Clinical and mechanism advances of neuronal intranuclear inclusion disease

Spontaneous distal middle cerebral artery aneurysm in a young male with full mutation of the fragile X syndrome with a high-functioning phenotype: illustrative case

BACKGROUND

Fragile X syndrome (FXS) is a genetic disorder that typically presents with neurodevelopmental abnormalities. Patients with FXS can present with signs and symptoms of connective tissue disorder (CTD) and occasionally with vascular disease. However, cerebrovascular disease is not well documented in these patients, and it is unknown whether there is a direct link between abnormal levels of fragile X protein (FMRP) and its mRNA.

OBSERVATIONS

Here, the authors present a rare case of an adult male with full mutation FXS of a high-functioning phenotype who presented with syncope, and on further evaluation, a fusiform dissecting aneurysm of the distal middle cerebral artery was identified. The patient was treated for the aneurysm and recovered successfully.

LESSONS

Previous clinical evidence suggests that there might be an association between FMRP and increased mRNA levels on CTD and vascular pathologies in patients with FXS. This leads the authors to believe that their patient's previous FXS diagnosis might have played a role in the spontaneous aneurysm and presents a novel area of inquiry in the clinical and pathological manifestations of this disease. Therefore, screening for underlying FXS genetic abnormalities in patients with CNS aneurysms and screening for aneurysms in those with these mutations might need to be considered. https://thejns.org/doi/10.3171/CASE24889.

A case of neuronal intranuclear inclusion disease (NIID) presenting with hydrocephalus-like clinical features: case report

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder characterized by the presence of inclusions within the nuclei of various cell types. The clinical manifestations of patients with NIID are diverse. Here, we present the case of a patient with NIID whose clinical presentation and magnetic resonance features closely resembled those of hydrocephalus.

CASE PRESENTATION

The patient was 71-year-old woman with no significant family history. Seven years previously, she began to experience tremors in both hands, which occurred at rest and while holding objects; this was accompanied by urinary incontinence. Four years previously, she developed weakness in both lower limbs, an unstable gait, and dizziness. Over the past year, she noticed stiffening at the root of her tongue, cognitive decline, and slower reaction times compared to her previous state. Upon admission, cranial magnetic resonance imaging (MRI) revealed hydrocephalus-like changes. A cerebrospinal fluid drainage test returned negative results. The patient presented with tremors and urinary incontinence. Physical examination indicated pupillary constriction, and electromyography suggested peripheral neuropathy. Genetic testing revealed 91 GGC repeats in the NOTCH2NLC gene, indicating abnormal expansion. The final diagnosis was NIID. We provided symptomatic treatment for the tremor and cognitive impairment, but there was no significant improvement in the clinical symptoms.

CONCLUSIONS

Our case suggests that when a patient presents with clinical symptoms and MRI findings resembling hydrocephalus, the possibility of NIID should be considered, especially in the presence of tremors and autonomic symptoms.

A case report of neuronal intranuclear inclusion disease and literature review

Neuronal intranuclear inclusion disease (NIID) is a rare progressive neurodegenerative disease with a characteristic pathological feature of eosinophilic hyaluronan inclusions in the nervous system and internal organs. The identification of GGC-repeat expansions in the Notch 2 N-terminal like C (NOTCH2NLC) gene facilitates the accurate diagnosis of NIID. Due to its rareness and high clinical heterogeneity, the diagnosis of NIID is often delayed or missed. Here, we report a case of NIID mimicking autoimmune encephalitis. A 55-year-old Chinese man presented with fever, headache, recurrent seizures, and weakness in the upper and lower left limbs. Brain MRI revealed diffuse T2/ FLAIR-hyperintense lesions in the bilateral basal ganglia, corpus callosum, and periventricular white matter, with swelling of the right temporal, frontal, and parietal cortices accompanied by meningeal enhancement. Abnormally high signal lesions were observed in the corticomedullary junction in diffusion-weighted imaging (DWI). The infectious or autoimmune disease screening of central nervous system using CSF was normal. The test of GGC-repeat expansion in the NOTCH2NLC gene by capillary electrophoresis indicated GGC repeats (48 and 110 GGC repeats), which supported the diagnosis of NIID. After treatment with glucocorticoid, the clinical symptoms of this patient improved significantly. In the literature, 12 cases of NIID presenting with encephalitis-like attacks were identified, most of which were recurrent, accompanied by progressive symptoms such as dementia, Parkinsonism symptoms, migraine, or dysuria. In this case, there was a single encephalitis-like episode without other progressive symptoms. In patients with encephalitis-like symptoms, NIID should be considered, especially when no other evidence of infection is found, as demonstrated in this case. In addition, long-term monitoring of disease progression is also very important.

