Introduction: The association and mechanism involved in swallowing disturbance and normal pressure hydrocephalus (NPH) needs to be established. We report a case report where a patient who showed progressive swallowing dysfunction was diagnosed with secondary NPH.

Methods: We retrospectively identified, via the electronic medical charts, cases where the development of NPH had been associated with swallowing disturbance. The institutional review board at our hospital approved the retrospective review protocols of this study. Sixty-five cases of ventriculoperitoneal shunt surgery performed at our center were identified between 2012 and 2015. Among those, 28 cases had a positive medical record of swallowing dysfunction at time of NPH diagnosis. Among them, ten patients had full pre and postoperative swallowing function levels recorded by the videofluoroscopic swallowing studies. These patients had complained of swallowing function deterioration at least within 3 months before NPH diagnosis.

Results: Tractography analysis showed corticobulbar tract compression by ventricular dilation. Drainage operation led to the recovery of tract volume with an improvement of swallowing function.These ten cases had previously sustained brain lesions and the time interval between the initial bran lesion and when secondary NPH was diagnosed was 122 ± 168 days. All patients had shown deterioration of swallowing function compared to their previous states when they had sustained their initial brain lesions. Swallowing disturbance had rendered them dependent on total tube feedings. After shunt operation, many showed marked improvement to restart oral feeding

Conclusions: Our findings suggest that involvement of the corticobulbar tract may be a possible cause of dysphagia in secondary NPH that may be reversible after shunt operation.

Patient Care: Future studies that investigate the association of NPH and dysphagia and also determine whether these tract involvements are also observed in those with other classic idiopathic NPH are warranted. So this finding may help neurosurgeon to decide shunt operation for improving quality of life in elderly patients when the cause of dysphasia is considered as secondary NPH.

Learning Objectives: By the conclusion of this session, participants should be able to 1) Describe identify an effectiveness of shunt operation in patients with secondary NPH. 2) Discuss in small group, DTI has been used as a noninvasive diagnostic method to detect microstructural changes in hydrocephalus to help differentiate NPH from other neurodegenerative diseases and identify those that may respond to shunt placement.

References: 1. Assaf Y, Ben-Sira L, Constantini S, Chang LC, Beni-Adani L (2006) Diffusion tensor imaging in hydrocephalus: initial experience. AJNR Am J Neuroradiol 27:1717–1724 2. Bradley WG Jr (2016) Magnetic resonance imaging of normal pressure hydrocephalus. Semin Ultrasound CT MR 37:120–128 3. Chankaew E, Srirabheebhat P, Manochiopinig S, Witthiwej T, Benjamin I (2016) Bulbar dysfunction in normal pressure hydrocephalus: a prospective study. Neurosurg Focus 41, E15 4. Crary MA, Mann GD, Groher ME (2005) Initial psychometric assessment of a functional oral intake scale for dysphagia in stroke patients. Arch Phys Med Rehabil 86:1516–1520