Improved lumbar infusion test analysis for normal pressure hydrocephalus diagnosis

OBJECTIVES

Constant infusion lumbar infusion test (LIT) is an important way to find which patients, of those with signs and symptoms corresponding to normal pressure hydrocephalus (NPH) who will improve from shunt operation. LIT is a stress test on the ability for cerebrospinal fluid re-absorbtion. The aim of this study is to show how the information from LIT can be improved by quantitative analysis and avoidance of methodological pitfalls.

MATERIAL AND METHODS

The potential pitfalls, and the analysis method, are described in detail. The analysis was applied on pre-operative constant infusion LIT from 31 patients operated for NPH, with known outcome. The pre- and post-operative walking speed was used to grade pathology progression or improvement.

RESULTS

The maximal, plateau, intra-spinal pressure at constant infusion LIT is an ambivalent indicator for NPH: while low maximal pressure indicates no cerebrospinal fluid (CSF) absorbtion pathology, too high pressure (≥47 mmHg) may mean no diagnosis, because of stenosis of the Sylvian aqueduct. When subjects with too high intra-spinal pressure were excluded, the new analysis gave a couple of diagnostic volume parameters, of which one appears to be an optimal LIT parameter for identifying NPH patients with 14% better accuracy than plateau pressure.

CONCLUSION

By avoiding methodological pitfalls, and optimal analysis of the results from lumbar infusion test, the number of NPH patients who do not have a successful outcome after shunt operation may be further decreased.

Comparison of the CSF dynamics between patients with idiopathic normal pressure hydrocephalus and healthy volunteers

OBJECTIVEIntracranial pressure (ICP), outflow resistance (Rout), and amplitude of cardiac-related ICP pulsations (AMPs) are established parameters to describe the CSF hydrodynamic system and are assumed, but not confirmed, to be disturbed in idiopathic normal pressure hydrocephalus (INPH). The aim of this study was to compare the CSF hydrodynamic profile between patients with INPH and healthy volunteers.METHODSSixty-two consecutive INPH patients (mean age 74 years) and 40 healthy volunteers (mean age 70 years) were included. Diagnosis was made by two independent neurologists who assessed patients' history, neurological status, and MRI studies. A CSF dynamic investigation through the lumbar route was performed: ICP and other CSF dynamic variables were blinded to the neurologists during the diagnostic process and were not used for establishing the diagnosis of INPH.RESULTSRout was significantly higher in INPH (Rout 17.1 vs 11.1; p < 0.001), though a substantial number of INPH subjects had normal Rout. There were no differences between INPH patients and controls regarding ICP (mean 11.5 mm Hg). At resting pressure, there was a trend that AMP in INPH was increased (2.4 vs 2.0 mm Hg; p = 0.109). The relationship between AMP and ICP was that they shared the same slope, but the curve was significantly shifted to the left for INPH (reduced P0 [p < 0.05]; i.e., higher AMP for the same ICP).CONCLUSIONSThis study established that the CSF dynamic profile of INPH deviates from that of healthy volunteers and that INPH should thus be regarded as a disease in which intracranial hydrodynamics are part of the pathophysiology.Clinical trial registration no.: NCT01188382 (clinicaltrials.gov).

Change in average peak cerebrospinal fluid velocity at the cerebral aqueduct, before and after lumbar CSF tapping by the use of phase contrast MRI, and its effect on gait improvement in patients with normal pressure hydrocephalus

Objectives

To compare the change in peak cerebrospinal (CSF) flow velocity at the cerebral aqueduct in patients with normal pressure hydrocephalus (NPH) before and after CSF tapping with clinical outcome of the patients, i.e., gait improvement.

Materials and Methods

Forty patients with NPH were evaluated before and after CSF tapping on 3 consecutive days at our institution. Gait improvement was compared with the average peak velocity at the cerebral aqueduct. The average peak velocity was also compared before and after lumbar CSF tapping using phase contrast magnetic resonance imaging (PC-MRI). The different flow parameters were compared using paired t-test.

Results

The average peak velocity before and after lumbar CSF tapping was 5.8196 ± 1.420 cm/s and 4.1411 ± 1.0638 cm/s, respectively. The peak positive, negative, and average velocity decreased in the post-tap group. In our study, 70% of the patients showed gait improvement, and a comparison of the gait improvement with the change in average peak velocity was statistically significant (P = 0.001). Comparison of the change in peak positive and negative velocity with gait improvement was also statistically significant, with a P value of 0.004 and <0.001, respectively. Rest of the CSF flow parameters were statistically insignificant.

Conclusion

PC-MRI is a sensitive method to support the diagnosis of NPH. Different flow parameters were comparable before and after CSF tapping. The parameters which might be useful for assessing clinical improvement include a change in the peak average, as well as positive, and negative velocity.

Gulliver's world: Persistent lilliputian hallucinations as manifestation of Charles Bonnet syndrome in a case of cataract and normal pressure hydrocephalus

Charles Bonnet Syndrome (CBS) typically occurs in elderly people with peripheral vision impairment, or interruptions in the connections from eyes to visual cortex. The heterogeneity of presentations and causal mechanisms warrants clinical caution. In this report, we describe a case of CBS developing in the form of Lilliputian Hallucinations in an elderly gentleman, on the background of cataract and normal pressure hydrocephalus, the complexities arising out of such aetiogenesis, and its management. We emphasize upon the fact that CBS might develop through two concurrent mechanisms in a given individual. Treating one of these would mean persistent symptoms, and failing to recognize these would lead to continued morbidity.

Shunt Intervention for Possible Idiopathic Normal Pressure Hydrocephalus Improves Patient Outcomes: A Nationwide Hospital-Based Survey in Japan

Background and Purpose: This study aimed to investigate the efficacy of cerebrospinal fluid shunt intervention for idiopathic normal pressure hydrocephalus (iNPH) using data from a nationwide epidemiological survey in Japan.

Methods: We conducted a cross-sectional study using data from a nationwide epidemiological survey performed in Japan. Propensity score matching was used to select 874 patients from 1,423 patients aged ≥60 years, who were diagnosed with iNPH based on clinical guidelines following a hospital visit in 2012. Patients who experienced an improvement of at least 1 modified Rankin Scale (mRS) grade after the intervention were classified as “improved,” while the remaining patients were classified as “non-improved.” In the shunt intervention (n = 437) and non-shunt intervention (n = 437) groups, the differences in mRS grade improvement were analyzed using the Mann-Whitney U-test. Finally, we examined subjects in the shunt intervention group (n = 974) to compare the outcomes and complications of ventriculoperitoneal (VP) shunt (n = 417) with lumboperitoneal (LP) shunt (n = 540).

Results: We examined subjects with iNPH to compare the non-shunt intervention group to the shunt intervention group following adjustment for age and mRS grade at baseline by propensity score matching (0.31–0.901). The mRS grade (mean [SD]) was found to improve with non-shunt intervention (2.46 [0.88]) and shunt intervention (1.93 [0.93]) (p < 0.001) in iNPH patients. The mRS outcome score and complications comparison between the VP and LP shunt groups did not show significant difference.

Conclusions: In this study, analysis of the efficacy of shunts for possible iNPH conducted in Japan indicated a significant improvement in the mRS grade between baseline and outcome within 1 year, regardless of the surgical technique, and shunt intervention was found to be effective.

Cerebrospinal Fluid Amyloid-β 42, Total Tau and Phosphorylated Tau are Low in Patients with Normal Pressure Hydrocephalus: Analogies and Differences with Alzheimer's Disease

Co-existence of Alzheimer's disease (AD) in normal pressure hydrocephalus (NPH) is a frequent finding, thus a common pathophysiological basis between AD and NPH has been postulated. We measured CSF amyloid-β 42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) concentrations in a sample of 294 patients with different types of dementia and 32 subjects without dementia. We then compared scores on neuropsychological tests of NPH patients with pathological and normal CSF Aβ42 values. Aβ42 levels were significantly lower in NPH than in control patients, with no significant differences between AD and NPH. On the contrary, t-tau and p-tau levels were significantly lower in NPH than in AD, with no differences between NPH and controls. NPH patients with pathological Aβ42 levels did not perform worse than NPH patients with normal Aβ42 levels in any cognitive domains. Our data seem to support the hypothesis of amyloid accumulation in brains of NPH patients. Nevertheless, amyloid does not seem to play a pathogenetic role in the development of cognitive deficits in NPH.

