Genetic analysis of 37 cases with primary periodic paralysis in Chinese patients.

BACKGROUND: Primary periodic paralysis (PPP) is an inherited disorders of ion channel dysfunction characterized by recurrent episodes of flaccid muscle weakness, which can classified as hypokalemic (HypoPP), normokalemic (NormoPP), or hyperkalemic (HyperPP) according to the potassium level during the paralytic attacks. However, PPP is charactered by remarkable clinical and genetic heterogeneity, and the diagnosis of suspected patients is based on the characteristic clinical presentation then confirmed by genetic testing. At present, there are only limited cohort studies on PPP in the Chinese population. RESULTS: We included 37 patients with a clinical diagnosis of PPP. Eleven (29.7%) patients were tested using a specific gene panel and 26 (70.3%) by the whole-exome sequencing (WES). Twenty-two cases had a genetic variant identified, representing a diagnostic rate of 59.5% (22/37). All the identified mutations were either in the SCN4A or the CACNA1S gene. The overall detection rate was comparable between the panel (54.5%: 6/11) and WES (61.5%: 16/26). The remaining patients unresolved through panel sequencing were further analyzed by WES, without the detection of any mutation. The novel atypical splicing variant c.2020-5G > A affects the normal splicing of the SCN4A mRNA, which was confirmed by minigene splicing assay. Among 21 patients with HypoPP, 15 patients were classified as HypoPP-2 with SCN4A variants, and 6 HypoPP-1 patients had CACNA1S variants. CONCLUSIONS: Our results suggest that SCN4A alleles are the main cause in our cohort, with the remainder caused by CACNA1S alleles, which are the predominant cause in Europe and the United States. Additionally, this study identified 3 novel SCN4A and 2 novel CACNA1S variants, broadening the mutation spectrum of genes associated with PPP.

Epidural Catheterization in Cardiac Surgery: A Systematic Review and Risk Assessment of Epidural Hematoma.

ABSTRACT: The potential benefits of epidural anesthesia on mortality, atrial fibrillation, and pulmonary complications must be weighed against the risk of epidural hematoma associated with intraoperative heparinization. This study aims to provide an updated assessment of the clinical risks of epidural anesthesia in cardiac surgery, focusing on the occurrence of epidural hematomas and subsequent paralysis. A systematic search of Embase, Medline, Ovid Central, Web of Science, and PubMed was conducted to identify relevant publications between 1966 and 2022. Two independent reviewers assessed the eligibility of the retrieved manuscripts. Studies reporting adult patients undergoing cardiac surgery with epidural catheterization were included. The incidence of hematomas was calculated by dividing the number of hematomas by the total number of patients in the included studies. Risk calculations utilized various denominators based on the rigor of trial designs, and the risks of hematoma and paralysis were compared to other commonly encountered risks. The analysis included a total of 33,089 patients who underwent cardiac surgery with epidural catheterization. No epidural hematomas were reported across all published RCTs, prospective, and retrospective trials. Four case reports associated epidural hematoma with epidural catheterization and perioperative heparinization. The risks of epidural hematoma and subsequent paralysis were estimated at 1:7643 (95% CI 1:3860 to 380,916) and 1:10,190 (95% CI 1:4781 to 0:1), respectively. The risk of hematoma is similar to the non-obstetric population (1:5405; 95% CI 1:4784 to 6134). The risk of hematoma in cardiac surgery patients receiving epidural anesthesia is therefore similar to that observed in some other surgical non-obstetric populations commonly exposed to epidural catheterization.

Iatrogenic botulism cases after gastric and axillary application of botulinum toxin and review of literature.

INTRODUCTION: Iatrogenic botulism is a rare, serious disease that progresses with descending paralysis and develops after cosmetic or therapeutic botulinum toxin-A (BoNT-A) application. CASE PRESENTATIONS: In this case series; six cases of iatrogenic botulism followed up in our center are presented. Four of these developed after gastric BoNT-A and two after axillary BoNT-A application. RESULTS: The most important cause for the disease was the use of unlicensed products and high-dose toxin applications. The first symptoms were blurred vision, double vision, difficulty in swallowing, and hoarseness. Symptoms appeared within 4-10 days after the application of BoNT-A. Symptoms progressed in the course of descending paralysis in the following days with fatigue, weakness in extremities and respiratory distress. Diagnosis was based on patient history and clinical findings. The main principles of foodborne botulism therapy were applied in the treatment of iatrogenic botulism. If clinical worsening continued, regardless of the time elapsed after BoNT-A application, the use of botulinum antitoxin made a significant contribution to clinical improvement and was recommended. CONCLUSIONS: Routine and new indications for BoNT-A usage are increasing and, as a result, cases of iatrogenic botulism will be encountered more frequently. Physicians should be alert for iatrogenic botulism in the follow-up after BoNT-A applications and in the differential diagnosis of neurological diseases that are presented with similar findings.

