Kevin R. Moore

Neurolymphomatosis of the lumbar plexus: High-resolution MR neurography findings

Perineural lumbosacral plexus infiltration is an unusual manifestation of systemic lymphoma that is difficult to diagnose using conventional imaging techniques. We report a case of lymphomatous lumbosacral plexus infiltration that was occult on lumbar MR and abdominopelvic CT imaging. High-resolution MR neurography (MRN) demonstrated a diffusely infiltrating lumbar plexus lesion, suggesting neurolymphomatosis (NL), subsequently confirmed at autopsy. MRN is a sensitive modality for characterizing plexus and peripheral nerve abnormalities1,2⇓ and may be diagnostic after inconclusive conventional MRI. We review NL and demonstrate the diagnostic utility of MRN. A 69-year-old man presented with stage IV thoracic B-cell lymphoma. Four cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) followed by cyclophosphamide produced a full response. One month after completing chemotherapy, he presented again with nocturnal right leg pain exacerbated by lying supine or by extended periods of sitting. The pain became constant and intensified in severity, and examination revealed new bilateral pedal edema. There was severe weakness of the right psoas, quadriceps, and gluteal muscles with moderate involvement of adductor and hamstring muscles. Distal leg …

The role of magnetoencephalography in “nonlesional” epilepsy

The surgical management of neocortical epilepsy is challenging because many patients are without obvious structural lesions, or lesions are small and easily overlooked during routine clinical interpretation of magnetic resonance imaging (MRI) data. Even when functional imaging data suggest focal epileptiform pathology, in the absence of a concordant structural lesion, invasive monitoring is often required to confirm that an appropriate surgical target has been identified. This study sought to determine the extent to which knowledge of magnetoencephalography (MEG) data can augment the MRI‐based detection of structural brain lesions. MRI and whole‐head MEG data were obtained from 40 patients with neocortical epilepsy. As a result of MEG data, 29 cases were sent for MRI reevaluation. In seven of these cases, MEG‐guided review led to specification of now clear, but previously unidentified, lesions. There were two additional cases for which follow‐up high‐resolution imaging did not confirm structural abnormalities. In patients with neocortical epilepsy, MEG is a useful adjunct to MRI for the identification of structural lesions.

Recognition and Management of Acute Flaccid Myelitis in Children

BACKGROUND In 2014-2015, several regions of the United States experienced an outbreak of acute flaccid myelitis in pediatric patients. A common, unique feature was disease localization to the gray matter of the spinal cord. METHODS We report 11 children, ages 13 months to 14 years (median 9 years), in the Intermountain West who presented with extremity weakness (n = 10) or cranial neuropathy (n = 1) of varying severity without an apparent etiology. RESULTS All children experienced acute paralysis, and 10 had symptoms or signs that localized to the spinal cord. Maximum paralysis occurred within 4 days of onset in all patients. All had spinal gray matter lesions consistent with acute myelitis detected by magnetic resonance imaging; no single infectious cause was identified. Despite therapy with intravenous immunoglobulin, corticosteroids, or plasma exchange, nine of 10 (90%) children had motor deficits at follow-up. CONCLUSIONS Recognition of this disorder enables clinicians to obtain appropriate imaging and laboratory testing, initiate treatment, and provide families with accurate prognostic information. In contrast to other causes of acute flaccid paralysis in childhood, most children with acute flaccid myelitis have residual neurological deficits.

Panhypopituitarism as an initial manifestation of primary central nervous system non-Hodgkin's lymphoma.

OBJECTIVE To report an unusual case of primary central nervous system non-Hodgkins lymphoma in which the initial manifestation was panhypopituitarism. METHODS We present a retrospective case review and discuss similar cases from the literature. RESULTS A 64-year-old woman with nausea, vomiting, diarrhea, and peripheral and periorbital edema was found to have panhypopituitarism. Magnetic resonance imaging showed minimal enlargement of the pituitary, and a transsphenoidal biopsy of the pituitary was nondiagnostic. Months later, abnormalities of extraocular movements developed. Repeated imaging and a second transsphe-noidal biopsy did not reveal the ultimate diagnosis. When further neurologic signs and symptoms subsequently developed, a right temporal open craniotomy was performed. It was not until this procedure, the patients third biopsy, that the cause of her illness was discovered to be diffuse large cell lymphoma. CONCLUSION Although idiopathic panhypopituitarism is a relatively common clinical entity, it remains a diagnosis of exclusion. The development of associated neurologic signs should prompt the clinician to initiate a new search for an underlying cause. This case underscores the protean manifestations of central nervous system lymphoma, both endocrine and neurologic, and the difficulties that may be encountered in attempts to establish a diagnosis.

Magnetic resonance imaging features of complex Chiari malformation variant of Chiari 1 malformation.

BackgroundComplex Chiari malformation is a subgroup of Chiari 1 malformation with distinct imaging features. Children with complex Chiari malformation are reported to have a more severe clinical phenotype and sometimes require more extensive surgical treatment than those with uncomplicated Chiari 1 malformation.ObjectiveWe describe reported MR imaging features of complex Chiari malformation and evaluate the utility of craniometric parameters and qualitative anatomical observations for distinguishing complex Chiari malformation from uncomplicated Chiari 1 malformation.Materials and methodsWe conducted a retrospective search of the institutional imaging database using the keywords “Chiari” and “Chiari 1” to identify children imaged during the 2006–2011 time period. Children with Chiari 2 malformation were excluded after imaging review. We used the first available diagnostic brain or cervical spine MR study for data measurement. Standard measurements and observations were made of obex level (mm), cerebellar tonsillar descent (mm), perpendicular distance to basion-C2 line (pB-C2, mm), craniocervical angle (degrees), clivus length, and presence or absence of syringohydromyelia, basilar invagination and congenital craniovertebral junction osseous anomalies. After imaging review, we accessed the institutional health care clinical database to determine whether each subject clinically met criteria for Chiari 1 malformation or complex Chiari malformation.ResultsObex level and craniocervical angle measurements showed statistically significant differences between the populations with complex Chiari malformation and uncomplicated Chiari 1 malformation. Cerebellar tonsillar descent and perpendicular distance to basion-C2 line measurements trended toward but did not meet statistical significance. Odontoid retroflexion, craniovertebral junction osseous anomalies, and syringohydromyelia were all observed proportionally more often in children with complex Chiari malformation than in those with Chiari 1 malformation.ConclusionCharacteristic imaging features of complex Chiari malformation, especially obex level, permit its distinction from the more common uncomplicated Chiari 1 malformation.