In normal pressure hydrocephalus, intracranial pressure monitoring is the only useful test

Good outcome in patients with normal-pressure hydrocephalus and factors indicating poor prognosis

OBJECT

The authors set out to describe the outcome in a subgroup of patients with normal-pressure hydrocephalus (NPH) in whom prognostic factors were poor. This subgroup of patients who had received shunts was selected according to strict criteria.

METHODS

From a cohort of 56 patients with NPH in whom shunts were placed, the authors selected a subgroup with four of the factors traditionally considered to indicate poor prognosis: idiopathic type, cortical atrophy, longstanding symptoms, and presence of dementia in addition to old age. Twelve patients met the inclusion criteria. After receiving shunts, 92% of the patients showed clinical improvement on the NPH scale; gait improved in 100% of patients, sphincter control in 90%, and dementia in 33%. Improvement was significant for gait and sphincter control, general NPH score, and most daily life activity scales. No significant differences regarding clinical, cognitive, or functional changes following surgery were found in comparison with the rest of patients (the good prognosis subgroup).

CONCLUSIONS

The clinical condition of patients with NPH who present with traditionally accepted markers of poor prognosis can improve after surgery, especially as regards gait and sphincter control. The authors assert that the presence of these markers should not be considered to be an absolute criterion for ruling out shunt surgery in cases of NPH syndrome.

Intraventricular or lumbar infusion test in adult communicating hydrocephalus? Practical consequences and clinical outcome of shunt operation

BACKGROUND

To investigate the therapeutic consequences of restricting the CSF dynamic evaluation to a lumbar infusion test (LIT), as opposed to our formerly applied intraventricular assessment (VIT), in patients with communicating hydrocephalus (CH).

METHOD

All patients over 18 years of age referred with clinical and radiological indication of treatment-requiring secondary CH (n = 50) or idiopathic normal-pressure hydrocephalus (INPH, n = 33) were subjected to a LIT. Subsequently, a combination of the results of the LIT (mainly the resistance to CSF outflow) and the clinical presentation determined whether to proceed with (a) VIT before a decision about shunt surgery, (b) shunt surgery or (c) no further diagnostic investigation or surgery.

FINDINGS

In 88 percent of the patients with secondary CH and 80 percent of the patients with INPH the decision on shunt surgery was made after performing exclusively a LIT. The shunting success rate was 90 percent in patients with secondary CH and 82 percent in patients with INPH, which however in the latter group decreased to 76 percent, when including the patients undergoing an additional VIT. The achieved shunt success rates are equal or better, compared to the results from previous studies using intraventricular assessment.

CONCLUSIONS

LIT and VIT are equally reliable for selecting shunt responsive patients with CH, using clinical improvement rate as the main criterion for comparison. The practical and economic consequences are substantial: the LIT can be performed in an outpatient setting, whereas VIT necessitates hospitalisation for 1-2 days including occupation of the neurosurgical theatre and postoperative neuro-intensive monitoring.

Is the placement of shunts in patients with idiopathic normal pressure hydrocephalus worth the risk? Results of a study based on continuous monitoring of intracranial pressure

Object. Data from many studies have demonstrated that shunt insertion in patients with idiopathic normal-pressure hydrocephalus (NPH) is associated with high morbidity and a lack of significant improvement; however, the use of strict diagnostic and treatment protocols can improve the results of surgery in these patients. The primary aim in this prospective study was to analyze the results of shunt placement in 43 patients with idiopathic NPH. A secondary aim was to determine the relationship between several clinical and neuroimaging factors, and patient outcome after surgery.

Methods. Thirty men and 13 women with a mean age of 71.1 ± 6.9 years participated in this study. All patients underwent clinical, neuropsychological, and radiological assessment before and 6 months after surgery. In all patients continuous monitoring of intracranial pressure was performed using a fiberoptic extradural sensor. In 31 patients cerebrospinal fluid dynamics were also determined. Eighty-six percent of patients showed clinical improvement after shunt insertion, 11.6% showed no change, and 2.3% exhibited some worsening. Gait improved in 81.4% of the patients, sphincter control in 69.8%, and cognitive dysfunction in 39.5%. There was no treatment-related death. Early or late postsurgical complications occurred in six patients (14%), although all of these complications were minor or were satisfactorily resolved. The complete clinical triad, cortical sulci size, and periventricular lucencies were related to outcome, whereas patient age, symptom duration, ventricular dilation, and the degree of presurgical dementia were unrelated to outcome.

Conclusions. Given the correct diagnosis, shunt insertion can produce marked improvement in patients with idiopathic NPH syndrome, causing few deaths and few clinically relevant complications.