Neuronal intranuclear inclusion disease with subclinical peripheral neuropathy: A case report

RATIONALE

Neuronal intranuclear inclusion disease (NIID) is a slowly progressing neurodegenerative disease with various manifestations and high heterogeneity. Clinical characteristics, imaging, skin biopsy, and genetic testing are necessary for its diagnosis. Electromyography may also be a useful tool for diagnosing NIID. In this study, we report a patient with motor and sensory nerve demyelination changes accompanied by axonal damage.

PATIENT CONCERNS

A 64-year-old woman was admitted to our department with gradually worsening forgetfulness for over a year. After 6 years of follow-up, the symptoms progressively deteriorated.

DIAGNOSES

Cerebrospinal fluid analysis revealed increased protein levels. Brain magnetic resonance imaging showed characteristic "ribbon-like" high signals in the corticomedullary junction area on diffusion-weighted imaging. High-intensity signals in the white matter were also observed on T2 and fluid-attenuated inversion recovery imaging. Electromyography revealed multiple peripheral nerve damage and conduction changes, including motor and sensory nerve demyelination changes, accompanied by axonal damage. Skin biopsy revealed inclusion bodies with strong positive staining for P62 and ubiquitin antibodies in the nuclei of sweat gland cells, adipocytes, and fibroblasts. Genetic testing indicated that the number of GGC repeats in NOTCH2NLC alleles were 14 and 134, respectively. Consequently, the patient was diagnosed with NIID.

INTERVENTIONS

Currently, no effective treatment is available to delay the progression of the disease.

LESSONS

We report a case of NIID with subclinical peripheral neuropathy, although the patient did not experience sensory symptoms such as numbness in the extremities. Electromyography can be used to detect subclinical peripheral nerve damage.

Neuronal Intranuclear Inclusion Disease Presenting with Acute-Onset Dementia and Cortical Edema: A Case Report

Background

Neuronal Intranuclear Inclusion Disease (NIID) is a neurodegenerative disorder characterized by the formation of eosinophilic inclusions in the neurons, visceral and skin cells. The cause is associated with the GGC nucleotide repeat expansion in the NOTCH2NLC gene. The imaging hallmark of NIID is hyperintensities on diffusion-weighted imaging (DWI) at the corticomedullary junction. Clinical manifestations of NIID are highly heterogeneous. Here, we report a case of NIID presenting with acute-onset dementia and cortical edema.

Case presentation

We describe an elderly male patient who presented with sudden dementia within a day. Considering the abrupt onset and the stroke history, we initially diagnosed vascular disease. However, further imaging revealed cortical edema in the temporo-parieto-occipital lobes. Blood and cerebrospinal fluid tests ruled out immunological, metabolic, infectious, or neoplastic etiologies. Genetic testing ultimately confirmed the diagnosis of NIID. Intravenous immunoglobulin (IVIG) therapy did not improve the patient's symptoms; However, about 1 month after treatment, spontaneous improvement was observed. It is noteworthy that 22 months before the onset of cognitive impairment, the patient's MRI for headaches already exhibited the typical imaging lesions of this disease in the cerebellum paravermal region.

Conclusion

Patients with encephalopathy syndrome exhibiting imaging features resembling mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome or Creutzfeldt-Jakob disease should consider the NIID as differential diagnosis. Chronic headaches and symmetric lesions in the cerebellar paravermal region on MRI may be noteworthy indicators of NIID during non-episodic phases.