Evaluation of computed tomography in the diagnosis of ultrasound-proven diaphragm dysfunction.

INTRODUCTION: Computed tomography (CT) is routinely employed on the evaluation of dyspnea, yet limited data exist on its assessment of diaphragmatic muscle. This study aimed to determine the capability of CT in identifying structural changes in the diaphragm among patients with ultrasound-confirmed diaphragmatic dysfunction. METHODS: Diaphragmatic ultrasounds conducted between 2018 and 2021 at our center in Marseille, France, were retrospectively collected. Diaphragmatic pillars were measured on CT scans at the L1 level and the celiac artery. Additionally, the difference in height between the two diaphragmatic domes in both diaphragmatic dysfunction cases and controls was measured and compared. RESULTS: A total of 65 patients were included, comprising 24 with diaphragmatic paralysis, 13 with diaphragmatic weakness, and 28 controls. In the case group (paralysis and weakness) with left dysfunctions (n = 24), the CT thickness of the pillars at the level of L1 and the celiac artery was significantly thinner compared with controls (2.0 mm vs. 7.4 mm and 1.8 mm vs. 3.1 mm, p < 0.001 respectively). Significantly different values were observed for paralysis (but not weakness) in the right dysfunction subgroup (n = 15) (2.6 mm vs. 7.4 mm and 2.2 mm vs. 3.8 mm, p < 0.001 respectively, for paralysis vs. controls). Regardless of the side of dysfunction, a significant difference in diaphragmatic height was observed between cases and controls (7.70 cm vs. 1.16 cm and 5.51 cm vs. 1.16 cm, p < 0.001 for right and left dysfunctions, respectively). Threshold values determined through ROC curve analyses for height differences between the two diaphragmatic domes, indicative of paralysis or weakness in the right dysfunctions, were 4.44 cm and 3.51 cm, respectively. Similarly for left dysfunctions, the thresholds were 2.70 cm and 2.48 cm, respectively, demonstrating good performance (aera under the curve of 1.00, 1.00, 0.98, and 0.79, respectively). CONCLUSION: In cases of left diaphragmatic dysfunction, as well as in paralysis associated with right diaphragmatic dysfunction, CT revealed thinner pillars. Additionally, a notable increase in the difference in diaphragmatic height demonstrated a strong potential to identify diaphragmatic dysfunction, with specific threshold values.

Ramsay Hunt Syndrome Associated with Varicella-Zoster Virus Encephalitis in a Child.

Ramsay Hunt syndrome (RHS) is a triad of peri-auricular pain, ipsilateral facial nerve palsy and vesicular rash around the ear pinna. It is caused by reactivation of varicella-zoster virus (VZV) that lies dormant in the geniculate ganglia. It can be complicated by VZV encephalitis rarely. We report the case of an 8-year-old previously healthy boy who presented to a tertiary care hospital in Muscat, Oman in 2021 with fever, progressive left ear pain, vesicular rash around his ear pinna and left-sided facial nerve palsy. His course was complicated by VZV encephalitis where he was managed with intravenous (IV) acyclovir and IV corticosteroids. He improved significantly and was asymptomatic with a normal neurology examination at the 6-months follow-up.

[Nerve Transfers in Children with Non-traumatic Amyoplasia] / Nerventransfers bei Kindern mit nicht traumatischer AmyoplasieNerve Transfers in Children with Non-traumatic Amyoplasia.

