Transverse Myelitis: A Case-Based Discussion of Infectious Etiologies.

Transverse myelitis (TM) is a frequently encountered inpatient neurological condition, usually with a broad differential of etiologies narrowed down by detailed history, temporal profile of symptom evolution, and pertinent diagnostic studies. We report a rare case of a 39-year-old man who presented with subacute onset of headaches and confusion, and three days later developed quadriplegia and areflexia. He was diagnosed with acute longitudinally extensive transverse myelitis (LETM) related to Epstein-Barr virus (EBV) superimposed on an initial presentation of streptococcal meningitis. As both etiologies are under-reported, we compare our case to the few similar cases in the literature to guide discussion of the clinical and radiologic findings of parainfectious TM related to EBV and streptococcal meningitis. Readers will have the challenge of attributing our patient's myelitis to one of these parainfectious sources and are encouraged to evaluate for rare infectious etiologies in acute settings.

Locked-In Syndrome: A Rare Manifestation of Neuropsychiatric Lupus.

Neuropsychiatric systemic lupus erythematosus (SLE) is a rare condition that has a multitude of mechanisms resulting in the emergence of variable clinical presentations. We describe a peculiar case of a 33-year-old female with a history of SLE presented with two weeks of fever, headache, and vomiting. On admission, she became obtunded and was emergently intubated. Initial lumbar puncture revealed pleocytosis (46% neutrophils, 320 corrected nucleated cells/µL), elevated protein (244 mg/dL; normal, 15-40 mg/dL), normal glucose (63 mg/dL), and negative cultures. Empiric acyclovir, ampicillin, ceftriaxone, and vancomycin were initiated without clinical improvement. Neurological examination was notable for limited ability to follow commands, vertical nystagmus, horizontal gaze palsy, diffuse hyperreflexia, and quadriparesis. Electroencephalogram (EEG) was consistent with diffuse encephalopathy. Brain magnetic resonance imaging demonstrated restricted diffusion and contrast enhancement in the posterior and central pons with edema. A cerebral angiogram showed no signs of vasculitis. Treatment with intravenous (IV) methylprednisolone 1 g and IV immunoglobulin 2 g/kg was initiated for five days. Despite these interventions, no discernible clinical improvement was observed, prompting the commencement of 500 mg/m2 cyclophosphamide and daily maintenance of IV methylprednisolone at 2 mg/kg. A repeat MRI three weeks later revealed a marked reduction in the size of the lesion involving the pons. The patient also improved clinically over the month with successful extubation, complete return in mental capabilities, and the ability to ambulate short distances with assistance.

Comparing FGFR-3 and TS-HDS Seropositive Small Fiber Neuropathy: Unique Patient Features, Symptoms, Laboratory, and Nerve Conduction Study Findings.

OBJECTIVES: Small fiber neuropathy presents a significant diagnostic and therapeutic challenge. To solve this challenge, efforts have been made to identify autoantibodies associated with this condition. Previous literature has often considered tri-sulfated heparin disaccharide (TS-HDS) and fibroblast growth factor receptor 3 (FGFR3) as a singular seropositive group and/or focused primarily on symptomatic associations. METHODS: One hundred seventy-two small fiber neuropathy patients with a Washington University Sensory Neuropathy panel were selected for TS-HDS seropositivity, FGFR-3 seropositivity, and seronegative controls. Data were collected to on the demographic, symptomatic, and laboratory profiles of each subgroup. RESULTS: Percent female (P = 0.0043), frequency of neuropathic pain symptoms (P = 0.0074), and erythrocyte sedimentation rate (P = 0.0293), vitamin D (P < 0.0001), and vitamin B12 (P = 0.0033) differed between the groups. Skin biopsy was more frequently normal within both the FGFR-3 and the TS-HDS cohort (P = 0.0253). CONCLUSIONS: TS-HDS and FGFR-3 display a distinct phenotype from both controls and one another. Immunoglobulin M (IgM) against FGFR-3 and IgM against TS-HDS may be individually valuable markers for the development of distinct clinical phenotypes.

When the Music Comes From the Brain: A Rare Case of Auditory Seizures Secondary to a Right Temporal Lobe Arteriovenous Malformation.

