A Case Report of Neuronal Intranuclear Inclusion Disease Presenting With Recurrent Migraine-Like Attacks and Cerebral Edema: A Mimicker of MELAS

Spatial and Temporal Distribution of White Matter Lesions in NOTCH2NLC-Related Neuronal Intranuclear Inclusion Disease

BACKGROUND AND OBJECTIVES

NOTCH2NLC-related neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease with characteristic white matter lesions (WMLs) visible on MRI. However, the distribution of WMLs and their clinical correlations remain poorly understood in NIID. This study aims to investigate the spatial and temporal distribution of WMLs in the brain of patients with NOTCH2NLC-related NIID.

METHODS

We retrospectively evaluated patients diagnosed with NOTCH2NLC-related NIID in Zhongshan Hospital, Fudan University. Detailed clinical information, including retrospective MRI data, was collected. Spatial distribution of WMLs with fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) hyperintensities was quantified, and the relationship between WML distribution and clinical presentations was analyzed by the Fisher exact test. The volume of whole-brain WMLs was quantified using ITK-SNAP software. The relationship between phenotypes and WML volume was analyzed by the Student t test, Mann-Whitney test, or correlation analysis. WML development patterns were summarized based on the longitudinal observation of MRI characteristics.

RESULTS

This study evaluated 45 patients with NOTCH2NLC-related NIID, with a median age of 66 years (range 55-82 years) and consisting of 30 women. Patients exhibited diverse clinical manifestations, with cognitive decline, autonomic dysfunction, and tremor being the 3 most frequent presentations. Severe WMLs were observed in 43 patients, with FLAIR hyperintensities predominantly in the corona radiata, centrum semiovale, and other brain regions. The presence of DWI hyperintensities was common in the corticomedullary junction (91.1%) and corpus callosum (53.3%). Analysis showed significant correlations between FLAIR hyperintensity volume and both age (r = 0.312, p = 0.042) and Montreal Cognitive Assessment scores (r = -0.371, p = 0.048). Longitudinal MRI retrospection in 7 patients over an average of 9.6 ± 2.9 years revealed 3 gradually progressed WML patterns: periventricular-subcortical, periventricular-dominant, and corticomedullary junction-dominant. In addition, 3 patients experienced rapid WML expansion associated with mitochondrial encephalomyopathy with lactic acidosis and stroke (MELAS)-like episodes.

DISCUSSION

Our analysis revealed the radiologic characteristics and spatial distribution of WMLs and demonstrated significant correlations between FLAIR hyperintensity volume and age/cognitive levels in NIID. Long-term retrospection revealed 3 types of gradual WML expansion patterns while MELAS-like episodes cause rapid WML aggravation. Although results should be confirmed in a larger cohort, these insights enhance understanding of NIID's clinical-radiologic relationships and pathogenesis.

Case report: 10-year follow-up of a patient with neuronal intranuclear inclusion disease and a literature review

Neuronal intranuclear inclusion disease (NIID) is a rare, progressive neurodegenerative disease with variable clinical manifestations. High signals on diffusion-weighted imaging (DWI) along the corticomedullary junction (CMJ) are a specific feature of NIID. Only a few reports have observed patients for a long period and demonstrated a relationship between magnetic resonance imaging (MRI) features and clinical manifestations. Herein, we present a case of a patient with NIID who underwent a 10-year brain MRI follow-up study and a literature review. A 78-year-old woman presented with severe cognitive dysfunction and disturbances of consciousness. Her brain MRI DWI signal intensity gradually increased over 10 years, and her cognitive function progressively declined. The DWI signal changes were related to the clinical manifestations in this case. In the literature review, we analyzed patients with NIID by classifying them into subgroups and found that high signals on fluid-attenuated inversion recovery (FLAIR) and DWI were related to dementia. Although high DWI signals along the CMJ are specific to NIID, many patients also show high signals on FLAIR in the deep subcortical white matter. In our literature review, dementia could have some correlation to MRI signals. In our case with longitudinal follow up, the DWI high intensity signal expansion could have correlation to cognitive decline. We found dementia and the dementia progression may have some relation to expansion of DWI with intensity signals from the CMJ to the deep subcortical white matter. Our report highlights that DWI signal changes are strongly correlated with the clinical manifestations of NIID.

