Disappearance of MRI imaging signals in a patient with neuronal intranuclear inclusion disease

Mapping macrostructural and microstructural brain alterations in patients with neuronal intranuclear inclusion disease

BACKGROUND AND PURPOSE

Neuronal intranuclear inclusion disease (NIID) is a rare complex neurodegenerative disorder presents with various radiological features. The study aimed to investigate the structural abnormalities in NIID using multi-shell diffusion MR.

MATERIALS AND METHODS

Twenty-eight patients with adult-onset NIID and 32 healthy controls were included. Volumetric and diffusion MRI measures, including volume, fractional anisotropy (FA), mean diffusivity (MD), intracellular volume fraction (ICVF), orientation dispersion index (ODI), and isotropic volume fraction (ISOVF) of six brain structures, including cortex, subcortical GM, cerebral WM, cerebellar GM and WM, and brainstem, were obtained and compared between NIID and healthy controls. Associations between MRI measures and clinical variables were investigated.

RESULTS

Brain lesions of NIID included corticomedullary junction lesions on DWI, confluent leukoencephalopathy, lesions on callosum, cerebellar middle peduncle, cerebellar paravermal area and brainstem, and brain atrophy. Compared to healthy controls, NIID showed extensive volume loss of all the six brain regions (all p < 0.001); lower FA in cerebral WM (p < 0.001); higher MD in all WM regions; lower ODI in cortex (p < 0.001); higher ODI in subcortical GM (p < 0.001) and brainstem (p = 0.016); lower ICVF in brainstem (p = 0.001), and cerebral WM (p < 0.001); higher ISOVF in all the brain regions (p < 0.001). Higher MD of cerebellar WM was associated with worse cognitive level as evaluated by MoCA scores (p = 0.011).

CONCLUSIONS

NIID patients demonstrated widespread brain atrophy but heterogeneous diffusion alterations. Cerebellar WM integrity impairment was correlated with the cognitive decline. The findings of the current study offer a sophisticated picture of brain structural alterations in NIID.

Clinical and multimodal imaging features of adult-onset neuronal intranuclear inclusion disease

OBJECTIVES

This study aimed to analyze the clinical and multimodal imaging manifestations of adult-onset neuronal intranuclear inclusion disease (NIID) patients and to investigate NIID-specific neuroimaging biomarkers.

METHODS

Forty patients were retrospectively enrolled from the Qilu Hospital of Shandong University. We analyzed the clinical and imaging characteristics of 40 adult-onset NIID patients and investigated the correlation between these characteristics and genetic markers and neuropsychological scores. We further explored NIID-specific alterations using multimodal imaging indices, including diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), and brain age estimation. In addition, we summarized the dynamic evolution pattern of NIID by examining the changes in diffusion weighted imaging (DWI) signals over time.

RESULTS

The NIID patients' ages ranged from 31 to 77 years. Cognitive impairment was the most common symptom (30/40, 75.0%), while some patients (18/40, 45.0%) initially presented with episodic symptoms such as headache (10/40, 25.0%). Patients with cognitive impairment symptoms had more cerebral white matter damage (χ2 = 11.475, P = 0.009). The most prevalent imaging manifestation was a high signal on DWI in the corticomedullary junction area, which was observed in 80.0% (32/40) of patients. In addition, the DWI dynamic evolution patterns could be classified into four main patterns. Diffusion tensor imaging (DTI) revealed extensive thinning of cerebral white matter fibers. The estimated brain age surpassed the patient's chronological age, signifying advanced brain aging in NIID patients.

CONCLUSIONS

The clinical manifestations of NIID exhibit significant variability, usually leading to misdiagnosis. Our results provided new imaging perspectives for accurately diagnosing and exploring this disease's neuropathological mechanisms.

