Neuronal intranuclear inclusion disease in patients with adult-onset non-vascular leukoencephalopathy

Neuronal intranuclear inclusion disease (NIID), caused by an expansion of GGC repeats in the 5'-untranslated region of NOTCH2NLC, is an important but underdiagnosed cause of adult-onset leukoencephalopathies. The present study aimed to investigate the prevalence, clinical spectrum, and brain MRI characteristics of NIID in adult-onset nonvascular leukoencephalopathies and assess the diagnostic performance of neuroimaging features. One hundred and sixty-one unrelated Taiwanese patients with genetically undetermined nonvascular leukoencephalopathies were screened for the NOTCH2NLC GGC repeat expansions using fragment analysis, repeat-primed PCR, southern blot analysis and/or nanopore sequencing with Cas9-mediated enrichment. Among them, 32 (19.9%) patients had an expanded NOTCH2NLC allele and diagnosed with NIID. We enrolled another two affected family members from one patient for further analysis. The size of the expanded NOTCH2NLC GGC repeats in the 34 patients ranged from 73 to 323 repeats. Skin biopsy from five patients all showed eosinophilic, p62-positive intranuclear inclusions in the sweat gland cells and dermal adipocytes. Among the 34 NIID patents presenting with nonvascular leukoencephalopathies, the median age at symptom onset was 61 years (range, 41-78 years) and the initial presentations included cognitive decline (44.1%; 15/34), acute encephalitis-like episodes (32.4%; 11/34), limb weakness (11.8%, 4/34), and parkinsonism (11.8%; 4/34). Cognitive decline (64.7%; 22/34) and acute encephalitis-like episodes (55.9%; 19/34) were also the most common overall manifestations. Two-thirds of the patients had either bladder dysfunction or visual disturbance. Comparing the brain MRI features between the NIID patients and individuals with other undetermined leukoencephalopathies, corticomedullary junction curvilinear lesion on diffusion weighted imaging (DWI) was the best biomarker to diagnose NIID with high specificity (98.4%) and sensitivity (88.2%). However, such DWI abnormality was absent in 11.8% of the NIID patients. When only fluid-attenuated inversion recovery images were available, presence of white matter hyperintensity lesions (WMH) either in paravermis or middle cerebellar peduncles also favored the diagnosis of NIID with a specificity of 85.3% and a sensitivity of 76.5%. Among the ten patients' MRI performed within 5 days of the onset of acute encephalitis-like episodes, five showed cortical DWI hyperintense lesions and two revealed focal brain edema. In conclusion, NIID accounts for 19.9% (32/161) of patients with adult-onset genetically undiagnosed nonvascular leukoencephalopathies in Taiwan. Half of the NIID patients ever developed encephalitis-like episodes with restricted diffusion in the cortical regions at the acute stage DWI. Corticomedullary junction hyperintense lesions, WMH in paravermis or middle cerebellar peduncles, bladder dysfunction and visual disturbance are useful hints to diagnose NIID.

Diagnostic performance of apparent diffusion coefficient values for the differentiation of intrahepatic cholangiocarcinoma from gastrointestinal adenocarcinoma liver metastases

Background

We aimed to investigate whether there is a difference between intrahepatic cholangiocarcinoma (IHCC) and liver metastases of gastrointestinal system (GIS) adenocarcinoma in terms of apparent diffusion coefficient (ADC) values.

Patients and methods

From January 2018 to January 2020, we retrospectively examined 64 consecutive patients with liver metastases due to gastrointestinal system adenocarcinomas and 13 consecutive IHCC in our hospital’s medical records. After exclusions, fifty-three patients with 53 liver metastases and 10 IHCC were included in our study. We divided the patients into two groups as IHCC and liver metastases of GIS adenocarcinoma. For mean apparent diffusion coefficient (ADC_mean) values, the region of interests (ROI) was placed in solid portions of the lesions. ADC_mean values of groups were compared.

Results

The mean age of IHCC group was 62.50 ± 13.49 and mean age of metastases group was 61.15 ± 9.18. ADC_mean values were significantly higher in the IHCC group compared to the metastatic group (p < 0.001). ROC curves method showed high diagnostic accuracy (AUC = 0.879) with cut-off value of < 1178 x 10^-6 mm²/s for ADC_mean (Sensitivity = 90.57, Specificity = 70.0, positive predictive value [PPV] = 94.1, negative predictive value [NPV] = 58.3) in differentiating adenocarcinoma metastases from IHCC.

Conclusions

The present study results suggest that ADC values have a potential role for differentiation between IHCC and GIS adenocarcinoma liver metastases which may be valuable for patient management.

