[Microscopic tumor embolisms in metastasized breast carcinoma]

In two patients, women of 54 and 46 years old, with metastatic carcinoma of the breast, multiple microscopic tumour emboli in the lungs were found at autopsy. Ante mortem, unexplained respiratory distress in the former and an atypical thrombotic thrombocytopenic purpura-like syndrome in the latter were the most characteristic clinical features. Pulmonary microscopic tumour embolism is a rare diagnosis but it may occur in all types of cancer. Clinically, thrombotic pulmonary emboli are difficult to distinguish from microscopic tumour embolism. Special attention is to be paid to typical findings on radionuclide perfusion lung scanning (multiple subsegmental perfusion defects at the periphery of the bronchopulmonary segments with a normal ventilation named "segmental contour pattern'). Microangiopathic haemolytic anaemia and consumption coagulopathy are associated disorders. Tumour-directed therapy is the treatment of choice.

Case 309

HISTORY

A 64-year-old man presented with a 6-month history of lightheadedness, intermittent balance, and coordination difficulties. Two months before admission, symptoms became more substantial and persistent, with a worsening sense of disequilibrium and unsteady gait. He reported difficulties pronouncing words and mild word-finding difficulties. His wife noted a change in his cognition and memory over the same time. His medical history included well-controlled chronic obstructive pulmonary disease (COPD) secondary to a long history of smoking with associated unintentional 30-lb (13.6-kg) weight loss over the previous 3 years, for which chest CT scanning was performed, revealing no abnormality. On clinical examination, the patient was alert and oriented but had slurred speech. A positive Romberg sign was noted, finger-to-nose and hand rapid alternating movement tests revealed impairment on the right side, and his gait was ataxic. The motor examination revealed normal muscle tone, bulk, and power in the upper and lower extremities. Sensory testing results were normal. Initial MRI of the brain at admission revealed abnormal findings in the left supratentorial brain (Figs 1-3). Of note, this patient's presentation predated the COVID-19 pandemic. Cerebrospinal fluid analysis revealed predominant pleocytosis (23 × 10⁶/L; normal range, [0-5] × 10⁶/L) (78% lymphocytes, 22% monocytes), elevated protein level (1.23 g/L; normal range, 0.19-0.64 g/L), oligoclonal bands (faint one or two), and a high immunoglobulin G index (0.130 g/L; normal reference, ≤0.059 g/L). Despite extensive initial work-up for inflammatory, infectious, autoimmune, or neoplastic causes, a definitive diagnosis was not reached. Thus, repeat MRI of the brain was performed 2 weeks after admission (Fig 4).

Association of the PRNP regulatory region polymorphisms with the occurrence of sporadic Creutzfeldt-Jakob disease

The prion protein (PrP) plays a central role in the pathogenesis of Creutzfeldt-Jakob disease and other transmissible spongiform encephalopathies (TSEs). Mutations in the coding region of the prion protein (PRNP) gene are linked to inherited forms of TSEs whereas aetiology of sporadic CJD (sCJD) remains obscure. It remains unclear whether the primary DNA sequence at non-coding region of PRNP gene influences development of the sCJD. Several recent reports showed non-coding region polymorphisms associated with sCJD but other could not support those findings. To test the hypothesis that there is a relationship between SNPs polymorphisms of PRNP non-coding regions and susceptibility to sCJD, we compared the primary structure of the regulatory region of the PRNP in 45 Dutch sCJD patients and in 135 healthy controls. We found a significant linkage of +310 C allele (OR 0.27, 95% CI 0.09-0.77; P = 0.009) and +310G/C genotype (OR 0.33, 95% CI 0.11-0.98; P = 0.048) with sCJD. No differences in frequencies of genotypes and allele of -101C/G and +258 G/A polymorphisms were found between sCJD patients and controls. We found two haplotypes protecting from sCJD (C-V in block 1 and G-C in block 2) and one susceptible haplotype for sCJD (G-G in block 2). Our findings support the hypothesis that polymorphism in the regulatory region of the PRNP gene may play an important role in the pathogenesis of sCJD.