Focal seizures with subjective auditory phenomena, known as auditory seizures, are uncommon and can include simple to complex auditory hallucinations. We present a case of a 59-year-old man who presented with motor and non-motor seizures. He had a four-month history of hearing things resembling continuous metallic sounds, pennies dropping into a bank, persistent music after radio cessation, and the sound of a passing train. Brain MRI showed multiple serpiginous flow voids in the right temporal lobes, consistent with an arteriovenous malformation that was confirmed eventually with a diagnostic brain angiogram. The etiology of the seizures was related to a structural lesion in the setting of a right temporal arteriovenous malformation (AVM). Treatment with 2000mg of levetiracetam twice daily and 300mg of oxcarbazepine twice daily improved symptoms, and subsequent stereotactic radiosurgery ablation successfully treated the AVM. Post-treatment MRI showed reduced visibility of parasitized vessels, with controlled generalized seizures but partial control of auditory seizures.

Anti-Plexin-D1 Seropositive Small Fiber Neuropathy: Clinical Phenotype, Demographics, and Literature Review.

OBJECTIVES: Small fiber neuropathy (SFN) is a subtype of painful neuropathies defined by dysfunction of the Aδ and unmyelinated C fibers. It presents with both neuropathic pain and dysautonomia symptoms, posing a significant diagnostic and therapeutic challenge. To address this challenge, research has been conducted to identify autoantibodies and define their association with phenotypes. METHODS: Eleven cases of anti-plexin-D1 seropositive SFN were reviewed, along with relevant literature, in attempt to better define anti-plexin-D1 SFN demographics, symptoms, associated medical conditions, and therapeutics. RESULTS: Anti-plexin-D1 SFN typically presents in female patients, with neuropathic pain, normal skin biopsy findings, and normal nerve conduction studies. Anti-plexin-D1 shows an association with concurrent chronic pain, with almost half of the patients undergoing an interventional procedure. CONCLUSIONS: Anti-plexin-D1 represents a unique subgroup of SFN, defined by distinct demographics, phenotype, biopsy findings, and therapeutic management.

Creutzfeldt-Jakob Disease Presenting as Posterior Reversible Encephalopathy Syndrome.

Creutzfeldt-Jakob disease (CJD) is the most common human prion disease presenting with subacute cognitive decline. Common MRI findings for CJD include the T2 prolongation signal of the putamen and head of caudate. Diffusion-weighted MRI (DW-MRI) is considered to be the most sensitive technique for the detection of CJD-related abnormalities, especially for cortical changes. We report the case of a 77-year-old female who presented with dizziness, visual hallucination, and a rapid decline in her mental state shortly after a right knee surgery. Brain MRI with contrast showed cortical and subcortical T2 fluid-attenuated inversion recovery (FLAIR) hyperintensities in bilateral posterior temporal lobes and the left occipital lobe without an associated enhancement, suggestive of posterior reversible encephalopathy syndrome (PRES). Workup including metabolic, infectious, and vasculitic panels were all within normal limits. A few days later, she developed persistent myoclonus, and a continuous electroencephalogram (EEG) revealed multifocal epileptiform and generalized discharges, forming multifocal periodic discharges and generalized periodic discharges (GPDs). Cerebrospinal fluid (CSF) analysis was positive for 14-3-3 and elevated T-tau protein consistent with a diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). This is a rare case of CJD presenting with a brain MRI resembling PRES. CJD may have various features on MRI, and a high degree of suspicion is required to confirm the diagnosis.

Successful Utilization of Levodopa in HIV-Induced Parkinsonism.

We report a case of a 63-year-old African American female patient with a past medical history of treatment naïve human immunodeficiency virus (HIV). She was referred to our hospital with altered mental status and rigidity with a history of progressive ambulation difficulties and decreased verbal output over the previous months as reported by her son. Her clinical presentation and brain MRI were consistent with HIV encephalopathy with bilateral basal ganglia involvement and HIV-induced parkinsonism. We initiated a trial of carbidopa/levodopa along with highly active antiretroviral therapy (HAART) (emtricitabine-tenofovir and dolutegravir). In the following three weeks, she demonstrated dramatic improvement, both clinically and radiologically. She tolerated carbidopa/levodopa well with no behavioral or neurological side effects. This case illustrates the safe utilization of carbidopa/levodopa in treating parkinsonism in an adult female patient with HIV encephalopathy.

Longitudinal 16-year study of dominant intermediate CMT type C neuropathy.

BACKGROUND: Dominant-intermediate Charcot-Marie-Tooth neuropathy subtype C (DI-CMTC) is associated with mutations in the YARS gene. The aim of this study is to investigate the long-term natural history of the disease. METHODS: In a 5-generation DI-CMTC family, we compared data from 2016 to that of 2000 in 13 of 21 original participants. RESULTS: Five women and 8 men were examined. While most symptoms and signs progressed, only gait progression was statistically significant (P = .016). The median CMT Neuropathy Score was 6.08 in 2000 and 11 in 2016 (P = .001). Quality of life (QOL) deteriorated in mobility (P = .008), pain/discomfort (P = .011), and anxiety/depression (P = .014). Median and ulnar compound muscle action potential amplitudes decreased from 9.35 ± 2.90 mV to 6.0 ± 2.9 mV (P = .002), and from 9.24 ± 2.10 mV to 6.06 ± 1.81 mV (P = .004), respectively, whereas motor nerve conduction velocities remained unchanged. CONCLUSIONS: DI-CMTC in this family is a slowly progressive disease with axonal degeneration, deteriorating mobility and QOL.

