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

Encephalitis-like episodes with cortical edema and enhancement in patients with neuronal intranuclear inclusion disease

OBJECTIVES

Neuronal intranuclear inclusion disease (NIID) exhibited significant clinical heterogeneities. However, the clinical features, radiographic changes, and prognosis of patients with encephalitis-like NIID have yet to be systematically elucidated.

METHODS

Clinical data including medical history, physical examination, and laboratory examinations were collected and analyzed. Skin and sural nerve biopsies were conducted on the patient. Repeat-primed PCR (RP-PCR) and fluorescence amplicon length PCR (AL-PCR) were used to detect the expansion of CGG repeat. We also reviewed the clinical and genetic data of NIID patients with cortical enhancement.

RESULTS

A 54-year-old woman presented with encephalitis-like NIID, characterized by severe headache and agitative psychiatric symptoms. The brain MRI showed cortical swelling in the temporo-occipital lobes and significant enhancement of the cortical surface and dura, but without hyperintensities along the corticomedullary junction on diffusion-weighted image (DWI). A biopsy of the sural nerve revealed a demyelinating pathological change. The intranuclear inclusions were detected in nerve and skin tissues using the p62 antibody and electron microscopy. RP-PCR and AL-PCR unveiled the pathogenic expansion of CGG repeats in the NOTCH2NLC gene. A review of the literature indicated that nine out of the 16 patients with cortical lesions and linear enhancement exhibited encephalitis-like NIID.

CONCLUSION

This study indicated that patients with encephalitis-like NIID typically exhibited headache and excitatory psychiatric symptoms, often accompanied by cortical edema and enhancement of posterior lobes, and responded well to glucocorticoid treatment. Furthermore, some patients may not exhibit hyperintensities along the corticomedullary junction on DWI, potentially leading to misdiagnosis.

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.

Review of Phenotypic Heterogeneity of Neuronal Intranuclear Inclusion Disease and NOTCH2NLC-Related GGC Repeat Expansion Disorders

Neuronal intranuclear inclusion disease (NIID) is an underdiagnosed neurodegenerative disorder caused by pathogenic GGC expansions in NOTCH2NLC. However, an increasing number of reports of NOTCH2NLC GGC expansions in patients with Alzheimer disease, essential tremor, Parkinson disease, amyotrophic lateral sclerosis, and oculopharyngodistal myopathy have led to the proposal of a new concept known as NOTCH2NLC-related GGC repeat expansion disorders (NREDs). The majority of studies have mainly focused on screening for NOTCH2NLC GGC repeat variation in populations previously diagnosed with the associated disease, subsequently presenting it as a novel causative gene for the condition. These studies appear to be clinically relevant but do have their limitations because they may incorrectly regard the lack of MRI abnormalities as an exclusion criterion for NIID or overlook concomitant clinical presentations not typically observed in the associated diseases. Besides, in many instances within these reports, patients lack pathologic evidence or undergo long-term follow-up to conclusively rule out NIID. In this review, we will systematically review the research on NOTCH2NLC 5' untranslated region GGC repeat expansions and their association with related neurologic disorders, explaining the limitations of the relevant reports. Furthermore, we will integrate subsequent studies to further demonstrate that these patients actually experienced distinct clinical phenotypes of NIID.

Case report: Neuronal intranuclear inclusion disease initially mimicking reversible cerebral vasoconstriction syndrome: serial neuroimaging findings during an 11-year follow-up

Neuronal intranuclear inclusion disease (NIID) is a rare, progressive neurodegenerative disorder known for its diverse clinical manifestations. Although episodic neurogenic events can be associated with NIID, no reported cases have demonstrated concurrent clinical features or MRI findings resembling reversible cerebral vasoconstriction syndrome (RCVS). Here, we present the inaugural case of an adult-onset NIID patient who initially displayed symptoms reminiscent of RCVS. The 59-year-old male patient's initial presentation included a thunderclap headache, right visual field deficit, and confusion. Although his brain MRI appeared normal, MR angiography unveiled left posterior cerebral artery occlusion, subsequently followed by recanalization, culminating in an RCVS diagnosis. Over an 11-year period, the patient encountered 10 additional episodes, each escalating in duration and intensity, accompanied by seizures. Simultaneously, cognitive impairment progressed. Genetic testing for NIID revealed an abnormal expansion of GGC repeats in NOTCH2NLC, with a count of 115 (normal range, <60), and this patient was diagnosed with NIID. Our report highlights that NIID can clinically and radiologically mimic RCVS. Therefore, in the differential diagnosis of RCVS, particularly in cases with atypical features or recurrent episodes, consideration of NIID is warranted. Additionally, the longitudinal neuroimaging findings provided the course of NIID over an 11-year follow-up period.