MRI dynamic color mapping: a new quantitative technique for imaging soft tissue motion in the orbit

PURPOSE

To investigate both feasibility and clinical potential of magnetic resonance imaging-dynamic color mapping (MRI-DCM) in measuring the motion of soft tissues in the orbit and in the diagnosis of orbital disorders by detecting changes in motion.

METHODS

Sequences of MRI scans were acquired (acquisition time, 5 seconds) in a shoot-stop manner, while the patient fixated at a sequence of 13 gaze positions (8 degrees intervals). Motion was quantified off-line (in millimeters per degree of gaze change) using an optical flow algorithm. The motion was displayed in a color-coded image in which color saturation of a pixel shows the displacement and the hue the displacement's orientation. Six healthy volunteers and four patients (two with an orbital mass and two with acrylic ball implant after enucleation) were studied.

RESULTS

The technique was found to be clinically feasible. For a gaze change of 1 degrees, orbital tissues moved between 0.0 and 0.25 mm/deg, depending on the type of tissue and location in the orbit. In the patients with an orbital mass, motion of the mass was similar to that of the medial rectus muscle, suggesting disease of muscular origin. In the enucleated orbits, soft tissue motion was decreased. One eye showed attachment of the optic nerve to the implant, which could be verified by biopsy.

CONCLUSIONS

MRI-DCM allows noninvasive and quantitative measurement of soft tissue motion and the changes in motion due to pathologic conditions. In cases in which the diagnosis of a tumor in the apex is in doubt, it may reduce the need for biopsy. In contrast to static computed tomographic (CT) scans and MRIs, it can differentiate between juxtaposition and continuity and may be a new and promising tool in the differential diagnosis of intraorbital lesions.

Cranial MR in Wilson disease: abnormal white matter in extrapyramidal and pyramidal tracts

PURPOSE

To describe abnormal white matter in the brain on MR in Wilson disease and to compare with anatomic location of white matter tracts.

METHODS

Forty-six patients with Wilson disease were examined. Axial T1-weighted inversion-recovery, axial T2-weighted spin-echo, and coronal T2*-weighted gradient-echo MR images were performed. Imaging studies were compared with clinical data.

RESULTS

Seventeen patients showed abnormalities in the region coinciding with the following white matter tracts: corticospinal tract (24%, n = 11), dentatorubrothalamic tract (24%, n = 11), and pontocerebellar tract (17%, n = 8).

CONCLUSION

Abnormal extrapyramidal and pyramidal white matter tracts are part of the neuroimaging spectrum of Wilson disease. No significant correlation was found with neurologic groups and individual white matter tracts affected.

Peripheral neuropathy in mice transgenic for a human MDR3 P-glycoprotein mini-gene

We have generated mice transgenic for a human MDR3 mini-gene, under control of a hamster vimentin promoter. Expression of the MDR3 transgene was found in mesenchymal tissues, peripheral nerves, and the eye lens. These MDR3 transgenic mice have a slowed motor nerve conduction and dysmyelination of their peripheral nerves. An extensive dysmyelination in some transgenic strains results in a severe peripheral neuropathy with paresis of the hind legs. How expression of the MDR3 transgene causes these abnormalities is unknown. The MDR3 gene encodes a large glycosylated plasma membrane protein with multiple transmembrane spanning domains, which are involved in the translocation of the phospholipid phosphatidylcholine through the hepatocyte canalicular membrane. The ability of the MDR3 P-glycoprotein to alter phsopholipid distribution in the plasma membrane of Schwann cells may cause the damage. It is also possible, however, that the presence of a large glycoprotein in the cell membrane may be sufficient to severely disturb myelination of peripheral nerves.

[Creutzfeldt-Jakob disease: diagnosis, incidence, prevention and treatment]

Creutzfeldt-Jakob disease (CJD) is a rare, neurodegenerative disorder belonging to the spongiform encephalopathies. A variant form (vCJD) is most likely the result of infection with the agent that causes bovine spongiform encephalopathy (BSE). Diagnostic information can be obtained by EEG, testing cerebrospinal fluid for the presence of the 14-3-3 protein, MRI, brain biopsy, tonsil biopsy, and postmortem brain examination. Some tests, such as MRI and postmortem brain examination, can be used to distinguish between CJD and vCJD. Pathological prions in a tonsil biopsy are only found with vCJD. In the Netherlands, there are four known cases of iatrogenic CJD. On the basis of certain exposure to BSE via the food chain, cases of vCJD are also to be expected. Chloropromazine and mepacrine are known to inhibit the formation of pathological prion conformations, but clinical trials have not yet been carried out.