Apathy in idiopathic normal pressure hydrocephalus: A marker of reversible gait disorders

OBJECTIVE

Apathy-the most common behavioral disturbance in idiopathic normal pressure hydrocephalus (iNPH)-is associated with poor gait, but the role of apathy on gait improvement after cerebrospinal fluid (CSF) tapping has not been studied yet. This study aims to compare gait improvement after CSF tapping in iNPH patients with and without apathy.

METHODS

Stride time variability (STV), a marker of higher level of gait control, was measured in 33 iNPH patients (78.4 ± 5.7 years; 36.4% women) with an optoelectronic system during usual walking (single task) and during walking while dual tasking of counting and verbal fluency before and 24 hours after CSF tapping. Apathy was defined by a score ≥14 on the Starkstein apathy scale.

RESULTS

Apathy was present in 60.6% of patients. Cerebrospinal fluid tapping led to greater improvement of STV (ie, decrease) during dual-task walking (and more specifically categorical verbal fluency) in apathetic compared to nonapathetic patients (-44.7 ± 58.1% versus +4.24 ± 67.6%, respectively; P = .040), even after adjusting for age and depressive symptoms. More severe apathy was correlated with better STV improvement while dual tasking (categorical verbal fluency) after CSF tapping (r = -0.412; P-value = 0.021), while it was not correlated with improvement on executive tests.

CONCLUSIONS

Our findings suggest that the presence of apathy is a predictor of better outcomes of gait disorders after CSF tapping in patients with iNPH.

Magnetoencephalography and normal pressure hydrocephalus: A case report

A 82-year-old male experiencing headaches, dementia, urinary incontinence and gait instability was diagnosed with normal pressure hydrocephalus (NPH) and underwent a resting state magnetoencephalography (MEG) examination. MEG data were recorded in a magnetically shielded room with a whole-head 122 channel biomagnetometer. Following MEG, a ventriculoperitoneal (VP) shunt was placed in his head and greatly improved his symptomatology. Spontaneous MEG recordings revealed lower magnetic fields at frontal and frontotemporal regions compared to central and posterior regions. This finding correlated well with the significant ventricular distention, and specifically the enlargement of the frontal horns of the lateral ventricles, observed in presurgical CT. The regional pattern of MEG signal decrease in NPH seems to be quite different from that encountered in brain atrophy. In the latter case, a more generalized distribution of low magnetic fields is observed, possibly reflecting the high sensitivity of MEG to activity originating in sulci. Acquired data suggest that MEG may be able to differentiate between NPH and brain atrophy. Furthermore, MEG could potentially constitute a non-invasive, non-imaging tool, useful in the selection of patients with NPH to undergo shunt surgery. The findings of this study warrant further research in patient groups before firm conclusions can be drawn.

Lyme Meningoencephalitis Masquerading as Normal Pressure Hydrocephalus

Lyme disease is a tick-borne illness caused primarily by the spirochete Borrelia burgdorferi. The disease is most prevalent in forested areas endemic for Ixodes tick, which transmits the spirochete. Here, we describe a case of Lyme meningoencephalitis masquerading as normal pressure hydrocephalus (NPH) which initially presented with urinary incontinence, gait instability, and neurological decline. Due to its non-specific symptoms and low incidence, Lyme meningoencephalitis causing NPH like syndrome poses a diagnostic conundrum for clinicians. Awareness of this disease entity is key for prompt diagnosis and treatment.

Cerebral autoregulation, cerebrospinal fluid outflow resistance, and outcome following cerebrospinal fluid diversion in normal pressure hydrocephalus

OBJECTIVE

Normal pressure hydrocephalus is not simply the result of a disturbance in CSF circulation, but often includes cardiovascular comorbidity and abnormalities within the cerebral mantle. In this study, the authors have examined the relationship between the global autoregulation pressure reactivity index (PRx), the profile of disturbed CSF circulation and pressure-volume compensation, and their possible effects on outcome after surgery.

METHODS

The authors studied a cohort of 131 patients in whom a clinical suspicion of normal pressure hydrocephalus was investigated. Parameters describing CSF compensation and circulation were calculated during the CSF infusion test, and PRx was calculated from CSF pressure and mean arterial blood pressure (MAP) recordings. A simple scale was used to mark the patients’ outcome 6 months after surgery (improvement, temporary improvement, and no improvement).

RESULTS

The PRx was negatively correlated with resistance to CSF outflow (R = -0.18; p = 0.044); patients with normal CSF circulation tended to have worse autoregulation. The correlation for patients who were surgically treated (n = 83) was R = -0.28; p = 0.01, and it was stronger in patients who experienced sustained improvement after surgery (n = 48, R = -0.43; p = 0.002). In patients who did not improve, the correlation was not significantly different from zero (n = 19, R = -0.07; p = 0.97). There was a trend toward higher values for PRx in nonresponders than in responders (0.16 ± 0.04 vs 0.09 ± 0.02, respectively; p = 0.061), associated with higher MAP values (107.2 ± 8.2 in nonresponders vs 89.5 ± 3.5 in responders; p = 0.195). The product of MAP × (1 + PRx), which was proposed as a measure of combined arterial hypertension and deranged autoregulation, showed a significant association with outcome (greater value in nonresponders; p = 0.013).

CONCLUSION

Autoregulation proves to associate with CSF circulation and appears strongest in shunt responders. Outcome following CSF diversion is possibly most favorable when CSF outflow resistance is increased and global cerebral autoregulation is intact, in combination with arterial normotension.

Deformable model reconstruction of the subarachnoid space

The subarachnoid space is a layer in the meninges that surrounds the brain and is filled with trabeculae and cerebrospinal fluid. Quantifying the volume and thickness of the subarachnoid space is of interest in order to study the pathogenesis of neurodegenerative diseases and compare with healthy subjects. We present an automatic method to reconstruct the subarachnoid space with subvoxel accuracy using a nested deformable model. The method initializes the deformable model using the convex hull of the union of the outer surfaces of the cerebrum, cerebellum and brainstem. A region force is derived from the subject's Tl-weighted and T2-weighted MRI to drive the deformable model to the outer surface of the subarachnoid space. The proposed method is compared to a semi-automatic delineation from the subject's T2-weighted MRI and an existing multi-atlas-based method. A small pilot study comparing the volume and thickness measurements in a set of age-matched subjects with normal pressure hydrocephalus and healthy controls is presented to show the efficacy of the proposed method.

Parkinsonism Differentiates Idiopathic Normal Pressure Hydrocephalus from Its Mimics

BACKGROUND

Parkinsonism is frequent in neurological conditions affecting gait and cognition, such as idiopathic normal pressure hydrocephalus (iNPH) and iNPH mimics, but its discriminating value between these two groups is still unidentified.

OBJECTIVE

This study aims to compare the prevalence of parkinsonism between iNPH and iNPH mimics and its discriminating value.

METHODS

Among 141 patients with suspicion of iNPH (75.7±7.1 years; 31.2% women), seventy-nine presented a possible or probable iNPH according to standardized diagnostic criteria and the remaining sixty-two were classified as iNPH mimics. Presence of parkinsonism and other seminal clinical symptoms of iNPH were systematically evaluated by a board-certified neurologist. Covariates include age, gender, comorbidities, and white matter disease burden using the age-related white matter changes scale. Logistic regressions were used to assess the association between parkinsonism and diagnostic groups.

RESULTS

Parkinsonism was present in 40.3% of iNPH mimics and 20.3% of iNPH (p-value: 0.015). The presence of parkinsonism, but not iNPH symptoms, was associated with the diagnosis of mimics in the adjusted model (adjusted odds ratio: 2.28; 95% CI: 1.06-4.93), even when age-related white matter changes were accounted for.

CONCLUSION

Compared to iNPH, the increased prevalence of parkinsonism in patients with iNPH mimics in the absence of significant white matter disease suggest an underlying neurodegenerative mechanism.