Epigenetics in the formation of pathological aggregates in amyotrophic lateral sclerosis

The progressive degeneration of motor neurons in amyotrophic lateral sclerosis (ALS) is accompanied by the formation of a broad array of cytoplasmic and nuclear neuronal inclusions (protein aggregates) largely containing RNA-binding proteins such as TAR DNA-binding protein 43 (TDP-43) or fused in sarcoma/translocated in liposarcoma (FUS/TLS). This process is driven by a liquid-to-solid phase separation generally from proteins in membrane-less organelles giving rise to pathological biomolecular condensates. The formation of these protein aggregates suggests a fundamental alteration in the mRNA expression or the levels of the proteins involved. Considering the role of the epigenome in gene expression, alterations in DNA methylation, histone modifications, chromatin remodeling, non-coding RNAs, and RNA modifications become highly relevant to understanding how this pathological process takes effect. In this review, we explore the evidence that links epigenetic mechanisms with the formation of protein aggregates in ALS. We propose that a greater understanding of the role of the epigenome and how this inter-relates with the formation of pathological LLPS in ALS will provide an attractive therapeutic target.

A family with neuronal intranuclear inclusion disease with focal segmental glomerulosclerosis

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease caused by the expansion of GGC repeats in the 5'-untranslated region (5'-UTR) of NOTCH2NLC. Although increasing evidence suggests that NIID affects various organs, its association with renal involvement remains unclear. We studied the genetic background of a family with NIID, in which four of five members presented with proteinuria as the initial manifestation. The renal pathology of three patients was diagnosed as focal segmental glomerulosclerosis (FSGS) at a previous hospital. These patients also presented with tremors, retinal degeneration, and episodic neurological events. Finally, one patient exhibited reversible bilateral thalamic high-intensity signal changes on diffusion-weighted imaging during episodic neurological events.

METHODS

Exome sequencing (ES) and nanopore long-read whole-genome sequencing (LR-WGS) were performed on the index case, followed by nanopore target sequencing using Cas9-mediated PCR-free enrichment and methylation analysis.

RESULTS

ES revealed no candidate variants; however, nanopore LR-WGS in the index case revealed expansion of short tandem repeats (STR) in NOTCH2NLC. Subsequent nanopore target sequencing using Cas9-mediated PCR-free enrichment showed STR expansion of NOTCH2NLC in an affected sibling and asymptomatic father. Methylation analysis using nanopore data revealed hypermethylation of the expanded allele in the asymptomatic father and partial hypermethylation in a mildly symptomatic sibling, whereas the expanded allele was hypomethylated in the index case.

CONCLUSIONS

This investigation expands the clinical spectrum of NIID, suggesting that STR expansion of NOTCH2NLC is a cause of renal diseases, including FSGS.

Retrospective review of bladder biopsy instead of skin biopsy provided clue for the diagnosis of neuronal intranuclear inclusion disease

The purpose of this study is to present a case of a patient with a negative skin biopsy who was diagnosed with neuronal intranuclear inclusion disease (NIID) through a retrospective review of a bladder biopsy specimen obtained 10 years ago. The patient initially presented with encephalitis-like symptoms, including fever, headache, and abnormal mental behavior. However, the DWI hyperintensity in the corticomedullary junction indicated the possibility of NIID. Due to the negative results of the skin biopsy, we initially refrained from hastily diagnosing the patient with NIID. However, 6 months later, the patient was readmitted to the hospital due to similar symptoms, and a follow-up MRI showed significant enlargement of the lesions at the corticomedullary junction. This time we identified intranuclear inclusions in her tissue specimens from bladder surgery. Subsequently, genetic testing was performed, leading to the diagnosis of NIID in the patient. Our case report indicates that detecting intranuclear inclusions from previous surgical specimens, rather than relying solely on skin biopsy, could significantly enhance diagnostic methods for NIID.

The 5HT4R agonist velusetrag efficacy on neuropathic chronic intestinal pseudo-obstruction in PrP-SCA7-92Q transgenic mice

Background

Chronic intestinal pseudo-obstruction (CIPO) is a type of intestinal dysfunction with symptoms of intestinal blockage but without the actual mechanical obstruction. Currently, there are no drugs available to treat this disease. Herein, we report the characterization of the PrP-SCA7-92Q transgenic (Tg) line as a valuable CIPO mouse model and investigated the tolerability and efficacy of the 5-hydroxytryptamine type-4 receptor (5HT4R) agonist velusetrag as a promising pharmacological treatment for CIPO.