Neuronal Intranuclear Inclusion Disease with NOTCH2NLC GGC Repeat Expansion: A Systematic Review and Challenges of Phenotypic Characterization

Neuronal intranuclear inclusion disease (NIID) is a highly clinically heterogeneous neurodegenerative disorder primarily attributed to abnormal GGC repeat expansions in the NOTCH2NLC gene. This study aims to comprehensively explore its phenotypic characteristics and genotype-phenotype correlation. A literature search was conducted in PubMed, Embase, and the Cochrane Library from September 1, 2019, to December 31, 2022, encompassing reported NIID cases confirmed by pathogenic NOTCH2NLC mutations. Linear regressions and trend analyses were performed. Analyzing 635 cases from 85 included studies revealed that familial cases exhibited significantly larger GGC repeat expansions than sporadic cases (p < 0.001), and this frequency significantly increased with expanding GGC repeats (p trend < 0.001). Age at onset (AAO) showed a negative correlation with GGC repeat expansions (p < 0.001). The predominant initial symptoms included tremor (31.70%), cognitive impairment (14.12%), and muscle weakness (10.66%). The decreased or absent tendon reflex (DTR/ATR) emerged as a notable clinical indicator of NIID due to its high prevalence. U-fiber was observed in 79.11% of patients, particularly prominent in paroxysmal disease-dominant (87.50%) and dementia-dominant cases (81.08%). Peripheral neuropathy-dominant cases exhibited larger GGC repeat expansions (median = 123.00) and an earlier AAO (median = 33.00) than other phenotypes. Moreover, a significant genetic anticipation of 3.5 years was observed (p = 0.039). This study provides a comprehensive and up-to-date compilation of genotypic and phenotypic information on NIID since the identification of the causative gene NOTCH2NLC. We contribute a novel diagnostic framework for NIID to support clinical practice.

Not your usual neurodegenerative disease: a case report of neuronal intranuclear inclusion disease with unconventional imaging patterns

Background

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative illness with characteristic brain magnetic resonance imaging (MRI) manifestations: diffuse symmetric white-matter hyperintensities in lateral cerebral ventricle areas in fluid-attenuated inversion recovery (FLAIR) and high-intensity signals along the corticomedullary junction of the frontal-parietal-temporal lobes in diffusion weighted imaging (DWI). Here, we report a case of adult-onset NIID who was misdiagnosed with Susac syndrome (SS) due to unusual corpus callosum imaging findings.

Case presentation

A 39-year-old man presented with chronic headache, blurred vision, tinnitus, and numbness in the hands as initial symptoms, accompanied by cognitive slowing and decreased memory. Brain MRI revealed round hypointense lesions on T1-weighted imaging (T1WI) and hyperintense lesions on T2WI/FLAIR/DWI in the genu and splenium of the corpus callosum. An initial diagnosis of SS was made based on the presence of the SS-typical symptoms and SS-characteristic radiology changes. Furthermore, the patient's symptoms improved upon completion of a combined pharmacotherapy plan. However, no significant changes were evident 18 months after the brain MRI scan. Eventually, the patient was then diagnosed with NIID based on a skin biopsy and detection of expanded GGC (guanine, guanine, cytosine) repeats in the NOTCH2NLC gene.

Conclusion

The present NIID case in which there was simultaneous onset of altered nervous and visual system functioning and atypical imaging findings, the atypical imaging findings may reflect an initial change of NIID leukoencephalopathy.

Longitudinal course of hyperintensity on diffusion weighted imaging in adult-onset neuronal intranuclear inclusion disease patients

Background

High signals on diffusion weighted imaging along the corticomedullary junction (CMJ) have demonstrated excellent diagnostic values for adult-onset neuronal intranuclear inclusion disease (NIID). However, the longitudinal course of diffusion weighted imaging high intensities in adult-onset NIID patients has rarely been investigated.

Methods

We described four NIID cases that had been discovered using skin biopsy and NOTCH2NLC gene testing, after diffusion weighted imaging exhibiting the distinctive corticomedullary junction high signals. Then using complete MRI data from NIID patients, we analyzed the chronological diffusion weighted imaging alterations of those individuals that had been published in Pub Med.