Brain comorbidities in normal pressure hydrocephalus

BACKGROUND AND PURPOSE

This cross-sectional study aims to compare gait changes after the cerebrospinal fluid (CSF) tap test between normal pressure hydrocephalus patients with and without brain comorbidities (NPH+ and NPH- respectively) and then to identify significant contributors to a poor CSF tap test amongst individuals with NPH+.

METHODS

Gait changes (during the single task and the dual task of backward counting) were quantified before and 24 h after the CSF tap test with an optoelectronic system in 52 NPH patients (77.4 ± 6.0 years; 34.6% women). Changes after the CSF tap test in stride time variability (STV, %) were our main outcome. CSF Alzheimer's disease biomarkers, cerebrovascular white matter changes assessed with brain imaging and neurodegenerative diseases with parkinsonian syndrome represented the three individual brain comorbidities.

RESULTS

Brain comorbidities were frequently identified, NPH+ patients representing 40 patients of our sample (76.9%). NPH- patients improved their STV better in the single task (delta of STV = -58.6% ± 54.3% vs. -14.1% ± 62.0%; P = 0.031) and in the dual task (delta of STV =-32.2% ± 33.7% vs. 6.3% ± 58.4%; P = 0.028) after the CSF tap test than NPH+ patients. Amongst NPH+ individuals, only comorbid Alzheimer's disease was associated with STV increase (i.e. deterioration of gait) in the dual task [β 38.4; 95% confidence interval (5.64; 71.24); P = 0.023] after the CSF tap test, whilst it was borderline in the single task [β 35.0; 95% confidence interval (-1.97; 71.90); P = 0.063].

CONCLUSIONS

Brain comorbidities affect gait improvement after the CSF tap test in NPH patients; this influence is driven by Alzheimer's disease-related pathology.

Targeted Serum Metabolite Profiling Identifies Metabolic Signatures in Patients with Alzheimer's Disease, Normal Pressure Hydrocephalus and Brain Tumor

Progression to AD is preceded by elevated levels of 2,4-dihydroxybutanoic acid (2,4-DHB), implicating hypoxia in early pathogenesis. Since hypoxia may play a role in multiple CNS disorders, we investigated serum metabolite profiles across three disorders, AD, Normal Pressure Hydrocephalus (NPH) and brain tumors (BT). Blood samples were collected from 27 NPH and 20 BT patients. The profiles of 21 metabolites were examined. Additionally, data from 37 AD patients and 46 controls from a previous study were analyzed together with the newly acquired data. No differences in 2,4-DHB were found across AD, NPH and BT samples. In the BT group, the fatty acids were increased as compared to HC and NPH groups, while the ketone body 3-hydroxybutyrate was increased as compared to AD. Glutamic acid was increased in AD as compared to the HC group. In the AD group, 3-hydroxybutyrate tended to be decreased with respect to all other groups (mean values −30% or more), but the differences were not statistically significant. Serine was increased in NPH as compared to BT. In conclusion, AD, NPH and BT have different metabolic profiles. This preliminary study may help in identifying the blood based markers that are specific to these three CNS diseases.

Alteration of Venous Drainage Route in Idiopathic Normal Pressure Hydrocephalus and Normal Aging

Idiopathic normal pressure hydrocephalus (iNPH) is a highly prevalent condition in the elderly population; however, the underlying pathophysiology in relation to the aging process remains unclear. To investigate the effect of removal of cerebrospinal fluid by lumbar “tap test” on the cerebral circulation in patients with iNPH, 14 patients with “probable” iNPH were studied using a novel blood tracking technique based on blood oxygenation level-dependent (BOLD) magnetic resonance signal intensity. By tracking the propagation of the low-frequency component of the BOLD signal, extended venous drainage times were observed in the periventricular region of the patients, which was reversed by tap test. Interestingly, the venous drainage time in the periventricular region exhibited an age-related prolongation in the healthy control group. Additional regression analyses involving 81 control subjects revealed a dissociation of deep and superficial venous systems with increasing age, presumably reflecting focal inefficiency in the deep system. Our results not only provide insights into the etiology of iNPH, but also point to a potential non-invasive biomarker for screening iNPH.

Reversed aqueductal cerebrospinal fluid net flow in idiopathic normal pressure hydrocephalus

OBJECTIVES

The changes of CSF flow dynamics in idiopathic normal pressure hydrocephalus (iNPH) are not fully elucidated. Most previous studies took the whole cardiac cycle as a unit. In this work, it is divided into systole and diastole phase and compared between iNPH patients and normal elderly and paid special attention to the change of netflow direction.

MATERIALS AND METHODS

Twenty iNPH patients according to international guideline and twenty healthy volunteers were included in this study and examined by MRI. Three categories of CSF flow parameters were measured: peak velocity (V_peak ), stroke volume (SV), and minute flow volume (MinV) covering the whole cycle; peak velocity (V_peak-s , V_peak-d ) and flow volume (Vol_s , Vol_d ) of the systole and diastole, respectively; net flow. Evans index (EI) was also measured and compared statistically between the two groups.

RESULTS

EI, V_peak , SV, MinV, Vol_s , Vol_d , and V_peak-d significantly increased in iNPH group (P<0.05). V_peak-s of the two groups were not significantly different (P>0.05). The net flow of 16 iNPH patients (16/20) was in the caudo-cranial direction, while 15 volunteers (15/20) were in the opposite direction, which showed statistically significant differences (P=.001).

CONCLUSIONS

INPH patients present hyperdynamic flow with increased velocity and volume both in systole and diastole phase. Degree of rising in diastole phase exceeds that of systole phase. The resulting reversal of netflow direction may play a key role in the occurrence of ventriculomegaly in iNPH patients.

White Matter Changes in Corpus Callosum in a Patient with Idiopathic Normal Pressure Hydrocephalus

Idiopathic normal pressure hydrocephalus (INPH) is characterized by the clinical triad of gait and cognitive dysfunction and urinary incontinence. Ventriculoperitoneal (VP) shunting is often required for treatment. Review of literature shows few case reports discussing benign magnetic resonance imaging (MRI) T2 hyperintense changes in the corpus callosum of NPH patients after shunting due to mechanical compression of the middle and posterior regions of the body against falx cerebri leading to ischemic demyelination. These changes can be a delayed phenomenon and may interfere with clinical evaluation and may lead to unnecessary procedures and investigations. We present a patient with NPH who was admitted to the neurocritical care unit in coma with quetiapine and trazodone overdose. Diffuse changes in the body of the corpus callosum were seen on MRI suspicious for acute vasogenic edema due to drug overdose. However, it was later determined to be due to the VP shunting for the NPH. We report this case to raise the awareness of neuroimaging changes in patients with NPH who have VP shunting.

Use of programmable versus nonprogrammable shunts in the management of normal pressure hydrocephalus: A multicenter retrospective study with cost-benefit analysis in Turkey

Ventriculoperitoneal shunt systems that are used in the treatment of normal pressure hydrocephalus are often associated with drainage problems. Adjustable shunt systems can prevent or treat these problems, but they may be expensive. The aim of our study is to compare the complications and total cost of several shunt systems.Patients with normal pressure hydrocephalus who underwent ventriculoperitoneal shunting between 2011 and 2016 were included in the study. The study involves patient consent and the informed consent was given. Complications and the average cost per person were compared between patients with adjustable and nonadjustable shunts. Shunt prices, surgical complications, and revision costs were taken into account to calculate the average cost.Of the 110 patients who were evaluated, 80 had a nonadjustable shunt and 30 had an adjustable shunt. In the group with adjustable shunts, the rates of subdural effusion and hematoma were 19.73% and 3.29%, respectively. In the group with nonadjustable shunts, these rates were 22.75% and 13.75%, respectively. One patient in the adjustable group underwent surgery for subdural hematoma, while 8 patients in the nonadjustable group underwent the same surgery. Ten patients required surgical intervention for subdural effusion and existing shunt systems in these patients were replaced by an adjustable shunt system. When these additional costs were factored into the analysis, the difference in cost between the shunt systems was reduced from 600 United States dollars (USD) to 111 USD.When the complications and additional costs that arise during surgical treatment of normal pressure hydrocephalus were considered, the price difference between adjustable and nonadjustable shunt systems was estimated to be much lower.

