Intracortical inhibitory and excitatory circuits in subjects with minimal hepatic encephalopathy: a TMS study.
Metab Brain Dis
; 31(5): 1065-70, 2016 10.
Article
em En
| MEDLINE
| ID: mdl-27255390
ABSTRACT
Minimal hepatic encephalopathy (MHE) is the earliest form of hepatic encephalopathy (HE) and affects up to 80 % of patients with liver cirrhosis. By definition, MHE is characterized by psychomotor slowing and subtle cognitive deficits, but obvious clinical manifestations are lacking. Given its covert nature, MHE is often underdiagnosed. This study was aimed at detecting neurophysiological changes, as assessed by means of transcranial magnetic stimulation (TMS), involved in the early pathogenesis of the HE. We investigated motor cortex excitability in 15 patients with MHE and in 15 age-matched age-matched cirrhotic patients without MHE; the resting motor threshold, the short-interval intracortical inhibition (SICI) and the intracortical facilitation (ICF) were examined. Paired-pulse TMS revealed significant increased SICI and reduced ICF in the patients with MHE. These findings may reflect abnormalities in intrinsic brain activity and altered organization of functional connectivity networks. In particular, the results suggest a shift in the balance between intracortical inhibitory and excitatory mechanisms towards a net increase of inhibitory neurotransmission. Together with other neurophysiological (in particular EEG) and neuroimaging techniques, TMS may thus provide early markers of cerebral dysfunction in cirrhotic patients with MHE.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Encefalopatia Hepática
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Estimulação Magnética Transcraniana
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Córtex Motor
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Rede Nervosa
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Inibição Neural
Limite:
Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Metab Brain Dis
Assunto da revista:
CEREBRO
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METABOLISMO
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Áustria