Gait apraxia: further clues to localization

Area of Science:

• Neuroscience
• Neurology
• Clinical Neuroimaging

Background:

• Gait apraxia, particularly gait ignition failure, is often associated with dorsomedial frontal lobe lesions.
• The supplementary motor area (SMA) has been hypothesized to play a role in gait disorders seen in various neurological conditions.
• This study reevaluates the hypothesis linking SMA dysfunction to gait apraxia.

Observation:

• Two subjects presented with severe gait apraxia, specifically difficulty initiating gait and turning.
• Both subjects had MRI-confirmed lesions affecting the SMA region and/or parasagittal convexity premotor cortex bilaterally.
• Lesions were caused by primary CNS lymphoma in one case and lobar atrophy in the other.

Findings:

• The observed lesions were notably focal and limited compared to previously reported cases of gait apraxia.
• Clinicopathologic correlation partially supports the hypothesis that SMA dysfunction contributes to gait apraxia.
• The findings also suggest that the parasagittal convexity premotor cortex may be implicated in the development of gait apraxia.

Implications:

• This research refines the understanding of the specific brain regions involved in gait ignition failure.
• It highlights the potential role of the SMA and parasagittal premotor cortex in gait control.
• Further investigation into these areas may lead to improved diagnostic and therapeutic strategies for gait apraxia.