Cryptogenic small-fiber neuropathies: Serum autoantibody binding to trisulfated heparan disaccharide and fibroblast growth factor receptor-3.

INTRODUCTION: Causes of small-fiber peripheral neuropathies (SFN) are often undefined. In this study we investigated associations of serum autoantibodies, immunoglobulin G (IgG) vs fibroblast growth factor receptor-3 (FGFR-3), and immunoglobulin M (IgM) vs trisulfated heparan disaccharide (TS-HDS) in cryptogenic SFN. METHODS: One hundred fifty-five patients with biopsy-proven SFN and no identified cause for their neuropathy were blindly tested for serum IgM vs TS-HDS and IgG vs FGFR-3. RESULTS: Forty-eight percent of SFN patients had serum antibodies, 37% with IgM vs TS-HDS and 15% with IgG vs FGFR-3. TS-HDS antibodies were more frequent in SFN patients than in controls (P = .0012). Both antibodies were more common in females, and with non-length-dependent nerve pathology. Nintey-two percent of patients with acute-onset SFN had serum IgM vs TS-HDS. DISCUSSION: Autoantibodies directed against TS-HDS and FGFR-3 suggest an immune disorder in otherwise idiopathic SFN. Serum IgM vs TS-HDS may be a marker for SFN with an acute onset.

Clinical and Laboratory Profiles of Idiopathic Small Fiber Neuropathy in Children: Case Series.

The role of autoimmune mechanisms in idiopathic small fiber neuropathy (SFN) is not completely understood. Serum IgM binding to trisulfated disaccharide IdoA2S-GlcNS-6S (TS-HDS) and IgG to fibroblast growth factor receptor 3 were associated with sensory motor polyneuropathies and sensory neuronopathy among others. In this retrospective case review, we describe the clinical and laboratory findings of idiopathic SFN in a small cohort of pediatric patients. Eight children were diagnosed with SFN clinically and confirmed by reduced epidermal nerve fiber density. No involvement of large fibers was confirmed by clinical examination and electrophysiological tests. Possible triggering factors were infectious mononucleosis in 4 patients and human papilloma virus vaccination in 1 patient. Tilt table test was positive in 1 patient, and clinical autonomic dysfunctions were noted in 6 patients. Five patients had positive IgM against TS-HDS, 3 of whom had lower extremity predominant paresthesia. In conclusion, a high proportion of patients with idiopathic SFN in our cohort had a positive IgM TS-HDS antibody.

Creutzfeldt-Jakob Disease: Analysis of Four Cases.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a rare, rapidly progressive neurodegenerative disease that almost always results in death in under a year from onset of symptoms. Here, we report four cases of CJD with different clinical presentations diagnosed at our institution over a 2-year period. CASES: The first patient is an 82-year-old woman who presented with depression, cognitive decline, and word-finding difficulty over 4 weeks. The patient deteriorated neurologically to akinetic mutism and death within 6 weeks of presentation. The second patient is a 54-year-old woman with liver cirrhosis who presented with confusion, ataxia, and multiple falls over 4 weeks. She was treated initially for hepatic encephalopathy but continued to progress to mutism, startle myoclonus, and obtundation. Death occurred within 4 weeks of presentation. The third patient is a 58-year-old woman who presented with an 8-week history of confusion, urinary incontinence, Parkinsonism, ataxia, and myoclonus. Death occurred within 2 months from presentation. The fourth patient is a 67-year-old man who presented with a 6-week history of headache, blurred vision, ataxia, and personality change and progressed to confusion, myoclonus, akinetic mutism, and obtundation. Death occurred within 3 weeks from presentation. CONCLUSION: These four cases highlight the varied possible clinical presentations of CJD and demonstrate the importance of considering CJD in patients with atypical presentations of rapidly progressive cognitive decline. To diagnose CJD, brain biopsy remains the gold standard. However, the presence of CSF protein 14-3-3, typical MRI findings and suggestive EEG abnormalities, all support the diagnosis.

Small Fiber Neuropathy Following Vaccination.

