Bulbar dysfunction in normal pressure hydrocephalus: a prospective study

Area of Science:

• Neurology
• Neurosurgery
• Speech and Hearing Sciences

Background:

• Normal pressure hydrocephalus (NPH) presents with gait disturbance, cognitive impairment, and urinary incontinence.
• Bulbar dysfunction has not been previously studied in correlation with NPH.

Purpose of the Study:

• To compare the prevalence of bulbar dysfunction before and after shunt surgery in NPH patients.
• To assess surgical outcomes for swallowing, speech, gait, cognition, and urination.
• To evaluate the correlation between bulbar dysfunction and the classic NPH triad symptoms.

Main Methods:

• Fifty-three NPH patients undergoing shunt placement were evaluated pre- and post-surgery (6 months).
• Bulbar function assessed via Swallowing Problem Questionnaire, Thai Articulation Test, Resonation Screening Test (RST), and Thai Nasality Test.
• Speech and nasometry used for objective speech measurement; triad symptoms assessed using standard methods.

Main Results:

• Preoperatively, 86% had swallowing and 75% had speech problems (RST).
• Postoperatively, significant improvements observed in swallowing (p < 0.001) and speech by RST (p = 0.008).
• Significant correlations found between swallowing and gait (r = 0.358, p = 0.009), and RST and cognition (r = -0.502, p < 0.001).

Conclusions:

• This is the first study to document high prevalence of bulbar dysfunction in NPH patients.
• Bulbar dysfunction correlates with classic NPH triad symptoms and improves significantly after shunt surgery.
• Bulbar dysfunction should be considered a core symptom in NPH diagnosis and management.