Childhood apraxia of speech (CAS) is conceived as an impairment of the central motor system's ability to program multiple speech movements, resulting in inaccurate transitions between and relative timing across speech sounds. However, the extant neuroimaging evidence base is scant and inconclusive, and the neurophysiological origins of these motor planning problems remain highly underspecified. In the first magnetoencephalography study of this disorder, we measured brain activity from typically developing (TD) children (N = 19, 11 males, 8 females) and children with CAS (N = 7 males) during performance of a speech task designed to interrogate function of the speech areas of the primary sensorimotor cortex. Relative to their TD peers, our sample of children with CAS showed abnormal speech-related responses within the mu-band motor rhythm, and beamformer source reconstruction analyses specify a brain origin of this speech rhythm in the left cerebral hemisphere, within or near pre-Rolandic motor areas crucial for the planning and control of speech and oromotor movements. These results provide a new and specific candidate mechanism for the core praxic features of CAS; point to a novel and robust neurophysiological marker of typical and atypical expressive speech development; and support an emerging neuroscientific consensus which assigns a central role for programming and coordination of speech movements to the motor cortices of the precentral gyrus.

Gerstmann's syndrome (GS) represents a still debated clinical condition, in terms of both symptoms' evolution and neural correlates. In depth, repeated neuropsychological assessments along with advanced methods of lesion analysis can contribute to a better understanding of the syndrome and clinical diagnosis. The study reports a patient suffering from GS and limb apraxia following a left hemisphere lesion. Two in-depth assessments, at two and four months from the lesion onset, in addition to video material, document the symptoms over time. An in-depth analysis of the grey and white matter lesions was carried out with 3D reconstruction and a disconnection map. The patient shows the characteristic tetrad of GS symptoms in both subacute and chronic phases, in the absence of other clinically relevant sensorimotor or cognitive deficits. Limb apraxia persists over time as well. The neuroanatomical investigation shows the involvement of cortical damage in the inferior parietal cortex that extends to the superior parietal cortex, anteriorly to the peri-rolandic area and medially to the precuneus. Furthermore, disconnections in the fronto-parietal networks and the corpus callosum were identified. This single case study supports previous neuropsychological evidence and neuroanatomical findings on healthy participants, suggesting a core neural network underlying the four GS symptoms, which involves the left superior parietal lobe, the intraparietal cortices and the white matter parietal and fronto-parietal tracts. Furthermore, the involvement of the three branches of the superior longitudinal fasciculus explains the co-occurrence of limb apraxia.

Here, we describe two patients who presented with focal cortical signs and underwent neuropathological examination. Case 1 was a 73-year-old woman with progressive speech disorder and abnormal behavior. She showed agraphia of the frontal lobe type, featured by the omission of kana letters when writing, other than pyramidal tract signs, pseudobulbar palsy, and frontal lobe dementia. Neuropathological examination, including TAR DNA-binding protein 43 (TDP-43) immunohistochemistry, revealed bilateral frontal and anterior temporal lobe lesions accentuated in the precentral gyrus and posterior part of the middle frontal gyrus. Both upper and lower motor neurons showed pathological changes compatible with amyotrophic lateral sclerosis. Case 2 was a 62-year-old man with progressive speech disorder and hand clumsiness. He had a motor speech disorder, compatible with apraxia of speech, and limb apraxia of the limb-kinetic and ideomotor type. Neuropathological examination revealed degeneration in the left frontal lobe, including the precentral gyrus, anterior temporal, and parietal lobe cortices. Moreover, numerous argyrophilic neuronal intracytoplasmic inclusions (Pick body) and ballooned neurons were observed in these lesions and the limbic system. The pathological diagnosis was Pick disease involving the peri-Rolandic area and parietal lobe. In these two cases, the distribution of neuropathological changes in the cerebral cortices correlated with the clinical symptoms observed.

self-limited epilepsy with centrotemporal spikes, previously considered benign focal childhood epilepsy with centrotemporal spikes show clinical signs of involvement of Rolandic areas, mainly lower area, which may affect the planning and execution of motor sequences. This study aimed to evaluated oral praxis in children with self-limited epilepsy with centrotemporal spikes and compare to the age-matched control group. This was a descriptive study with 74 children with self-limited epilepsy with centrotemporal spikes, with the classical forms according to International League Against Epilepsy, and between 4 and 15 years of age, selected from the child neurology outpatient clinic of the Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil, and 239 age-matched and educational level-matched (convenience sampling) control children. All children were submitted to the battery of oral volitional movements, which consisted of 44 tests for oral movement (tongue, lip, cheek, jaw, and palate) and 34 phonemes and consonant cluster tasks, with simple and sequenced oral movements. The mean age and standard deviation (SD) of children with epilepsy was 9.08 years (SD 2.55) and of controls 9.61 years (SD 3.12). The results showed significant differences between the groups with a poorer performance of children with epilepsy compared to children without epilepsy in simple and particularly in sequenced movements. These findings can be attributed to the genetically determined immaturity of cortical structures related to motor planning in children with self-limited epilepsy with centrotemporal spikes.

The site of crucial damage that causes acquired apraxia of speech (AOS) has been debated in the literature. This study presents five in-depth cases that offer insight into the role of brain areas involved in AOS. Four of the examined participants had a primary impairment of AOS either with (n = 2) or without concomitant mild aphasia (n = 2). The fifth participant presented with a lesion relatively isolated to the left anterior insula (AIns-L), damage that is rarely reported in the literature, but without AOS. Taken together, these cases challenge the role of the AIns-L and implicate the left motor regions in AOS.