Heritable essential tremor-idiopathic normal pressure hydrocephalus (ETINPH)

Brain structure comparison among Parkinson disease, essential tremor, and healthy controls using 7T MRI

Both Parkinson disease (PD) and Essential tremor (ET) are movement disorders causing tremors in elderly individuals. Although PD and ET are different disease, they often present with similar initial symptoms, making their differentiation challenging with magnetic resonance imaging (MRI) techniques. This study aimed to identify structural brain differences among PD, ET, and health controls (HCs) using 7-Tesla (T) MRI. We assessed the whole-brain parcellation in gray matter volume, thickness, subcortical volume, and small regions of basal ganglia in PD (n = 18), ET (n = 15), and HCs (n = 18), who were matched for age and sex. Brain structure analysis was performed automatic segmentation through Freesurfer software. Small regions of basal ganglia were manually segmented by ITK-SNAP. Additionally, we examined the associations between clinical indicators (symptom duration, unified Parkinson diseases rating scale (UPDRS), and clinical rating scale for tremor (CRST)) and brain structure. PD showed a significant reduction in gray matter volume in the postcentral region compared to ET. ET showed a significant reduction in cerebellum volume compared to HCs. There was a negative correlation between CRST scores (B and C) and gray matter thickness in right superior frontal in ET. This study demonstrated potential of 7T MRI in differentiating brain structure differences among PD, ET, and HCs. Specific findings, such as parietal lobe atrophy in PD compared to ET and cerebellum atrophy in ET compared to HCs, the importance of advanced imaging techniques in accurately diagnosing and distinguishing between movement disorders that present with similar initial symptoms.

A role for mutations in AK9 and other genes affecting ependymal cells in idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is an enigmatic neurological disorder that develops after age 60 and is characterized by gait difficulty, dementia, and incontinence. Recently, we reported that heterozygous CWH43 deletions may cause iNPH. Here, we identify mutations affecting nine additional genes (AK9, RXFP2, PRKD1, HAVCR1, OTOG, MYO7A, NOTCH1, SPG11, and MYH13) that are statistically enriched among iNPH patients. The encoded proteins are all highly expressed in choroid plexus and ependymal cells, and most have been associated with cilia. Damaging mutations in AK9, which encodes an adenylate kinase, were detected in 9.6% of iNPH patients. Mice homozygous for an iNPH-associated AK9 mutation displayed normal cilia structure and number, but decreased cilia motility and beat frequency, communicating hydrocephalus, and balance impairment. AK9+/- mice displayed normal brain development and behavior until early adulthood, but subsequently developed communicating hydrocephalus. Together, our findings suggest that heterozygous mutations that impair ventricular epithelial function may contribute to iNPH.

WT, Arnold SE, Frosch MP, Duy PQ, Kahle KT. Cases of familial idiopathic normal pressure hydrocephalus implicate genetic factors in disease pathogenesis

Idiopathic normal pressure hydrocephalus is a disorder of unknown pathophysiology whose diagnosis is paradoxically made by a positive response to its proposed treatment with cerebrospinal fluid diversion. There are currently no idiopathic normal pressure hydrocephalus disease genes or biomarkers. A systematic analysis of familial idiopathic normal pressure hydrocephalus could aid in clinical diagnosis, prognosis, and treatment stratification, and elucidate disease patho-etiology. In this 2-part analysis, we review literature-based evidence for inheritance of idiopathic normal pressure hydrocephalus in 22 pedigrees, and then present a novel case series of 8 familial idiopathic normal pressure hydrocephalus patients. For the case series, demographics, familial history, pre- and post-operative symptoms, and cortical pathology were collected. All novel familial idiopathic normal pressure hydrocephalus patients exhibited improvement following shunt treatment and absence of neurodegenerative cortical pathology (amyloid-beta and hyperphosphorylated tau), in contrast to many sporadic cases of idiopathic normal pressure hydrocephalus with variable clinical responses. Analysis of the 30 total familial idiopathic normal pressure hydrocephalus cases reported herein is highly suggestive of an autosomal dominant mechanism of inheritance. This largest-ever presentation of multiply affected idiopathic normal pressure hydrocephalus pedigrees provides strong evidence for Mendelian inheritance and autosomal dominant transmission of an idiopathic normal pressure hydrocephalus trait in a subset of patients that positively respond to shunting and lack neurodegenerative pathology. Genomic investigation of these families may identify the first bona fide idiopathic normal pressure hydrocephalus disease gene.

Cerebrospinal fluid biomarkers and genetic factors associated with normal pressure hydrocephalus and Alzheimer’s disease: a narrative review

Background

Normal pressure hydrocephalus is a neurologic disease leading to enlargement of ventricles which is presented with gait and balance disturbance, cognitive decline, and urinary incontinence. Diagnosis of normal pressure hydrocephalus is challenging due to the late onset of signs and symptoms. In this review, we summarize the cerebrospinal fluid, plasma, pathology, and genetic biomarkers of normal pressure hydrocephalus and related disorders.