OBJECTIVE: To identify clinical and quantitative relationship between vaccinations and small fiber neuropathy (SFN). SFN refers to damaged unmyelinated or thinly myelinated sensory and/or autonomic fibers. Diagnosis is primarily based on clinical presentation. Intraepidermal nerve fiber density can provide diagnostic confirmation with a sensitivity of 88% and a specificity of 91%. However, the possible association between vaccination and small fiber polyneuropathy is not well defined. METHODS: Case study. RESULTS: Fourteen-year-old white adolescent girl presented with intractable generalized pain for 1.5 years. Burning dysesthetic pain began in the lower back and progressed to all extremities 9 days following human papillomavirus vaccination. The pain persisted despite various pain medications. Examination was significant for allodynia of right scapula (T4-T6) and decreased pinprick sensation in feet. MRI Brain with and without contrast, MR Face, Orbit with and without contrast, and MR Cervical, Lumbar spines with and without contrast were all normal. Nerve Conduction Studies/Electromyogram studies were unremarkable, and skin biopsy of the right thigh and foot showed low intraepidermal nerve fiber density with normal sweat gland nerve fiber density. CONCLUSIONS: This case report describes an acute onset of non-length-dependent SFN potentially related to human papillomavirus vaccine administration. Literature review includes several similar case studies, and various pathological processes have been proposed for vaccine-associated polyneuropathies. Some theories describe immune-mediated hypersensitivity to the solvents/adjuvants and/or invasion of nervous system through a prolonged, less virulent infection. However, the lack requires that evidence must be carefully reviewed.

Role of capsid sequence and immature nucleocapsid proteins p9 and p15 in Human Immunodeficiency Virus type 1 genomic RNA dimerization.

HIV-1 genomic RNA (gRNA) dimerization is important for viral infectivity and is regulated by proteolytic processing of the Gag precursor protein (Pr55gag) under the direction of the viral protease. The processing occurs in successive steps and, to date, the step associated with formation of a wild-type (WT) level of gRNA dimers has not been identified. The primary cleavage divides Pr55gag into two proteins. The C-terminal polypeptide is termed NCp15 (NCp7-p1-p6) because it contains the nucleocapsid protein (NC), a key determinant of gRNA dimerization and packaging. To examine the importance of precursor polypeptides NCp15 and NCp9 (NCp7-p1), we introduced mutations that prevented the proteolytic cleavages responsible for the appearance of NCp9 or NCp7. Using native Northern blot analysis, we show that gRNA dimerization was impaired when both the secondary (p1-p6) and tertiary (p7-p1) cleavage sites of NCp15 were abolished, but unaffected when only one or the other site was abolished. Though processing to NCp9 therefore suffices for a WT level of gRNA dimerization, we also show that preventing cleavage at the p7-p1 site abolished HIV-1 replication. To identify the minimum level of protease activity compatible with a WT level of gRNA dimers, we introduced mutations Thr26Ser and Ala28Ser in the viral protease to partially inactivate it, and we prepared composite HIV-1 resulting from the cotransfection of various ratios of WT and protease-inactive proviral DNAs. The results reveal that a 30% processing of Pr55gag into mature capsid proteins (CA/CA-p2) yielded a WT level of gRNA dimers, while a 10% Pr55gag processing hardly increased gRNA dimerization above the level seen in protease-inactive virions. We found that full gRNA dimerization required less than 50% WT NC in complementation asssays. Finally, we show that if we destroy alpha helix 1 of the capsid protein (CA), gRNA dimerization is impaired to the same extent as when the viral protease is inactivated. Cotransfection studies show that this CA mutation, in contrast to the NC-disabling mutations, has a dominant negative effect on HIV-1 RNA dimerization, viral core formation, and viral replication. This represents the first evidence that a capsid mutation can affect HIV-1 RNA dimerization.

Mapping of nucleocapsid residues important for HIV-1 genomic RNA dimerization and packaging.