Dynamic Susceptibility Contrast Perfusion Magnetic Resonance Imaging Demonstrates Reduced Periventricular Cerebral Blood Flow in Dogs with Ventriculomegaly

The nature of ventriculomegaly in dogs is still a matter of debate. Signs of increased intraventricular pressure and atrophy of the cerebral white matter have been found in dogs with ventriculomegaly, which would imply increased intraventricular pressure and, therefore, a pathological condition, i.e., to some extent. Reduced periventricular blood flow was found in people with high elevated intraventricular pressure. The aim of this study was to compare periventricular brain perfusion in dogs with and without ventriculomegaly using perfusion weighted-magnetic-resonance-imaging to clarify as to whether ventriculomegaly might be associated with an increase in intraventricular pressure. Perfusion was measured in 32 Cavalier King Charles spaniels (CKCS) with ventriculomegaly, 10 CKCSs were examined as a control group. Cerebral blood flow (CBF) was measured using free-hand regions of interest (ROI) in five brain regions: periventricular white matter, caudate nucleus, parietal cortex, hippocampus, and thalamus. CBF was significantly lower in the periventricular white matter of the dogs with ventriculomegaly (p = 0.0029) but not in the other ROIs. Reduction of periventricular CBF might imply increase of intraventricular pressure in ventriculomegaly.

Cerebrospinal Fluid Total Tau is Increased in Normal Pressure Hydrocephalus Patients who Undergo Successful Lumbar Drain Trials

BACKGROUND

Idiopathic normal pressure hydrocephalus (INPH) is a neurologic disease that affects <1% of those aged >65 years, but is difficult to distinguish from other diseases that present in this age group, such as Alzheimer's disease. Large volume lumbar puncture and an external lumbar drain trial (ELD) are used to make a clinical diagnosis of INPH, but the accuracy of ELD is suspected.

OBJECTIVE

To investigate proteomic cerebrospinal fluid (CSF) biomarker patterns in patients with INPH undergoing ELD to develop a quantitative diagnostic.

METHODS

Twenty patients with suspected INPH underwent an ELD trial and the CSF biomarkers AB_1-42, total tau, and tau phosphorylated at amino acid 181 (p-tau) were quantified with immunoassays in specimens taken prior to ELD placement, after the ELD trial, and from ventricular samples collected at the time of permanent ventriculoperitoneal shunt placement.

RESULTS

CSF total tau was elevated, on average, in pre- and post-ELD samples from patients who failed to improve clinically during the ELD trial, but the findings were marginally significant after correction for multiple comparisons. AB_1-42 and p-tau concentrations were not significantly different in patients who either did or did not clinically improve after the ELD.

CONCLUSIONS

CSF total tau is a potential novel biomarker for suspected INPH patients who will clinically improve, or have clinically improved, after an ELD trial. The small sample size of this study, which was due to the relative rarity of this condition, indicates that larger studies are needed to confirm the utility of this approach.

Cerebrospinal fluid dynamics study in communicating hydrocephalus

Context:

Communicating hydrocephalus often poses a challenge in diagnosis and management decisions.

Aims:

The objective of this study is to measure the opening pressure (P_o), pressure volume index (PVI), and cerebrospinal fluid outflow resistance (R_out), in patients with communicating hydrocephalus using bolus lumbar injection method and to evaluate its diagnostic and prognostic value.

Materials and Methods:

The study was conducted in 50 patients with communicating hydrocephalus, including normal pressure hydrocephalus (NPH) (19), post-meningitic hydrocephalus (23) and post-traumatic hydrocephalus (8). An improvised bolus lumbar injection method [the Madras Institute of Neurology (MIN) method] was used.

Results:

In the NPH Group, the CSF dynamics studies correlated well with the clinico-radiological classification. The prediction of shunt responsiveness by CSF dynamics studies correlated with good outcome in 87.5%. In the post-meningitic hydrocephalus group, the value of CSF dynamics studies in predicting patients needing shunt was 89.5%. The CSF dynamics studies detected patients who needed shunt earlier than clinical or radiological indications. In the post-traumatic hydrocephalus group, 62.5% of patients improved with the treatment based on CSF dynamics studies.

Conclusions:

The improvised bolus lumbar injection method (MIN method) is a very simple test with fairly reliable and reproducible results. Study of CSF dynamics is a valuable tool in communicating hydrocephalus for confirmation of diagnosis and predicting shunt responsiveness. This is the first time that the value of CSF dynamics has been studied in patients with post-meningitic hydrocephalus. It was also useful for early selection of cases for shunting and for identifying patients with atrophic ventriculomegaly, thereby avoiding unnecessary shunt.

Cerebrospinal fluid and blood flow patterns in idiopathic normal pressure hydrocephalus

OBJECTIVES

Increased aqueduct cerebrospinal fluid (CSF) flow pulsatility and, recently, a reversed CSF flow in the aqueduct have been suggested as hallmarks of idiopathic normal pressure hydrocephalus (INPH). However, these findings have not been adequately confirmed. Our objective was to investigate the flow of blood and CSF in INPH, as compared to healthy elderly, in order to clarify which flow parameters are related to the INPH pathophysiology.

MATERIALS AND METHODS

Sixteen INPH patients (73 years) and 35 healthy subjects (72 years) underwent phase-contrast magnetic resonance imaging (MRI). Measurements included aqueduct and cervical CSF flow, total arterial inflow (tCBF; i.e. carotid + vertebral arteries), and internal jugular vein flow. Flow pulsatility, net flow, and flow delays were compared (multiple linear regression, correcting for sex and age).

RESULTS

Aqueduct stroke volume was higher in INPH than healthy (148±95 vs 90±50 mL, P<.05). Net aqueduct CSF flow was similar in magnitude and direction. The cervical CSF stroke volume was lower (P<.05). The internal carotid artery net flow was lower in INPH (P<.05), although tCBF was not. No differences were found in internal jugular vein flow or flow delays.

CONCLUSIONS

The typical flow of blood and CSF in INPH was mainly characterized by increased CSF pulsatility in the aqueduct and reduced cervical CSF pulsatility. The direction of mean net aqueduct CSF flow was from the third to the fourth ventricle. Our findings may reflect the altered distribution of intracranial CSF volume in INPH, although the causality of these relationships is unclear.

Revisiting secondary normal pressure hydrocephalus: does it exist? A review

OBJECTIVE There are several etiologies that can lead to the development of secondary normal pressure hydrocephalus (sNPH). The aim of this study was to evaluate the etiology, diagnosis, treatment, and outcome in patients with sNPH and to highlight important differences between the separate etiologies. METHODS A comprehensive review of the literature was performed to identify studies conducted between 1965 and 2015 that included data regarding the etiology, treatment, diagnosis, and outcome in patients with sNPH. Sixty-four studies with a total of 1309 patients were included. The inclusion criteria of this study were articles that were written in English, included more than 2 patients with the diagnosis of sNPH, and contained data regarding the etiology, diagnosis, treatment, or outcome of NPH. The most common assessment of clinical improvement was based on the Stein and Langfitt grading scale or equivalent improvement on other alternative ordinal grading scales. RESULTS The main etiologies of sNPH were subarachnoid hemorrhage (SAH) in 46.5%, head trauma in 29%, intracranial malignancies in 6.2%, meningoencephalitis in 5%, and cerebrovascular disease in 4.5% of patients. In 71.9% of patients the sNPH was treated with ventriculoperitoneal shunt placement, and 24.4% had placement of a ventriculoatrial shunt. Clinical improvement after shunt placement was reported in 74.4% and excellent clinical improvement in 58% of patients with sNPH. The mean follow-up period after shunt placement was 13 months. Improvement was seen in 84.2% of patients with SAH, 83% of patients with head trauma, 86.4% of patients with brain tumors, 75% of patients with meningoencephalitis, and 64.7% of patients with NPH secondary to stroke. CONCLUSIONS Secondary NPH encompasses a diverse group of clinical manifestations associated with a subset of patients with acquired hydrocephalus. The most common etiologies of sNPH include SAH and traumatic brain injury. Secondary NPH does indeed exist, and should be differentiated from idiopathic NPH based on outcome and on clinical, pathophysiological, and epidemiological characteristics, but should not be considered as a separate entity.