[A case of recurrent transient global amnesia showing different symptom duration and MRI findings]

A 66-year-old man was admitted to our department with anterograde amnesia. He was diagnosed with transient global amnesia (TGA) because of the symptom lasting for several hours and no abnormal findings on MRI and EEG. About a year after the episode, he recurred amnesia lasting only for 20 minutes. MRI diffusion weighted image (DWI) revealed a small hyperintense signal in the right hippocampus, while there was no abnormality on EEG. We diagnosed him with recurrent TGA. This case may be interesting in that symptom duration and MRI-DWI finding are much different between two attacks of TGA.

Cerebral Microbleeds in the Patients With Acute Stroke Symptoms

Background: Some patients with acute stroke symptoms do not show hyperintensities on diffusion-weighted image (DWI). A few case reports have indicated that acutely developed cerebral microbleeds (CMBs) might cause focal symptoms. This study sought to investigate the incidence and characteristics of symptomatic CMBs in the patients with acute stroke symptoms but without DWI ischemic lesions.

Methods: We enrolled the patients with acute stroke symptoms who underwent magnetic resonance imaging including DWI and gradient echo (GRE) sequences within 7 days after symptom onset, at our prospective stroke registry. We then identified patients without DWI-positive ischemic lesions but with CMBs in the relevant brain regions.

Results: Between January 2005 and February 2012, we identified 235 DWI-negative transient ischemic attack (n = 221) and stroke (n = 14) patients from 2129 consecutive patients at our registry. In total, 16 patients had CMBs corresponding to the focal symptoms. Among these 16 patients, 12 patients showed a hyperintense rim on DWI around a microbleed suspected to be related to focal symptoms; of the 12 patients, 7 experienced stroke symptoms for more than 24 h. However, the symptoms in the remaining patients (5 patients with the hyperintense rim and 4 patients without the hyperintense rim) improved within 24 h.

Conclusion: Symptomatic microbleeds are infrequent but not rare in the patients with acute stroke symptoms. Perihematomal edema around an acute CMB can cause a hyperintense rim on DWI. Our results suggest that a combination of DWI and GRE imaging can help diagnose acute symptomatic CMBs.

Metanephric adenoma with low apparent diffusion coefficient value mimicking renal cell carcinoma: A case report

RATIONALE

Metanephric adenoma (MA) is a rare and often benign tumor. Most MAs were misdiagnosed as renal cell carcinomas (RCCs) preoperatively. Diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping can help to differentiate benign and malignant tumors. However, there are still pitfalls in using DWI and ADC to discriminate benign and malignant lesions.

PATIENT CONCERNS

A 56-year-old woman had a right renal metanephric adenoma. The tumor showed very low ADC value preoperatively and was misdiagnosed as a renal cell carcinoma.

DIAGNOSIS

Intraoperative ultrasound-guided percutaneous biopsy of tumor was performed. Based on the histopathological findings and immunohistochemical stains, a diagnosis of metanephric adenoma was suggested.

INTERVENTIONS

The patient received percutaneous cryoablation of this tumor. Five years later, she underwent right partial nephrectomy because local recurrence was revealed on a follow-up computed tomography (CT).

OUTCOMES

MA was confirmed again by histological examination. The patient was uneventful after surgery.

LESSONS

ADC mapping can be used for differentiating RCCs from other benign tumors by their lower ADC values. However, some benign and malignant lesions have overlapped low ADC values. This case illustrated that a benign lesion such as MA could mimic RCC on ADC, by its highly cellular component. Cryoablation is an optional treatment, which has an increased risk of local recurrence. Follow-up CT or MRI is useful and necessary for detection of local recurrence by depicting enhancing solid parts in a tumor over time.

Preoperative diffusion-weighted magnetic resonance imaging and intraoperative frozen sections for predicting the tumor grade in endometrioid endometrial cancer

Objective

The histological tumor grade is a strong predictor of nodal metastasis in endometrial cancer; as such, an accurate pre- or intraoperative diagnosis is important for performing lymphadenectomy.

Methods

Ninety-one patients with endometrioid endometrial cancer were imaged on DW-MRI with the apparent diffusion coefficient (ADC) calculated and a frozen section (FS) diagnosis made before and at hysterectomy. The diagnostic accuracy for predicting the tumor grade for diffusion weighted magnetic resonance inaging (DW-MRI) and the FS diagnosis compared to the ultimate histologic status was analyzed.