Retroviral genomic RNA (gRNA) dimerization appears essential for viral infectivity, and the nucleocapsid protein (NC) of human immunodeficiency virus type 1 (HIV-1) facilitates HIV-1 gRNA dimerization. To identify the relevant and dispensable positions of NC, 34 of its 55 residues were mutated, individually or in small groups, in a panel of 40 HIV-1 mutants prepared by site-directed mutagenesis. It was found that the amino-terminus, the proximal zinc finger, the linker, and the distal zinc finger of NC each contributed roughly equally to efficient HIV-1 gRNA dimerization. The N-terminal and linker segments appeared to play predominantly electrostatic and steric roles, respectively. Mutating the hydrophobic patch of either zinc finger, or substituting alanines for their glycine doublet, was as disabling as deleting the corresponding finger. Replacing the CysX(2)CysX(4)HisX(4)Cys motif of either finger by CysX(2)CysX(4)CysX(4)Cys or CysX(2)CysX(4)HisX(4)His, interchanging the zinc fingers or, replacing one zinc finger by a copy of the other one, had generally intermediate effects; among these mutations, the His23-->Cys substitution in the N-terminal zinc finger had the mildest effect. The charge of NC could be increased or decreased by up to 18%, that of the linker could be reduced by 75% or increased by 50%, and one or two electric charges could be added or subtracted from either zinc finger, without affecting gRNA dimerization. Shortening, lengthening, or making hydrophobic the linker was as disabling as deleting the N-terminal or the C-terminal zinc finger, but a neutral and polar linker was innocuous. The present work multiplies by 4 and by 33 the number of retroviral and lentiviral NC mutations known to inhibit gRNA dimerization, respectively. It shows the first evidence that gRNA dimerization can be inhibited by: 1) mutations in the N-terminus or the linker of retroviral NC; 2) mutations in the proximal zinc finger of lentiviral NC; 3) mutations in the hydrophobic patch or the conserved glycines of the proximal or the distal retroviral zinc finger. Some NC mutations impaired gRNA dimerization more than mutations inactivating the viral protease, indicating that gRNA dimerization may be stimulated by the NC component of the Gag polyprotein. Most, but not all, mutations inhibited gRNA packaging; some had a strong effect on virus assembly or stability.

Role of the 5' TAR stem--loop and the U5-AUG duplex in dimerization of HIV-1 genomic RNA.

The HIV-1 genome consists of two identical RNAs that are linked together through noncovalent interactions involving nucleotides from the 5' untranslated region (5' UTR) of each RNA strand. The 5' UTR is the most conserved part of the HIV-1 RNA genome, and its 335 nucleotide residues form regulatory motifs that mediate multiple essential steps in the viral replication cycle. Here, studying the effect of selected mutations both singly and together with mutations disabling SL1 (SL1 is a 5' UTR stem-loop containing a palindrome called the dimerization initiation site), we have done a rather systematic survey of the 5' UTR requirements for full genomic RNA dimerization in grown-up (i.e., predominantly >/=10 h old) HIV-1 viruses produced by transfected human and simian cells. We have identified a role for the 5' transactivation response element (5' TAR) and a contribution of a long-distance base pairing between a sequence located at the beginning of the U5 region and nucleotides surrounding the AUG Gag initiation codon. The resulting intra- or intermolecular duplex is called the U5-AUG duplex. The other regions of the 5' UTR have been shown to play no systematic role in genomic RNA dimerization, except for a sequence located around the 3' end of a large stem-loop enclosing the primer binding site, and the well-documented SL1. Our data are consistent with a direct role for the 5' TAR in genomic RNA dimerization (possibly via a palindrome encompassing the apical loop of the 5' TAR).

HIV-1 viral RNA is selected in the form of monomers that dimerize in a three-step protease-dependent process; the DIS of stem-loop 1 initiates viral RNA dimerization.

We have characterized the viral RNA conformation in wild-type, protease-inactive (PR-) and SL1-defective (DeltaDIS) human immunodeficiency virus type 1 (HIV-1), as a function of the age of the viruses, from newly released to grown-up (>or=24 h old). We report evidence for packaging HIV-1 genomic RNA (gRNA) in the form of monomers in PR- virions, viral RNA rearrangement (not maturation) within PR- HIV-1, protease-dependent formation of thermolabile dimeric viral RNAs, a new form of immature gRNA dimer at about 5 h post virion release, and slow-acting dimerization signals in SL1-defective viruses. The rates of gRNA dimer formation were >or=3-fold and >or=10-fold slower in DeltaDIS and PR- viruses than in wild-type, respectively. Thus, the DIS, i.e. the palindrome in the apical loop of SL1, is a dimerization initiation signal, but its role can be masked by one or several slow-acting dimerization site(s) when grown-up SL1-inactive virions are investigated. Grown-up PR- virions are not flawless models for immature virions because gRNA dimerization increases with the age of PR- virions, indicating that the PR- mutation does not "freeze" gRNA conformation in a nascent primordial state. Our study is the first on gRNA conformation in newly released mutant or primate retroviruses. It shows for the first time that the packaged retroviral gRNA matures in more than one step, and that formation of immature dimeric viral RNA requires viral protein maturation. The monomeric viral RNAs isolated from budding HIV-1, as modeled by newly released PR- virions, may be seen as dimers that are much more fragile than thermolabile dimers.