Body

Recently, cerebrospinal fluid and serum biomarkers analysis alongside gene analysis has received a lot of attention. Interpreting a set of serum and cerebrospinal fluid biomarkers along with genetic testing for candidate genes could differentiate NPH from other neurological diseases such as Alzheimer's disease, Parkinson's disease with dementia, and other types of dementia.

Conclusion

Better understanding the pathophysiology of normal pressure hydrocephalus through genetic studies can aid in evolving preventative measures and the early treatment of normal pressure hydrocephalus patients.

Deletions in CWH43 cause idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a neurological disorder that occurs in about 1% of individuals over age 60 and is characterized by enlarged cerebral ventricles, gait difficulty, incontinence, and cognitive decline. The cause and pathophysiology of iNPH are largely unknown. We performed whole exome sequencing of DNA obtained from 53 unrelated iNPH patients. Two recurrent heterozygous loss of function deletions in CWH43 were observed in 15% of iNPH patients and were significantly enriched 6.6‐fold and 2.7‐fold, respectively, when compared to the general population. Cwh43 modifies the lipid anchor of glycosylphosphatidylinositol‐anchored proteins. Mice heterozygous for CWH43 deletion appeared grossly normal but displayed hydrocephalus, gait and balance abnormalities, decreased numbers of ependymal cilia, and decreased localization of glycosylphosphatidylinositol‐anchored proteins to the apical surfaces of choroid plexus and ependymal cells. Our findings provide novel mechanistic insights into the origins of iNPH and demonstrate that it represents a distinct disease entity.

Diabetes is associated with familial idiopathic normal pressure hydrocephalus: a case-control comparison with family members

BACKGROUND

The pathophysiological basis of idiopathic normal pressure hydrocephalus (iNPH) is still unclear. Previous studies have shown a familial aggregation and a potential heritability when it comes to iNPH. Our aim was to conduct a novel case-controlled comparison between familial iNPH (fNPH) patients and their elderly relatives, involving multiple different families.

METHODS

Questionnaires and phone interviews were used for collecting the data and categorising the iNPH patients into the familial (fNPH) and the sporadic groups. Identical questionnaires were sent to the relatives of the potential fNPH patients. Venous blood samples were collected for genetic studies. The disease histories of the probable fNPH patients (n = 60) were compared with their ≥ 60-year-old relatives with no iNPH (n = 49). A modified Charlson Comorbidity Index (CCI) was used to measure the overall disease burden. Fisher's exact test (two-tailed), the Mann-Whitney U test (two-tailed) and a multivariate binary logistic regression analysis were used to perform the statistical analyses.

RESULTS

Diabetes (32% vs. 14%, p = 0.043), arterial hypertension (65.0% vs. 43%, p = 0.033), cardiac insufficiency (16% vs. 2%, p = 0.020) and depressive symptoms (32% vs. 8%, p = 0.004) were overrepresented among the probable fNPH patients compared to their non-iNPH relatives. In the age-adjusted multivariate logistic regression analysis, diabetes remained independently associated with fNPH (OR = 3.8, 95% CI 1.1-12.9, p = 0.030).

CONCLUSIONS

Diabetes is associated with fNPH and a possible risk factor for fNPH. Diabetes could contribute to the pathogenesis of iNPH/fNPH, which motivates to further prospective and gene-environmental studies to decipher the disease modelling of iNPH/fNPH.

Alzheimer's Disease-Related Polymorphisms in Shunt-Responsive Idiopathic Normal Pressure Hydrocephalus

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a late onset, surgically treated progressive brain disease caused by impaired cerebrospinal fluid dynamics and subsequent ventriculomegaly. Comorbid Alzheimer's disease (AD) seems to be frequent in iNPH.

OBJECTIVE

We aim to evaluate the role of AD-related polymorphisms in iNPH.

METHODS

Overall 188 shunt-operated iNPH patients and 688 controls without diagnosed neurodegenerative disease were included into analysis. Twenty-three single-nucleotide polymorphisms (SNPs FRMD4A [rs7081208_A, rs2446581_A, rs17314229_T], CR1, BIN, CD2AP, CLU, MS4A6A, MS4A4E, PICALM, ABCA7, CD33, INPP5D, HLA_DRB5, EPHA1, PTK2B, CELF1, SORL1, FERMT2, SLC24A, DSG2, CASS4, and NME8) adjusted to APOE were analyzed between groups by using binary logistic regression analysis. Neuroradiological characteristics and AD-related changes in the right frontal cortical brain biopsies were available for further analysis.