The role of diffusion tensor imaging and fractional anisotropy in the evaluation of patients with idiopathic normal pressure hydrocephalus: a literature review

OBJECTIVE Diffusion tensor imaging (DTI) for the assessment of fractional anisotropy (FA) and involving measurements of mean diffusivity (MD) and apparent diffusion coefficient (ADC) represents a novel, MRI-based, noninvasive technique that may delineate microstructural changes in cerebral white matter (WM). For example, DTI may be used for the diagnosis and differentiation of idiopathic normal pressure hydrocephalus (iNPH) from other neurodegenerative diseases with similar imaging findings and clinical symptoms and signs. The goal of the current study was to identify and analyze recently published series on the use of DTI as a diagnostic tool. Moreover, the authors also explored the utility of DTI in identifying patients with iNPH who could be managed by surgical intervention. METHODS The authors performed a literature search of the PubMed database by using any possible combinations of the following terms: "Alzheimer's disease," "brain," "cerebrospinal fluid," "CSF," "diffusion tensor imaging," "DTI," "hydrocephalus," "idiopathic," "magnetic resonance imaging," "normal pressure," "Parkinson's disease," and "shunting." Moreover, all reference lists from the retrieved articles were reviewed to identify any additional pertinent articles. RESULTS The literature search retrieved 19 studies in which DTI was used for the identification and differentiation of iNPH from other neurodegenerative diseases. The DTI protocols involved different approaches, such as region of interest (ROI) methods, tract-based spatial statistics, voxel-based analysis, and delta-ADC analysis. The most studied anatomical regions were the periventricular WM areas, such as the internal capsule (IC), the corticospinal tract (CST), and the corpus callosum (CC). Patients with iNPH had significantly higher MD in the periventricular WM areas of the CST and the CC than had healthy controls. In addition, FA and ADCs were significantly higher in the CST of iNPH patients than in any other patients with other neurodegenerative diseases. Gait abnormalities of iNPH patients were statistically significantly and negatively correlated with FA in the CST and the minor forceps. Fractional anisotropy had a sensitivity of 94% and a specificity of 80% for diagnosing iNPH. Furthermore, FA and MD values in the CST, the IC, the anterior thalamic region, the fornix, and the hippocampus regions could help differentiate iNPH from Alzheimer or Parkinson disease. Interestingly, CSF drainage or ventriculoperitoneal shunting significantly modified FA and ADCs in iNPH patients whose condition clinically responded to these maneuvers. CONCLUSIONS Measurements of FA and MD significantly contribute to the detection of axonal loss and gliosis in the periventricular WM areas in patients with iNPH. Diffusion tensor imaging may also represent a valuable noninvasive method for differentiating iNPH from other neurodegenerative diseases. Moreover, DTI can detect dynamic changes in the WM tracts after lumbar drainage or shunting procedures and could help identify iNPH patients who may benefit from surgical intervention.

Disease duration: the key to accurate CSF tap test in iNPH

OBJECTIVES

The cerebrospinal fluid tap test for idiopathic normal pressure hydrocephalus (iNPH) is one of the good predictors of the shunt treatment, although this test has a low sensitivity. We aimed to identify key parameters that could be used to improve this sensitivity.

MATERIALS & METHODS

During 2010-2011, we recruited and then followed 93 patients with possible iNPH for 12 months after shunt. Among them, 82 patients were finally enrolled in this study. The modified Rankin Scale, iNPH grading scale, and several quantitative measurements were evaluated at entry, after the tap test, before and after shunt. Area under the receiver-operating characteristic curves (AUCs), sensitivities, and specificities of the tap test for predicting shunt effectiveness were calculated for each measurement. They were additionally assessed after stratification by disease duration since the initial presentation of iNPH symptoms.

RESULTS

The gait disturbance on the iNPH grading scale had the highest accurate scale at the tap test for predicting effectiveness 12 months after shunt: AUC 0.74, sensitivity 56.5%, specificity 91.7%. This AUC increased to 0.76, 0.91 and 0.94 in the subgroup of disease duration <24, <12, and <6 months, respectively. The sensitivity and specificity of the gait disturbance on the iNPH grading scale in the subgroup of <12 months' duration were 92.3% and 90.0%.

CONCLUSIONS

The shorter period of clinical symptoms, for example, <12 months, made the tap test sufficiently accurate examination for predicting improvement 12 months after shunt surgery. The findings imply that the tap test should be applied to patients being considered for shunt surgery as soon as possible.

Rare complication of ventriculoperitoneal shunt: Catheter protrusion to subcutaneous tissue - Case report

Background:

Ventriculoperitoneal (VP) shunt is a day-to-day procedure performed by a neurosurgeon. The most frequent associated complications are obstructive and infectious. Although rare, there are well-reported complications related to the poor positioning of the distal catheter, with perforation of organs and tissues. Still rarer are the complications related to the migration of this catheter.

Case Description:

We describe an atypical case of VP shunt postoperative by normal pressure hydrocephalus. After well-documented proper positioning of the distal catheter into the intraperitoneal cavity, it protruded into the subcutaneous space. Even on a new documented satisfactory abdominal tomography, this catheter migrated back again to the subcutaneous tissue.

Conclusion:

We did not find plausible explanation for this rare event.

Hakim-Adams Syndrome: An Unusual Cause of Reversible Postoperative Coma

We report the case of a 72-year-old patient presenting in our ICU with persistent postoperative coma in a context of recent unexplored neurological dysfunction. Detailed medical history taking from the patient's family revealed he recently suffered from gait instability, urinary incontinence, and slight cognitive impairment. These constituted the clinical triad of normal pressure hydrocephalus syndrome. The presence of normal cerebrospinal fluid (CSF) pressure and distinctive radiological findings confirmed the diagnosis of normal pressure hydrocephalus or Hakims-Adams syndrome. After CSF volume subtraction (soustraction), the patient recovered a normal level of consciousness and was successfully weaned from mechanical ventilation. Normal pressure hydrocephalus should be included in the differential diagnosis of delayed postoperative arousal, especially in the elderly.

A Curious Distal Tibiofibular Neuropathic Fracture: A Case Report

Hindfoot and distal leg neuropathic fracture collapse secondary to normal pressure hydrocephalus is a very rare clinical pathology. The authors present a case of a 69-year-old woman who sustained a distal tibiofibular fracture that resulted in a recurvatum deformity with idiopathic neuropathy and gait instability on initial presentation. A subtalar and ankle joint arthrodesis was performed achieving rectus alignment of the lower extremity with no postoperative complications. Her neuropathic etiology was negative for common causative factors, including diabetes, infection, nutritional deficiencies, congenital neuropathy, and trauma. Approximately 6 months postoperatively, the patient had persistent bilateral lower extremity weakness with the sensation of her "feet sticking to the floor" on ambulation. A referral to neurology revealed a normal pressure hydrocephalus as a possible etiology for her gait abnormalities and neuropathy. She required a ventriculoperitoneal shunt, with resolved gait disturbance and associated weakness approximately 1.5 years postoperatively.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Case report.

Association between shunt-responsive idiopathic normal pressure hydrocephalus and alcohol

OBJECTIVE Idiopathic normal pressure hydrocephalus (iNPH) is characterized by ventriculomegaly, gait difficulty, incontinence, and dementia. The symptoms can be ameliorated by CSF drainage. The object of this study was to identify factors associated with shunt-responsive iNPH. METHODS The authors reviewed the medical records of 529 patients who underwent shunt placement for iNPH at their institution between July 2001 and March 2015. Variables associated with shunt-responsive iNPH were identified using bivariate and multivariate analyses. Detailed alcohol consumption information was obtained for 328 patients and was used to examine the relationship between alcohol and shunt-responsive iNPH. A computerized patient registry from 2 academic medical centers was queried to determine the prevalence of alcohol abuse among 1665 iNPH patients. RESULTS Bivariate analysis identified associations between shunt-responsive iNPH and gait difficulty (OR 4.59, 95% CI 2.32-9.09; p < 0.0001), dementia (OR 1.79, 95% CI 1.14-2.80; p = 0.01), incontinence (OR 1.77, 95% CI 1.13-2.76; p = 0.01), and alcohol use (OR 1.98, 95% CI 1.23-3.16; p = 0.03). Borderline significance was observed for hyperlipidemia (OR 1.56, 95% CI 0.99-2.45; p = 0.054), a family history of hyperlipidemia (OR 3.09, 95% CI 0.93-10.26, p = 0.054), and diabetes (OR 1.83, 95% CI 0.96-3.51; p = 0.064). Multivariate analysis identified associations with gait difficulty (OR 3.98, 95% CI 1.81-8.77; p = 0.0006) and alcohol (OR 1.94, 95% CI 1.10-3.39; p = 0.04). Increased alcohol intake correlated with greater improvement after CSF drainage. Alcohol abuse was 2.5 times more prevalent among iNPH patients than matched controls. CONCLUSIONS Alcohol consumption is associated with the development of shunt-responsive iNPH.