Temporal lobe epilepsy: the various MR appearances of histologically proven mesial temporal sclerosis

PURPOSE

To determine the frequency of appearance of various MR signs in mesial temporal sclerosis, to determine the optimal scanning planes for their visualization, and to propose a histologic explanation for the diminished demarcation between gray and white matter in the temporal lobe, a frequent MR finding in patients with mesial temporal sclerosis.

METHODS

MR scans of 14 surgically treated patients with epilepsy and histologically proven mesial temporal sclerosis were assessed for the presence of six features: feature 1, high signal intensity in the hippocampus; 2, reduced hippocampal size; 3, ipsilateral atrophy of the hippocampal collateral white matter; 4, enlarged temporal horn; 5, reduced gray-white matter demarcation in the temporal lobe; and 6, decreased temporal lobe size.

RESULTS

Feature 1 was present in 14 patients and was best appreciated on the T2-weighted images in planes parallel to the long axes of the hippocampi. Feature 2, present in 12 patients, and feature 6, present in 9 patients, were optimally seen in the coronal planes and on the inversion-recovery sequences in particular. Feature 3, present in 12 patients, was optimally seen on the coronal T2-weighted images. Feature 4, seen in 11 patients, was equally well seen in all planes (transverse, coronal, and parallel to the long axes of the hippocampi). Feature 5, seen in 10 patients, was best appreciated on the T2-weighted images in the planes of the long axes of the hippocampi. Histologic investigation of the temporal lobe white matter in the 10 patients with feature 5 demonstrated on the MR scan showed abnormalities in 7 cases. Oligodendroglia cell clusters were found in 6, with concomitant corpora amylacea in 1 case and perivascular macrophages with pigment a sole finding in another case.

CONCLUSION

Of the six features found in cases of mesial temporal sclerosis on MR, increased hippocampal signal intensity is the most consistent. A decreased gray-white matter demarcation in the temporal lobe parenchyma is also a frequent feature of this disease. A combination of multiple scanning planes results in an optimal demonstration of lesions.

Diagnostic Accuracy of Centrally Restricted Diffusion Sign in Cerebral Metastatic Disease: Differentiating Radiation Necrosis from Tumor Recurrence

Purpose: The centrally restricted diffusion sign of diffusion-weighted imaging (DWI) is associated with radiation necrosis (RN) in treated gliomas. Our goal was to evaluate its diagnostic accuracy to distinguish RN from tumor recurrence (TR) in treated brain metastases. Methods: Retrospective study of consecutive patients with brain metastases who developed a newly centrally necrotic lesion after radiotherapy (RT). One reader placed regions of interest (ROI) in the enhancing solid lesion and the non-enhancing central necrosis on the apparent diffusion coefficient (ADC) map. Two readers qualitatively assessed the presence of the centrally restricted diffusion sign. The final diagnosis was made by histopathology (n = 39) or imaging follow-up (n = 2). Differences between groups were assessed by Fisher's exact or Mann-Whitney U tests. Diagnostic accuracy and inter-reader agreement were evaluated using receiver operating characteristic (ROC) curve analysis and kappa scores. Results: Forty-one lesions (32 predominant RN; 9 predominant TR) were analyzed. An ADC value ≤ 1220 × 10-6 mm2/s (sensitivity 74%, specificity 89%, area under the curve [AUC] .85 [95% confidence interval {CI}, .70-.94] P < .0001) from the necrosis and an ADC necrosis/enhancement ratio ≤1.37 (sensitivity 74%, specificity 89%, AUC .82 [95% CI, .67-.93] P < .0001) provided the highest performance for RN diagnosis. The qualitative centrally restricted diffusion sign had a sensitivity of 69% (95% CI, .50-.83), specificity of 77% (95% CI, .40-.96), and a moderate (k = .49) inter-reader agreement for RN diagnosis. Conclusions: Radiation necrosis is associated with lower ADC values in the central necrosis than TR. A moderate interobserver agreement might limit the qualitative assessment of the centrally restricted diffusion sign.