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.

Adult-onset neuronal nuclear inclusion disease presenting with mental and behavioral disorders: A case report and literature review

Neuronal nuclear inclusion disease (NIID) is a rare and chronic progressive neurological degenerative disease. We presented a 68-year-old man with paroxysmal orientation disorder 1 year prior, mental and behavioral disorders for 2 days, and confirmed the diagnosis of NIID with skin biopsy. We suggest that patients with atypical clinical symptoms showed characteristic high signal in the dermatomedullary junction on DWI; NIID should be considered.

Unraveling rare form of adult-onset NIID by characteristic brain MRI features: A single-center retrospective review

Adult-onset neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder with high clinical heterogeneity. Previous studies indicated that the high-intensity signals in the corticomedullary junction on diffusion-weighted imaging (DWI) on brain MRI, known as the "ribbon sign," could serve as a strong diagnostic clue. Here we used the explorative approach to study the undiagnosed rate of adult-onset NIID in a single center in China via searching for the ribbon sign in picture archive and communication system (PACS) and report the clinical and radiological features of initially undiagnosed NIID patients. Consecutive brain MRI of 21,563 adult individuals (≥18 years) in the PACS database in 2019 from a tertiary hospital were reviewed. Of them, 4,130 were screened out using the keywords "leukoencephalopathy" and "white matter demyelination." Next, all 4,130 images were read by four neurologists. The images with the suspected ribbon sign were reanalyzed by two neuroradiologists. Those with the ribbon sign but without previously diagnosed NIID were invited for skin biopsy and/or genetic testing for diagnostic confirmation. The clinical features of all NIID patients were retrospectively reviewed. Five patients with high-intensity in the corticomedullary junction on DWI were enrolled. Three patients were previously diagnosed with NIID confirmed by genetic or pathological findings and presented with episodic encephalopathy or cognitive impairment. The other two patients were initially diagnosed with limb-girdle muscular dystrophy (LGMD) with rimmed vacuoles (RVs) and normal pressure hydrocephalus (NPH) in one each. Genetic analysis demonstrated GGC repeat expansion in the NOTCH2NLC gene of both, and skin biopsy of the first patient showed the presence of intranuclear hyaline inclusion bodies. Thus, five of the 21,563 adult patients (≥18 years) were diagnosed with NIID. The distinctive subcortical high-intensity signal on DWI was distributed extensively throughout the lobes, corpus callosum, basal ganglia, and brainstem. In addition, T2-weighted imaging revealed white matter hyperintensity of Fazekas grade 2 or 3, atrophy, and ventricular dilation. Distinctive DWI hyperintensity in the junction between the gray and white matter can help identify atypical NIID cases. Our findings highly suggest that neurologists and radiologists should recognize the characteristic neuroimaging pattern of NIID.

Clinical-neuroimaging-pathological relationship analysis of adult onset Neuronal Intranuclear Inclusion Disease (NIID)

BACKGROUND

Neuronal Intranuclear Inclusion Disease (NIID) is a degenerative disease with heterogeneous clinical manifestations. We aim to analysis the relationship between clinical manifestations, neuroimaging and skin pathology in a Chinese NIID cohort.

METHODS

Patients were recruited from a Chinese cohort. Detail clinical information were collected. Visual rating scale was used for evaluation of neuroimaging. The relationship between clinical presentations and neuroimaging, as well as skin pathology was statistically analyzed.