Bulbar dysfunction in normal pressure hydrocephalus: a prospective study

OBJECTIVE Normal pressure hydrocephalus (NPH) is clinically characterized by gait disturbance, cognitive impairment, and urinary incontinence, as well as enlargement of the ventricles. To the best of the authors' knowledge, there have been no previous publications regarding the correlation between bulbar dysfunction and NPH. The primary objective of this study was to compare preoperative and postoperative prevalence of bulbar dysfunction in patients with NPH. Secondary objectives included assessing the results of surgery for swallowing, speech, gait, cognition, and urination, and evaluating the correlation between bulbar dysfunction and triad symptoms. METHODS Fifty-three patients with NPH who underwent shunt placement surgery at Siriraj Hospital were included in the study. Patients were evaluated for gait, cognition, urination, swallowing, and speech before and 6 months after shunt placement. Triad symptoms were assessed using standard methods. Bulbar dysfunctions were assessed using the Swallowing Problem Questionnaire, Thai Articulation Test, Resonation Screening Test (RST), and Thai Nasality Test. The Thai Speech Assessment Program and nasometer were used for objective speech measurement. RESULTS Preoperatively, 86% (43/50) of patients had swallowing problems and 75% (37/49) had speech problems, as measured by the RST. Postoperatively, there was significant improvement in swallowing (p < 0.001), speech problems by RST (p = 0.008), and voice volume (p = 0.009), but no significant change in the nasometer test. All triad symptoms were improved. There were significant correlations between swallowing impairment and gait disturbance (r = 0.358, p = 0.009), and RST and cognitive impairment (r = -0.502, p < 0.001). CONCLUSIONS This is the first study of bulbar dysfunction in patients with NPH. The results showed that the prevalence of bulbar dysfunction is very high. The correlation between bulbar dysfunction and the classic NPH triad has been documented and published. These bulbar symptoms also significantly improved after surgery. As such, bulbar dysfunction should be regarded as a core symptom that should be considered along with the classic triad in the clinical diagnosis and management of NPH.

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Zusammenfassung. Das Krankheitsbild des Normaldruckhydrocephalus ist seit 50 Jahren bekannt. Etwa genau so lange existiert mit der Möglichkeit einer internen Liquordrainage durch einen Liquorshunt die Möglichkeit einer effektiven Therapie. Moderne Shuntsysteme lassen sich sehr genau den Bedürfnissen der Patienten anpassen, und die operativen Eingriffe selbst haben nur noch eine sehr geringe Morbidität und Mortalität. Trotzdem wird nur ungefähr jeder zehnte Patient erkannt und einer Behandlung zugeführt. Bei Erfolgsaussichten von über 80% einer signifikanten Reduktion der Beschwerden entsteht für die unbehandelten Patienten, aber auch für die Gesellschaft, ein erheblicher Schaden durch den Verlust der Selbständigkeit und durch vermeidbare Pflegebedürftigkeit. Der Information über dieses Krankheitsbild und Aufklärung über die Abgrenzung gegenüber häufigen Differenzialdiagnosen kommt daher eine zentrale Bedeutung zu.

Asymmetric and Upper Body Parkinsonism in Patients with Idiopathic Normal-Pressure Hydrocephalus

Background and Purpose

Our aims were to analyze the characteristics of parkinsonian features and to characterize changes in parkinsonian motor symptoms before and after the cerebrospinal fluid tap test (CSFTT) in idiopathic normal-pressure hydrocephalus (INPH) patients.

Methods

INPH subjects were selected in consecutive order from a prospectively enrolled INPH registry. Fifty-five INPH patients (37 males) having a positive response to the CSFTT constituted the final sample for analysis. The mean age was 73.7±4.7 years. The pre-tap mean Unified Parkinson's Disease Rating Scale motor (UPDRS-III) score was 24.5±10.2.

Results

There was no significant difference between the upper and lower body UPDRS-III scores (p=0.174). The parkinsonian signs were asymmetrical in 32 of 55 patients (58.2%). At baseline, the Timed Up and Go Test and 10-meter walking test scores were positively correlated with the total motor score, global bradykinesia score, global rigidity score, upper body score, lower body score, and postural instability/gait difficulties score of UPDRS-III. After the CSFTT, the total motor score, global bradykinesia score, upper body score, and lower body score of UPDRS-III significantly improved (p<0.01). There was a significant decrease in the number of patients with asymmetric parkinsonism (p<0.05).

Conclusions

In the differential diagnosis of elderly patients presenting with asymmetric and upper body parkinsonism, we need to consider a diagnosis of INPH. The association between gait function and parkinsonism severity suggests the involvement of similar circuits producing gait and parkinsonian symptoms in INPH.

A Review of Clinical Outcomes for Gait and Other Variables in the Surgical Treatment of Idiopathic Normal Pressure Hydrocephalus

BACKGROUND

Idiopathic normal pressure hydrocephalus (INPH) is a treatable cause of gait disturbance, cognitive impairment, and urinary incontinence. This clinical triad of symptoms occurs in association with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. Although the treatment outcomes after CSF shunting for INPH have improved significantly since its first description in 1965, shortcomings in our understanding still remain. Not all INPH patients exhibit clinical improvement after shunting, and it is challenging to identify patients who are more likely to benefit from shunting.

METHODS

The Cochrane Library, Medline, Embase, and PubMed databases were searched for English-language publications between 1965 and October 2015. Reference lists of publications were also manually searched for additional publications.

RESULTS

The findings of this review indicate that, despite efforts to improve patient selection, the degree of clinical improvement after shunting continues to demonstrate significant variability both within and between studies. These discrepancies in treatment outcomes are the result of controversies in 3 distinct but interrelated domains: the underlying pathophysiology of INPH, the diagnosis of INPH, and the identification of likely shunt-responders.

CONCLUSIONS

This review focuses on these 3 areas and their relation to surgical treatment outcomes. Despite the limitations of published outcome studies and limitations in our understanding of INPH pathophysiology, shunting is a safe and effective means of achieving meaningful clinical improvement in most patients with INPH.

NPH Log: Validation of a New Assessment Tool Leading to Earlier Diagnosis of Normal Pressure Hydrocephalus

Introduction:

Early treatment of normal pressure hydrocephalus (NPH) yields better postoperative outcomes. Our current tests often fail to detect significant changes at early stages. We developed a new scoring system (LP log score) to determine if this tool is more sensitive in detecting clinical differences than current tests.

Material and Methods:

Sixty-two consecutive new patients with suspected idiopathic NPH were studied. Secondary, previously treated and obstructive cases were not included. We collected age, pre- and post-lumbar puncture (LP) Tinetti, Timed Up and Go (TUG) Test, European NPH scale, and LP log scores. The LP log score is recorded at baseline and for seven consecutive days after removing 40 cc of cerebrospinal fluid (CSF) via LP. We studied the diagnostic accuracy of the tests for surgical indication.

Results:

The post-LP log showed improvement in 90% of people with good baseline gait tests and in 93% of people who did not show any pre-LP and post-LP change in gait tests. Sensitivity, specificity, and accuracy to detect intention to treat when positive post-LP improvements were 4%, 100%, and 24%, respectively, for TUG, 21%, 86%, and 34%, respectively, for the Tinetti Mobility Test, 66%, 29%, and 58%, respectively, for Medical College of Virginia (MCV) grade, and 98%, 33%, and 85%, respectively, for LP log score. Pre-LP and post-LP TUG improvement and pre-LP and post-LP Tinetti improvement were not associated with a surgical indication (p > 0.05). LP log improvement was associated with surgical indication odds ratio (OR): 24.5 95% CI (2.4-248.12) (p = 0.007).