Episodic headaches and cognitive decline: uncovering neuronal intranuclear inclusion disease in a young patient

A male in his 20s presented with episodic headache and subsequently developed episodic unilateral weakness, dysphasia and encephalopathy. These paroxysmal episodes persisted over time with the development of background cognitive impairment and neuropsychiatric symptoms. MRI surveillance demonstrated progressive T2 hyperintensity with focal cortical oedema correlating to symptoms observed during clinical episodes.Genetic testing for hemiplegic migraine, mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes along with exome sequencing and high-density microarray did not reveal a cause for the clinical phenotype. The diagnosis of neuronal intranuclear inclusion disease (NIID) was confirmed by the detection of large guanine-guanine-cytosine repeat expansion in the Notch 2 N-terminal-like C gene using long-read nanopore sequencing.NIID is a genetic neurodegenerative disease, more common in Asian populations. It can present with a varied neurological phenotype, including an episodic event type that can mimic hemiplegic migraine and encephalopathy. This case report highlights the importance of considering NIID in cases of paroxysmal headache and encephalopathy.

Stroke-like episodes in patients with adult-onset neuronal intranuclear inclusion disease and patients with late-onset MELAS: A comparative study

OBJECTIVE

To delineate the characteristics of stroke-like episodes (SLEs) in patients with adult-onset neuronal intranuclear inclusion disease (NIID) and to compare these characteristics with those of patients with MELAS.

METHODS

Twenty-three adult-onset NIID patients who presented with acute or subacute brain disorders and 13 late-onset MELAS patients were enrolled in the study. Patients with NIID were categorized into the SLEs group and the encephalopathy-like episodes (ELEs) group according to the associated stroke-like lesions (SLLs) findings. Clinical characteristics were compared between the SLEs group and the ELEs group among NIID patients and between NIID patients with SLEs and MELAS patients.

RESULTS

Eleven (47.8%) NIID patients who manifested acute or subacute brain disorders had detectable associated SLLs and were categorized into SLEs group. SLEs patients were more likely to report fever, headache, and seizures instead of sleep disorders than ELEs patients. Four (36.4%) NIID patients with SLEs absence of diagnostic or suggestive NIID imaging features. The clinical manifestations, laboratory test results, and neuroimaging and muscle biopsy histological features of NIID patients with SLEs majorly overlapped with those of late-onset MELAS patients. Older age at the first SLE (OR [95% CI], 1.203 [1.045-1.384]), symptoms of movement disorders on admission (OR [95% CI], 9.625 [1.378-67.246]), and white matter hyperintensity in corpus callosum (OR [95% CI], 16.00 [1.542-166.46]) associated with the NIID diagnosis in patients with SLEs.

INTERPRETATION

NIID patients with SLEs exhibit evident features of mitochondrial disorders. Interventions aimed at mitochondrial dysfunction might be a promising therapeutic approach for treating this disease.

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.

Prevalence and Characterization of NOTCH2NLC GGC Repeat Expansions in Koreans: From a Hospital Cohort Analysis to a Population-Wide Study

Background and Objectives

GGC repeat expansions in the NOTCH2NLC gene are associated with a broad spectrum of progressive neurologic disorders, notably, neuronal intranuclear inclusion disease (NIID). We aimed to investigate the population-wide prevalence and clinical manifestations of NOTCH2NLC-related disorders in Koreans.

Methods

We conducted a study using 2 different cohorts from the Korean population. Patients with available brain MRI scans from Seoul National University Hospital (SNUH) were thoroughly reviewed, and NIID-suspected patients presenting the zigzag edging signs underwent genetic evaluation for NOTCH2NLC repeats by Cas9-mediated nanopore sequencing. In addition, we analyzed whole-genome sequencing data from 3,887 individuals in the Korea Biobank cohort to estimate the distribution of the repeat counts in Koreans and to identify putative patients with expanded alleles and neurologic phenotypes.

