recommendations for the diagnosis and treatment of peripheral facial palsy in children and adults. METHODS: Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on peripheral facial palsy were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions. RESULTS: The topics were divided into 2 main parts: (1) Evaluation and diagnosis of facial palsy: electrophysiologic tests, idiopathic facial palsy, Ramsay Hunt syndrome, traumatic peripheral facial palsy, recurrent peripheral facial palsy, facial nerve tumors, and peripheral facial palsy in children; and (2) Rehabilitation procedures: surgical decompression of the facial nerve, facial nerve grafting, surgical treatment of long-term peripheral facial palsy, and non-surgical rehabilitation of the facial nerve. CONCLUSIONS: Peripheral facial palsy is a condition of diverse etiology. Treatment should be individualized according to the cause of facial nerve dysfunction, but the literature presents better evidence-based recommendations for systemic corticosteroid therapy.

Acute sensorimotor paraneoplastic neuropathy in a patient with small cell prostate cancer.

The authors describe a patient with a background of metastatic small cell prostate cancer who presented with a rapidly evolving sensorimotor neuropathy with bulbar features closely resembling Guillain-Barré syndrome, with a good initial response to intravenous immunoglobulins and platinum-based chemotherapy. This represented a likely paraneoplastic manifestation of the patient's urological malignancy.

Case Report and Literature Review: Isolated Trochlear Nerve Palsy due to Herpes Zoster Infection.

Introduction: Trochlear nerve palsy (TNP) is a common cause of vertical diplopia resulting from superior oblique muscle weakness. While herpes zoster is a well-documented cause of cranial neuropathies, reports of TNP associated with herpes zoster infection remain limited. Case Presentation: We report a case of a 65-year-old patient with typical herpes zoster ophthalmicus on the left side of his face with subsequent corneal endotheliitis and isolated TNP. The MRI revealed a faint enhancement at the cavernous sinus on the same side as the TNP. Cerebrospinal fluid detected human herpesvirus 3, confirming the diagnosis. An intravenous antiviral was administered for 14 days with prolonged maintenance to prevent recurrence. Oral corticosteroids were also used as an adjuvant to reduce inflammation. After treatment, the uveitis subsided, and the vertical diplopia recovered partially. TNP from herpes zoster is a rare presentation. The underlying pathogenic mechanisms, including potential direct viral invasion, inflammatory responses, and possible vasculopathy affecting the trochlear nerve, are explored. Conclusion: TNP can be a rare neuro-ophthalmic complication of herpes zoster infection. Clinicians should maintain a high index of suspicion when assessing patients with cranial neuropathies in the context of herpes zoster. Prompt antiviral therapy and supportive measures can aid in the resolution of symptoms and alleviate potential long-term sequelae.

Guillain-Barré syndrome following primary cytomegalovirus infection in a patient with liver transplantation.

We present the case of a man in his 60s with a 5-month medical history of deceased donor liver transplantation, who developed Guillain-Barré syndrome (GBS) secondary to a primary cytomegalovirus (CMV) infection. This was confirmed by molecular tests and serology antibodies that ruled out other frequent aetiologies. Therapy with intravenous immunoglobulin and valganciclovir was started and the patient gradually improved over the weeks. GBS is the most common aetiology of paralysis worldwide, and it is an autoimmune-mediated neuropathy that is frequently caused by a preceding infection. Few cases of GBS have been reported in the context of liver transplant recipients, and those related to CMV infection are extremely rare. This case highlights the importance of considering GBS as a possible differential diagnosis in patients with solid organ transplantation, and it contributes to the knowledge of other infrequent aetiologies of this condition.

Surgical management of dysthyroid optic neuropathy: A systematic review.