Results

Among 91 patients with endometrioid endometrial cancer, high-grade (endometrioid G3) tumors had lower ADC values than low-grade (endometrioid G1/2) tumors. The cut-off of the mean ADC_mean values for predicting high-grade tumors resulted in 743×10^-6 mm²/sec according to the receiver operating characteristic curve. The true positive rates of ADC values and FSs for the prediction of high-grade tumors did not differ to a statistically significant extent (73.3% vs. 66.7%, p=0.7), however, the true negative rate of ADC values for the prediction of low-grade tumors was significantly lower than that of the FSs (64.5% vs. 98.7%, p=0.01). The kappa statistics of ADC values and FSs were 0.23 and 0.73, respectively. Of note, all five patients with high-grade tumors for whom intraoperative FSs indicated low-grade tumors were predicted to have high-grade tumors on preoperative DW-MRI.

Conclusion

A FS diagnosis is more suitable for predicting high-grade tumors than DW-MRI; however, physicians should pay close attention to tumors with low ADC values on preoperative DW-MRI.

[Symmetrical lesions of the cerebral peduncles and internal capsules on MRI in a patient with extranodal NK/T cell lymphoma]

A 72-year-old man was admitted to our hospital because of subacute progressive consciousness disturbance. FLAIR images showed diffuse high intensity areas in the bilateral thalamus, basal ganglia, and white matter. Chest CT revealed a mass in the right lung. The patient was diagnosed with extranodal natural killer/T cell lymphoma (ENKL) according to the results of a biopsy of the right pulmonary mass. The FLAIR images showed diffuse white matter lesions, without a mass such as lymphomatosis cerebri. On diffusion-weighted images, symmetrical high-intensity lesions of the cerebral peduncle and the internal capsule suggested high-density lymphoma cells around neurons. ENKL of the central nervous system and lung is a very rare neoplasm, and this case showed characteristic images.

MR imaging biomarkers for evaluating therapeutic effects shortly after near infrared photoimmunotherapy

Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of antibodies for targeting tumors with the toxicity induced by photon absorbers after irradiation with NIR light. The purpose of this study was to determine if MR imaging can detect changes in the MR properties of tumor within several hours of NIR-PIT. A431 cells were injected subcutaneously in the right and left dorsi of 12 mice. Six days later, the mice were injected with a photon absorber, IR700, conjugated to panitumumab, an antibody targeting epidermal growth factor receptor. One day later, only right sided tumor was exposed to NIR light (treated tumor). MRI was performed 1 day before and 1-2 hours after NIR-PIT using gadofosveset for six mice and gadopentetate dimeglumine for another six mice. T2 relaxation times, the apparent diffusion coefficient (ADC) for the following combinations of b-values: 0-1000, 200-1000 and 500-1000 s/mm2 and enhancement indices were compared before and after NIR-PIT using a two-sided paired t-test. For treated tumors, T2 relaxation time increased after NIR-PIT (p < 0.01) and all three ADC values decreased after NIR-PIT (p < 0.01). Moreover, the enhancement area under the curve (AUC) using gadofosveset increased after NIR-PIT (p = 0.02). In conclusion, prolongation of T2, reductions in ADC and increased enhancement using gadofosveset are seen within 2 hours of NIR-PIT treatment of tumors. Thus, MRI can be a useful imaging biomarker for detecting early therapeutic changes after NIR-PIT.

DWI and SPARCC scoring assess curative effect of early ankylosing spondylitis

Background

To investigate the magnetic diffusion weighted imaging (DWI) sequence and Spondyloarthritis Research Consortium of Canada (SPARCC) scoring in assessing curative effect of combined treatment of Chinese and Western medicine for early ankylosing spondylitis (AS).

Methods

48 cases diagnosed as early AS and treated with Chinese and Western medicine were included in the study. Magnetic routine and DWI sequence scanning image were performed to obtain the mean apparent diffusion coefficient (ADC) value of sub-articular surface bone marrow. Combined with SPARCC scoring, statistical analysis was conducted to compare the difference with the information obtained in the previous study.

Results

The mean ADC value in the sub-articular surface bone marrow of patients after clinical treatment: (4.34±0.55)×10-4mm2/s in ilium and (3.96±0.23)×10-4mm2/s in sacrum, which were both significantly lower than that before treatment (p< 0.05). There was highly positive correlation between mean ADC value and SPARCC scoring (P<0.05). The regression relationship could be demonstrated as Y=-64.420+21.262X(Y: SPARCC scoring value; X: mean ADC value).

Conclusions

Magnetic DWI and SPARCC scoring could be applied in accessing AS inflammation activity changes and in reflect of curative effect of early AS patients as well as in providing reliable radiologist evidence for clinical therapeutic efficacy.

A rare case of white pearls in brainstem

Intrinsic brainstem epidermoid is extremely rare, and only 14 cases have been reported. Authors report a classic case of brainstem epidermoid in a 14-year-old male child presenting with symptoms of brainstem involvement. The child underwent a successful surgical excision. The lesion was intrinsic and caused diagnostic dilemma based on conventional radiological images. Based on our experience in this case and a thorough review of literature, we are of the opinion that diffusion-weighted images are very important in establishing the diagnosis. Such lesions are challenging and attempt to remove adherent tumor capsule may produce additional neurological deficits.