Results

We discussed 135 NIID cases with comprehensive MRI data, including our four cases, of whom 39 had follow-up outcomes. The following are the four primary diffusion weighted imaging dynamic change patterns: (1) high signal intensities in the corticomedullary junction were negative on diffusion weighted imaging even after an 11-year follow-up (7/39); (2) diffusion weighted imagings were initially negative but subsequently revealed typical findings (9/39); (3) high signal intensities vanished during follow-up (3/39); (4) diffusion weighted imagings were positive at first and developed in a step-by-step manner (20/39). We discovered that NIID lesions eventually damaged the deep white matter, which comprises the cerebral peduncles, brain stem, middle cerebellar peduncles, paravermal regions, and cerebellar white matter.

Conclusion

The longitudinal dynamic changes in NIID of diffusion weighted imaging are highly complex. We find that there are four main patterns of dynamic changes on diffusion weighted imaging. Furthermore, as the disease progressed, NIID lesions eventually involved the deep white matter.

Current advances in neuronal intranuclear inclusion disease

Neuronal intranuclear inclusion disease (NIID) is a rare but probably underdiagnosed neurodegenerative disorder due to pathogenic GGC expansions in the NOTCH2NLC gene. In this review, we summarize recent developments in the inheritance features, pathogenesis, and histopathologic and radiologic features of NIID that subvert the previous perceptions of NIID. GGC repeat sizes determine the age of onset and clinical phenotypes of NIID patients. Anticipation may be absent in NIID but paternal bias is observed in NIID pedigrees. Eosinophilic intranuclear inclusions in skin tissues once considered pathological hallmarks of NIID can also present in other GGC repeat diseases. Diffusion-weighted imaging (DWI) hyperintensity along the corticomedullary junction once considered the imaging hallmark of NIID can frequently be absent in muscle weakness and parkinsonism phenotype of NIID. Besides, DWI abnormalities can appear years after the onset of predominant symptoms and may even disappear completely with disease progression. Moreover, continuous reports of NOTCH2NLC GGC expansions in patients with other neurodegenerative diseases lead to the proposal of a new concept of NOTCH2NLC-related GGC repeat expansion disorders (NRED). However, by reviewing the previous literature, we point out the limitations of these studies and provide evidence that these patients are actually suffering from neurodegenerative phenotypes of NIID.

Imaging findings and pathological correlations of subacute encephalopathy with neuronal intranuclear inclusion disease–Case report

Neuronal intranuclear inclusion disease (NIID) is a slowly progressive neurodegenerative disease and may sometimes present with symptoms of subacute encephalopathy, including fever, headache, vomiting, and loss of consciousness. We present a case of adult-onset NIID with subacute encephalopathy, which is confirmed by skin and brain biopsied. The magnetic resonance imaging findings show cortical swelling and hyperintensities in the right temporooccipital lobes on T2-weighted images and magnetic resonance angiography demonstrates vasodilatations of the right middle cerebral artery and posterior cerebral artery. Abnormal enhancement is mainly observed in the gyral crowns (crown enhancement). Pathological examinations reveal new infarcts in the deep layers of the cortices. NIID should be considered in the presence of subacute encephalopathy with cortical swelling, contrast enhancement in the temporooccipital lobes, and vasodilation in adult patients. The encephalopathy targeted on the cortices, and the pathological background included infarctions.

Clinical and mechanism advances of neuronal intranuclear inclusion disease

Due to the high clinical heterogeneity of neuronal intranuclear inclusion disease (NIID), it is easy to misdiagnose this condition and is considered to be a rare progressive neurodegenerative disease. More evidence demonstrates that NIID involves not only the central nervous system but also multiple systems of the body and shows a variety of symptoms, which makes a clinical diagnosis of NIID more difficult. This review summarizes the clinical symptoms in different systems and demonstrates that NIID is a multiple-system intranuclear inclusion disease. In addition, the core triad symptoms in the central nervous system, such as dementia, parkinsonism, and psychiatric symptoms, are proposed as an important clue for the clinical diagnosis of NIID. Recent studies have demonstrated that expanded GGC repeats in the 5′-untranslated region of the NOTCH2NLC gene are the cause of NIID. The genetic advances and possible underlying mechanisms of NIID (expanded GGC repeat-induced DNA damage, RNA toxicity, and polyglycine-NOTCH2NLC protein toxicity) are briefly summarized in this review. Interestingly, inflammatory cell infiltration and inflammation were observed in the affected tissues of patients with NIID. As a downstream pathological process of NIID, inflammation could be a therapeutic target for NIID.