OBJECTIVE: There is currently no recommendation on the optimal surgical management for dysthyroid optic neuropathy (DON). The aim of this study is to systematically review the surgical management of DON and its outcome on visual acuity (VA). DATA SOURCES: MEDLINE, Cochrane Library, and clinicaltrials.gov REVIEW METHODS: A systematic review of studies about the surgical management of DON was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Articles were included if preoperative and postoperative VA in logMAR (Logarithm of the Minimum Angle of Resolution) were available. RESULTS: Fifteen articles were included in the study accounting for 669 orbits. The mean VA improvement was of 0.44 logMAR overall, 0.41 logMAR for 1-wall, 0.41 logMAR for 2-wall, and 0.55 logMAR for 3-wall decompressions. The mean reduction in exophthalmos was 4.9 mm overall, 4.3 mm for 1-wall, 4.54 mm for 2-wall, and 6.02 for 3-wall decompressions. The mean new onset diplopia (NOD) rate was 19.84% overall, 19,12% for 1-wall, 20.75% for 2-wall, and 19.83% for 3-wall decompressions. CONCLUSION: The results are limited due to the high number of biases in the included studies. It seems that 3-wall decompression offers the best VA improvement and proptosis reduction although also the highest NOD and complications rate. Two-wall balanced decompression or 1-wall inferomedial decompression seems to be effective with less morbidity.

Treatment-induced neuropathy of diabetes: challenges in diagnosing neuropathic pain, value of sudomotor function testing.

A patient in his 60s was admitted for an extensive neurological work-up due to progressive asymmetrical, distally pronounced pain in both feet and legs. Conventional pain relievers did not help in pain reduction. A Sudoscan revealed small fibre damage in all extremities indicating an underlying neuropathy. The patient had started insulin treatment around 6 months prior to hospitalisation because of a newly diagnosed late-onset diabetes. Due to a rapid drop in glycated haemoglobin (from over 14% to 6% in 4 months), treatment-induced neuropathy of diabetes (TIND) was hypothesised. On increasing the dose of pregabalin and adding duloxetine, the patient reported improvement of symptoms, which further underlined the suspected diagnosis. Hence, in patients with severe hyperglycaemia, changes in glycaemic control should be stepwise and not rapid; however, to date, no guidelines exist how to avoid TIND.

Epithelioid malignant peripheral nerve sheath tumour of the ulnar nerve around the elbow: a diagnostic and therapeutic challenge.

Epithelioid malignant peripheral nerve sheath tumour (EMPNST) is a rare histological subtype of malignant peripheral nerve sheath tumour (MPNST), accounting for 5% to 17% of MPNSTs. The clinical and MRI findings of EMPNST mimic those of nerve abscesses, similar to the presentation in Hansen's disease. We present one such case with this kind of diagnostic dilemma. Intraoperative findings suggest a tumour changed the course of management subsequently. The development of neurological deficits postoperatively after tumour resection was a reconstructive challenge. To provide motor power and sensation through a procedure that provides a complete functional outcome for a young patient, distal nerve transfers were chosen. This provided an improvement in the quality of life and hastened the neurological recovery of the involved limb. Level of evidence: V.

Parkes Weber syndrome: a rare cause of foot drop.

This case report describes a patient in her late 60s, previously diagnosed with Klippel-Trenaunay syndrome who presented with difficulty walking. A year prior to her presentation she had a fall which made her notice a painless foot drop on the right. Her right leg was profoundly hypertrophied compared with the left, and a port-wine stain was present on the lateral side, extending from the hip to the mid-shin. The patient's differential diagnosis based on clinical examination and investigations is discussed leading to a final diagnosis of sciatic neuropathy secondary to an arteriovenous malformation due to Parkes Weber syndrome.

A New Finding on Magnetic Resonance Imaging for Diagnosis of Hemifacial Spasm with High Accuracy and Interobserver Correlation.

Among patients with clinical hemifacial spasm (HFS), imaging exams aim to identify the neurovascular conflict (NVC) location. It has been proven that the identification in the preoperative exam increases the rate of surgical success. Despite the description of specific magnetic resonance image (MRI) acquisitions, the site of neurovascular compression is not always visualized. The authors describe a new MRI finding that helps in the diagnosis of HFS, and evaluate the sensitivity, specificity, and interobserver correlation of the described sign. A cross-sectional study including cases of hemifacial spasm treated surgically from 1 August 2011 to 31 July 2021 was performed. The MRIs of the cases were independently evaluated by two experienced neuroradiologists, who were blinded regarding the side of the symptom. The neuroradiologists were assigned to evaluate the MRIs in two separate moments. Primarily, they evaluated whether there was a neurovascular conflict based on the standard technique. Following this initial analysis, the neuroradiologists received a file with the description of the novel sign, named Prevedello Sign (PS). In a second moment, the same neuroradiologists were asked to identify the presence of the PS and, if it was present, to report on which side. A total of 35 patients were included, mostly females (65.7%) with a mean age of 59.02 (+0.48). Since the 35 cases were independently evaluated by two neuroradiologists, a total of 70 reports were included in the analysis. The PS was present in 66 patients (sensitivity of 94.2%, specificity of 91.4% and positive predictive value of 90.9%). When both analyses were performed in parallel (standard plus PS), the sensitivity increased to 99.2%. Based on the findings of this study, the authors conclude that PS is helpful in determining the neurovascular conflict location in patients with HFS. Its presence, combined with the standard evaluation, increases the sensitivity of the MRI to over 99%, without increasing risks of harm to patients or resulting in additional costs.

