Test Your Knowledge on Normal Pressure Hydrocephalus (NPH)

Update on Normal Pressure Hydrocephalus

• Normal Pressure Hydrocephalus (NPH) is a syndrome characterized by gait disturbance, urinary incontinence, and cognitive decline.

• NPH is more frequent in the elderly population.

• The diagnosis of NPH must be careful for an adequate selection of patients for treatment with ventricular shunt, since the symptoms are potentially reversible.

• The tap test has a high positive predictive value as a predictor of therapeutic response, but a negative test does not exclude the possibility of treatment.

• There have been recent debates challenging the classic concepts of NPH, including the theory of neurodegenerative NPH.

• The prevalence of NPH is difficult to estimate due to the inherent difficulties in diagnosis, but studies have shown an average prevalence of 1.1% in the elderly population.

• NPH has normal opening pressure on lumbar puncture and a disproportionate ventricular dilation to the cortical atrophy degree.

• The pathophysiology of NPH includes an inflammatory process of the arachnoid granulations, reduced CSF reabsorption, alteration of the CSF flow dynamics, and brain dysfunction, mainly subcortical dysfunction.

• The diagnosis of NPH is primarily based on history and neurological examination, with the classic triad of gait disturbance, cognitive deterioration, and urinary incontinence.

• Gait disturbance is the most frequent symptom and is labeled mainly as “apraxic gait” or “magnetic gait”.

• Cognitive decline is secondary to frontal-subcortical pathway dysfunction, which mainly leads to a slowing of information processing speed and executive dysfunction.

• Urinary symptoms are defined as an uninhibited neurogenic bladder, with urgency, increased frequency, with or without incontinence in the early stages.Diagnosis and Differential Diagnosis of Idiopathic Normal Pressure Hydrocephalus

• Idiopathic Normal Pressure Hydrocephalus (iNPH) is a neurological disorder that presents with gait disturbance, cognitive impairment, and urinary incontinence.

• The diagnosis of iNPH requires ruling out multiple possibilities of differential diagnosis, including neurodegenerative diseases and comorbidities that can lead to the cardinal symptoms of iNPH.

• Neuroimaging, including brain CT and MRI, is essential for diagnosis and exclusion of iNPH mimics. Ventriculomegaly is a key finding, but it is not specific to iNPH.

• SPECT and PET-CT can aid in the diagnosis, revealing hypometabolism in the periventricular and frontal regions, respectively.

• Magnetic resonance spectroscopy (MME) has been suggested as potentially useful in the diagnosis and follow-up of patients with iNPH, but its value is controversial.

• Radioisotope cisternography is useful for investigating CSF obstruction but is not indicated for the diagnosis of iNPH.

• The Tap Test is a simple, easy-to-perform pre-surgical evaluation that helps in the diagnosis when the response is positive. Gait is the symptom that most responds to the Tap Test.

• The CSF infusion test (CSF-IT) is based on the disturbance of CSF hydrodynamics observed in iNPH and is considered a central aspect of its pathophysiology. Its utility as a predictor of shunt response is controversial.

• CSF analysis is often normal, notably opening pressure, and can be used to rule out other pathologies.

• External lumbar drainage consists of the constant removal of CSF from the lumbar subarachnoid space and can be used to predict the response to the shunt, but its invasive profile limits its routine application.

• Ventricular shunting is the treatment of choice in iNPH, but it carries a potential risk of complications, and responses can be variable or short-term.

• Continuous monitoring of intracranial pressure and biomarkers may be useful in the evaluation and follow-up of patients with iNPH, but more studies are necessary to establish their utility.Diagnosis and Treatment of Normal Pressure Hydrocephalus

• Normal Pressure Hydrocephalus (NPH) is a relatively prevalent medical condition, especially in older age groups.

• The triad of gait disturbance, cognitive impairment, and urinary incontinence is well-known, but not present in all patients with NPH.

• Neuroimaging is essential to determine the typical findings of NPH, such as ventriculomegaly, DESH, and narrow callosal angle.

• The tap test is an objective evaluation of the clinical response and should be performed before indicating shunting in suggestive cases of NPH.