The polyG diseases: a new disease entity

Recently, inspired by the similar clinical and pathological features shared with fragile X-associated tremor/ataxia syndrome (FXTAS), abnormal expansion of CGG repeats in the 5' untranslated region has been found in neuronal intranuclear inclusion disease (NIID), oculopharyngeal myopathy with leukoencephalopathy (OPML), and oculopharyngodistal myopathy (OPDMs). Although the upstream open reading frame has not been elucidated in OPML and OPDMs, polyglycine (polyG) translated by expanded CGG repeats is reported to be as a primary pathogenesis in FXTAS and NIID. Collectively, these findings indicate a new disease entity, the polyG diseases. In this review, we state the common clinical manifestations, pathological features, mechanisms, and potential therapies in these diseases, and provide preliminary opinions about future research in polyG diseases.

Sporadic adult-onset neuronal intranuclear inclusion disease without high-intensity signal on DWI and T2WI: a case report

Background

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in cells in the central and peripheral nervous system. High-intensity signal in the corticomedullary junction on diffusion-weighted imaging (DWI) is supportive to the diagnosis of NIID. We describe a patient with sporadic adult-onset NIID but without any high-intensity signal on DWI and T2-weighted imaging (T2WI).

Case presentation

A 58-year-old woman without special family history developed mild persistent tremor in the right hand and deteriorated 2 years later. At 60 years of age, the patient began to conceive the bank, police and internet being deceptive, further presented apathy and confusion after two and a half years, as well as fabrication of non-existent things. Despite the treatment of antipsychotic drugs due to a diagnosis of mental disorder, the patient appeared weakness in the right limbs. Neurological examination revealed mutism, resting tremor, cogwheel-like rigidity in upper limbs, and weakness in all limbs. Brain magnetic resonance imaging displayed no cerebral atrophy initially but atrophy of frontal, temporal and parietal lobes 5 years later. No any high-intensity signal on DWI and T2WI was revealed. However, hypometabolism in the cortexes with atrophy and the right putamen nucleus were showed on ¹⁸F-fluoro-deoxy-glucose positron emission tomography/magnetic resonance. On the basis of 107 GGC repeats (normal number <40) in NOTCH2NLC gene and intranuclear inclusions with p62 immunoreactivity in the adipocyte of cutaneous sweat duct by skin biopsy, NIID was finally diagnosed. The symptomatic treatment was given but the patient had no evident improvement.

Conclusions

Our case highlights that despite the lack of high-intensity signal on DWI and T2WI, NIID is still considered for patients with parkinsonism and mental impairment.

Cognitive Dysfunction in Repeat Expansion Diseases: A Review

With the development of the sequencing technique, more than 40 repeat expansion diseases (REDs) have been identified during the past two decades. Moreover, the clinical features of these diseases show some commonality, and the nervous system, especially the cognitive function was affected in part by these diseases. However, the specific cognitive domains impaired in different diseases were inconsistent. Here, we survey literature on the cognitive consequences of the following disorders presenting cognitive dysfunction and summarizing the pathogenic genes, epidemiology, and different domains affected by these diseases. We found that the cognitive domains affected in neuronal intranuclear inclusion disease (NIID) were widespread including the executive function, memory, information processing speed, attention, visuospatial function, and language. Patients with C9ORF72-frontotemporal dementia (FTD) showed impairment in executive function, memory, language, and visuospatial function. While in Huntington's disease (HD), the executive function, memory, and information processing speed were affected, in the fragile X-associated tremor/ataxia syndrome (FXTAS), executive function, memory, information processing speed, and attention were impaired. Moreover, the spinocerebellar ataxias showed broad damage in almost all the cognitive domains except for the relatively intact language ability. Some other diseases with relatively rare clinical data also indicated cognitive dysfunction, such as myotonic dystrophy type 1 (DM1), progressive myoclonus epilepsy (PME), Friedreich ataxia (FRDA), Huntington disease like-2 (HDL2), and cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS). We drew a cognitive function landscape of the related REDs that might provide an aspect for differential diagnosis through cognitive domains and effective non-specific interventions for these diseases.