Conclusions:

LP log showed better sensitivity, diagnostic accuracy, and association with surgical indication than the current diagnostic approach. An LP log may be useful detecting NPH patients at earlier stages and, therefore, yield better surgical outcomes.

Hydrocephalus in Patient with Multiple System Atrophy: Innocent Bystander or Guilty Party?

Background

Normal pressure hydrocephalus (NPH) is a poorly understood condition, which typically presents with the triad of gait disturbance, urinary incontinence and cognitive decline. Diagnosis of NPH is often challenging due to its varied presentation and overlap with other neurodegenerative diseases including multiple system atrophy (MSA).

Case Report

A 68-year-old male developed rapidly progressive gait difficulty, urinary incontinence and memory impairment. Neurologic examination showed parkinsonism affecting the right side and impaired postural reflexes. Brain MRI showed enlargement of the ventricles and narrowing of the high convexity cerebrospinal fluid (CSF) spaces with relative dilated Sylvian fissure, the supporting features of NPH. 18F-fluorinated-N-3-fluoropropyl-2-b-carboxymethoxy-3-b-(4-iodophenyl) nortropane (¹⁸F-FP-CIT) PET showed decreased FP-CIT binding in the left posterior putamen and ¹⁸F-fluorodeoxyglucose PET showed decreased metabolism in the left basal ganglia, consistent with findings of MSA. CSF removal was performed and the symptoms were improved. The patient underwent ventriculo-peritoneal shunt and his gait and cognition improved.

Conclusions

NPH is a potentially treatable neurological disorder. Therefore, it is necessary to consider the possibility of accompanying NPH when hydrocephalus is present in other neurodegenerative diseases.

Risk of idiopathic normal pressure hydrocephalus in older inpatients with schizophrenia

BACKGROUND

The mean age of inpatients with schizophrenia has gradually increased in Japan and the risk of fracture in older schizophrenia patients is elevated. One possible cause may be idiopathic normal pressure hydrocephalus (iNPH). The present study aimed to evaluate the prevalence and symptoms of iNPH in older inpatients with schizophrenia.

METHODS

We prospectively examined older inpatients with schizophrenia (N = 21, mean age = 70.5 ± 5.9) in a psychiatric ward. We evaluated iNPH symptoms using the idiopathic Normal-Pressure Hydrocephalus Grading Scale (iNPHGS), Timed Up-and-Go test (TUG), Gait Status Scale (GSS), Mini-Mental State Examination (MMSE), and Neuropsychiatric Inventory (NPI). We also evaluated symptoms of schizophrenia using the Brief Psychiatric Rating Scale (BPRS) and Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). We conducted cerebrospinal fluid (CSF) tap tests for patients with possible-iNPH.

RESULTS

In total, three (14.3%) patients were diagnosed with possible iNPH: age, GS-Gait, GS-Cognition, TUG, 10-meter walking test, GSS, and DIEPSS were significantly increased in these compared to patients without iNPH; however, GS-Urine, MMSE, NPI, and BPRS did not differ significantly. Probable iNPH was diagnosed for two (9.5%) patients because of positive CSF tap tests.

CONCLUSION

The prevalence of possible and probable iNPH in older patients with schizophrenia was much higher than that reported for older people without mental illness. Of the symptoms evaluated with the tests employed, only gait disturbances, particularly walking speed, distinguished schizophrenia patients with iNPH. These findings suggest that we should pay more attention to the possibility of iNPH in older patients with schizophrenia.

Subdural haematoma complicating shunting for normal pressure hydrocephalus in the setting of concomitant antiplatelet medication - a report of 11 cases

OBJECTIVE

To report on the occurrence and management of subdural haematoma after shunt implantation for normal pressure hydrocephalus and to determine the risk of recurrence in the setting of antiplatelet medication.

METHODS

From a consecutive series of 80 patients implanted with a cerebrospinal fluid shunt for normal pressure hydrocephalus, records from 11 patients taking antiplatelet drugs, who subsequently had surgery for subdural haematoma were extracted and retrospectively reviewed.

RESULTS

Patients were followed up for a mean of 1819 days after shunt implantation. Subdural haematomas occurred at a median of 335 days after shunt implantation - four ipsilateral, five contralateral and two bilateral with respect to the ventricular catheter. Three patients had reoperations done within a week without having resumed antiplatelet medication in the interim. One of them had three further reoperations done before the subdural collection disappeared. Only one patient had a late recurrence almost 11 years after shunt implantation.

CONCLUSIONS

Subdural haematoma in the setting of a ventriculoperitoneal implantation for normal pressure hydrocephalus and concomitant antiplatelet medication can be managed along usual lines. Antiplatelet medication can be recommenced in due course with a low risk of recurrence.

Idiopathic Normal Pressure Hydrocephalus: A Review for General Practitioners

Idiopathic normal pressure hydrocephalus (iNPH) is a potentially reversible neurodegenerative disease commonly characterized by a triad of dementia, gait, and urinary disturbance. Advancements in diagnosis and treatment have aided in properly identifying and improving symptoms in patients. However, a large proportion of iNPH patients remain either undiagnosed or misdiagnosed. Using PubMed search engine of keywords "normal pressure hydrocephalus," "diagnosis," "shunt treatment," "biomarkers," "gait disturbances," "cognitive function," "neuropsychology," "imaging," and "pathogenesis," articles were obtained for this review. The majority of the articles were retrieved from the past 10 years. The purpose of this review article is to aid general practitioners in further understanding current findings on the pathogenesis, diagnosis, and treatment of iNPH.

Idiopathic normal pressure hydrocephalus: diagnostic and predictive value of clinical testing, lumbar drainage, and CSF dynamics

OBJECTIVE The aim of the study was to analyze the diagnostic and predictive values of clinical tests, CSF dynamics, and intracranial pulsatility tests, compared with external lumbar drainage (ELD), for shunt response in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS Sixty-eight consecutive patients with suspected iNPH were prospectively evaluated. Preoperative assessment included clinical tests, overnight intracranial pressure (ICP) monitoring, lumbar infusion test (LIFT), and ELD for 24-72 hours. Simple and multiple linear regression analyses were conducted to identify predictive parameters concerning the outcome after shunt therapy. RESULTS Positive response to ELD correctly predicted improvement after CSF diversion in 87.9% of the patients. A Mini-Mental State Examination (MMSE) value below 21 was associated with nonresponse after shunt insertion (specificity 93%, sensitivity 67%). Resistance to outflow of CSF (ROut) > 12 mm Hg/ml/min was false negative in 21% of patients. Intracranial pulsatility parameters yielded different results in various parameters (correlation coefficient between pulse amplitude and ICP, slow wave amplitude, and mean ICP) but did not correlate to outcome. In multiple linear regression analysis, a calculation of presurgical MMSE versus the value after ELD, ROut, and ICP amplitude quotient during LIFT was significantly associated with outcome (p = 0.04). CONCLUSIONS Despite a multitude of invasive tests, presurgical clinical testing and response to ELD yielded the best prediction for improvement of symptoms following surgery. The complication rate of invasive testing was 5.4%. Multiple and simple linear regression analyses indicated that outcome can only be predicted by a combination of parameters, in accordance with a multifactorial pathogenesis of iNPH.

Cerebrospinal fluid diversion in patients with enlarged Virchow-Robin spaces without ventriculomegaly

OBJECTIVE

Enlarged Virchow-Robin spaces (eVRS) are an MRI biomarker in several neurological diseases of inflammatory, neurodegenerative, vascular, metabolic, or genetic origin. We report on a further condition in which eVRS were observed in patients with an ongoing chronic hydrocephalus-like clinical picture without ventriculomegaly who improved after CSF diversion, and we discuss the possible mechanisms underlying this finding.

MATERIALS AND METHODS

A retrospective study of seven patients presenting progressive gait, cognitive, and urinary disturbances in association with eVRS was undertaken.