Results

In the SNUH cohort, among 90 adult-onset leukoencephalopathy patients with unknown etiologies, we found 20 patients with zigzag edging signs. Except for 2 diagnosed with fragile X-associated tremor/ataxia syndrome and 2 with unavailable samples, all 16 patients (17.8%) were diagnosed with NIID (repeat range: 87-217). By analyzing the Korea Biobank cohort, we estimated the distribution of repeat counts and threshold (>64) for Koreans, identifying 6 potential patients with NIID. Furthermore, long-read sequencing enabled the elucidation of transmission and epigenetic patterns of NOTCH2NLC repeats within a family affected by pediatric-onset NIID.

Discussion

This study presents the population-wide distribution of NOTCH2NLC repeats and the estimated prevalence of NIID in Koreans, providing valuable insights into the association between repeat counts and disease manifestations in diverse neurologic disorders.

Reversible encephalitis-like episodes in fragile X-associated tremor/ataxia syndrome: a case report

BACKGROUND

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder caused by CGG repeat expansion of FMR1 gene. Both FXTAS and neuronal intranuclear inclusion disease (NIID) belong to polyglycine diseases and present similar clinical, radiological, and pathological features, making it difficult to distinguish these diseases. Reversible encephalitis-like attacks are often observed in NIID. It is unclear whether they are presented in FXTAS and can be used for differential diagnosis of NIID and FXTAS.

CASE PRESENTATION

A 63-year-old Chinese male with late-onset gait disturbance, cognitive decline, and reversible attacks of fever, consciousness impairment, dizziness, vomiting, and urinary incontinence underwent neurological assessment and examinations, including laboratory tests, electroencephalogram test, imaging, skin biopsy, and genetic test. Brain MRI showed T2 hyperintensities in middle cerebellar peduncle and cerebrum, in addition to cerebellar atrophy and DWI hyperintensities along the corticomedullary junction. Lesions in the brainstem were observed. Skin biopsy showed p62-positive intranuclear inclusions. The possibilities of hypoglycemia, lactic acidosis, epileptic seizures, and cerebrovascular attacks were excluded. Genetic analysis revealed CGG repeat expansion in FMR1 gene, and the number of repeats was 111. The patient was finally diagnosed as FXTAS. He received supportive treatment as well as symptomatic treatment during hospitalization. His encephalitic symptoms were completely relieved within one week.

CONCLUSIONS

This is a detailed report of a case of FXTAS with reversible encephalitis-like episodes. This report provides new information for the possible and rare features of FXTAS, highlighting that encephalitis-like episodes are common in polyglycine diseases and unable to be used for differential diagnosis.

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.

A case report of neuronal intranuclear inclusion disease with paroxysmal peripheral neuropathy-like onset lacking typical signs on diffusion-weighted imaging

Background

Neuronal intranuclear inclusion disease (NIID) is a slowly progressive neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions and the GGC repeats in the 5'-untranslated region of NOTCH2NLC. The prevalent presence of high-intensity signal along the corticomedullary junction on diffusion-weighted imaging (DWI) helps to recognize this heterogeneous disease despite of highly variable clinical manifestations. However, patients without the typical sign on DWI are often misdiagnosed. Besides, there are no reports of NIID patients presenting with paroxysmal peripheral neuropathy-like onset to date.

Case presentation

We present a patient with NIID who suffered recurrent transient numbness in arms for 17 months. Magnetic resonance imaging (MRI) showed diffuse, bilateral white matter lesions without typical subcortical DWI signals. Electrophysiological studies revealed mixed demyelinating and axonal sensorimotor polyneuropathies involving four extremities. After excluding differential diagnosis of peripheral neuropathy through body fluid tests and a sural nerve biopsy, NIID was confirmed by a skin biopsy and the genetic analysis of NOTCH2NLC.

Conclusion

This case innovatively demonstrates that NIID could manifest as paroxysmal peripheral neuropathy-like onset, and addresses the electrophysiological characteristics of NIID in depth. We broaden the clinical spectrum of NIID and provide new insights into its differential diagnosis from the perspective of peripheral neuropathy.

Diffuse Cortical Injury and Basal Ganglia High Signals on Diffusion-Weighted Imaging in Neuronal Intranuclear Inclusion Disease

This case report describes a patient who was admitted to the hospital owing to sudden-onset involuntary and irregular movements of his left limbs.

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.