Methods

To test the pharmacodynamics of velusetrag, 8-week-old SCA7 Tg mice, which express human mutated Ataxin-7 gene containing 92 CAG repeats under the mouse prion protein promoter, were treated for 5 weeks by oral route with velusetrag at 1 and 3 mg/kg doses or vehicle. Body weight was monitored throughout the treatment. After sacrifice, the small intestine and proximal colon were collected for whole-mount immunostaining. Untreated, age-matched, C57BL/6J mice were also used as controls in comparison with the other experimental groups.

Results

Analysis of SCA7 Tg mice showed tissue damage and alterations, mucosal abnormalities, and ulcers in the distal small intestine and proximal colon. Morphological changes were associated with significant neuronal loss, as shown by decreased staining of pan-neuronal markers, and with accumulation of ataxin-7-positive inclusions in cholinergic neurons. Administration of velusetrag reversed intestinal abnormalities, by normalizing tissue damage and re-establishing the normal level of glia/neuron's count in both the small and large intestines.

Conclusion

We demonstrated that the PrP-SCA7-92Q Tg line, a model originally developed to mimic spinocerebellar ataxia, is suitable to study CIPO pathology and can be useful in establishing new therapeutic strategies, such as in the case of velusetrag. Our results suggest that velusetrag is a promising compound to treat patients affected by CIPO or intestinal dysmotility disease.

Clinical features of neuronal intranuclear inclusion disease with seizures: a systematic literature review

Background

Infant, junior, and adult patients with neuronal intranuclear inclusion disease (NIID) present with various types of seizures. We aimed to conduct a systematic literature review on the clinical characteristics of NIID with seizures to provide novel insight for early diagnosis and treatment and to improve prognosis of these patients.

Methods

We used keywords to screen articles related to NIID and seizures, and data concerning the clinical characteristics of patients, including demographic features, disease characteristics of the seizures, treatment responses, imaging examinations, and other auxiliary examination results were extracted.

Results

The included studies comprised 21 patients with NIID with seizures. The most common clinical phenotypes were cognitive impairment (76.20%) and impaired consciousness (57.14%), and generalized onset motor seizures (46.15%) represented the most common type. Compared with infantile and juvenile cases, the use of antiepileptic drugs in adults led to significant seizure control and symptom improvement, in addition to providing a better prognosis. The number of GGC sequence repeats in the NOTCH2NLC gene in six NIID patients with seizures who underwent genetic testing ranged 72-134.

Conclusion

The most common clinical phenotypes in patients with NIID with seizures were cognitive impairment and consciousness disorders. Patients with NIID presented with various types of seizures, with the most common being generalized onset motor seizures. Adult patients had a better prognosis and were relatively stable. The early diagnosis of NIID with seizures is of great significance for treatment and to improve prognosis.

Neuronal intranuclear inclusion disease misdiagnosed as Parkinson's disease: a case report

Neuronal intranuclear inclusion disease (NIID) is a rare progressive neurodegenerative disease that mainly manifests as dementia, muscle weakness, sensory disturbances, and autonomic nervous dysfunction. Herein, we report a 68-year-old Chinese woman who was hospitalized because of resting tremor and bradykinesia that had been present for 7 years. Five years prior, bradykinesia and hypermyotonia had become apparent. She had urinary incontinence and rapid eye movement sleep behavior disorder. She was diagnosed with Parkinson's disease (PD) and received levodopa and pramipexole, which relieved her motor symptoms. During hospitalization, diffusion-weighted imaging revealed a high-intensity signal along the cortical medullary junction. Moreover, a skin biopsy revealed the presence of intranuclear inclusions in adipocytes, fibroblasts, and sweat gland cells. NIID was diagnosed by testing the Notch 2 N-terminal-like C (NOTCH2NLC) gene. We report this case to remind doctors to consider NIID when diagnosing patients with symptoms indicative of Parkinson's disease. Moreover, we note that further research is needed on the mechanism by which levodopa is effective for NIID.

