Clinical studyPredicting the outcome of shunt surgery in normal pressure hydrocephalus
Introduction
Normal pressure hydrocephalus (NPH) was first described by Adams and Hakim1 as a clinical syndrome with the classic symptom triad of dementia, gait disturbance, and urinary incontinence combined with widening of the cerebral ventricles, but without overt symptoms or signs of raised intracranial pressure. The symptoms are potentially reversible, and diversion of cerebrospinal fluid (CSF) either by a ventriculoperitoneal, ventriculoatrial or lumboperitoneal shunt can be successful, provided a correct diagnosis has been made.
Patient selection for cerebrospinal fluid diversion in NPH is difficult and remains a diagnostic and therapeutic challenge: many patients do not display the classic clinical and neuroimaging patterns, NPH mimics other neurodegenerative disorders such as Binswanger disease (subcortical white matter arteriosclerotic encephalopathy) or Alzheimer’s disease and many patients with suspected NPH may suffer from both disorders and shunt procedures do not always result in clinical improvement. Hence, the usefulness of a shunt may be questioned. Even though the surgical procedure is technically simple, there are risks of complications, both short- and long-term, hence various methods and clinical tests have been used to predict the outcome of a shunt procedure.
In the study of any dementia or gait impairment syndrome, NPH is of particular interest as it may be treated and cured. However, prediction of which patients will benefit from surgery is one of the most important aspects of diagnosis.2 Our departments have used three methods for several years to select patients assumed to have NPH for shunt surgery: the repeated lumbar CSF tap test (RTT), lumbar external CSF drainage (LED) and radioisotope cisternography (RIC), explained in detail later.
We studied retrospectively the effectiveness of RTT, LED and RIC in predicting the outcome of shunt operations, as well as the diagnostic and prognostic value of periventricular hyperintensity (PVH) and of the clinical triad in 270 unselected patients with suspected NPH.
Section snippets
Material and methods
The study covers the period between December 1983 to December 2003, when 291 patients with suspected NPH were referred to the Departments of Neurosurgery at the University Hospital in Nancy, France and Haydarpasa Numune Education and Research Hospital in Istanbul, Turkey. The patients and close relatives were informed and gave their consent for all aspects of the treatment. They all fulfilled the clinical criteria of presumed NPH, but 21 had to be excluded for the following reasons: refusal to
Repeated lumbar CSF tap test
This test was performed on 155 patients and resulted in clinical improvements in 129, who were consequently shunted. Following surgery 111 of these were considered as having improved when evaluated according to the criteria mentioned previously. During follow-up 10 shunts needed revision because of temporary clinical deterioration; two ventricular and eight peritoneal catheters were revised. For 18 patients who did not improve after surgery, revision of their shunt was proposed, 10 accepted,
Discussion
Normal pressure hydrocephalus is in many ways a misnomer. Cerebrospinal fluid (CSF) pressure is not normal in these patients.[4], [11] The historical labelling NPH was based on the finding that all three reported patients by Adams and Hakim1 showed low CSF pressures at lumbar puncture, namely 150, 180, and 160 mm H2O. It is now widely recognized that a single, limited-in-time, CSF pressure measurement by lumbar puncture yields a poor estimation of the real intracranial pressure (ICP) profile of
Conclusion
The results suggest that both the RTT and the LED can accurately predict the outcome of shunt surgery prior to shunt procedures in patients with suspected NPH. The low costs and the simplicity of these tests compared to the invasiveness and the possibility of serious test-related complications of other tests show their usefulness in managing patients with presumed NPH. It has been shown that good results after shunting can be expected in patients showing improvement after a CSF tap test, so
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Impact of Subjective Evaluations in Predicting Response to Ventriculoperitoneal Shunt for Idiopathic Normal Pressure Hydrocephalus
2022, World NeurosurgeryCitation Excerpt :Permanent CSF diversion by ventriculoperitoneal (VP) shunt is the mainstay of treatment, with a favorable postoperative outcome in >70% of cases.11 Despite a large number of studies, reliable predictors of favorable outcomes after shunt surgery are still debated.5,12-17 Furthermore, surgery is associated with an overall complication rate of approximately 20%, with 16% shunt revision rate, 3% infection, 6% subdural hematoma, and 1% mortality.11
Evaluation of the effect comorbid Parkinson syndrome on normal pressure hydrocephalus assessment
2021, Clinical Neurology and NeurosurgeryCitation Excerpt :One of the most common comorbidities for NPH is Parkinson syndromes, with approximately 46.5–71% of patients with NPH also having evidence to suggest comorbid Parkinson syndromes [7,8]. Even with how common comorbid Parkinson syndromes are with NPH, evidence is sparse regarding the effect Parkinson syndromes have on diagnostic CSF TT [6]. New advances in imaging technology have helped clinicians in the differential diagnosis of Parkinson’s syndromes.
CSF tap test - Obsolete or appropriate test for predicting shunt responsiveness? A systemic review
2016, Journal of the Neurological SciencesCitation Excerpt :It seems that the amount of CSF removed affects certain parameters of the test validity; higher sensitivity and negative predictive values were observed in the studies where greater amounts of cerebrospinal fluid were removed [20,25] than in the studies of Malm [24], and Walchenbach [26]. This was also highlighted by Kilic et al. [30] and Damasceno [31]. They introduced the removal of larger amounts of fluid by repeating CSF-TT (RTT) during two or three consecutive days, removing 30–50 ml/d, to the total of 100–120 ml.
Nervous System
2014, Acute Care Handbook for Physical Therapists: Fourth EditionChapter 14 Normal Pressure Hydrocephalus<sup>1</sup>
2009, International Review of NeurobiologyCitation Excerpt :Both thrice repeated high volume (30–40 cc) and continuous lumbar drainage (150–250 cc over 3 days) had fairly good rates of improvement in gait disturbance (88 and 91%, respectively) whereas cisternography only had 66% responders (Kilic et al., 2007) (Figs. 3–6).