RESULTS

Logistic regression analysis adjusted to age, gender, and other SNPs indicated allelic variation of NME8 between iNPH patients and non-demented controls (p = 0.014). The allelic variation of NME8 was not related to the neuropathological changes in the brain biopsies of iNPH patients. However, periventricular white matter changes (p = 0.017) were more frequent in the iNPH patients with the AA-genotype, an identified risk factor of AD.

CONCLUSIONS

Our findings increase the evidence that iNPH is characterized by genetic and pathophysiological mechanisms independent from AD. Considering that NME8 plays a role in the ciliary function and displays SNP-related diversity in white matter changes, the mechanisms of NME8 in iNPH and other neurodegenerative processes are worth further study.

Endoscope-Assisted Microsurgical Removal of an Intraventricular Ependymal Cyst That Manifested with Tremor

BACKGROUND

Intraventricular ependymal cysts (ECs) are rare, histologically benign neuroepithelial cysts. Most of these cysts are clinically silent and discovered incidentally. Rarely, they become symptomatic, leading to obstruction of the cerebrospinal fluid circulation. ECs located inside the ventricles may manifest with signs of increased intracranial pressure.

CASE DESCRIPTION

A 32-year-old woman presented with a 6-year history of tremor affecting her left hand. In the last month, she had been experiencing headache as well, and the tremor of the left hand was affecting her quality of life. The patient demonstrated a fine resting and intention tremor of the left hand and a voice tremor. Magnetic resonance imaging revealed a large cystic, nonenhancing lesion within the right lateral ventricle. The fluid within the cyst was isointense to cerebrospinal fluid on all sequences. Because of the rapid progression of her symptoms and no response to medication, surgical decompression of the cyst was considered. The cyst was removed by an endoscope-assisted microsurgical technique. Her postoperative course was uneventful. A marked reduction in her tremor was noted in the immediate postoperative period. Histopathologic diagnosis was of an EC. During the follow-up period, the patient's tremor, although still present, had improved dramatically. At 6 months postoperatively, she could hold a drinking glass without spilling.

CONCLUSIONS

This is a unique case of an intraventricular EC that manifested with tremor, which improved by endoscope-assisted microsurgical removal of the cyst. This case also supports the important role of endoscopic surgery in the treatment of intraventricular cystic lesions.

Panventriculomegaly with a wide foramen of Magendie and large cisterna magna

OBJECT The authors' goal in this paper is to provide the first clinical, radiological, and genetic studies of panventriculomegaly (PaVM) defined by a wide foramen of Magendie and large cisterna magna. METHODS Clinical and brain imaging data from 28 PaVM patients (including 10 patients from 5 families) were retrospectively studied. Five children were included. In adult patients, the age at onset was 56.0 ± 16.7 years. Tetraventricular dilation, aqueductal opening with flow void on T2-weighted images, and a wide foramen of Magendie and large cisterna magna (wide cerebrospinal fluid space at the fourth ventricle outlet) were essential MRI findings for PaVM diagnosis. 3D fast asymmetrical spin echo sequences were used for visualization of cistern membranes. Time-spatial labeling inversion pulse examination was performed to analyze cerebrospinal fluid movement. Copy number variations were determined using high-resolution microarray and were validated by quantitative polymerase chain reaction with breakpoint sequencing. RESULTS Adult patients showed gait disturbance, urinary dysfunction, and cognitive dysfunction. Five infant patients exhibited macrocranium. Patients were divided into 2 subcategories, those with or without downward bulging third ventricular floors and membranous structures in the prepontine cistern. Patients with bulging floors were successfully treated with endoscopic third ventriculostomy. Genetic analysis revealed a deletion in DNAH14 that encodes a dynein heavy chain protein associated with motile cilia function, and which co-segregated with patients in a family without a downward bulging third ventricular floor. CONCLUSIONS Panventriculomegaly with a wide foramen of Magendie and a large cisterna magna may belong to a subtype of congenital hydrocephalus with familial accumulation, younger age at onset, and symptoms of normal pressure hydrocephalus. In addition, a family with PaVM has a gene mutation associated with dysfunction of motile cilia.

Familial aggregation of idiopathic normal pressure hydrocephalus: novel familial case and a family study of the NPH triad in an iNPH patient cohort

OBJECTIVE

Idiopathic normal pressure hydrocephalus (iNPH) is considered sporadic, yet familial cases involving single pedigrees are being increasingly recognized. As current evidence does not extend beyond isolated pedigrees, we aimed to determine the putative heritability of iNPH by examining the prevalence of the iNPH triad among the family members of iNPH probands.

METHOD

We present a case-control family study of the iNPH symptom triad among the relatives of iNPH patients (n=20) identified from a cohort of patients undergoing CSF diversion and matched comparison subjects (n=21). A total of 291 first-degree relatives from 41 families were characterized using semi-structured family history interviews. Independent from the family study, we present a novel well-characterized familial case of iNPH.

