Normal pressure hydrocephalus: an update

Neurocognitive change over the course of a multiday external lumbar drain trial in patients with suspected normal pressure hydrocephalus

Objective: To characterize neurocognitive response to cerebrospinal fluid (CSF) diversion during a multiday external lumbar drainage (ELD) trial in patients with suspected normal pressure hydrocephalus (NPH). Methods: Inpatients (N = 70) undergoing an ELD trial as part of NPH evaluation participated. Cognition and balance were assessed using standardized measures before and after a three-day ELD trial. Cognitive change pre- to post-ELD trial was assessed in relation to change in balance, baseline neuroimaging findings, NPH symptoms, demographics, and other disease-relevant clinical parameters. Results: Multiday ELD resulted in significant cognitive improvement (particularly on measures of memory and language). This improvement was independent of demographics, test-retest interval, number of medical and psychiatric comorbidities, NPH symptom duration, estimated premorbid intelligence, baseline level of cognitive impairment, cerebrovascular disease burden, degree of ventriculomegaly, or other NPH-related morphological brain alterations. Balance scores evidenced a greater magnitude of improvement than cognitive scores and were weakly, but positively correlated with cognitive change scores. Conclusions: Findings suggest that cognitive improvement associated with a multiday ELD trial can be sufficiently captured with bedside neurocognitive testing. These findings support the utility of neuropsychological consultation, along with balance assessment, in informing clinical decision-making regarding responsiveness to temporary CSF diversion for patients undergoing elective NPH evaluation. Implications for the understanding of neuroanatomical and cognitive underpinnings of NPH are discussed.

Construction and verification of risk predicting models to evaluate the possibility of hydrocephalus following aneurysmal subarachnoid hemorrhage

BACKGROUND

Hydrocephalus following a ruptured aneurysm portends a poor prognosis. The authors aimed to establish a nomogram to predict the risk of hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

A total of 421 patients with aSAH who were diagnosed by digital subtraction angiography in The General Hospital of Northern Theater Command center from January 2020 to June 2021 were screened to establish the training cohort. An additional 135 patients who enrolled between July 2021 and May 2022 were used for the validation cohort. Variate difference analysis and stepwise logistic regression (model A) and univariate and multivariate logistic regressions (model B) were respectively used to construct two models. Then, the net reclassification improvement (NRI), integrated discrimination improvement (IDI), and receiver operating characteristic (ROC) curve were used to compare the predictive abilities of the two models. Finally, two nomograms were constructed and externally validated.

RESULTS

After screening, 556 patients were included. The area under the ROC curve of models A and B in the training cohort were respectively 0.884 (95 % confidence interval [CI]: 0.847-0.921) and 0.834 (95 % CI: 0.787-0.881). The prediction ability of the model A was superior to model B (NRI > 0, IDI > 0, p < 0.05). The C-index of models A and B was 0.8835 and 0.8392, respectively. Regarding clinical usefulness, the two models offered a net benefit with a threshold probability of between 0.12 and 1 in the decision curve analysis, suggesting that the two models can accurately predict hydrocephalus events.

CONCLUSIONS

Both models have good prediction accuracy. Compared with model B, model A has better discrimination and calibration. Further, the easy-to-use nomogram can help neurosurgeons to make rapid clinical decisions and apply early treatment measures in high-risk groups, which ultimately benefits patients.

Normal-Pressure Hydrocephalus-Like Appearance in Myotonic Dystrophy Type 1

Myotonic dystrophy type 1 (DM1) is one of the monogenic neurological diseases that neurologists most often experience. DM1 can develop several symptoms, including muscle weakness, gait disturbance, urinary incontinence, and cognitive decline. Other hand, normal pressure hydrocephalus (NPH) is more frequent in the elderly population and is characterized by a triad of symptoms, gait disturbance, urinary urge incontinence, and cognitive decline. Therefore, some symptoms overlap between DM1 and NPH. In this report, we described a case of DM1 that presented with a triad of NPH, and NPH-like changes in brain images. A 54-year-old man with DM1 visited our hospital for rehabilitation. He had a history of dyslipidemia, diabetes, and cataracts. He developed muscle weakness, blepharoptosis, and dysarthria at 43 years. Neuro-exam revealed percussion and grip myotonia, distal muscle weakness and atrophy, broad-based gait, and urinary incontinence. The mini-mental state examination score was 18. Brain magnetic resonance imaging revealed enlarged lateral and third ventricles and Evans index was 0.38 (NPH criterion; >0.3), which was mimicking for NPH. Tap test (TT) was evaluated twice. First TT improved clinical symptoms slightly, but second was unremarkable. Based on the second TT result, we could not diagnose with NPH and could prevent unnecessary surgical shunting. Brain imaging of DM1 can show an NPH-like appearance in patients older than 50. Although TT is the gold standard for diagnosing NPH, its sensitivity and specificity vary among reports. TT results should be interpreted with caution before performing a surgical shunt. If necessary, multiple TTs should be considered in DM1 patients.