Skin biopsy and neuronal intranuclear inclusion disease

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease with variable clinical phenotypes. There is a considerable delay in the definite diagnosis, which primarily depends on postmortem brain pathological examination. Although CGG repeat expansion in the 5'-untranslated region of NOTCH2NLC has been identified as a disease-associated variant, the pathological diagnosis is still required in certain NIID cases. Intranuclear inclusions found in the skin tissue of patients with NIID dramatically increased its early detection rate. Skin biopsy, as a minimally invasive method, has become widely accepted as a routine examination to confirm the pathogenicity of the repeat expansion in patients with suspected NIID. In addition, the shared developmental origin of the skin and nerve system provided a new insight into the pathological changes observed in patients with NIID. In this review, we systematically discuss the role of skin biopsy for NIID diagnosis, the procedure of skin biopsy, and the pathophysiological mechanism of intranuclear inclusion in the skin.

Expression of expanded GGC repeats within NOTCH2NLC causes cardiac dysfunction in mouse models

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder characterized by widespread intranuclear inclusions in the nervous system as well as multiple visceral organs. In 2019, expanded GGC repeats within the 5' untranslated region of the NOTCH2NLC gene was identified as the causative factor. NIID is a heterogeneous disorder with variable clinical manifestations including cognitive impairment, cerebellar ataxia, parkinsonism, paroxysmal symptoms, autonomic dysfunction, and muscle weakness. Although NIID primarily affects the central and peripheral nervous systems, growing evidence suggests potential cardiac abnormalities in NIID. However, the link between expanded GGC repeats within NOTCH2NLC and cardiac dysfunction remains uncertain.

RESULTS

In this study, we utilized two transgenic mouse models, expressing NOTCH2NLC-(GGC)98 ubiquitously or specifically in cardiomyocytes, and identified p62 (also known as sequestosome 1, SQSTM1)-positive intranuclear NOTCH2NLC-polyG inclusions in cardiomyocytes in two mouse models. We observed that both models exhibited cardiac-related pathological and echocardiographic changes, albeit exhibiting varying degrees of severity. Transcriptomic analysis revealed shared downregulation of genes related to ion channels and mitochondria in both models, with the cardiomyocyte-specific mice showing a more pronounced downregulation of mitochondria and energy metabolism-related pathways. Further investigations revealed decreased expression of mitochondria-related genes and electron transport chain activity. At last, we conducted a retrospective review of cardiac-related examination results from NIID patients at our hospital and also identified some cardiac abnormalities in NIID patients.

CONCLUSIONS

Our study provided the first in vivo evidence linking GGC repeat expansions within NOTCH2NLC to cardiac abnormalities and highlighted the contribution of mitochondrial dysfunction in the development of cardiac abnormalities.

A case of unusual renal manifestation in a patient with neuronal intranuclear inclusion disease treated with steroids

Neuronal intranuclear inclusion disease (NIID) is a progressive neurodegenerative disorder characterized by intranuclear inclusions. Kidney injury involvement and successful treatment for NIID have rarely been reported. A NIID patient developed crescentic IgA nephropathy. Steroid therapy resolved digestive symptoms and recovered renal function. Steroids are considered for concomitant symptoms of NIID.

Skin biopsies for diagnosing neuronal intranuclear inclusion disease: A retrospective study of 12 cases

Neuronal intranuclear inclusion disease (NIID) is a progressive neurodegenerative condition. Skin biopsies taken from the lower leg were reported to be a standard diagnostic procedure for NIID; however, no studies have addressed the optimal skin biopsy locations. We retrospectively analyzed 12 cases in which skin biopsies were performed for diagnosing NIID. We collected clinical information including age, sex, skin biopsy site, the presence of nuclear inclusion bodies, the results of p62 immunostaining, the final diagnosis from the department of neurology, and the presence of abnormal GGC repeats in the NOTCH2NLC gene. Four of the 12 cases had a final diagnosis of NIID. One of the four cases was biopsied from the lower leg, whereas the other three cases were biopsied from the abdomen or thigh. Biopsy specimens of the four definite NIID cases revealed the average rates of nuclear inclusion body-positive cells in adipocytes, sweat gland cells, and fibroblasts to be 13.2%, 10.3%, and 6.3%, respectively. GGC repeat abnormalities in the NOTCH2NLC gene were observed in two of the four cases. The present study indicates that sites with ample subcutaneous fat tissue could be promising for diagnostic skin biopsies for NIID.