NOTCH2NLC-related repeat expansion disorders: an expanding group of neurodegenerative disorders

The NOTCH2NLC gene 5' untranslated region (UTR) GGC repeat expansion mutations were identified as a genetic contributor of neuronal intranuclear inclusion disease (NIID) in 2019. Since then, the number of reported cases with NOTCH2NLC GGC repeat expansion in Asian and European populations has increased rapidly, indicating that the expanded mutation not only leads to the onset or progression of the NIID, but also may play an important role in multiple progressive neurological disorders, including Parkinson's disease, essential tremor, multiple system atrophy, Alzheimer's disease, frontotemporal dementia, amyotrophic lateral sclerosis, leukoencephalopathy, and oculopharyngodistal myopathy type 3. Nevertheless, the underlying pathogenic mechanism of the NOTCH2NLC 5' UTR region GGC repeat expansion in these disorders remains largely unknown. This review aims to present recent breakthroughs on this mutation and improve our knowledge of a newly defined spectrum of disease: NOTCH2NLC-related repeat expansion disorder.

Neuronal intranuclear inclusion disease: recognition and update

Neuronal intranuclear inclusion disease (NIID) used to be considered as a neurodegenerative disease. Due to the availability of skin biopsy, the diagnostic efficiency of the disease has been greatly improved. Recently, researchers have successfully identified that the GGC repeat expansion in the 5'-untranslated region of the NOTCH2NLC gene is the causative mutation of NIID. Besides the typical phenotype of brain degeneration, peripheral neuropathy, and autonomic disturbance, the gene mutation is also associated with Alzheimer's disease, frontotemporal dementia, Parkinson's disease, multiple system atrophy, essential tremor, adult leukoencephalopathy, and oculopharyngodistal myopathy. However, it still needs more studies to elucidate whether those variable NIID phenotypes can categorize into NOTCH2NLC repeat expansion related disorders. We update the discovery milestone, clinical phenotype, laboratory examinations, as well as new insight into the diagnosis and treatment of NIID. NIID is an unusual degenerative disease that can involve multiple systems, especially involves the nervous system. Originally, it is named after the pathological characteristics with extensive intranuclear eosinophilic inclusions in central and peripheral nervous tissues, as well as in multiple other organs (Sone et al., Brain 139:3170-3186, 2016). In 2019, several research teams from China and Japan have simultaneously identified that the GGC repeat expansion in the 5'-untranslated region (5'UTR) of the NOTCH2NLC gene is the pathogenic mutation of NIID (Ishiura et al., Nat Genet 51:1222-1232, 2019; Deng et al., J Med Genet 56:758-764, 2019; Sone et al., Nat Genet 51:1215-1221, 2019; Sun et al., Brain 143:222-233, 2020; Tian et al., Am J Hum Genet 105:166-176, 2019). Since then, the number of reported NIID cases is rapidly increasing, and the spectrum of NOTCH2NLC repeat expansion related disorders is significantly broadening (Westenberger and Klein, Brain 143:5-8, 2020). However, the NIID associated with GGC repeat expansion of the NOTCH2NLC gene might be account for a part of patients, probably more frequently in the Asian population, because this expansion has not been identified in an European series with postmortem confirmed NIID cases (Chen et al., Ann Clin Transl Neurol 2020). In order to better understand of the disease, we need to revisit the current state of NIID in combination with the findings based on our experiences in recent years and update the concepts about the clinical and pathogenic progression of NIID.

Neuronal intranuclear inclusion disease with mental abnormality: a case report

Background

Neuronal intranuclear inclusion disease (NIID) is a chronic progressive neurodegenerative disease that is characterized by the discovery of eosinophilic hyaline intranuclear inclusions in the central and peripheral nervous systems and visceral organs. In this paper, we report a case of an adult-onset neuronal intranuclear inclusion disease presenting with mental abnormality in China.

