Katrin Rabiei

Prevalence of idiopathic normal-pressure hydrocephalus.

Objectives: The aim of this study was to determine the prevalence of idiopathic normal-pressure hydrocephalus (iNPH) in elderly persons in a large population-based sample using radiologic and clinical examinations. Methods: We examined representative elderly populations aged 70 years and older that had undergone neuropsychiatric evaluations and CT of the brain between 1986 and 2000 (n = 1,238). Gait was evaluated by clinical examination and history of walking difficulty. Cognitive function was evaluated with the Mini-Mental State Examination and urinary incontinence by self-report. iNPH was diagnosed in concordance with the American-European iNPH guidelines. Exclusion criteria were history of meningitis, severe head trauma, and subarachnoid hemorrhage. Results: The prevalence of probable iNPH was 0.2% in those aged 70–79 years (n = 2) and 5.9% (n = 24) in those aged 80 years and older, with no difference between men and women. Only 2 of these persons had been treated for iNPH. Hydrocephalic ventricular enlargement, i.e., a CT image consistent with NPH, was found in 56 persons (4.5%). An Evans Index >0.3 was found in 256 (20.7%) and occluded sulci at the high convexity in 67 persons (5.4%). All of these findings were more common in the older age groups. Conclusions: Many elderly possess clinical and imaging features of iNPH, especially those older than 80 years. The number of persons with iNPH is probably much higher than the number of persons currently treated.

Vascular factors in suspected normal pressure hydrocephalus: A population-based study

Objective: We examined clinical and imaging findings of suspected idiopathic normal pressure hydrocephalus (iNPH) in relation to vascular risk factors and white matter lesions (WMLs), using a nested case-control design in a representative, population-based sample. Methods: From a population-based sample, 1,235 persons aged 70 years or older were examined with CT of the brain between 1986 and 2000. We identified 55 persons with hydrocephalic ventricular enlargement, i.e., radiologic findings consistent with iNPH. Among these, 26 had clinical signs that fulfilled international guideline criteria for probable iNPH. These cases were labeled suspected iNPH. Each case was matched to 5 controls from the same sample, based on age, sex, and study cohort. Data on risk factors were obtained from clinical examinations and the Swedish Hospital Discharge Register. History of hypertension, diabetes mellitus (DM), smoking, overweight, history of coronary artery disease, stroke/TIA, and WMLs on CT were examined. Risk factors associated with iNPH with a p value <0.1 in χ2 tests were included in conditional logistic regression models. Results: In the regression analyses, suspected iNPH was related to moderate to severe WMLs (odds ratio [OR] 5.2; 95% confidence interval [CI]: 1.5–17.6), while hydrocephalic ventricular enlargement was related to hypertension (OR 2.7; 95% CI: 1.1–6.8), moderate to severe WMLs (OR 6.5; 95% CI: 2.1–20.3), and DM (OR 4.3; 95% CI: 1.1–16.3). Conclusions: Hypertension, WMLs, and DM were related to clinical and imaging features of iNPH, suggesting that vascular mechanisms are involved in the pathophysiology. These findings might have implications for understanding disease mechanisms in iNPH and possibly prevention.

Diverse arachnoid cyst morphology indicates different pathophysiological origins

BackgroundThere are few, limited, and to some extent contradictory, reports on the cellular and subcellular morphology of arachnoid cysts. In the literature cyst membranes are described as similar to, or as vastly different from, normal arachnoid membranes.MethodsThis paper reports electron microscopic analyses of symptomatic cysts from 24 patients (12 males and 12 females; age 10–79), that underwent fenestration surgery. Fourteen cysts were located in the middle cranial fossa (temporal), one in the interpeduncular cistern, five in the posterior fossa, and four were overlying the frontal cortex.ResultsMicroscopic findings confirmed the diverse nature of this clinical condition. Twelve cyst walls resembled normal arachnoid, four had a conspicuous core of dense fibrous tissue with a simple epithelial lining, and the remaining aberrant cysts exhibited non-arachnoid luminal epithelia with plentiful microvilli and/or cilia, and also nervous tissue components in the wall. The possible identity and origin of various cyst types are discussed. We hypothesize that cysts are formed mostly at an early stage of embryonic development, as a teratological event.ConclusionsCysts with various epithelial linings and extracellular components most likely have different barrier properties and fluid turnover characteristics. Further studies are needed to elucidate relations between cyst morphology, fluid composition, pathogenesis, and clinical behaviour including growth rate and relapse tendency.

