Seventy four consecutive patients diagnosed as normal pressure hydrocephalus (NPH) and operated with a ventriculo-peritoneal shunt were followed prospectively for an average of 2.1 years. The mean age was 64 years. The effect of the operation was estimated by calculating 6 indices expression social functioning, neurological signs, gait ability, continence, psychometric performance and psychiatric condition. Ninety-six % had mental symptoms, 95% gait disturbances and 75% incontinence. Improvement was observed in 78% after shunt surgery, while 22% deteriorated. Psychiatric improvement was seen in 80% and 76% improved in gait ability. Improvement was highest in the group caused by subarachnoid hemorrhage (98%) while 73% with idiopathic NPH improved. Old age was not correlated to poorer response, while long-standing pre-operative symptoms yielded worse results. No single symptom or sign could predict a positive outcome of the operation. Eleven % of the patients could leave long-term care institutions and there was a 36% reduction of aid in daily living. Complications to shunt surgery were observed in 50% of the patients and shunt related mortality was 1%. Shunt malfunction was the most frequent complication (31%) followed by infection (19%). Epilepsy developed in 9% after surgery. All shunt complication except one appeared within the first year after surgery.

This study demonstrates no factual support for existence of a transmantle pressure gradient in nonacute communicating or noncommunicating hydrocephalus.

Relative regional cerebral blood flow (rrCBF) was measured by single-photon emission tomography (SPET), using technetium-99m-d,l-hexamethylpropylene amine oxime (HMPAO) as flow tracer, in 23 patients with normal pressure hydrocephalus (NPH). 1000 MBq 99mTc-HMPAO was given intravenously and the rrCBF calculated as regional/cerebellar count level ratios. The patients were examined before and 3-12 months after ventriculoperitoneal shunt surgery. rrCBF was also determined in ten healthy aged matched volunteers who served as controls. The NPH patients had decreased rrCBF in the hippocampal regions and in the frontal and parietal white matter as compared to the controls. The frontal/parietal rrCBF ratio correlated with both psychiatric disability and the preoperative degree of incontinence. Decreased flow in frontal white matter, frontoparietal and hippocampal grey matter and a low frontalparietal grey matter flow ratio preoperatively correlated with improvement in both Mini Mental State score and psychiatric disability after shunt surgery. After shunt surgery the rrCBF increased in the mesencephalon, frontal grey and white matter, parietal white matter and hippocampus. The flow increase in hippocampal regions and frontal white matter correlated with improvement in psychiatric symptomatology. The results of this study regarding the frontal and hippocampal rrCBF patterns, and the clinical correlation, support the hypothesis that CBF changes in these regions are of pathophysiological and prognostic importance in NPH.

R(out) intraventricularly and in the subarachnoid space could not predict the outcome of the ETV, but the reduction in R(out) correlated positively with clinical improvement. Preoperative elastance correlated positively with clinical improvement, and elastance was unchanged after ETV. Clinical improvement correlated positively with reduction in ventricle size.

A prospective developmental assessment was performed on 26 patients operated on with dynamic cranioplasty for sagittal synostosis. Because this technique entails the application of compressive force, it was of great concern to assess the effect of surgery on development and mental status. The surgical technique used was a modified pi procedure. Perioperative variables were recorded. Six patients underwent preoperative intracranial pressure (ICP) measurements. To evaluate objectively the developmental outcome, the Griffiths' Mental Development Scales was used for analysis before and after surgery. A parental questionnaire was used for subjective outcome measurement. Preoperative ICP recordings during sleep ranged from 12.8 to 22.8 mmHg (mean, 16.1 mmHg). The mean age at the time for surgery was 6.9 months (range, 4-16 months; standard deviation [SD], 2.32 months). The surgical technique included shortening of the anteroposterior diameter of the skull by a mean of 16.6 mm. The mean global development quotient (GDQ) preoperatively was 104.5 (range, 82-144; SD, 12.4) and the mean GDQ postoperatively was 101.4 (range, 62-129; SD, 13.6). Mean age at follow-up was 16.3 months (range, 9-40 months; SD, 4.04 months). There was no significant correlation between the amount of intraoperative shortening and mental development. In comparison of means, the GDQ preoperatively did not differ significantly from the GDQ postoperatively. The modified pi procedure is safe and efficient. When surgery was performed before 1 year of age, no significant (p = 0.33) effect on mental development-either detrimental or beneficial-was demonstrated.

A therapy focusing on treatment of the assumed vasogenic edema in combination with aggressive neurosurgery resulted in an outcome as good as the best previously reported.

Background: B waves, slow and rhythmic oscillations in intracranial pressure (ICP), are claimed to be one of the best predictors of outcome after surgery for normal pressure hydrocephalus (NPH). Object: To determine the relation between the percentage of B waves and outcome in patients with hydrocephalus, and also the diurnal variation of B waves. Methods: ICP and patient behaviour were recorded overnight (17 to 26 hours) in 29 patients with noncommunicating hydrocephalus and 26 with NPH. The B wave activity, measured with an amplitude threshold of 0.5, 0.75, 1.0, 1.5, 2.0, 3.0, and 5.0 mm Hg, was estimated as the percentage of total monitoring time (% B waves) using a computer algorithm, and correlated with postoperative outcome, defined as changes in 12 standardised symptoms and signs. Results: There was no linear correlation between improvement after surgery in the 55 patients and total % B waves, but a correlation was found between improvement and % B waves during sleep (r = 0.39, p = 0.04). The percentage of B waves was the same during sleep and wakefulness, and patients with NPH had the same proportion of B waves as the non-communicating patients. Conclusions: B waves are commonly observed in patients with both communicating and noncommunicating hydrocephalus, but are only weakly related to the degree of postsurgical improvement.

In our experience, the long-term effectiveness of ETVs for adult patients with noncommunicating hydrocephalus was sufficient in only 50% of the cases. One-third of the patients exhibited temporary improvements, lasting 1 to 12 months (average duration, 5 mo) after the ETVs, and then demonstrated deterioration to even worse clinical conditions, despite patent ventriculostomies. All patients who did not exhibit permanent improvements after the ETVs benefited from shunt surgery. Efforts should be made to establish methods for the selection of patients for ETV or ventriculoperitoneal shunt surgery.