Case presentation

A 62-year-old woman presented with mental abnormality and forgetfulness for 3 months before she was admitted to our hospital. There were prodromal symptoms of fever before she had the mental disorder. Encephalitis was first suspected, and the patient underwent lumbar puncture and brain magnetic resonance imaging (MRI). A cerebrospinal fluid (CSF) examination indicated normal pressure, a normal white blood cell count, and slightly elevated protein and glucose levels. Coxsackie B virus, enterovirus, and cytomegalovirus tests showed normal results. Bacterial culture and Cryptococcus neoformans test results were negative. The contrast-enhanced MRI of the brain was normal. The brain diffusion-weighted imaging (DWI) showed a symmetrically distributed strip-shaped hyperintensity signal of the corticomedullary junction in the bilateral frontal, parietal, and temporal lobes. We considered the diagnosis of the NIID, and therefore, skin biopsy was performed. The electron microscopy revealed that intranuclear inclusions in the nucleus of fibrocytes existed and were composed of filaments.

Conclusions

NIID is a rare neurodegenerative disease with diverse clinical manifestations. In clinical work, when a patient presents with abnormal mental behavior and exhibits hyperintensity signals on DWI images of the corticomedullary junction, it is crucial to consider the diagnosis of NIID.

Neuronal intranuclear inclusion disease: two case report and literature review

Neuronal intranuclear inclusion disease (NIID) is a rare and slowly progressing neurodegenerative disease characterized by the presence of eosinophilic intranuclear inclusions in the nervous system and multiple visceral organs. Sporadic NIID case was more frequently encountered than familial. In our study, we reported two adult-onset NIID patients from a family and described their clinical, imaging, and pathological features. The first patient was a 61-year-old man who only presented with non-specific headache and dizziness; however, Brain MRI with diffusion-weighted images (DWI) sequence showed high-intensity signal involving a small regional portion of corticomedullary junction in the frontal and parietal lobe. The older sister of former, a 64-year-old female, who developed sudden onset of weakness of the right limb was admitted to our neurology department. Compared with the first patient, similar DWI high-intensity signal but more extensive area in the corticomedullary junction was found in her brain MRI examination, also prominent leukoencephalopathy in T2-weighted image. Significantly, skin pathology of the first patient showed that typical inclusions with strongly positive P62 and ubiquitin antibody could be seen in the nuclei of sweat gland cells, adipocytes, and fibroblasts. FMR1 gene was negative. Although rare, adult-onset NIID should be considered when the characteristic radiology changes of high intensity signal involving the corticomedullary junction in the brain DWI sequence was found. In addition, the pathological result of skin biopsy combined with negative genetic testing FMR1 or NOTCH2NLC can contribute to the accurate diagnosis of the disease. This article aims to improve the radiologists' knowledge of NIID by our cases presentation and reviewing literature.

A case of neuronal intranuclear inclusion disease with recurrent vomiting and without apparent DWI abnormality for the first seven years

Neuronal intranuclear inclusion disease (NIID) is a rare, neurodegenerative disorder characterized by the presence of eosinophilic hyaline intranuclear inclusions, which are ubiquitin-positive and p62-positive, in neuronal and somatic cells; this can be observed on skin biopsy. Although patients with NIID present with a variety of symptoms that often make the diagnosis difficult, characteristic high-signal intensity of the corticomedullary junction on diffusion-weighted imaging (DWI) often provides a clue to the diagnosis of NIID. We present a case of NIID in a 57-year-old woman who only had recurrent vomiting for four years, which is uncommon as the presenting symptom; moreover, DWI showed no apparent abnormality until a slightly abnormal intensity lesion appeared at the right frontal corticomedullary junction seven years after the first episode of recurrent vomiting. Skin biopsies revealed multiple p62-positive nuclear inclusions, and genetic test showed GGC repeat expansion in NOTCH2NLC; this may form the genetic basis for NIID. Retrospectively, we found that abnormal cerebellar signals besides the vermis in the fluid attenuation inversion recovery (FLAIR) images were detected early-on in the disease. Periodic vomiting may be the only symptom of NIID in the early stages of the disease, and cerebellar abnormalities in FLAIR may serve as an important finding in the diagnosis of NIID, even in the absence of characteristic clinical symptoms or abnormal DWI signals at the cerebral corticomedullary junction.