Transient lateral rectus palsy associated with acute coronary syndrome treated with percutaneous coronary intervention: a case report.

BACKGROUND: Patients who experience angina and acute myocardial infarction often receive diagnostic coronary angiography and percutaneous coronary intervention. CASE PRESENTATION: A 54-year-old Persian man with acute coronary syndrome was admitted to the hospital and underwent elective percutaneous coronary intervention. Two hours after the procedure, the patient experienced ophthalmoplegia and diplopia. The diagnosis was abducens nerve palsy resulting in transient lateral rectus palsy. The cause is presumed to have been an ischemic event affecting the unilateral abducens nerve. This could have occurred owing to the microembolism during the percutaneous coronary intervention, which resulted in left lateral rectus palsy. Within 1 month, the diplopia was relieved completely, and the physical examination was normal. CONCLUSION: The occurrence of neuro-ophthalmic complications that may arise from percutaneous coronary intervention is extremely rare. To our knowledge, this is the second reported case of unilateral rectus palsy associated with percutaneous coronary intervention.

COVID-19 and sudden-onset ocular neurogenic palsy in prior healthy patients: a systematic review.

BACKGROUND: The aim of this systematic review is to identify cases of neurogenic ocular palsy in the presence of COVID-19 and to document patient characteristics, type of palsy and possible aetiologies. METHODS: A systematic search of PubMed, Medline and CINAHL databases was conducted on the 6th of January 2023 to identify cases of neurogenic ocular palsy in patients with current or previous COVID-19 infection. Data were pooled to summarise the neurogenic palsy, patient clinical characteristics and proposed palsy mechanisms. RESULTS: The combined database search yielded 1197 articles. Of these, 23 publications consisting of 25 patients met the inclusion criteria. Most patients were male (68%) and ranged in age from 2 to 71 years (median=32.7, SD=21.4). Seven patients (28%) were children aged 2 to 10 years old. Abducens palsies were most common (68%) and the most common ocular presentation was diplopia (76%) with an average time of onset 15 days from testing positive to COVID-19 or having symptoms of the virus. Proposed mechanism of development of a neurogenic palsy secondary to COVID-19 infection was classified into one of three categories: vascular/thrombotic, a viral neuro-invasive or inflammatory virus-mediated immune response. DISCUSSION: This study suggests that COVID-19 infection may be linked to oculomotor, trochlear and abducens nerve palsies and the underlying mechanisms may vary but are difficult to definitively establish. Further studies investigating the onset of neurogenic palsy secondary to COVID-19 infection is required.

Development of microscopic polyangiitis following idiopathic pleuroparenchymal l fibroelastosis: A case report.

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare type of idiopathic interstitial pneumonia, which is characterised by pleural fibrosis and subjacent parenchymal fibroelastosis of the upper lobes. Herein, we present a case of microscopic polyangiitis (MPA) following PPFE. The patient had abnormal shadows on chest radiographs 15 years before the onset of MPA, and the patient was diagnosed with PPFE. Four years after the PPFE diagnosis, the patient was diagnosed with MPA based on persistent fever, purpura, mononeuritis multiplex, myeloperoxidase-antineutrophil cytoplasmic antibody positivity, and pathological findings of peritubular capillaritis on kidney biopsy. The patient was treated with glucocorticoids, including methylprednisolone pulse therapy and rituximab, followed by maintenance therapy with rituximab. One year after treatment, the PPFE had not worsened. PPFE occasionally occurs secondary to connective tissue disease, including MPA; however, to the best of our knowledge, this is the first report of PPFE preceding MPA. Our case suggests that PPFE, as other interstitial lung diseases, may be associated with MPA and precede the onset of MPA. The accumulation of more cases is needed to clarify the characteristics of MPA-associated PPFE.