Orbital Apex Metastases From Primary Colorectal Adenocarcinoma: A Rare Cause for Unilateral Vision Loss.

Colorectal cancer is one of the most common causes of cancer-related death in the United States. Although it frequently metastasizes to adjacent structures such as the liver, orbital metastases are exceedingly uncommon. Additionally, the morbidity and mortality associated with colorectal cancer appear to be shifting to a younger population, a phenomenon that is exacerbated in minority populations. We present a case of orbital metastasis from colorectal carcinoma in a young Hispanic male. This uncommon presentation of disease emphasizes the link between healthcare disparity and differential outcomes of colorectal cancer.

Intervertebral Disc Calcification and Klippel-Feil Syndrome.

Intervertebral disc calcification is rare in the pediatric population and is associated with sudden neurological manifestations. Although commonly symptomatic, conservative management yields excellent prognosis in the vast majority of cases. The following case illustrates the finding of intervertebral disc calcification in a patient with vertebral body segmentation anomaly consistent with Klippel-Feil Syndrome. As both entities are associated with potential neurological sequelae, this case of coexistent pathologies highlights the importance of recognizing the potential presence of intervertebral disc calcifications in pediatric Klippel-Feil Syndrome patients.

Primary Central Nervous System Lymphoma with Associated Demyelination and Creutzfeldt Astrocytes.

A previously healthy 54-year-old woman presented with weight loss, progressive weakness that was more pronounced on the left side, and intermittent occipital headaches. Imaging studies showed multiple enhancing lesions along the white matter, compatible with a demyelinating process. The patient's previous history included relapsing-remitting symptoms of weakness over the past 3 years. A stereotactic brain biopsy showed histological features of demyelination with an associated population of neoplastic lymphoid cells. These unusual findings raise the question of whether demyelinating disease preceded the development of primary CNS lymphoma (PCNSL), or whether PCNSL induced demyelination. Although rare, cases of "sentinel lesions" heralding the diagnosis of PCNSL have been reported. This case emphasizes the importance of having a high index of suspicion of PCNSL in the setting of suspected demyelinating lesion in an adult patient.

Spinal cord injuries containing asymmetrical damage in the ventrolateral funiculus is associated with a higher incidence of at-level allodynia.

UNLABELLED: Approximately 70% of male rats receiving severe T8 spinal contusions develop allodynia in T5-7 dermatomes (at-level) beginning 2 weeks after injury. In contrast, rats having either complete transections or dorsal hemisections do not develop allodynia at-level after chronic spinal cord injury (SCI). In the present study, incomplete laceration and contusion injuries were made to test for neuroanatomical correlates between areas of white matter damage/sparing at the lesion epicenter and the presence/absence of allodynia. After incomplete laceration lesions and 6 weeks of behavioral testing, histological reconstruction and analysis of the lesion epicenters revealed a significant difference (P < .001) in the amount of ventrolateral funiculus (VLF) asymmetry between rats showing pain-like responses evoked by touch (74.5% +/- 8.4% side-to-side difference in VLF damage) versus those not responding to touch (11.3% +/- 4.4% side-to-side difference in VLF damage). A 5-week mean allodynia score for each rat that incorporates a full range of forces that are all innocuous in intact controls revealed that the degree of hypersensitivity at level is related to the extent of VLF asymmetry after SCI. No other damaged spinal white matter or gray matter area was correlated with sensitivity to touch. Similar findings were obtained for rats receiving T8 contusions, a more clinically relevant injury. These data suggest that different extents of damage/sparing between the 2 sides of VLF probably are a requisite for the development of allodynia after SCI. PERSPECTIVE: A side-to-side lesion asymmetry after chronic SCI in a rodent model was found to be highly correlated with the presence and degree of allodynia. Greater insight of key factors contributing to the development and maintenance of chronic neuropathic pain is important for improving quality of life.