Neuronal intranuclear inclusion disease presenting with dysphagia: a report of three cases

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease that is pathologically characterized by the presence of eosinophilic hyaline intranuclear inclusions in neurons, astrocytes, and specific somatic cells. Previously reported cases of NIID displayed various neurological symptoms, including dementia, muscle weakness, ataxia, etc. However, dysphagia associated with NIID have rarely been reported. Here, we report on three cases of NIID with dysphagia. Bolus mastication and transport were impaired in all three cases. Delay of the initiation of pharyngeal swallowing and silent aspiration was observed in two cases. Combined with the brain magnetic resonance imaging (MRI) findings, oropharyngeal dysphagia associated with NIID was suggested to be attributed to diffuse subcortical lesions.

Phenotypic bases of NOTCH2NLC GGC expansion positive neuronal intranuclear inclusion disease in a Southeast Asian cohort

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disorder associated with GGC repeats of >60 to 500 copies in the 5'-untranslated region of NOTCH2NLC. The clinical and genetic characterization of NIID outside of East Asia remains unknown. We identified twelve patients who underwent genetic testing using long-read sequencing or repeat primed polymerase chain reaction. All were positive for a GGC repeat expansion; the median repeat length was 107 (range 92-138). Ten were Chinese and two of Malay ethnicity. Age at onset ranged from 50 to 69 years. Eight (66.7%) patients had dementia, while four (33.3%) patients were oligosymptomatic, without typical NIID symptoms of dementia, Parkinsonism, or muscle weakness. GGA interruptions within the GGC expansion were present in four patients; the number of GGA interruptions was highest (6.71%) in the patient with the earliest age at onset (50 years). Median plasma neurofilament light level was 47.3 pg/mL in seven patients (range 26-380 pg/mL). The highest level (380 pg/mL) was found in one patient who experienced an encephalitic episode. Overall, we describe a cohort of genetically confirmed NIID patients from Southeast Asia and provide further information that the presence of GGA interruptions within GGC repeat expansions may serve as a potential genetic modifier in NIID.

Clinical and pathological features in adult-onset NIID patients with cortical enhancement

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in multiple organs. On conventional MRI, high signals on diffused weight image (DWI) along the corticomedullary junction have demonstrated great diagnostic values for adult-onset NIID. However, changes of contrast MRI in the acute period of the encephalopathy-like episode have rarely been investigated.

METHODS

Patients with enhanced lesions were retrieved in our database including 35 patients with adult-onset NIID between October 2017 and December 2019. Conventional and contrast MRI were conducted in all patients. Standard procedures of skin biopsy were performed in all patients. Repeat-primed PCR and amplicon length PCR were used to screen the GGC expansion in the 5'UTR of the NOTCH2NLC gene.

RESULTS

Four of 35 patients (11.4%) were identified to have a cortical enhancement in this study. The enhanced lesions were selectively spread along the surface of posterior cortex and were clinically associated with encephalopathy-like episodes. These patients had a younger age of onset, shorter duration of disease, and a higher incidence of a headache than those without enhancement. Typical p62-postive intranuclear inclusions were observed in all patients, while patient 1 simultaneously had many nuclei full of abnormal substance immunopositive to p62, as well as short-curly filament materials on electron microscopy. All patients were identified to have GGC repeat expansion in the NOTCH2NLC gene.

CONCLUSION

Post-contrast MRI should be routinely performed in the adult-onset NIID patients. Some patients with adult-onset NIID showed cortical enhancement and edema along the surface of posterior cortex, indicating that dehydrate and anti-inflammatory drugs might be potential therapies for these patients.

