Neuromuscular pathology.

In this chapter, we discuss the indications for muscle, nerve, and skin biopsies, the techniques and normal processing of biopsy specimens, normal histological appearance, and the commonest histopathological abnormalities of different myopathies and neuropathies.

Corticotroph hyperplasia and Cushing disease: diagnostic features and surgical management.

Objective: This study was done to compare corticotroph hyperplasia and histopathologically proven adenomas in patients with Cushing disease by analyzing diagnostic features, surgical management, and clinical outcomes.

Methods: Patients with suspected pituitary Cushing disease were included in a retrospective cohort study and were excluded if results of pathological analysis of the surgical specimen were nondiagnostic or normal. Cases were reviewed by two experienced neuropathologists.

Surgical resection of granular cell tumor of the sellar region: three indications.

Purpose: This case series evaluates the surgical management of granular cell tumor (GCT) of the sellar region. This rare entity presents a unique diagnostic and surgical challenge.

Methods: Institutional neuropathology databases at Brigham and Women's Hospital and Massachusetts General Hospital were searched for cases with a tissue diagnosis of GCT, and with a location in the sellar region.

Fatal Powassan Encephalitis (Deer Tick Virus, Lineage II) in a Patient With Fever and Orchitis Receiving Rituximab.

Importance: Powassan virus is a rare but increasingly recognized cause of severe neurological disease.

Objective: To highlight the diagnostic challenges and neuropathological findings in a fatal case of Powassan encephalitis caused by deer tick virus (lineage II) in a patient with follicular lymphoma receiving rituximab, with nonspecific anti-GAD65 antibodies, who was initially seen with fever and orchiepididymitis.

Design, Setting, And Participants: Comparison of clinical, radiological, histological, and laboratory findings, including immunohistochemistry, real-time polymerase chain reaction, antibody detection, and unbiased sequencing assays, in a single case report (first seen in December 2016) at an academic medical center.

Spinal cord.

We first present a brief historic review of developments in the understanding of spinal cord clinical neuroanatomy and neurophysiology over the past 200 years. We then discuss the technical aspects that apply to the examination of the human spinal cord giving details on the interrelations between the spinal cord and the overlying structures, including the meninges and vertebrae. The subsequent discussion focuses on diseases of the spinal cord.

Fatal Eastern Equine Encephalitis in a Patient on Maintenance Rituximab: A Case Report.

A 63-year-old woman on rituximab maintenance for follicular lymphoma presented with headaches, vomiting, and fever, and was diagnosed with eastern equine encephalomyelitis by cerebrospinal fluid polymerase chain reaction. Eastern equine encephalomyelitis immunoglobulin (Ig)G/IgM remained negative due to rituximab treatment, and magnetic resonance imaging showed minimal abnormalities, making this a diagnostically challenging case. Despite therapy with intravenous Ig, the patient rapidly declined and died on hospital day 12.

A Woman in Her 40s With Headache and New-Onset Seizures.

A woman in her 40s with a history of plasma cell leukemia presented with 1 month of intermittent headaches followed by a seizure. Results from laboratory studies were notable for a cerebrospinal fluid opening pressure of 28 mm H2O and 8 white blood cells, including 1 atypical plasma cell. Imaging studies revealed confluent bifrontal white matter fluid-attenuated inversion recovery hyperintensities, as well as a contrast-enhancing sellar lesion.

Brain and liver pathology, amyloid deposition, and interferon responses among older HIV-positive patients in the late HAART era.

Background: HIV+ patients on highly active antiretroviral therapy (HAART) with suppressed viral loads have a low incidence of HIV-associated dementia, but increased prevalence of milder forms of HIV-associated neurocognitive disorders (HAND). These milder forms of HAND are often associated with minimal histological abnormalities, and their pathophysiology is unclear. Comorbidities, altered amyloid metabolism, accelerated brain aging, and activated interferon responses are suspected to play a role in HAND pathogenesis in HAART-treated persons.

Novel mutation in CNTNAP1 results in congenital hypomyelinating neuropathy.

Introduction: Congenital hypomyelinating neuropathy (CHN) is a rare congenital neuropathy that presents in the neonatal period and has been linked previously to mutations in several genes associated with myelination. A recent study has linked 4 homozygous frameshift mutations in the contactin-associated protein 1 (CNTNAP1) gene with this condition.

Methods: We report a neonate with CHN who was found to have absent sensory nerve and compound muscle action potentials and hypomyelination on nerve biopsy.

Central Versus Extraventricular Neurocytoma in Children: A Clinicopathologic Comparison and Review of the Literature.

Background: Central neurocytomas (CN) are rare pediatric CNS tumors most often with a benign clinical course. Occasionally, these tumors occur outside the ventricles and are called extraventricular neurocytomas (EVN). We present a retrospective institutional analysis of children with neurocytoma with prolonged follow-up.

Functional Gonadotroph Adenomas: Case Series and Report of Literature.

Background: Functional gonadotroph adenomas (FGAs) are rare tumors of the pituitary gland that secrete biologically active gonadotropins.

Objective: To advance clinical understanding of FGAs.