BACKGROUND: The treatment of obstetric brachial plexus palsy through primary reconstruction and nerve transfers has been established in the past decades. In the case of non-traumatic diseases that lead to flaccid paralysis and the inability to move the extremities, such as transverse myelitis (TM) or arthrogryposis multiplex congenita (AMC), which can have a wide variety of causes, the focus has been on rehabilitative therapy so far, while surgical interventions have been used to a lesser extent, e. g., in the form of osteotomies or muscle transfers. Our aim is to establish nerve transfers as a surgical option to improve mobility in non-traumatic amyoplasia. PATIENTS: This work presents the needs-adapted treatment of a total of 23 patients (aged 4 months to 64 months, 18 with AMC and 5 with TM) using nerve transfers on the upper extremity. RESULTS: We were able to show that early nerve transfers in the upper extremity enabled the reanimation of muscles in both AMC and TM. CONCLUSION: This work shows that the treatment of non-traumatic amyoplasia in children with selective nerve grafts is a successful method. Nerve transfers allow patients to gain or regain important functions for managing independent everyday life. The surgical methods have been established in the treatment of traumatic nerve injuries. They are well-known and can be carried out safely. We believe that this is an important treatment option for paediatric patients with paralysis associated with TM or AMC, which should also be known to the treating physicians.

Incidence of Nerve Palsies During Pavlik Harness Treatment for Developmental Dysplasia of the Hip: A Retrospective Cohort Study.

BACKGROUND: The Pavlik harness has been used for approximately a century to treat developmental dysplasia of the hip (DDH). Femoral nerve palsy is a documented complication of Pavlik harness use, with an incidence ranging from 2.5% to 11.2%. Rare reports of brachial plexus palsy have also been documented. The primary purpose of the current study was to evaluate the incidence of various nerve palsies in patients undergoing Pavlik harness treatment for DDH. Secondary aims were to identify patient demographic or hip characteristics associated with nerve palsy. METHODS: We performed a retrospective review of patients diagnosed with DDH and treated with a Pavlik harness from February 1, 2016, to April 1, 2023, at a single tertiary care orthopaedic hospital. Hip laterality, use of a subsequent rigid abduction orthosis, birth order, breech positioning, weight, and family history were collected. The median (and interquartile range [IQR]) or mean (and standard deviation [SD]) were reported for all continuous variables. Independent 2-sample t tests and Mann-Whitney U tests were conducted to identify associations between the variables collected at the initiation of Pavlik harness treatment and the occurrence of nerve palsy. RESULTS: Three hundred and fifty-one patients (547 hips) were included. Twenty-two cases of femoral nerve palsy (4% of all treated hips), 1 case of inferior gluteal nerve palsy (0.18%), and 2 cases of brachial plexus palsy (0.37%) were diagnosed. Patients with nerve palsy had more severe DDH as measured by the Graf classification (p < 0.001) and more severe DDH as measured on physical examination via the Barlow and Ortolani maneuvers (p = 0.003). CONCLUSIONS: Nerve palsies were associated with more severe DDH at the initiation of Pavlik harness use. Upper and lower-extremity neurological status should be scrutinized at initiation and throughout treatment to assess for nerve palsies. The potential for femoral, gluteal, and brachial plexus palsies should be included in the discussion of risks at the beginning of treatment. Families may be reassured that nerve palsies associated with Pavlik harness can be expected to resolve with a short break from treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Chronic bee paralysis virus exploits host antimicrobial peptides and alters gut microbiota composition to facilitate viral infection.

The significance of gut microbiota in regulating animal immune response to viral infection is increasingly recognized. However, how chronic bee paralysis virus (CBPV) exploits host immune to disturb microbiota for its proliferation remains elusive. Through histopathological examination, we discovered that the hindgut harbored the highest level of CBPV, and displayed visible signs of damages. The metagenomic analysis showed that a notable reduction in the levels of Snodgrassella alvi and Lactobacillus apis, and a significant increase in the abundance of the opportunistic pathogens such as Enterobacter hormaechei and Enterobacter cloacae following CBPV infection. Subsequent co-inoculation experiments showed that these opportunistic pathogens facilitated the CBPV proliferation, leading to accelerated mortality in bees and exacerbation of bloated abdomen symptoms after CBPV infection. The expression level of antimicrobial peptide (AMP) was found to be significantly up-regulated by over 1000 times in response to CBPV infection, as demonstrated by subsequent transcriptome and quantitative real-time PCR investigations. In particular, through correlation analysis and a bacteriostatic test revealed that the AMPs did not exhibit any inhibitory effect against the two opportunistic pathogens. However, they did demonstrate inhibitory activity against S. alvi and L. apis. Our findings provide different evidence that the virus infection may stimulate and utilize the host's AMPs to eradicate probiotic species and facilitate the proliferation of opportunistic bacteria. This process weakens the intestinal barrier and ultimately resulting in the typical bloated abdomen.