RESULTS

Thirty-two patients were recruited. The average onset age was 54.3 y/o. 28.1% had positive family history. Dementia, autonomic nervous system dysfunction, episodic attacks were three main presentations. CSF analysis including Aβ₄₂ and tau level was almost normal. The most frequently involved on MRI was periventricular white matter (100%), frontal subcortical and deep white matter (96.6%), corpus callosum (93.1%) and external capsule (72.4%). Corticomedullary junction DWI high intensity was found in 87.1% patients. Frontal and external capsule DWI high intensity connected to form a "kite-like" specific image. Severity of dementia was significantly related to leukoencephalopathy (r = 0.465, p = 0.0254), but not cortical atrophy and ventricular enlargement. Grey matter lesions were significantly associated with encephalopathy like attacks (p = 0.00077) but not stroke like attacks. The density of intranuclear inclusions in skin biopsy was not associated with disease duration, severity of leukoencephalopathy and dementia.

CONCLUSIONS

Specific distribution of leukoencephalopathy and DWI high intensity were indicative. Leukoencephalopathy and subcortical mechanism were critical in pathogenesis of NIID. Irrelevant of inclusion density and clinical map suggested the direct pathogenic factor need further investigation.

Typical imaging manifestation of neuronal intranuclear inclusion disease in a man with unsteady gait: A case report

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is a rare neurological degenerative disorder with diverse manifestations and inadequate awareness. Only a few cases of NIID have been reported, and typical imaging findings can provide certain clues for the diagnosis of the disease. Furthermore, skin biopsy and genetic testing are important to confirm the diagnosis.

CASE SUMMARY

An 84-year-old man presented to the Neurology Department of our hospital complaining of a progressive course of cognitive impairment and unsteady gait for 2 years. The symptoms gradually progressed and affected his daily life. The patient was initially diagnosed with Parkinson’s disease and vascular dementia. The patient did not respond to conventional treatment, such as dopasehydrazine. Therefore, magnetic resonance imaging (MRI) was performed. Based on the imaging findings, we suspected an NIID diagnosis. During the 3-year follow-up in our hospital, his clinical symptoms gradually progressed, and imaging findings became more significant. A high signal intensity along the corticomedullary junction persisted on MRI. Gene testing and skin biopsy were recommended in our hospital; however, the patient refused these procedures. NIID was also considered when he went to a superior hospital in Shanghai. The patient eventually agreed to undergo gene testing. This revealed abnormal GGC repeat expansions in the NOTCH2NLC gene.

CONCLUSION

The clinical manifestations of NIID are diverse. Patients with clinical manifestations similar to Parkinson’s disease and dementia may have NIID.

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.

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.

Neurodegenerative diseases associated with non-coding CGG tandem repeat expansions

Non-coding CGG repeat expansions cause multiple neurodegenerative disorders, including fragile X-associated tremor/ataxia syndrome, neuronal intranuclear inclusion disease, oculopharyngeal myopathy with leukodystrophy, and oculopharyngodistal myopathy. The underlying genetic causes of several of these diseases have been identified only in the past 2-3 years. These expansion disorders have substantial overlapping clinical, neuroimaging and histopathological features. The shared features suggest common mechanisms that could have implications for the development of therapies for this group of diseases - similar therapeutic strategies or drugs may be effective for various neurodegenerative disorders induced by non-coding CGG expansions. In this Review, we provide an overview of clinical and pathological features of these CGG repeat expansion diseases and consider the likely pathological mechanisms, including RNA toxicity, CGG repeat-associated non-AUG-initiated translation, protein aggregation and mitochondrial impairment. We then discuss future research needed to improve the identification and diagnosis of CGG repeat expansion diseases, to improve modelling of these diseases and to understand their pathogenesis. We also consider possible therapeutic strategies. Finally, we propose that CGG repeat expansion diseases may represent manifestations of a single underlying neuromyodegenerative syndrome in which different organs are affected to different extents depending on the gene location of the repeat expansion.

