The Practicalities of Assessing Freezing of Gait

Abstract

Background: Freezing of gait (FOG) is a mysterious, complex and debilitating phenomenon in Parkinson’s disease. Adequate assessment is a pre-requisite for managing FOG, as well as for assigning participants in FOG research. The episodic nature of FOG, as well as its multiple clinical expressions make its assessment challenging.Objective: To highlight the available assessment tools and to provide practical, experience-based recommendations for reliable assessment of FOG.Methods: We reviewed FOG assessment from history taking, questionnaires, lab and home-based measurements and examined how these methods account for presence and severity of FOG, their limits and advantages. The practicalities for their use in clinical and research practice are highlighted.Results: According to the available assessment tools severity of FOG is marked by one or a combination of multiple clinical expressions including frequency, duration, triggering circumstances, response to levodopa, association with falls and fear of falling, or need for assistance to avoid falls.Conclusions: To date, a unique methodological tool that encompasses the entire complexity of FOG is lacking. Combining methods should give a better picture of FOG severity, in accordance with the precise clinical or research context. Further development of any future assessment tool requires understanding and thorough analysis of the specific clinical expressions of FOG.

Does transcranial direct current stimulation during writing alleviate upper limb freezing in people with Parkinson’s disease? A pilot study

“…Of the ten included PD patients, eight experienced at least one freezing episode in our funnel paradigm (Table 2), even though they were all optimally medicated. The discrepancy between self-reported and actual occurrence of FOUL has been reported repeatedly in FOG (Barthel, Mallia, Debu, Bloem, & Ferraye, 2016). In the case of FOUL, perception of these problems in daily life is less marked than freezing when walking, explaining the incongruity.…”

Clinical features of freezing of gait in Parkinson's disease patients

“…However, this technology is still in the research stage and is not used in clinical practice. On the other hand, evaluation of FOG via questionnaire is simple and less burdensome for patients (Barthel, Mallia, Debu, Bloem, & Ferraye, ). High sensitivity and specificity have been reported using the New Freezing of Gait Questionnaire (NFOG‐Q), which uses a video that explains FOG (Barthel et al., ; Nieuwboer et al., ).…”

Clinical and methodological challenges for assessing freezing of gait: Future perspectives

“…In other words, gait improves when patients consciously focus on walking, and this is what typically happens when the gait pattern is being examined by a clinician. Second, the typically well‐lit and broad hospital corridors without obstacles—where patients are often assessed—are, in many ways, ideal for not provoking FOG, given that the phenomenon is commonly provoked in narrow spaces and while turning, or in dimly lit environmnets where patients cannot use visual feedback to compensate . Third, patients are typically on dopaminergic medication when they visit the clinician, whereas FOG occurs more often (and is more severe) when the dopaminergic medication has worn off …”