• Ventricular or lumbar shunting can be performed in patients with good response to the tap test, after careful discussion with the patient and family regarding the risks and benefits of the procedure.

• Patients with nonspecific symptoms and without benefit of the tap test should not be considered eligible for shunting.

• The immediate response to ventricular shunting is good, with evident clinical benefit in 90% and 80% of patients at six and 12 months after the procedure, respectively.

• The most sensitive parameter for evaluating response to shunting is gait, with around 83% of patients presenting improvement in gait evaluation.

• The risk of severe complications from shunting is estimated at 10-11%.

• Older age by itself is not considered a predictor of a bad response to shunting.

• LP shunting can be performed in patients with contraindications to ventricular shunting, but it has a greater risk of system malfunction.

• There is no evidence that the temporary benefit of ventricular shunting can be sustained over years, and there are no studies investigating the long-term outcome of patients not eligible for shunting.Diagnosis and Treatment of Normal Pressure Hydrocephalus: A Review of Literature

• Normal pressure hydrocephalus (NPH) is a neurological disorder that primarily affects older individuals and is characterized by an abnormal accumulation of cerebrospinal fluid (CSF) in the brain's ventricles.

• NPH is often misdiagnosed and underdiagnosed, with many patients initially being diagnosed with other conditions such as Alzheimer's disease or Parkinson's disease.

• The diagnosis of NPH involves a combination of clinical evaluation, imaging studies, and CSF pressure measurements.

• Treatment options for NPH include shunt surgery, which involves the insertion of a tube to drain excess CSF from the brain, and endoscopic third ventriculostomy (ETV), which involves creating a hole in the floor of the third ventricle to allow CSF to flow more freely.

• Shunt surgery is the most common treatment for NPH and has been shown to improve symptoms in many patients, although there is a risk of complications such as infection and overdrainage.

• ETV is a less invasive alternative to shunt surgery, but its effectiveness is still being studied and it may not be appropriate for all patients.

• The success of NPH treatment depends on proper patient selection, with patients who have a shorter duration of symptoms and a better response to CSF drainage being more likely to benefit from surgery.

• There are several diagnostic tests that can help predict which patients are likely to respond to shunt surgery, including external lumbar drainage, programmable shunt valves, and MRI-based measurements of the callosal angle.

• The long-term outcomes of NPH treatment are generally positive, with many patients experiencing significant improvement in their symptoms and quality of life.

• However, there is still a need for more research on the optimal diagnostic and treatment strategies for NPH, as well as the underlying mechanisms of the disease.

• Additionally, there are various factors that can influence NPH outcomes, such as age, comorbidities, and surgical technique, which should be taken into account when evaluating individual patients.

• Overall, NPH is a challenging but treatable condition that requires a multidisciplinary approach and careful consideration of each patient's unique circumstances.

Diagnosis and Differential Diagnosis of Idiopathic Normal Pressure Hydrocephalus: A Comprehensive Review

• Idiopathic Normal Pressure Hydrocephalus (iNPH) is a neurological disorder characterized by the triad of gait disturbance, cognitive impairment, and urinary incontinence.

• The diagnosis of iNPH requires a broad investigation to rule out its multiple possibilities of differential diagnosis, such as Parkinson's disease, vascular dementia, vascular Parkinsonism, and progressive supranuclear palsy.

• Neuroimaging showing ventriculomegaly is essential for diagnosis, as well as for excluding NPH mimics. Several findings are described and together they help to define the diagnosis, such as Evans index, flattening of the cortical sulci, marginal hypersignal to the lateral ventricles, dilation of the third ventricle, reduction of the callosal angle, and increased CSF flow in the Sylvius aqueduct.

• SPECT and PET-CT can aid in the diagnosis, revealing hypometabolism in the periventricular and frontal regions, respectively.

• The treatment of iNPH is surgical and carries a potential risk of complications. Tests that can predict the therapeutic response after surgery are indicated, such as the Tap Test, lumbar infusion resistance test, CSF analysis, continuous monitoring of intracranial pressure, and external lumbar drainage.

• The Tap Test is considered important as a pre-surgical evaluation and helps in the diagnosis when the response is positive. Gait improvement was prevalent, but cognitive response occurred in only two studies in the meta-analysis. Improvement in urinary continence was not observed.