RESULTS

≥ 2 insidious, progressive and idiopathic iNPH symptoms were identified among first degree relatives in 6 iNPH pedigrees (2 multiply affected) and 1 control pedigree, with an incidence of 7.1% among iNPH relatives and 0.7% among control relatives (OR=11.53). Gait disturbance and memory impairment began at a younger age among the relatives of iNPH probands. Independent of our family study, we present a novel case report of a large iNPH pedigree with multiple affected relatives.

INTERPRETATION

Our family study and novel familial case suggest familial aggregation of iNPH. A larger family study with full characterization of affected and unaffected relatives is warranted. Confirmation of heritability may allow identification of individuals at high-risk for iNPH, early intervention, and improved aetiological elucidation.

Familial normal pressure hydrocephalus (NPH) with an autosomal-dominant inheritance: a novel subgroup of NPH

Normal pressure hydrocephalus (NPH) has two clinical forms: secondary NPH and idiopathic NPH (iNPH). Most patients with NPH occur sporadically: until now, only two families have been reported to have sibling cases of NPH. We here report a large family with 4 patients with elderly-onset NPH in three generations. All of them had cognitive impairment, gait disturbance, and urinary problems, along with normal pressure of cerebrospinal fluid. Their brain MRI showed enlargement of the ventricles and a disproportional narrowing of the subarachnoid space and cortical sulci at the high convexity of the cerebrum, which are the features of iNPH on MRI. The family interview also disclosed additional 4 patients who were suspected as having NPH. The disease seems to be inherited in an autosomal-dominant fashion. No known causes of secondary NPH were found in any of the patients. This is the first report to show a large family with NPH patients in three generations, who had clinical and MRI features indistinguishable from iNPH. This seems to represent a novel subgroup of NPH, familial NPH.

Successful treatment of tremor by endoscopic third ventriculostomy in an adolescent with obstructive hydrocephalus due to tectal glioma: case report

Hydrocephalus presenting with movement disorder is very rare, especially in children. We present the case of a 16-year-old boy who presented with bilateral intention tremor and slowed speech as a result of obstructive hydrocephalus secondary to a tectal glioma. Treatment with endoscopic third ventriculostomy improved his symptoms. We review the literature regarding this unusual presentation of an otherwise common condition.

Normal-pressure hydrocephalus: is there a genetic predisposition?

BACKGROUND

Normal-pressure hydrocephalus (NPH) is characterized by gait disturbance, cognitive impairment, with or without urinary incontinence, enlarged ventricles with or without cerebral atrophy and normal cerebrospinal fluid pressure.

METHODS

We report two sisters with NPH who lived together their entire lives and whose natural history might provide insights into genetic and environmental mechanisms underlying this disorder. Both patients were in their early seventies, single, had similar daily habits and hypertension. No other family members had NPH.

RESULTS

They both underwent shunt placement and showed improvement documented by history and neuropsychological assessment. Both showed a delayed deterioration due to vasculopathy. Both patients were homozygous for the apolipoprotein E (ApoE) e3 allele on chromosome 19. No environmental factors that might have influenced the development of NPH were identified.

CONCLUSION

Our report of two sisters with NPH may indicate the presence of genetic predisposition and further studies involving genetics and environmental factors are necessary to elucidate their role in the pathogenesis of NPH.

Normal pressure hydrocephalus

Normal Pressure Hydrocephalus first became recognized as a treatable, reversible disorder in the 1960s. The classic triad of magnetic apraxia, urinary incontinence, and dementia remain relevant into the 21(st) century as being the basis for symptomatic diagnosis and predicting potential benefit from ventriculoperitoneal shunting, though they have been greatly augmented by the addition of modern neuroimaging, particularly MRI. Modern criteria recognize a wider range of diagnostic criteria, and new positive and negative prognostic indicators for treatment benefit have been discovered, though the mainstay remains initial drainage of a large volume of cerebrospinal fluid and monitoring for clinical improvement. Even with our advances in understanding both primary and secondary normal pressure hydrocephalus, diagnosis, management, and counseling remain challenging in this disorder.

Normal pressure hydrocephalus: diagnosis and treatment

Normal pressure hydrocephalus (NPH) is a syndrome of gait dysfunction and enlarged cerebral ventricles in the absence of another cause. It is frequently accompanied by frontal and subcortical cognitive deficits and bladder detrusor overactivity. NPH is rare relative to other potential causes of these symptoms in the elderly, but timely diagnosis can lead to reversal of symptoms through ventricular shunting. There are many tests used to predict possible response to surgery, such as MRI of the brain, formalized neuropsychological and gait testing, large-volume lumbar puncture, and prolonged lumbar drainage, but no one test has been validated to rule out potential response to surgery.