You are here

Article Text

Article menu
Download PDFPDF
Letter
Changes in excitability of motor cortex in severe hepatic failure
  1. A Oliviero1,
  2. R Gaspari2,
  3. P A Tonali1,3,
  4. M A Pennisi2,
  5. G Mercurio2,
  6. F Pilato1,
  7. R Proietti2,
  8. V Di Lazzaro1
  1. 1Institute of Neurology, Catholic University, Largo A Gemelli 8, 00168 Rome, Italy
  2. 2Institute of Anesthesiology, Catholic University, Rome, Italy
  3. 3IRCCS “Casa Sollievo della Sofferenza”, San Giovanni Rotondo, Italy
  1. Correspondence to:
 Dr V Di Lazzaro, Istituto Di Lazzaro, Università Cattolica, Largo A Gemelli 8, 00168 Rome, Italy;
 vdilazzaro{at}rm.unicatt.it

https://doi.org/10.1136/jnnp.72.3.414

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Severe liver failure causes accumulation of both albumin bound and water soluble substances that exhibit toxic effects on the brain and lead to hepatic encephalopathy. This is a complex neuropsychiatric syndrome determined by a neurotransmission failure rather than from primary energy deficit.1 Transcranial magnetic stimulation represents a non-invasive method that can be used to study the physiology of the human brain.2 Commonly used transcranial magnetic stimulation parameters include motor thresholds, cortical silent period (CSP), central motor conduction time (CMCT), intracortical inhibition (ICI), and intracortical facilitation. The threshold for producing motor evoked potentials reflects the excitability of a central core of neurons, which arises from the membrane excitability and a balance between inhibitory and excitatory input from local circuits. The CMCT provides information on the corticospinal tract anatomical integrity, CSP and ICI reflect the activity of GABAergic inhibitory circuits.2–6 Additional in vivo information on central motor circuits can be obtained using transcranial electrical stimulation of the motor cortex. transcranial electrical stimulation stimulates the motor areas of the human brain deeply in the white matter and is therefore insensitive to changes in cortical excitability.6 Combining the data from transcranial electrical stimulation and transcranial magnetic stimulation it is possible to determine the site, cortical or subcortical, where brain functional changes have taken place. We used transcranial magnetic stimulation to explore function of the cerebral cortex in five patients affected by severe liver failure. Recently, a molecular adsorbent recirculating system (MARS) has been proposed as a new extracorporeal detoxifying treatment.7 We used transcranial magnetic stimulation to evaluate the effects of MARS treatment on functions of the cerebral cortex in these patients and also the effects of orthotopic liver transplantation in one of them.

    Clinical and neurophysiological examinations were recorded at baseline and 12–18 hours after the …

    View Full Text