• Lumbar infusion resistance test is performed by injecting saline or artificial CSF into the subarachnoid space and measuring the initial and final pressures (plateau) and then calculating resistance parameters. However, the utility of CSF-IT as a predictor of shunt response has been difficult to establish, due to conflicting results.

• CSF analysis is often normal, notably opening pressure, and can be used to rule out other pathologies. Regarding biomarkers, a reduction in proteins derived from the amyloid precursor (Aß38, Aß40 and Aß442) stands out, in contrast to the decline specific to the Aß42 found in the AD.

• Continuous monitoring of intracranial pressure is seen in the patients, especially during the night. Among the related alterations, the increase in the frequency of B waves is marked, particularly during REM sleep. The occurrence of B waves was associated with a greater response rate to shunting.

• External lumbar drainage consists of the constant removal of CSF from the lumbar subarachnoid space, with a drainage system connected to a valve and a collection bag. A positive response to the external lumbar drainage has been associated with an increased chance of responding to the shunt, but the negative predictive value is low.

• Ventricular shunting is the treatment ofDiagnosis and Management of Normal Pressure Hydrocephalus

• Normal pressure hydrocephalus (NPH) is a relatively prevalent medical condition, especially in older adults.

• The classic triad of gait disturbance, cognitive impairment, and urinary incontinence is not always present and should not be relied upon for diagnosis.

• Neuroimaging, particularly MRI, is essential for diagnosis and typical findings include ventriculomegaly, disproportionately enlarged subarachnoid space hydrocephalus (DESH), and narrow callosal angle.

• The tap test can help objectively evaluate clinical response to treatment, but careful patient selection is important in deciding whether to proceed with ventricular or lumbar shunting.

• Patients with nonspecific symptoms or asymptomatic ventriculomegaly should not be considered eligible for shunting.

• The immediate response to shunting is good, with 90% and 80% of patients showing clinical benefit at six and twelve months after the procedure, respectively.

• The most sensitive evaluation parameter for improvement is gait, with around 83% of patients showing improvement.

• There are different types of valves used for shunting, with adjustable valves being more appropriate due to fewer associated complications and a lower risk of system malfunction compared to fixed-pressure valves.

• The risk of severe complications associated with shunting is estimated at 10-11%.

• Older age is not considered a predictor of a poor response to shunting.

• Comorbidities that could influence the outcome or increase the procedure risk should be assessed in patients who are candidates for ventricular shunting.

• Long-term outcomes for patients who are not eligible for shunting are unknown, and there is no evidence that the temporary benefit of ventricular shunting can be sustained over years.Overview of Normal Pressure Hydrocephalus: Diagnosis and Treatment

• Normal pressure hydrocephalus (NPH) is a neurological disorder characterized by an enlarged ventricular system and cerebrospinal fluid (CSF) accumulation in the brain, leading to gait disturbance, cognitive decline, and urinary incontinence.

• The exact cause of NPH is unknown, but it has been associated with head trauma, meningitis, subarachnoid hemorrhage, and other conditions.

• Diagnosis of NPH involves a clinical evaluation, imaging studies (such as MRI and CT scans), and CSF tap tests.

• CSF tap tests involve removing a small amount of CSF through a lumbar puncture and assessing the patient's response to the removal of CSF.

• Cisternography, a nuclear medicine imaging study, can also be used to diagnose NPH and determine the presence of CSF flow obstruction.

• Treatment of NPH typically involves surgical placement of a shunt, which drains excess CSF from the brain into another part of the body, such as the abdomen.

• Shunt surgery can improve gait and cognitive symptoms in some patients with NPH, but not all patients respond to treatment.

• External lumbar drainage can also be used to predict the response to shunt surgery.

• Complications of shunt surgery include subdural hematomas, infections, and shunt malfunction or failure.

• Other potential treatments for NPH, such as endoscopic third ventriculostomy and lumboperitoneal shunting, are less commonly used and have varying success rates.

• There is ongoing research into the pathophysiology and treatment of NPH, including the use of SPECT/CT imaging and the development of new shunt devices.

• Early diagnosis and treatment of NPH may improve outcomes and quality of life for affected individuals.