Diagnostic Accuracy of 1H-MRS Using PRESS and MEGA-PRESS Techniques in the Preoperative Grading of Patients With Gliomas

BACKGROUND

Edited MRS technique such as MEshcher-GArwood Point RESolved Spectroscopy (MEGA-PRESS) can determine isocitrate dehydrogenase mutation (IDH) mutation status in patients with gliomas but its accuracy in assessing glioma grade has not yet been formally evaluated.

PURPOSE

To evaluate the diagnostic accuracy of metabolites such as lactate obtained from the PRESS and MEGA-PRESS sequences in the preoperative grading of glioma. To assess the prognostic value of those metabolite ratios in the overall survival of patients with gliomas.

STUDY TYPE

Prospective.

SUBJECTS

Sixty-nine subjects with gliomas (16 grade 2, 21 grade 3, and 32 grade 4). Mean age was 50.5 ± 16.7 years; 38 were male and 31 were female.

FIELD STRENGTH/SEQUENCE

3 T/MEGA-PRESS, PRESS.

ASSESSMENT

Single voxel PRESS and MEGA-PRESS spectra were obtained from tumors in patients undergoing preoperative MRI. Several tumor metabolites were measured from the PRESS, MEGA-PRESS edit-off, and difference spectra using LCModel (Linear Combination of Model Spectra) software. Diagnosis and glioma grading was done using the World Health Organization (WHO) 2016 classification. Overall survival was assessed.

STATISTICAL TESTS

Diagnostic accuracy was measured using receiver-operating characteristic (ROC) curve. Univariate and multivariate Cox proportional hazards modeling was used for the assessment of prognostic factors for time to death.

RESULTS

In the differentiation between low- vs. high-grade gliomas, tCr/tCho ratios obtained from PRESS and MEGA-PRESS sequences had similar accuracies (area under the ROC curves [AUCs] = 0.71) while Lac/NAA from PRESS had a lower accuracy (AUC = 0.65). The presence of a detectable 2-hydroxyglutarate peak on the difference spectrum was a favorable prognostic factor in univariate analysis (hazard ratio = 0.25, 95% confidence interval: 0.08-0.83). No other metabolite was found to be a significant prognostic factor in univariate and multivariate analyses.

DATA CONCLUSION

Edited MRS can be used to detect metabolites which can help in the preoperative grading of gliomas and in determination of the overall survival. A separate PRESS acquisition is needed for lactate quantification.

PLAIN LANGUAGE SUMMARY

Gliomas are brain tumors that vary in severity. This study explored the use of two advanced MR spectroscopy techniques (PRESS and MEGA-PRESS) in detecting tumor metabolites. The authors found that both techniques' choline/creatine ratio showed moderate accuracy in identifying high-grade gliomas. Lactate was better revealed with the PRESS technique and was associated with high-grade gliomas. They confirmed that the MEGA-PRESS technique allowed additional detection of 2-hydroxyglutarate in IDH-mutant gliomas, which was linked to better survival. These findings emphasize that advanced MR spectroscopy can extract metabolic information time-efficiently, which can be used to improve the preoperative diagnosis of patients with gliomas.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 2.

[Totally paralyzed or brain dead?]

In two patients, men aged 23 and 42 years, a condition that mimicked brain death was observed as a consequence of rapidly progressive complete peripheral paralyses, which included the intrinsic and extrinsic eye muscles. However, the EEG revealed a waking pattern. Maximal supportive therapy was provided, which included haemodialysis for the first patient and artificial ventilation for both patients. A slow recovery was seen after four weeks. The first patient was paralyzed following the ingestion of a large quantity of ethylene glycol and the second by botulism due to the consumption of injudiciously canned food. In patients with catastrophic brain injury, the diagnosis of brain death can be confirmed by a clinical neurological examination. In considering the diagnosis 'brain death', the most important criterion is that the cause of the brain damage is established. If the cause is insufficiently, the presence of brain death should be seriously doubted, unless an isoelectric EEG is observed.