COVID-19 Vaccine Related Cervical Radiculitis and Parsonage-Turner Syndrome: Case Report and Review of the Literature.

Parsonage-Turner Syndrome, or neuralgic amyotrophy, is an acute-onset upper limb and shoulder girdle palsy that can occur in a post-viral, post-surgical or idiopathic setting. There have also been some reported cases of the syndrome occurring following vaccinations. The pathophysiology of neuralgic amyotrophy is not completely understood and many of the commonly used diagnostic imaging modalities we use to try and diagnose this syndrome are inaccurate and misleading. We present the case of a 40-year-old gentleman who presented with acute onset burning pain and fasciculations in his right upper extremity following vaccination with the second dose of the Pfizer-BioNTech COVID-19 vaccine. His symptoms progressed to weakness in isolated muscle groups with electromyographic evidence of decreased nerve conduction. MRI of the cervical spine demonstrated multilevel central and foraminal stenosis, suggesting a diagnosis of cervical radiculopathy. The patient underwent a C4-5/C5-6 and C6-7 laminoforaminotomy and tolerated the procedure well. Post-operatively, the patient has experienced gradual symptom improvement with residual right triceps and pectoralis muscle weakness as well as paresthesias of the right elbow and forearm. Parsonage-Turner Syndrome is a brachial plexus palsy that can affect one or multiple branches of the brachial plexus. It causes acute-onset pain and weakness, and the diagnosis can be difficult to make with the commonly used diagnostic imaging methods. We reviewed other case reports about neuralgic amyotrophy following vaccinations as well as the current literature on more accurate diagnostic imaging modalities that may help our diagnosis and understanding of the pathophysiology of this condition.

[Selective Neurectomy in Spastic Paralysis of the Upper Extremity]. / Die hyperselektive Neurektomie bei spastischen Lähmungen der oberen Extremität.

Selective neurectomy refers to the targeted transection of motor nerve fibres at their entry into the muscle in order to reduce the increased muscle tone in cases of spastic paralysis. This procedure has regained popularity in recent years, especially in the upper extremity. First and foremost, it requires an exact knowledge of the topographical anatomy of muscle innervation. To be able to control the extent and localisation of the denervation, the terminal nerve branches must be visualized precisely during the procedure. For a meaningful reduction of muscle tone, 2/3 to 4/5 of nerve fibres must be resected. This article presents the historical development, principles and operative details of this technique as well as clinical results.

Forensic Identification and Evaluation of 25 Obstetric Brachial Plexus Palsy Medical Damage Cases.

OBJECTIVES: To analyze the high risk factors of obstetric brachial plexus palsy (OBPP), and to explore how to evaluate the relationship between fault medical behavior and OBPP in the process of medical damage forensic identification. METHODS: A retrospective analysis was carried out on 25 cases of medical damage liability disputes related to OBPP from 2017 to 2021 in Beijing Fayuan Judicial Science Evidence Appraisal Center. The shortcomings of hospitals in birth weight assessment, delivery mode selection, labor process observation and shoulder dystocia management, and the causal relationship between them and the damage consequences of the children were summarized. RESULTS: Fault medical behavior was assessed as the primary cause in 2 cases, equal cause in 10 cases, secondary cause in 8 cases, minor cause in 1 case, no causal relationship in 1 case, and unclear causal force in 3 cases. CONCLUSIONS: In the process of forensic identification of OBPP, whether medical behaviors fulfill diagnosis and treatment obligations should be objectively analyzed from the aspects of prenatal evaluation, delivery mode notification, standardized use of oxytocin, standard operation of shoulder dystocia, etc. Meanwhile, it is necessary to fully consider the objective risk of different risk factors and the difficulty of injury prevention, and comprehensively evaluate the causal force of fault medical behavior in the damage consequences.

A Case of Superior Oblique Palsy without Brown Syndrome Induced by a Dog Bite.