RESULTS

All patients presented an Evans ratio <0.30 and >20 eVRS at the level of basal ganglia and periventricular parenchyma as assessed by T2-weighted MRI. All patients underwent prolonged external lumbar drainage (PELD) with good response. Six patients received ventriculoperitoneal shunt with improvement of their clinical status compared to that before PELD (follow-up: 8-58 months, mean 24.6). The seventh patient did not undergo ventriculoperitoneal shunt and received a second PELD with persistent improvement (follow-up: 14 months).

CONCLUSIONS

Our results indicate that a mechanism involving CSF accumulation and stasis in the subarachnoid space was at least a concurrent factor of this clinical picture. This study should stimulate new perspectives on the role of CSF disturbances in the pathogenesis of diseases associated with VRS enlargement.

Ventriculoperitoneal shunt placement in poor-grade patients with chronic normal pressure hydrocephalus after aneurysmal subarachnoid haemorrhage

OBJECTIVE

The aim of this study was to analyse the shunt placement in patients who had normal pressure hydrocephalus after poor-grade aneurysmal subarachnoid haemorrhage (aSAH).

METHODS

Patients diagnosed with NPH after poor-grade aSAH were divided into a treatment group and control group, based on whether they had received ventriculoperitoneal shunt placement. The treatment group was then divided into an improvement group and non-improvement group according to their recovery. The Glasgow Outcome Scale and Mini Mental Scale Examination were used for 3 month and 1 year follow-up rehabilitation measures.

RESULTS

Of the 46 total patients, significant improvement was observed at the 3 month and 1 year follow-ups (p < 0.01) after shunt implantation in the treatment group compared to the control group. Furthermore, patients who were younger (p = 0.022), had better neurological function (higher Glasgow Coma Score, p < 0.01) and less severe hydrocephalus (lower EI, p < 0.01) appears to be more likely to benefit from the shunt.

CONCLUSIONS

Patients who had NPH due to poor-grade aSAH would benefit from shunt placement when given the correct candidates and timely management of shunt malfunction. Additionally, the curative effect of the shunt should have been regarded as a long-term goal of rehabilitation in these patients.

Neuroimaging in normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) is a syndrome characterized by the triad of gait disturbance, mental deterioration and urinary incontinence, associated with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. The clinical presentation (triad) may be atypical or incomplete, or mimicked by other diseases, hence the need for supplementary tests, particularly to predict postsurgical outcome, such as CSF tap-tests and computed tomography (CT) or magnetic resonance imaging (MRI). The CSF tap-test, especially the 3 to 5 days continuous external lumbar drainage of at least 150 ml/day, is the only procedure that simulates the effect of definitive shunt surgery, with high sensitivity (50-100%) and high positive predictive value (80-100%). According to international guidelines, the following are CT or MRI signs decisive for NPH diagnosis and selection of shunt-responsive patients: ventricular enlargement disproportionate to cerebral atrophy (Evans index >0.3), and associated ballooning of frontal horns; periventricular hyperintensities; corpus callosum thinning and elevation, with callosal angle between 40º and 90º; widening of temporal horns not fully explained by hippocampal atrophy; and aqueductal or fourth ventricular flow void; enlarged Sylvian fissures and basal cistern, and narrowing of sulci and subarachnoid spaces over the high convexity and midline surface of the brain. On the other hand, other imaging methods such as radionuclide cisternography, SPECT, PET, and also DTI or resting-state functional MRI, although suitable for NPH diagnosis, do not yet provide improved accuracy for identifying shunt-responsive cases.

Intracranial hypotension-like syndrome after a spinal tap test performed for idiopathic normal pressure hydrocephalus

It is somewhat unexpected to have headaches in patients with idiopathic normal pressure hydrocephalus (INPH) for which the treatment is drainage of cerebrospinal fluid (CSF) using shunt. Moreover, intracranial hypotension syndrome (IHS) can be a challenging diagnosis, as CSF leak may be difficult to confirm as imaging findings can be normal. This report describes a woman with INPH who developed symptoms of IHS after a spinal tap test. There might be cases with IHS, like our case, who do not completely fulfill the current diagnostic criteria in terms of not having any objective evidence of intracranial hypotension but who also could not be explained by other conditions and recovered totally after classical IHS treatment. Current diagnostic criteria for IHS might be revised for those having normal neuroimaging and not accepting lumbar puncture. Nevertheless, when the history, signs, and symptoms strongly suggest IHS even with normal imaging, treatment should be started immediately.

Neuroleptic malignant syndrome in an elderly patient with normal pressure hydrocephalus overlapping corticobasal degeneration

In this case report, neuroleptic malignant syndrome (NMS) in an elderly patient with normal pressure hydrocephalus overlapping corticobasal degeneration was reported. The case highlights the need for clinicians to be cautious when using dopaminergic medication in the elderly patients, since these agents have risks for NMS which is a life-threatening complication. Additionally, co-occurrence of primary and secondary parkinsonian dementia syndromes should be kept in mind to avoid additional complications in the elderly patients.

Apathy, ventriculomegaly and neurocognitive improvement following shunt surgery in normal pressure hydrocephalus

INTRODUCTION

Apathy - impaired motivation and goal-directed behaviour - is a common yet often overlooked symptom in normal pressure hydrocephalus (NPH). Caudate atrophy often yields apathetic symptoms; however, this structural and functional relationship has not yet been explored in NPH. Additionally, little is known about the relationship between apathy and post-shunt cognitive recovery.

METHODS

This audit investigated whether apathetic symptoms improve following shunt surgery in NPH, and whether this relates to cognitive response. In addition, we assessed the relationship between ventriculomegaly and apathy using the bicaudate ratio. Twenty-two patients with NPH completed the Mini-Mental State Examination (MMSE), the Apathy Evaluation Scale (AES) and the Geriatric Depression Scale (GDS) before and 3-9 months after shunt surgery. Pre-operative ventriculomegaly was correlated with pre-operative AES and GDS scores. Difference scores (post-shunt minus baseline values) for AES and GDS were correlated with cognitive outcome.

RESULTS

Greater pre-operative ventriculomegaly was associated with increased level of apathy and depression. A reduction in apathetic symptoms following shunt surgery was associated with improved performance on the MMSE.

CONCLUSIONS

Apathy may be indicative of a greater degree of subcortical atrophy in NPH and may relate to functional outcome.

Simple and reproducible linear measurements to determine ventricular enlargement in adults

Background:

Recent studies have suggested that Evan's Index (EI) is not accurate and instead endorse volumetric measurements. Our aim was to evaluate the reproducibility of linear measurements and their correlation to ventricular volume.

Methods:

Using magnetic resonance (MR) images of 30 patients referred for normal pressure hydrocephalus (NPH), EI, frontal-occipital horn ratio (FOR), third ventricular width and height, frontal horn width (FHW), and callosal angle (CA) at the foramen of Monro and the posterior commissure (PC) were independently measured by residents in neurosurgery and radiology, a neurosurgeon and radiologist, and a medical student. Intraclass correlation coefficients (ICC) were calculated to establish inter-rater agreement among the reviewers. Pearson's correlation coefficients were done to assess the relationship of the linear measurements with total ventricular volume. Kappa analyses were performed to assess the degree of agreement between cutpoints determined by the ROC analysis for the linear measurements and reviewers’ gestalt impression about ventricular size with volumetric abnormality.

Results:

The overall inter-rater agreement among reviewers was almost perfect for EI (ICC = 0.913), FOR (ICC = 0.830), third ventricular width, FHW (ICC = 0.88), and CA at PC (ICC = 0.865), substantial for temporal horn width (ICC = 0.729) and CA at foramen of Monro (ICC = 0.779), and moderate for third ventricular height (ICC = 0.496). EI, FOR, third ventricular width, temporal horn width, and CA at PC measures correlated with total ventricular volume. There was fair-to-almost-perfect agreement of the individual reviewer's gestalt responses of abnormatility with volumetric abnormality. Gestalt responses were better for more senior raters.

Conclusion:

Linear measurements are reliable and reproducible methods for determining ventricular enlargement.

Normal pressure hydrocephalus presenting as delusional disorder

Normal pressure hydrocephalus (NPH) is caused by aqueductal stenosis resulting in syndrome of gait disturbance, cognitive impairment, and urinary incontinence. Late onset psychosis should be evaluated thoroughly to rule out any organic cause. We present the case of a female patient presenting with delusions, gait disturbances, urinary incontinence in her 50s.