[Diagnostic image (336). A woman with a calcified pelvic mass]

In a 34-year-old woman with uterine fibroids, one of the fibroids was calcified and was therefore visible on a conventional radiograph.

Multiomic analyses direct hypotheses for Creutzfeldt-Jakob disease risk genes

Prions are assemblies of misfolded prion protein that cause several fatal and transmissible neurodegenerative diseases, with the most common phenotype in humans being sporadic Creutzfeldt-Jakob disease (sCJD). Aside from variation of the prion protein itself, molecular risk factors are not well understood. Prion and prion-like mechanisms are thought to underpin common neurodegenerative disorders meaning that the elucidation of mechanisms could have broad relevance. Herein we sought to further develop our understanding of the factors that confer risk of sCJD using a systematic gene prioritization and functional interpretation pipeline based on multiomic integrative analyses. We integrated the published sCJD genome-wide association study (GWAS) summary statistics with publicly available bulk brain and brain cell type gene and protein expression datasets. We performed multiple transcriptome and proteome-wide association studies (TWAS & PWAS) and Bayesian genetic colocalization analyses between sCJD risk association signals and multiple brain molecular quantitative trait loci signals. We then applied our systematic gene prioritization pipeline on the obtained results and nominated prioritized sCJD risk genes with risk-associated molecular mechanisms in a transcriptome and proteome-wide manner. Genetic upregulation of both gene and protein expression of syntaxin-6 (STX6) in the brain was associated with sCJD risk in multiple datasets, with a risk-associated gene expression regulation specific to oligodendrocytes. Similarly, increased gene and protein expression of protein disulfide isomerase family A member 4 (PDIA4), involved in the unfolded protein response, was linked to increased disease risk, particularly in excitatory neurons. Protein expression of mesencephalic astrocyte derived neurotrophic factor (MANF), involved in protection against endoplasmic reticulum stress and sulfatide binding (linking to the enzyme in the final step of sulfatide synthesis, encoded by sCJD risk gene GAL3ST1), was identified as protective against sCJD. In total 32 genes were prioritized into two tiers based on the level of evidence and confidence for further studies. This study provides insights into the genetically-associated molecular mechanisms underlying sCJD susceptibility and prioritizes several specific hypotheses for exploration beyond the prion protein itself and beyond the previously highlighted sCJD risk loci through the newly prioritized sCJD risk genes and mechanisms. These findings highlight the importance of glial cells, sulfatides and the excitatory neuron unfolded protein response in sCJD pathogenesis.

Antibodies against enteroviruses in intravenous Ig preparations: great variation in titres and poor correlation with the incidence of circulating serotypes

Antibody titres in immunoglobulin preparations for intravenous use were tested against 24 different enterovirus serotypes and varied between 1:100 and 1:10,000 within a single batch. Differences up to 8-fold were found for homologous titres between two different batches that were prepared 6 years apart. The lowest titre obtained was 1:40. The observed differences within and between the two batches could not be explained by different incidence of serotypes of enteroviruses circulating at the time blood was collected. Differences in titres of up to 18-fold were observed when several strains of the same serotype were tested suggesting that intratypic variation influences antibody titres. It is concluded that immunoglobulin preparations contain antibodies against many enteroviruses, but that titres can be low and cannot be predicted from the incidence of any particular serotype circulating in the community. Because of intratypic variation, selection of a batch for specific treatment should be based on results obtained with the patient's own isolate, and not with a reference strain.