BACKGROUND Pseudo-Brown syndrome is characterized by dysfunction of the superior oblique tendon-trochlear complex. Canine tooth syndrome, which involves superior oblique palsy with pseudo-Brown syndrome, results from damage to the trochlear and superior oblique tendon from dog bites around the eye. This report describes a variant of canine tooth syndrome without pseudo-Brown syndrome following a dog bite around the left upper eyelid. In this case, magnetic resonance imaging (MRI) facilitated early diagnosis and therapeutic intervention. CASE REPORT A 19-year-old man presented with torsional diplopia following a dog bite around the left upper eyelid and forehead. Five days after the injury, an alternate prism cover test revealed 6 prism diopters (Δ) exotropia and 5Δ left hypertropia. Ocular motility showed no significant limitation in elevation or depression during adduction. MRI performed on the same day showed a high-signal area extending from the superior oblique tendon to the trochlear region and the superior oblique muscle belly of the left eye. A diagnosis of canine tooth syndrome without pseudo-Brown syndrome was made and oral steroids were administered. Ocular alignment did not improve, so left inferior oblique myotomy was performed 7 months after the injury. The patient's cyclovertical diplopia resolved postoperatively. CONCLUSIONS Dog bites around the eye can result in abnormalities of the extraocular muscles. Early MRI may be useful for diagnosis and determining treatment strategies. This report has highlighted the importance of rapid assessment and management of patients with dog bites involving the eye.

Studies on the sequential pathology of Kyasanur Forest Disease (KFD) in Mouse brain: KFD virus induces apoptosis of neurons in cerebrum and hippocampus.

The sequential pathology of Kyasanur forest disease (KFD) in mouse brain was assessed in this study. Kyasanur forest disease virus (KFDV) strain P9605 used in this study was confirmed by real-time reverse transcriptase-polymerase chain reaction targeting the NS5 gene. Mouse Lethal Dose 50 (MLD50) of the virus was determined by in-vivo mice inoculation test. One MLD50 of the KFDV was inoculated intra-cerebrally into 36 mice aged 2-3 weeks. Another group of 36 age-matched mice that served as control group were inoculated with plain media. Six mice each from infected and control groups were euthanized every 24 hrs intervals for six days. Brain tissues were collected in 10% NBF. The collected brain tissues were processed and subjected to histopathological studies by Hematoxylin and Eosin staining. Grossly, the infected mice showed symptoms of dullness, hunched back appearance, weakness, sluggish movements with indication of hind quarter paralysis on day four post-infection. These symptoms got aggravated with complete paralysis of the hind quarters, inability to move and death on 5th and 6th day post-infection. Microscopically, the brain showed apoptosis of neurons, perivascular cuffing, gliosis, congestion, neuropil vacuolation, meningitis, degeneration, and necrotic neurons. The real-time RT-PCR on hippocampus of the KFDV-infected mouse brain showed three-fold higher expression levels of Caspase 3, a crucial mediator of apoptosis. The cerebral cortex, cerebellum and hippocampus that control the motor neuron activities and muscle tone were primarily affected, possibly correlating with the gross symptoms of hind quarter paralysis, ataxia, and other motor neuron dysfunctions noticed. Taken together, these findings reveal that KFDV induces apoptosis of neurons in the cerebrum and hippocampus of KFDV infected mice. Further studies are needed to confirm if the lesions noticed in mice brain simulate the brain lesions in humans since gross motor-neuron symptoms are similar in mice as well as humans.

Long-term outcome of endovascular treatment for indirect carotid-cavernous fistulas.

OBJECTIVE: Endovascular treatment (EVT) is the primary approach used to treat indirect carotid-cavernous fistulas (CCFs). In this study, the authors evaluated the immediate and long-term efficacy and safety of different endovascular techniques for indirect CCFs. METHODS: The databases of two endovascular centers were retrospectively reviewed to collect the patients with indirect CCFs treated using endovascular techniques between 2013 and 2023. Demographics, clinical presentation, CCF features, EVT characteristics, and clinical and radiological outcomes were evaluated and analyzed. The analysis was performed to compare the clinical and radiological data between different endovascular approaches and different embolic materials. RESULTS: Ninety-eight patients were included in the study. EVT was successful in 95 patients (96.9%). Immediate complete obliteration of the CCF was achieved in 93.9% of patients, with 98% undergoing embolization with liquid embolic agents (LEAs) and 95.6% undergoing coiling alone. Complete CCF obliteration was higher in the transvenous than in the transarterial approach (94.3% vs 75%, p = 0.010). At ≥ 6 months follow-up, complete CCF obliteration was achieved in all patients (100%). The rate of procedure-related complications was higher following LEAs than with coiling alone (32.0% vs 15.6%). New cranial nerve (CN) palsy was diagnosed in 26.0% and 2.2% after embolization with LEAs and coiling alone, respectively (p = 0.001), with complete CN palsy recovery in 78.6%. Procedure-related intracranial hemorrhage occurred in 3 patients (3.1%). Two patients experienced an ischemic stroke following Onyx migration into the internal carotid artery. Ocular symptoms improved in 93% (83/89) of the patients who were followed. CONCLUSIONS: In this study, complete obliteration of an indirect CCF was achieved in more than 90% of patients. Despite the occurrence of some new postprocedural ocular CN palsy, ocular symptoms improved in most patients in long-term follow-up. The transvenous approach was the most effective method for treating the indirect CCF. Coiling was safer than LEAs for the embolization of the indirect CCF.

