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  • Importance of the Second Day of Testing in a Two-Day Outpatient Lumbar Tap Trial (LTT)

    Final Number:

    Dorian Mambelli MD Candidate; Jody Leonardo MD

    Study Design:

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2018 Annual Meeting

    Introduction: Selecting patients with hydrocephalus who might benefit from shunt surgery is challenging. Current methods such as external lumbar drainage (ELD) requires in-patient monitoring for three to four days and exposes patients to unnecessary risks. In this prospective study we utilize specialized objective gait measurements to assess if a two-day outpatient lumbar tap trial can reliably predict shunt responsiveness.

    Methods: Forty-two patients with suspected communicating hydrocephalus were diagnosed based on a history and physical exam, the presence of gait dysfunction, and ventriculomegaly on imaging. Work-up was performed by a neurosurgeon and a physical therapist who specializes in gait abnormalities. Timed walk (TW), timed up and go (TUG), and timed up and go with a cognitive distractor (TUGD) measurements were obtained immediately before and after high volume CSF diversion. Repeat measurements were obtained on post-tap day two. Patients who demonstrated pre-defined improvements in times were offered a shunt. Within one month of shunt surgery patients returned for follow-up evaluation.

    Results: Twenty-three patients responded positively to the LTT and underwent a shunt procedure. On post-tap day two the percentage of patients demonstrating improvement from immediate post-tap measurements was greater among LTT responders (79% vs. 78% in TW, 79% vs. 44% in TUG, and 74% vs. 67% in TUGD). Degree of improvement during the same interval was also greater among LTT responders (7.71% vs 5.45% in TW, 7.69% vs. -6.18% in TUG, and 4.37% vs. -12.85% in TUGD). After shunt surgery nineteen patients (95%) experienced improvements in gait with a mean reduction of 30%, 26%, and 34% in TW, TUG, and TUGD, respectively.

    Conclusions: A two-day outpatient LTT can more reliably select patients with communicating hydrocephalus who might benefit from shunt surgery by assessing timed gait measurements on post-tap day two.

    Patient Care: Will hopefully allows physicians to more reliably select patients who might respond to shunt surgery. Also reduces morbidity associated with other methods i.e. ELD and reduces health care costs.

    Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the benefits of performing an outpatient LTT 2) Understand the benefits offered by a second day of testing 3) Identify specialized gait evaluations that can help select patients for shunt surgery


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