Apraxia
Apraxia, a disorder of higher (cognitive) motor functions, is a common sequela of stroke, caused primarily by lesions in fronto-parietal praxis networks of the left hemisphere. Notably, a recent study suggests that these praxis networks are organised differently in men and women: it shows that male apraxic patients were significantly more likely to have lesions in the inferior frontal gyrus than female apraxic patients, while the apraxic deficits did not differ between men and women (Kleineberg et al., 2025).
Current definitions of apraxia as a motor-cognitive disorder deny a role of the primary motor cortex in apraxia. However, a recent study showed that the left primary motor cortex is specifically involved in gesture imitation when a high degree of (motor) attention and sensorimotor integration is required (Perlova et al., 2025).
Besides, apraxia also frequently occurs in neurodegenerative conditions such as Alzheimer’s disease (AD; Schmidt et al., 2025). Research into the pathomechanism of apraxia in AD identified localised tau aggregation in praxis-related brain regions (including parietal and temporal regions) that were associated with the severity of apraxia in patients with AD (Bischof et al., 2024). A recent study further showed that apraxic imitation deficits in AD patients were associated with altered functional connectivity in praxis-related brain networks (Kuzu et al., 2026). At the behavioural level, it was found that AD patients were impaired particularly in imitating finger gestures and complex hand movements, even when controlling for general cognitive impairment. Moreover, apraxic deficits explained about 60% of the variance in dementia severity and were significant predictors of general cognitive impairment (Schmidt et al., 2025).
Selected publications:
- Bischof GN, Jaeger E, Giehl K, Jessen F, Onur OA, O'Bryant S, Kara E, Weiss PH, Drzezga A (2024). Cortical tau aggregation patterns associated with apraxia in patients with Alzheimer disease. Neurology, 103(12), e210062. doi: 10.1212/WNL.0000000000210062
- Kleineberg NN, Schmidt CC, Fink GR, Weiss PH (2025). Differential lesion patterns associated with stroke-induced apraxia in women and men. European Journal of Neurology, 32(5), e70201. doi: 10.1111/ene.70201
- Kuzu TD, Brinkmann E, Bonkoff AK, Wunderle V, Bischof GN, Giehl K, Schmiescheck MHT, Onur OA, Jessen F, Fink GR, Drzezga A, Weiss PH (2026). Apraxic deficits in Alzheimer's disease are associated with altered dynamic connectivity in praxis-related networks. Neurobiology of Aging, 157, 36-47. doi: 10.1016/j.neurobiolaging.2025.09.007
- Perlova K, Schmidt CC, Fink GR, Weiss PH (2025). The role of the left primary motor cortex in apraxia. Neurological Research and Practice, 7(1), 2. doi: 10.1186/s42466-024-00359-8
- Schmidt CC, Bardakan MM, Jaeger E, Richter N, Bischof GN, Giehl K, Onur OA, Jessen F, Fink GR, Drzezga A, Weiss PH (2025). Apraxic deficits predict general cognitive impairment in patients with biomarker-verified Alzheimer's pathology. Journal of Neurology, 272(10), 654. doi: 10.1007/s00415-025-13401-9