Scalp acupuncture for post-stroke spastic hemiparesis: A systematic review and meta-analysis.

BACKGROUND: Spastic paralysis is one of the most common sequelae of stroke, severely affecting patients' limb function and reducing their quality of life. Scalp acupuncture (SA) has been shown to significantly improve cerebral blood supply and reduce the severity of limb spasticity. This meta-analysis aims to systematically evaluate the clinical efficacy of SA in the treatment of post-stroke spastic paralysis, providing evidence-based medicine for clinical management of this condition. METHODS: We comprehensively searched databases including China National Knowledge Infrastructure, Wanfang Data, VIP Chinese Science and Technology Periodical Database, China Biomedical Literature Database, PubMed, Embase, and Cochrane Library. Randomized controlled trials investigating the efficacy of SA in post-stroke spastic paralysis were identified until July 28, 2023. Meta-analysis was conducted using RevMan 5.4 and Stata17.0. RESULTS: A total of 16 studies were included. Meta-analysis showed that the modified Ashworth spasticity assessment scale in the SA group was significantly higher than that in the rehabilitation group (mean difference [MD] = -0.56, 95% confidence interval [CI] [-0.75, -0.37], Z = 5.67, P < .00001). The simplified Fugl-Meyer motor function assessment scale in the SA group was significantly higher than that in the rehabilitation group (MD = 5.86, 95% CI [3.26, 8.46], Z = 4.41, P < .0001). The modified Barthel index assessment scale in the SA group was significantly higher than that in the rehabilitation group (MD = 5.79, 95% CI [4.73, 6.84], Z = 10.77, P < .00001). Additionally, the clinical effective rate in the SA group was significantly higher than that in the rehabilitation group (relative risk = 1.25, 95% CI [1.16, 1.36], Z = 5.42, P < .00001). CONCLUSION: SA combined with rehabilitation therapy has certain advantages in reducing limb spasticity, improving limb function, and enhancing activities of daily living in patients with post-stroke spastic paralysis. This study provides reference and theoretical support for the promotion of SA in the treatment of this condition.

Gross and histopathological findings in hindlimb paralysis syndrome in wild Carnaby's black cockatoos (Zanda laitirostris).

The aim of this study was to describe the gross and histopathological features of a neurological syndrome in endangered Western Australian Carnaby's black cockatoos (Zanda laitirostris) that was first observed in 2012. The syndrome, named hindlimb paralysis syndrome in Carnaby's cockatoos (CHiPS), is characterized by annual outbreaks of hindlimb paralysis with occasional loss of deep pain and cloacal tone, typically occurring between January and March. Previous limited investigations suggested a possible toxic aetiology. Full gross necropsy and histopathology examinations were performed on 17 CHiPS cases and on 11 control birds for reference. Histopathological examination was carried out on all major organs including brain, spinal cord, brachial plexus, sciatic nerve and wing and hindlimb muscles. Gross and histopathological examinations did not elucidate a definitive cause of the clinical signs seen in CHiPS cases. There were no substantial gross or histopathological changes within the brain, spinal cord, sciatic nerve or brachial plexus that could explain the hindlimb paralysis. The most noteworthy changes were seen in the hindlimb and wing muscles, with a monophasic to polyphasic myopathy present in the hindlimb muscles of 15 of the 17 CHiPS cases and in the wing muscles in 11 of those cases. The cause and significance of the myopathy is unclear and requires further investigation. Based on the above findings, the most likely differential diagnoses include neurotoxicoses (eg, organophosphate, organochlorine and carbamate) and, less likely, myotoxicosis (eg, ionophore toxicosis), nutritional myopathy (eg, vitamin E/selenium deficiency) or botulism.