[A case of neuronal intranuclear inclusion disease with serial MRI changes observed from before onset of forgetfulness]

A 70-year-old woman presented with a 6-year history of cognitive dysfunction, neurogenic bladder, constipation and recurrent vomiting, and gradual worsening of symptoms. At the first admission to our department, she was also found to have hepatic encephalopathy due to intrahepatic portosystemic shunt. Head MRI revealed abnormal signal intensity at the corticomedullary junction, the splenium of the corpus callosum, and bilateral middle cerebellar peduncles on DWI. She was diagnosed with intranuclear inclusion disease (NIID) based on skin biopsy and genetic testing of NOTCH2NLC. In a retrospective review of serial head MRI findings for ten years, abnormal signal intensity at the corticomedullary junction and the splenium of the corpus callosum on MRI existed prior to the onset of cognitive dysfunction, and expanded gradually. For early diagnosis of NIID, it is important to focus not only on the characteristic high signal intensity at the corticomedullary junction, but also on the signal at the splenium of the corpus callosum from the early stage.

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.

Case Report: Neuronal Intranuclear Inclusion Disease With Oromandibular Dystonia Onset

Background: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease. Because of variable clinical manifestations, NIID was often misdiagnosed. According to published case reports, the common clinical manifestations of NIID include dementia, muscle weakness, autonomic impairment, sensory disturbance, rigidity, ataxia convulsions, etc. However, no cases of oromandibular dystonia were mentioned. Case Presentation: We describe a case of a 58-year-old woman presenting with mouth involuntary chewing initially. She started to show hand tremors, ataxia, and walking instability until 2 years later. Diffusion-weighted imaging showed high intensity signal along the corticomedullary junction. Fluid-attenuated inversion recovery imaging showed white matter hyperintensity. Electromyography (EMG) indicated peripheral nerve degeneration. Neuropsychological testing showed memory loss. Finally, skin biopsy and GGC repeat expansions in the NOTCH2NLC (Notch 2 N-terminal like C) gene confirmed the diagnosis of NIID. Conclusion: This case demonstrated that oromandibular dystonia could be the first symptom of NIID. This case report provides new characteristics of NIID and broadens its clinical spectrum.

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.

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.

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.

Repeat expansion scanning of the NOTCH2NLC gene in patients with multiple system atrophy

OBJECTIVE

Trinucleotide GGC repeat expansion in the 5'UTR of the NOTCH2NLC gene has been recognized as the pathogenesis of neuronal intranuclear inclusion disease (NIID). Previous studies have described that some NIID patients showed clinical and pathological similarities with multiple system atrophy (MSA). This study aimed to address the possibility that GGC repeat expansion in NOTCH2NLC might be associated with some cases diagnosed as MSA.

METHODS

A total of 189 patients with probable or possible MSA were recruited to screen for GGC repeat expansion in NOTCH2NLC by repeat-primed PCR (RP-PCR). In addition, long-read sequencing (LRS) was performed for all patients with RP-PCR-positive expansion, five patients with RP-PCR-negative expansion, and five controls on the Nanopore platform. Skin biopsies were performed on two patients with GGC expansion.

RESULTS

Five of 189 patients (2.6%) were found to have GGC expansion in NOTCH2NLC. LRS results identified that the five patients had GGC expansion between 101 and 266, but five patients with RP-PCR-negative expansion and five controls had GGC expansion between 8 and 29. Besides the typical symptoms and signs of MSA, patients with GGC expansion might have longer disease duration, severe urinary retention, and prominent cognitive impairment. In the skin samples from the patients with GGC expansion, typical p62-postive but alpha-synuclein-negative intranuclear inclusions were found in fibroblasts, adipocyte and ductal epithelial cells of sweat glands.

CONCLUSION

Trinucleotide GGC repeat expansion in NOTCH2NLC could be observed in patients with clinically diagnosed MSA. Adult-onset NIID should be considered as a differential diagnosis of MSA.

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.

Interrelated Pathogenesis? Neuronal Intranuclear Inclusion Disease Combining With Hemiplegic Migraine

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is considered a heterogeneous disease because of its highly variable clinical manifestations. To date, there are no reports of NIID patients presenting with hemiplegic migraine (HM)-like headache, or of HM and NIID co-occurring as comorbidity, and the connection between these 2 seemingly unrelated clinical conditions has yet to be established.

METHOD

We present a patient with NIID who was previously diagnosed with HM. To determine the pathogenesis of HM in this NIID patient, we systematically reviewed published NIID and HM cases and cataloged them based on their clinical manifestations.