Diffusion weighted images of metastatic as compared with nonmetastatic axillary lymph nodes in patients with newly diagnosed breast cancer

BACKGROUND

To investigate the ability of diffusion weighted images (DWI) to differentiate between metastatic and nonmetastatic axillary lymph nodes (LNs) in patients with newly diagnosed breast cancer.

METHODS

From January 2010 to February 2012, DWI was performed at b values of 0 and 800 for 16 metastatic LNs from 16 patients with breast cancer, and 20 nonmetastatic LNs from 20 women without breast cancer. The metastatic LNs were proven by ultrasound (US) guided core biopsy and the same LNs were identified on MRI by comparing the US images with MR images. Nonmetastatic LNs were verified by the stability in size and shape for at least 2 years on MRI. The apparent diffusion coefficient (ADC) value of the metastatic and nonmetastatic axillary LNs was compared. Receiver-operating-characteristics (ROC) analysis was performed to evaluate the diagnostic performance of the ADC value in differentiating between metastatic and nonmetastatic axillary LNs.

RESULTS

The mean ADC value was 0.746 × 10(-3) for metastatic LNs and 1.033 × 10(-3) for nonmetastatic LNs (P < 0.001). The area under the ROC curve was 0.884. The sensitivity and specificity for differentiating metastatic from nonmetastatic axillary LNs using a cutoff ADC value of 0.852 were 85% and 81%, respectively.

CONCLUSION

There is a statistically significant difference between the ADC values of pathologically proven metastatic LNs and nonmetastatic LNs. DWI and ADC values are a useful tool for differentiating metastatic from nonmetastatic axillary LNs.

Thalamic lesions in acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

We aimed to assess the characteristics of thalamic lesions in children with acute encephalopathy with biphasic seizures and late reduced diffusion.

METHODS

Using the Tokai Pediatric Neurology Society database, we identified and enrolled 18 children with acute encephalopathy with biphasic seizures and late reduced diffusion from 2008 to 2010. Using diffusion-weighted images, we identified patients with thalamic lesions and compared their clinical factors with those of patients without thalamic lesions. We analyzed the time sequence of thalamic, sucortical, and cortical lesions. To study the topography of thalamic lesions, we divided the thalamus into five sections: anterior, medial, anterolateral, posterolateral, and posterior. Subsequently, we analyzed the relationship between the topography of thalamic lesions and the presence of central-sparing.

RESULTS

Seven children presented with symmetrical thalamic lesions associated with bilateral subcortical or cortical lesions. No statistical difference in the clinical features was observed between individuals with and without thalamic lesions. These lesions were observed only when subcortical or cortical lesions were present. In 5 children, thalamic lesions were present in bilateral anterior or anterolateral sections and were associated with subcortical or cortical lesions in bilateral frontal lobes with central-sparing. In the other two children, thalamic lesions were extensive and accompanied by diffuse subcortical and cortical lesions without central-sparing.

CONCLUSION

Thalamic lesions in patients with acute encephalopathy with biphasic seizures and late reduced diffusion involve the anterior sections. The thalamocortical network may play a role in development of thalamic lesions in patients with acute encephalopathy with biphasic seizures and late reduced diffusion.

Early features in neuroimaging of two siblings with molybdenum cofactor deficiency

We report the features of neuroimaging within 24 hours after birth in 2 siblings with molybdenum cofactor deficiency. The first sibling was delivered by emergency cesarean section because of fetal distress and showed pedaling and crawling seizures soon after birth. Brain ultrasound revealed subcortical multicystic lesions in the frontal white matter, and brain MRI at 4 hours after birth showed restricted diffusion in the entire cortex, except for the area adjacent to the subcortical cysts. The second sibling was delivered by elective cesarean section. Cystic lesions were seen in the frontal white matter on ultrasound, and brain MRI showed low signal intensity on T1-weighted image and high signal intensity on T2-weighted image in bifrontal white matter within 24 hours after birth, at which time the infant sucked sluggishly. Clonic spasm appeared at 29 hours after birth. The corpus callosum could not be seen clearly on ultrasound or MRI in both infants. Cortical atrophy and white matter cystic lesions spread to the entire hemisphere and resulted in severe brain atrophy within ~1 month in both infants. Subcortical multicystic lesions on ultrasound and a cortex with nonuniform, widespread, restricted diffusion on diffusion-weighted images are early features of neuroimaging in patients with molybdenum cofactor deficiency type A.