Normal-Pressure Hydrocephalus, Sleep Apnea Syndrome, and Quality of Life in an Octagenarian

Prevalence of Alternative Diagnoses and Implications for Management in Idiopathic Normal Pressure Hydrocephalus Patients

BACKGROUND

Following Bayes theorem, ventriculomegaly and ataxia confer only a 30% chance of idiopathic Normal Pressure Hydrocephalus (NPH). When coupled with positive responses to best diagnostic testing (extended lumbar drainage), 70% of patients recommended for shunting will not actually have NPH. This is inadequate clinical care.

OBJECTIVE

To determine the proportion of alternative and treatable diagnoses in patients referred to a multidisciplinary NPH clinic.

METHODS

Patients without previously diagnosed NPH were queried from prospectively collected data. At least 1 neurosurgeon, cognitive neurologist, and neuropsychologist jointly formulated best treatment plans.

RESULTS

Of 328 total patients, 45% had an alternative diagnosis; 11% of all patients improved with treatment of an alternative diagnosis. Of 87 patients with treatable conditions, the highest frequency of pathologies included sleep disorders, and cervical stenosis, followed by Parkinson disease. Anti-cholinergic burden was a contributor for multiple patients. Of 142 patients undergoing lumbar puncture, 71% had positive responses and referred to surgery. Compared to NPH patients, mimickers were statistically significantly older with lower Montreal Cognitive Assessment (MoCA) score and worse gait parameters. Overall, 26% of the original patients underwent shunting. Pre-post testing revealed a statistically significant improved MoCA score and gait parameters in those patients who underwent surgery with follow-up.

CONCLUSION

Because the Multidisciplinary NPH Clinic selected only 26% for surgery (corroborating 30% in Bayes theorem), an overwhelming majority of patients with suspected NPH will harbor alternative diagnoses. Identification of contributing/confounding conditions will support the meticulous work-up necessary to appropriately manage patients without NPH while optimizing clinical responses to shunting in correctly diagnosed patients.

Decreased Cerebrospinal Fluid Flow Is Associated With Cognitive Deficit in Elderly Patients

Background: Disruptions in cerebrospinal fluid (CSF) flow during aging could compromise protein clearance from the brain and contribute to the etiology of Alzheimer’s Disease (AD).

Objective: To determine whether CSF flow is associated with cognitive deficit in elderly patients (>70 years).

Methods: We studied 92 patients admitted to our geriatric unit for non-acute reasons using phase-contrast magnetic resonance imaging (PC-MRI) to calculate their ventricular and spinal CSF flow, and assessed their global cognitive status, memory, executive functions, and praxis. Multivariable regressions with backward selection (criterion p < 0.15) were performed to determine associations between cognitive tests and ventricular and spinal CSF flow, adjusting for depression, anxiety, and cardiovascular risk factors.

Results: The cohort comprised 71 women (77%) and 21 (33%) men, aged 84.1 ± 5.2 years (range, 73–96). Net ventricular CSF flow was 52 ± 40 μL/cc (range, 0–210), and net spinal CSF flow was 500 ± 295 μL/cc (range, 0–1420). Ventricular CSF flow was associated with the number of BEC96 figures recognized (β = 0.18, CI, 0.02–0.33; p = 0.025). Spinal CSF flow was associated with the WAIS Digit Span Backward test (β = 0.06, CI, 0.01–0.12; p = 0.034), and categoric verbal fluency (β = 0.53, CI, 0.07–0.98; p = 0.024) and semantic verbal fluency (β = 0.55, CI, 0.07–1.02; p = 0.024).

Conclusion: Patients with lower CSF flow had significantly worse memory, visuo-constructive capacities, and verbal fluency. Alterations in CSF flow could contribute to some of the cognitive deficit observed in patients with AD. Diagnosis and treatment of CSF flow alterations in geriatric patients with neurocognitive disorders could contribute to the prevention of their cognitive decline.

Idiopathic normal-pressure hydrocephalus and obstructive sleep apnea are frequently associated: A prospective cohort study

BACKGROUND

Idiopathic normal-pressure hydrocephalus (iNPH) is defined by ventriculomegaly, cognitive decline, urinary incontinence and gait problems. Vascular risk factors (VRF) are associated with iNPH but obstructive sleep apnea (OSA) -a well-known independent VRF- is seldom mentioned.

METHODS

We investigated the presence of sleep-disordered breathing in a prospective cohort of 31 consecutive unselected patients with iNPH using sleep questionnaires and nocturnal polysomnography (PSG).

RESULTS

We found OSA in 90·3% (28/31) patients with iNPH; all had undiagnosed sleep abnormalities (snoring, awakenings, nocturia) and excessive daytime sleepiness (Epworth scale = 11·4 ± 6·4; normal <8). Nocturnal PSG showed moderate-to-severe OSA in 25 patients (80·6%) with mean apnea-hypopnea index (AHI) 31·6 ± 23·6/h; mean respiratory distress index (RDI) 34·5/h; and, mean SaO₂ desaturation at nadir, 82·2 ± 7·5%. The observed OSA prevalence is statistically significant: 90·3%, 95%CI 74·3-97·5; p = 0·000007. Other VRF included overweight body-mass index (BMI >25- < 30 kg/m²) in 59%, hyperhomocysteinemia 57%, hypertension 43%, hyperlipidemia 39%, diabetes 32%, smoking 21%, coronary disease 18%, and previous stroke 10%.

CONCLUSION

Abnormal sleep breathing is frequently associated with iNPH. Validation in larger series is required but we suggest including sleep evaluation in patients suspected of iNPH.

Nonmotor Symptoms in Vascular and Other Secondary Parkinsonism

Vascular parkinsonism (VP) is a relatively frequent variant of secondary parkinsonism caused by ischemic or hemorrhagic lesions of basal ganglia, midbrain, or their links with frontal cortex. According to different investigations, various forms of cerebrovascular disease cause 1%-15% of parkinsonism cases. Nonmotor symptoms are frequently found in VP and may negatively influence on quality of life. However, nonmotor symptoms such as hallucinations, orthostatic hypotension, REM-sleep behavior disorder, and anosmia are rarely revealed in VP, which may be noted to another diagnosis or mixed pathology. Clinical value of nonmotor symptoms in normal pressure hydrocephalus, toxic, and drug-induced parkinsonism is also discussed.