Idiopathic normal pressure hydrocephalus (iNPH) is a condition characterized by gait disturbance, dementia and/or urinary incontinence without causative disorders, as well as dilation of ventricular system due to disturbance of cerebrospinal fluid (CSF) circulation with normal CSF pressure and no secondary cause [1][2][3] . It is a differential diagnosis for most of the dementia syndromes and occurs mainly in elderly populations 4 .The known incidence is approximately 6 per 100,000 and it has a prevalence of 22 per 100,000 for suspected iNPH.There are associations with hypertension, cerebrovascular and Alzheimer diseases [1][2][3] .The clinical evolution of iNPH is not clear 5 . Without surgery, most iNPH patients present early clinical deterioration. A small number of patients might improve without shunting; however, the extent of improvement is not clear 3 .Ventricular CSF shunting is the main treatment in the management of iNPH and its results in reducing the caregiver's burden when caring for iNPH patients are well-established 6 .
ABSTRACTIdiopathic normal pressure hydrocephalus (iNPH) is characterized by gait disturbance, dementia and /or urinary incontinence, dilation of the ventricular system and normal opening cerebrospinal fluid pressure. Shunt surgery is the standard treatment of iNHP. Diversions with programmable valves are recommended, once drainage pressure can be changed. However, well-defined protocols still lack guiding the steps to attain proper pressure for each patient. Methods: In our study, we reported the experience of shunting 24 patients with iNPH using Strata ® (Medtronic) valve, following a protocol based on a positive Tap Test. Results: We observed clinical improvement in 20 patients and stability/ worsening in 4 patients. Complications occurred in five patients, including one death. The results display improvement, and complications occurred at a lower rate than reported in other studies. Conclusions: The Strata ® valve used in the proposed protocol represents an efficient and safe tool in the treatment of iNPH.Key words: hydrocephalus, normal pressure, cerebrospinal fluid shunts, treatment.
RESUMOA hidrocefalia de pressão normal idiopática (iNPH) é caracterizada por alterações na marcha, demência e/ou incontinência urinária, além de dilatação dos ventrículos com pressão normal de abertura no líquido cefalorraquidiano. A cirurgia de derivação é o principal tratamento da iNHP. São recomendadas válvulas programáveis, pois a pressão de drenagem pode ser alterada. Embora as válvulas programáveis sejam utilizadas, não há protocolos para atingir a pressão adequada de cada paciente. Métodos: Neste estudo, relatamos nossa experiência com 24 pacientes com iNPH que usaram a válvula Strata ® (Medtronic), seguindo protocolo baseado em um Tap test positivo. Resultados: Observamos melhora em 20 pacientes e estabilidade ou piora em 4. Ocorreram complicações em cinco pacientes, tendo um deles falecido. Houve importante melhora clínica, e as complicações ocorreram em taxa mais baixa do que as relatad...