Mortality and risk of dementia in normal-pressure hydrocephalus: A population study

We examined mortality, dementia, and progression of hydrocephalic symptoms among untreated individuals with idiopathic normal‐pressure hydrocephalus (iNPH) in a population‐based sample.

Estimated ventricle size using Evans index: reference values from a population-based sample.

Evans index is an estimate of ventricular size used in the diagnosis of idiopathic normal‐pressure hydrocephalus (iNPH). Values >0.3 are considered pathological and are required by guidelines for the diagnosis of iNPH. However, there are no previous epidemiological studies on Evans index, and normal values in adults are thus not precisely known. We examined a representative sample to obtain reference values and descriptive data on Evans index.

Does subjective improvement in adults with intracranial arachnoid cysts justify surgical treatment

OBJECTIVE Subjective improvement of patients who have undergone surgery for intracranial arachnoid cysts has justified surgical treatment. The current study aimed to evaluate the outcome of surgical treatment for arachnoid cysts using standardized interviews and assessments of neuropsychological function and balance. The relationship between arachnoid cyst location, postoperative improvement, and arachnoid cyst volume was also examined. METHODS The authors performed a prospective, population-based study. One hundred nine patients underwent neurological, neuropsychological, and physiotherapeutic examinations. The arachnoid cysts were considered symptomatic in 75 patients, 53 of whom agreed to undergo surgery. In 32 patients, results of the differential diagnosis revealed that the symptoms were due to a different underlying condition and were unrelated to an arachnoid cyst. Neuropsychological testing included target reaction time, Grooved Pegboard, Rey Auditory Verbal Learning, Rey Osterrieth complex figure, and Stroop tests. Balance tests included the extended Falls Efficacy Scale, Romberg, and sharpened Romberg with open and closed eyes. The tests were repeated 5 months postoperatively. Cyst volume was pre- and postoperatively measured using OsiriX software. RESULTS Patients who underwent surgery did not have results on balance and neuropsychological tests that were different from patients who declined or had symptoms unrelated to the arachnoid cyst. Patients with a temporal arachnoid cyst performed within the normal range on the neuropsychological tests. Seventy-seven percent of the patients who underwent surgery reported improvement, yet there were no differences in test results before and after surgery. Arachnoid cysts in the temporal region and posterior fossa did not influence the preoperative results of neuropsychological and motor tests. The arachnoid cyst volume decreased postoperatively (p < 0.0001), but there was no relationship between volume reduction and clinical improvement. CONCLUSIONS The results of this study speak against objectively verifiable improvement following surgical treatment in adults with intracranial arachnoid cysts.

Ultrastructure of Arachnoid Cysts

Abstract Arachnoid cyst (AC) morphology has been studied in a few cases and described to be similar to that of the arachnoid membrane. However, there are a rather large number of reports that describe cysts with a different morphological appearance compared to the classic description of AC. In a systematic study of 24 consecutive cases of ACs, three different types of cyst could be described, all residing in the subarachnoid space. This chapter gives an overview of the AC wall morphology as well as findings of immunohistochemical studies. A brief description of the differential diagnosis of ACs is also provided, followed by a discussion on the similarities in morphological appearance of the different intracranial cysts.

Mortality and dementia in untreated iNPH: a 25-year follow-up of a population-based cohort.

We examined mortality and risk of dementia in persons with untreated possible and probable iNPH using a large, prospective population-based cohort.

Clinical signs and symptoms of adult patients with intracranial arachnoid cysts

Background Patients with arachnoid cysts have a wide range of symptoms from asymptomatic to a variety of symptoms and signs. Indication for surgical treatment can be challenging in case of the most common symptoms; headache and vertigo which are both subjective and common. The aim of this prospective study was to describe variety of symptoms in relation to cyst location and volume and their response to treatment.

Long term follow up after surgery for benign intracranial cysts in children

Arachnoid cysts are cystic malformations in cerebrospinal axis found in both adults and children. While most arachnoid cysts are asymptomatic and usually go undetected, some cause symptoms and warrant surgical treatment. In this prospective study we aimed to describe the result of short- and long term follow up in children referred to our center with a cystic malformation.