Genome wide association study of clinical duration and age at onset of sporadic CJD

Human prion diseases are rare, transmissible and often rapidly progressive dementias. The most common type, sporadic Creutzfeldt-Jakob disease (sCJD), is highly variable in clinical duration and age at onset. Genetic determinants of late onset or slower progression might suggest new targets for research and therapeutics. We assembled and array genotyped sCJD cases diagnosed in life or at autopsy. Clinical duration (median:4, interquartile range (IQR):2.5-9 (months)) was available in 3,773 and age at onset (median:67, IQR:61-73 (years)) in 3,767 cases. Phenotypes were successfully transformed to approximate normal distributions allowing genome-wide analysis without statistical inflation. 53 SNPs achieved genome-wide significance for the clinical duration phenotype; all of which were located at chromosome 20 (top SNP rs1799990, pvalue = 3.45x10-36, beta = 0.34 for an additive model; rs1799990, pvalue = 9.92x10-67, beta = 0.84 for a heterozygous model). Fine mapping, conditional and expression analysis suggests that the well-known non-synonymous variant at codon 129 is the obvious outstanding genome-wide determinant of clinical duration. Pathway analysis and suggestive loci are described. No genome-wide significant SNP determinants of age at onset were found, but the HS6ST3 gene was significant (pvalue = 1.93 x 10-6) in a gene-based test. We found no evidence of genome-wide genetic correlation between case-control (disease risk factors) and case-only (determinants of phenotypes) studies. Relative to other common genetic variants, PRNP codon 129 is by far the outstanding modifier of CJD survival suggesting only modest or rare variant effects at other genetic loci.

Fast spin-echo MR of contact points on implanted intracerebral stainless steel multicontact electrodes

A three-dimensional fast spin-echo MR technique is proposed for locating contact points on implanted intracerebral multicontact electrode bundles, Coronal or sagittal reformatting shows the entire trajectory of the electrode bundles. The contract points are clearly visible owing to the absence of coating material associated with a slightly larger susceptibility artifact. Potentially, this technique may preclude postimplantation thin-section CT, with its associated high radiation dose.

Development of an Automated Capillary Immunoassay to Detect Prion Glycotypes in Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob disease (CJD) comprises a group of transmissible neurodegenerative diseases with vast phenotypic diversity. Sporadic CJD heterogeneity is predominantly influenced by the genotype at codon 129 of the prion-encoding gene and the molecular weight of PrP^Sc fragments after protease digestion, resulting in a classification of 6 subtypes of CJD (MM1, MM2, MV1, MV2, VV1, and VV2). The majority of cases with CJD can be distinguished using this classification system. However, a number of reported CJD cases are phenotypically unique from others within their same subtype, such as variably protease-sensitive prionopathies, or exist as a mixture of subtypes within the same patient. Western blotting of brain tissue, along with the genotyping of codon 129 of the prion-encoding gene, is considered the "gold standard" for the biochemical characterization of CJD. Western blotting requires a significant amount of prion protein for detection, is labor-intensive, and is also associated with high interassay variability. In addition to these limitations, a growing body of research suggests that unique subtypes of CJD are often undetected or misdiagnosed using standard diagnostic western blotting protocols. Consequently, we successfully optimized and developed a capillary-based western assay using the JESS Simple Western (ProteinSimple) to detect and characterize prion proteins from patients with CJD. We found that this novel assay consistently differentiated CJD type 1 and type 2 cases with a limit of detection 10 to 100× higher than traditional western blotting. Cases with CJD in which type 1 and type 2 coexist within the same brain region can be detected using type 1-specific and type 2-specific antibodies, and we found that there was remarkable specificity for the detection of cases with variably protease-sensitive prionopathy. The assay presented displays outstanding sensitivity, allowing for the preservation of valuable samples and enhancing current detection methods.

Expression pattern of the von Hippel-Lindau protein in human tissues

von Hippel-Lindau (VHL) disease is an autosomal dominant inherited disorder characterized by extensively vascularized tumors and cysts in specific organs. The VHL gene product plays a critical role in the regulation of transcription elongation by RNA polymerase II. To provide insight into which cells the VHL protein is expressed, we performed immunohistochemistry on human tissue and tumors. The VHL protein was widely expressed in normal human tissue. The cellular distribution of the protein was confined to the cytoplasm of specific cell types. High levels of expression of the protein were observed in neural tissue, especially in Purkinje cells, Golgi type II cells, and dentate nucleus of the cerebellum, pontine nuclei, the inferior olivary nucleus of the medulla oblongata, orthosympathetic ganglia, myenteric, and submucous plexus of the colon. In the other target organs of the VHL disease, high expression was observed in the renal tubule system, the exocrine pancreas, the adrenal cortex, and liver parenchyma. The VHL protein was also expressed in organs not at risk for the disease. The eosinophilic cells of the pituitary gland, epithelial cells of the follicles of the thyroid, epithelial cells of the intestines, bile ducts, and bronchial epithelia showed strong VHL immunoreactivity. Immunohistochemistry did not facilitate the discrimination of tumors obtained from VHL patients or tumors unrelated to the VHL disease. Renal cell carcinomas, hemangioblastomas, and pheochromocytomas, either VHL-related or sporadic, demonstrated positive staining for the VHL protein, which suggests that the antibody also recognizes the mutated VHL protein. The present study suggests a role for the VHL gene that goes beyond the organs involved in the disease. The recognition of cell-specific VHL expression provides a framework for further studies to elucidate the normal function of the VHL gene and to determine its role in specific cell types.

