Resting-state fMRI functional connectome of C9orf72 mutation status.

OBJECTIVE: The resting-state functional connectome has not been extensively investigated in amyotrophic lateral sclerosis (ALS) spectrum disease, in particular in relationship with patients' genetic status. METHODS: Here we studied the network-to-network connectivity of 19 ALS patients carrying the C9orf72 hexanucleotide repeat expansion (C9orf72+), 19 ALS patients not affected by C9orf72 mutation (C9orf72-), and 19 ALS-mimic patients (ALSm) well-matched for demographic and clinical variables. RESULTS: When compared with ALSm, we observed greater connectivity of the default mode and frontoparietal networks with the visual network for C9orf72+ patients (P = 0.001). Moreover, the whole-connectome showed greater node degree (P < 0.001), while sensorimotor cortices resulted isolated in C9orf72+. INTERPRETATION: Our results suggest a crucial involvement of extra-motor functions in ALS spectrum disease. In particular, alterations of the visual cortex may have a pathogenic role in C9orf72-related ALS. The prominent feature of these patients would be increased visual system connectivity with the networks responsible of the functional balance between internal and external attention.

Reduced Self-Awareness Following a Combined Polar and Paramedian Bilateral Thalamic Infarction. A Possible Relationship With SARS-CoV-2 Risk of Contagion?

Reduced self-awareness is a well-known phenomenon investigated in patients with vascular disease; however, its impact on neuropsychological functions remains to be clarified. Importantly, selective vascular lesions provide an opportunity to investigate the key neuropsychological features of reduced self-awareness in neurocognitive disorders. Because of its rarity, we present an unusual case of a woman affected by a combined polar and paramedian bilateral thalamic infarction. The patient underwent an extensive neuropsychological evaluation to assess cognitive, behavioral, and functional domains, with a focus on executive functions. She was assessed clinically in the acute phase and after 6 months from the stroke, both clinically and by magnetic resonance imaging. The patient developed a cognitive impairment, characterised by prevalent executive dysfunction associated with reduced self-awareness and mood changes, in terms of apathy and depression. Such condition persisted after 6 months. In May 2020, the patient underwent the serology test in chemiluminescence to detect IgG antibodies against SARS-CoV-2. The result of the quantitative test highlighted a high probability of previous contact with the virus. We suggest that reduced self-awareness related to executive dysfunction and behavioral changes may be due to combined polar and paramedian bilateral thalamic lesion. Metacognitive-executive dysfunction affecting the instrumental abilities of everyday life might make people less able to take appropriate precautions, facilitating the risk of SARS-CoV-2 contagion.

Selective Emotional Dysregulation in Splenium Agenesis. A Case Report of a Patient With Normal Cognitive Profile.

Objective: Patients with lesions of the corpus callosum are rare and may present different symptoms of the disconnection syndrome. However, to-date studies on callosotomized patients have not been conclusive, likely because of the non-uniform nature of clinical features, the extent of resection, and methods used to investigate specific and related deficits. Agenesis of the corpus callosum (AgCC) may be asymptomatic and discovered incidentally or associated with very slight deficits diagnosed during neurological examinations. In this study, we reported a case of an apparently completely asymptomatic 23-year-old woman with appreciable agenesis of the splenium of the corpus callosum. Methods: She underwent a neurological evaluation, a comprehensive battery of neuropsychological tests to identify any subclinical dysfunction that may affect the functionality of the subject in the daily life. Specifically, the possible presence of emotion dysregulation was examined by using a self-report questionnaire. Results: She showed normal neuropsychological and emotional functioning, performing efficiently on tests measuring acquired brain impairment. Discussion: The present case is discussed in terms of neuroplasticity - with a focus on putative compensatory mechanisms - emphasizing the variegated clinical feature patterns of brain defects present from birth.

Neural correlates underlying the comprehension of deceitful and ironic communicative intentions.

Neuroimaging studies have shown that a left fronto-temporo-parietal cerebral network is recruited in the comprehension of both deceitful and ironic speech acts. However, no studies to date have directly compared neural activation during the comprehension of these pragmatic phenomena. We used fMRI to investigate the existence of common and specific neural circuits underlying the comprehension of the same speech act, uttered with different communicative intentions, i.e., of being sincere, deceitful or ironic. In particular, the novelty of the present study is that it explores the existence of a specific cerebral area involved in the recognition of irony versus deceit. We presented 23 healthy participants with 48 context stories each followed by a target sentence. For each story we designed different versions eliciting, respectively, different pragmatic interpretations of the same target sentence - literal, deceitful or ironic-. We kept the semantic and syntactic complexity of the target sentence constant across the conditions. Our results showed that the recognition of ironic communicative intention activated the left temporo-parietal junction (lTPJ), the left inferior frontal gyrus (lIFG), the left middle frontal gyrus (lMFG), the left middle temporal gyrus (lMTG), and the left dorsolateral prefrontal cortex (lDLPFC). Comprehension of deceitful communicative intention activated the lIFG, the lMFG, and the lDLPFC. fMRI analysis revealed that a left fronto-temporal network-including the inferior frontal gyrus (IFG), the dorsolateral prefrontal cortex (DLPFC) and the middle frontal gyrus (MFG)-is activated in both irony and deceit recognition. The original result of the present investigation is that the lMTG was found to be more active in the comprehension of ironic versus deceitful communicative intention, thus suggesting its specific role in irony recognition. To conclude, our results showed that common cerebral areas are recruited in the comprehension of both pragmatic phenomena, while the lMTG has a key role in the recognition of ironic versus deceitful communicative intention.