Methods: We performed a retrospective review of adult patients who underwent resection of a pituitary lesion between August 1997 and October 2014 and remain under care at our center.

Expanding the phenotype associated with the NEFL mutation: neuromuscular disease in a family with overlapping myopathic and neurogenic findings.

Importance: Newer sequencing technologies in combination with traditional gene mapping techniques, such as linkage analysis, can help identify the genetic basis of disease for patients with rare disorders of uncertain etiology. This approach may expand the phenotypic spectrum of disease associated with those genetic mutations.

Objective: To elucidate the molecular cause of a neuromuscular disease among a family in which 4 members, a mother and her 3 sons, were affected.

Cytologic characterization of atypical teratoid/rhabdoid tumor in cerebrospinal fluid.

Background: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare and highly aggressive intracranial malignancy with a predilection to spread along the cerebrospinal fluid (CSF) pathways. To the authors' knowledge, the cytopathologic characteristics of this tumor have not been extensively studied in CSF. Herein the authors report CSF cytomorphology from a series of patients with histologically documented AT/RT.

RYR1 mutations as a cause of ophthalmoplegia, facial weakness, and malignant hyperthermia.

Importance: Total ophthalmoplegia can result from ryanodine receptor 1 (RYR1) mutations without overt associated skeletal myopathy. Patients carrying RYR1 mutations are at high risk of developing malignant hyperthermia. Ophthalmologists should be familiar with these important clinical associations.

Neuropathology of sleep disorders: a review.

Sleep disorders are important manifestations of neurodegenerativediseases and sometimes are clinically evident well before the onset of other neurological manifestations. This review addresses theneuroanatomical basis and the mechanisms of sleep regulation in humans in relation to the neuropathology of entities associated with sleep disturbances in selected diseases, including Alzheimer disease, progressive supranuclear palsy, Lewy body disorders, multiple-system atrophy, and fatal familial insomnia. This includes abnormalities of circadian rhythm, insomnia, narcolepsy, rapid eye movements sleep behavior disorders, and excessive daytime sleepiness.

Molecular classification of low-grade diffuse gliomas.

The current World Health Organization classification recognizes three histological types of grade II low-grade diffuse glioma (diffuse astrocytoma, oligoastrocytoma, and oligodendroglioma). However, the diagnostic criteria, in particular for oligoastrocytoma, are highly subjective. The aim of our study was to establish genetic profiles for diffuse gliomas and to estimate their predictive impact.

Pixel-based comparison of spinal cord MR diffusion anisotropy with axon packing parameters.

Water diffusion in nerve fibers is strongly influenced by axon architecture. In this study, fractional diffusion anisotropy and transverse and longitudinal diffusion coefficients were measured in excised human cervical spinal cord with MR line-scan diffusion imaging, at 625 microm in-plane resolution and 3 mm slice thickness. A pixel-based comparison of fractional diffusion anisotropy, transverse diffusion coefficient, and longitudinal diffusion coefficient data with axon packing parameters derived from corresponding stained histological sections was performed for four slices.

An absorbable local anesthetic matrix provides several days of functional sciatic nerve blockade.

Background: Functional blockade of peripheral nerves is the primary objective of local anesthesia, and it is often desirable to have a persistent blockade, sustained throughout and beyond a surgical procedure. Current local anesthetics give effective analgesia for <8-12 h after a single bolus injection. We report on an implantable, controlled-release drug delivery system intended for use in bone and consisting of a Food and Drug Administration-approved matrix containing lidocaine that is capable of local delivery for several days.

Neuropathology of central nervous system arterial syndromes. Part I: the supratentorial circulation.

The objective of this review is to illustrate the principal cerebrovascular arterial pathoanatomical syndromes using the unique collection of whole brain sections in the Raymond Escourolle Neuropathology Laboratory at Salpêtrière in Paris. The arterial supratentorial syndromes are presented in Part I; the infratentorial and spinal cord syndromes will be presented subsequently in Part II. No attempt is made to be all-inclusive in the review of the literature; rather, we cite only those bibliographic references that are historically noteworthy and with some exceptions that particularly emphasize the neuropathologic rather than radiographic/imaging aspects of the vascular syndromes.

Prognostic value of tumor microinvasion and metalloproteinases expression in intracranial pediatric ependymomas.

Ependymomas are common pediatric intracranial neoplasms that often appear well circumscribed on imaging but may recur when they are treated by surgical resection alone. The current World Health Organization histological grading system does not accurately predict clinical behavior. The aim of this study was to identify histological and immunohistochemical features that correlate with clinical course in patients with ependymomas treated by gross total resection.

Cerebrospinal fluid cytology in patients with ependymoma: a bi-institutional retrospective study.

Background: Ependymoma cells are known to occasionally exfoliate into cerebrospinal fluid (CSF). However, the frequency of CSF involvement in patients with ependymoma is unclear, and to the authors' knowledge the cytomorphologic features of the tumor cells have not been described in detail to date. In this study, the CSF findings in patients with ependymal neoplasms are summarized and the cytomorphologic features of ependymoma, including its variants, are illustrated.