Multiple reversible encephalitic attacks: a rare manifestation of neuronal intranuclear inclusion disease

Background

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative condition characterized by the loss of neurons and the presence of eosinophilic nuclear inclusions in the central and peripheral nervous system, skin and visceral organs. In this paper, we present a case of NIID with recurrent encephalitic attacks that remained stable and nonprogressive for seven years; no such case has previously been reported.

Case presentation

A 63-year-old female was hospitalized due to light-headedness, vomiting, unstable gait and cognitive impairment. Seven years prior, she had experienced an episode of light-headedness, central facial paralysis, unstable gait, aphasia, nausea, vomiting and loss of consciousness. She regained consciousness within 12 h, and her other symptoms were completely resolved within one week. During the present hospitalization, a brain magnetic resonance imaging (MRI) examination detected high signal intensity on diffusion-weighted imaging (DWI) of the bilateral frontal grey matter–white matter junction. We reviewed the patient’s previous MRI results and found that she had also had high signal intensity on DWI of the bilateral frontal grey matter–white matter junction seven years prior. In the intervening seven years, the high signal intensity in the frontal lobes had spread along the grey matter–white matter junction, but the deep white matter remained unaffected. Skin biopsy was performed, and intranuclear inclusions were found in adipocytes, fibroblasts and sweat gland cells. GGC repeat expansions in the NOTCH2NLC (Notch 2 N-terminal like C) gene confirmed the diagnosis of NIID. She received supportive treatment such as nutrition support therapy and vitamin B and C supplementation, as well as symptomatic treatment during hospitalization. The patient’s symptoms were completely relieved within one week.

Conclusion

This is a detailed report of a case of NIID with multiple reversible encephalitic attacks, diagnosed by clinical symptoms, intranuclear inclusions, characteristic DWI signals, and genetic tests.

Adult-onset neuronal intranuclear inclusion disease presenting with typical MRI changes

BACKGROUND

This study aims to analyze the clinical, imaging, electrophysiological, and dermatopathological features of a patient with adult-onset neuronal intranuclear inclusion disease (NIID) and to explore the diagnostic methods of adult-onset NIID.

CASE PRESENTATION

We here report a 63-year-old male with recurrent acute encephalopathy syndrome and autonomic nervous system damage syndrome characterized by sexual dysfunction and urinary and fecal dysfunction. Cranial diffusion-weighted magnetic resonance imaging (DWI) demonstrated symmetrically distributed strip-shaped high-intensity signal in bilateral fronto-occipital-parietal cortical-medullary junction. Electrophysiological test revealed that the main site of injury was myelin sheath in both motor and sensory nerves. Skin biopsy revealed eosinophilic spherical inclusion bodies in the nucleus of sweat gland epithelial cells.

CONCLUSION

This case suggests that adult NIID is a chronic neurodegenerative disease with high clinical heterogeneity. Subcortical strip-shaped high-intensity signal on DWI has high diagnostic significance. Eosinophilic intranuclear inclusion bodies detected by skin biopsy contribute to diagnosis.

A long time radiological follow-up of neuronal intranuclear inclusion disease: Two case reports

RATIONALE

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease identified with diffusion-weighted imaging (DWI) high-intensity signal in magnetic resonance imaging (MRI). The disappearance of the abnormal signal is extremely rare.

PATIENT CONCERNS

We present the 2 cases of patients, both of them were suffering from heterogeneous symptoms. We followed up one of them for 7 years with MRI, the other accepted comprehensive MRI inspections.

DIAGNOSES

DWI high-intensity signal were observed along the corticomedullary junction in MRI plan scan of heads of 2 patients. For patient 1, the hyperintensities in DWI and fluid-attenuated inversion recovery (FLAIR) images in the occipital lobe disappeared 5 years after onset. Based on the biopsy, patient 1 and 2 were diagnosed as NIID.

INTERVENTIONS

There have not effective medication and prevention for NIID. Patient 1 and 2 received symptomatic treatment.

OUTCOMES

Up until now, the patients are alive but the disease is progressing.

LESSONS

DWI high-intensity signal is a strong clue for the diagnosis of NIID, but the rare case of the disappearance of it may lead to misdiagnosis.