RESULT

The clinical manifestations of NIID is highly various; however, there is no case reported to date that shows HM-like symptoms or cerebral edema. All documented symptomatic HM cases show vascular dysfunction to various degrees, but none of them has been shown to be correlated with NIID.

CONCLUSION

Our patient is the first documented case in which HM and NIID occur simultaneously. Vascular dysfunctions that cause cerebral hypoperfusion and glucose hypometabolism, two of the dominant causes of symptomatic HM, may be associated with the accumulation of eosinophilic hyaline inclusions that cause NIID. However, the existence of inclusions may also alter neuronal behavior and indirectly cause cerebral hypoperfusion and glucose hypometabolism. Further research and observations are needed to examine the relationship between HM and NIID.

Long-read sequencing identified repeat expansions in the 5'UTR of the NOTCH2NLC gene from Chinese patients with neuronal intranuclear inclusion disease

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is a heterogenous neurodegenerative disorder named after its pathological features. It has long been considered a disease of genetic origin. Recently, the GGC repeated expansion in the 5'-untranslated region (5'UTR) of the NOTCH2NLC gene has been found in adult-onset NIID in Japanese individuals. This study was aimed to investigate the causative mutations of NIID in Chinese patients.

METHODS

Fifteen patients with NIID were identified from five academic neurological centres. Biopsied skin samples were analysed by histological staining, immunostaining and electron microscopic observation. Whole-genome sequencing (WGS) and long-read sequencing (LRS) were initially performed in three patients with NIID. Repeat-primed PCR was conducted to confirm the genetic variations in the three patients and the other 12 cases.

RESULTS

Our patients included 14 adult-onset patients and 1 juvenile-onset patient characterised by degeneration of multiple nervous systems. All patients were identified with intranuclear inclusions in the nuclei of fibroblasts, fat cells and ductal epithelial cells of sweat glands. The WGS failed to find any likely pathogenic variations for NIID. The LRS successfully identified that three patients with adult-onset NIID showed abnormalities of GGC expansion in 5'UTR of the NOTCH2NLC gene. The GGC repeated expansion was further confirmed by repeat-primed PCR in seven familial cases and eight sporadic cases.

CONCLUSION

Our findings provided evidence that confirmed the GGC repeated expansion in the 5'UTR of the NOTCH2NLC gene is associated with the pathogenesis of NIID. Additionally, the GGC expansion was not only responsible for adult-onset patients, but also responsible for juvenile-onset patients.

Identifying patients with neuronal intranuclear inclusion disease in Singapore using characteristic diffusion-weighted MR images

PURPOSE

Adult-onset neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder described mainly in the Japanese population, with characteristic DWI abnormalities at the junction between gray and white matter. We identify possible cases of NIID in the picture archive and communication system (PACS) of a tertiary neurological referral hospital in Singapore and describe their radiological features.

METHODS

The neuroradiology imaging database was reviewed using keyword search of radiological reports to identify patients who had "subcortical U fibre" abnormalities on DWI. MRI were retrospectively reviewed, and those fulfilling inclusion criteria were invited for skin biopsy to detect nuclear inclusions by light and electron microscopy.

RESULTS

Twelve Chinese patients (nine female; median age 70.5 years) were enrolled. Seven patients were being assessed for dementia and five for other neurological indications. In all patients, DWI showed distinctive subcortical high signal with increased average apparent diffusion coefficient (ADC), involving frontal, parietal, and temporal more than occipital lobes; the corpus callosum and external capsule were affected in some patients. On T2-weighted images, cerebral and cerebellar atrophy and white matter hyperintensity of Fazekas grade 2 and above were seen in all patients. Three patients underwent skin biopsy; all were positive for intranuclear hyaline inclusion bodies on either p62 staining or electron microscopy, which are pathognomonic for NIID.

CONCLUSION

Previously undiagnosed patients with NIID can be identified by searching for abnormalities at the junction between gray and white matter on DWI in PACS and subsequently confirmed by skin biopsy. Radiologists should recognize the distinctive neuroimaging pattern of this dementing disease.