Patients with persistent pain after enucleation studied by MRI dynamic color mapping and histopathology

PURPOSE

To study possible causes of persistent pain in patients who underwent enucleation of the globe and in whom all other noninvasively detectable causes of pain had been ruled out.

METHODS

Twenty patients were studied, 10 with intractable pain (score >5 on a 0-to-9 self-reporting pain scale) persisting for more than 6 months after enucleation (for various reasons) and 10 without pain (score <4) at least 6 months after enucleation. Magnetic resonance imaging (MRI) with dynamic color mapping (MRI-DCM) was used to quantify the motion of the optic nerve in millimeters per degree of gaze, 2 to 3 mm behind the implant. Histopathologic study of biopsy specimens was used to verify imaging findings.

RESULTS

The optic nerve was attached to the implant in almost all (19/20) patients. On average, the motion was significantly less in patients with persistent intractable pain (0.04 mm/deg) than in patients without pain (0.08 mm/deg; normal orbit, 0.13 mm/deg). A biopsy specimen was available in 5 of 10 patients with persistent pain, and in 4 of those 5, microscopic neuroma was found close to the optic nerve-implant junction.

CONCLUSIONS

In the enucleated orbit, the optic nerve is usually attached to the implant and soft tissue motion is decreased. In patients who have persistent pain after enucleation, motion is decreased even more, and a high percentage of microscopic amputation neuromas are found. Increased stiffness of orbital soft tissue and optic nerve attachment after enucleation are detectable using MRI-DCM, and may play a role in susceptible patients in the development of microscopic amputation neuroma and pain.

Case 309: Autoimmune Glial Fibrillary Acidic Protein Astrocytopathy

HISTORY

A 64-year-old man presented with a 6-month history of lightheadedness and intermittent balance and coordination difficulties. Two months before admission, symptoms became more substantial and persistent, with a worsening sense of disequilibrium and unsteady gait. He reported difficulties pronouncing words and mild word-finding difficulties. His wife noted a change in his cognition and memory over the same time. His medical history included well-controlled chronic obstructive pulmonary disease (COPD) secondary to a long history of smoking with associated unintentional 30-lb (13.6-kg) weight loss over the previous 3 years, for which chest CT scanning was performed, revealing no abnormality. On clinical examination, the patient was alert and oriented but had slurred speech. A positive Romberg sign was noted, finger-to-nose and hand rapid alternating movement tests revealed impairment on the right side, and his gait was ataxic. The motor examination revealed normal muscle tone, bulk, and power in the upper and lower extremities. Sensory testing results were normal. Initial MRI of the brain at admission revealed abnormal findings in the left supratentorial brain. Of note, this patient's presentation predated the COVID-19 pandemic. Cerebrospinal fluid (CSF) analysis revealed predominant pleocytosis (23 × 106/L; normal range, [0-5] × 106/L) (78% lymphocytes, 22% monocytes), elevated protein level (1.23 g/L; normal range, 0.19-0.64 g/L), oligoclonal bands (faint one or two), and a high immunoglobulin G (IgG) index (0.130 g/L; normal reference, ≤0.059 g/L). Despite extensive initial work-up for inflammatory, infectious, autoimmune, or neoplastic causes, a definitive diagnosis was not reached. Thus, repeat MRI of the brain was performed 2 weeks after admission.