Altered interoceptive processing in Multiple sclerosis.

GARCÍA-CORDERO, INDIRA; ESTEVES, SOL,; FLORENCIA ALIFANO; MARTORELL, MIGUEL; PAGANI CASSARÁ, FÁTIMA; SINAY, VLADIMIRO J.; SEDENO, LUCAS; GARCÍA, ADOLFO; SALAMONE, PAULA CELESTE; ABREVAYA, SOFÍA; LEGAZ, AGUSTINA; BRUNO, DIANA; IBÁÑEZ, AGUSTÍN

Buenos Aires

Encuentro; 2nd LABMAN meeting.; 2017

LABMAN (Latin American Brain Mapping Network)

Multiple sclerosis is a chronic and idiopathic disorder characterized by multifocal inflammation and demyelination of the central nervous system. It involves alterations in the in the processing of bodily signals and fatigue. It has recently been proposed that fatigue could be related to interoceptive deficits in these patients. However, no study so far has directly assessed electrophysiology, neuroanatomical, and hemodynamic markers to research interoceptive mechanisms that may be distinctively disrupted in these patients. We performed two studies in 80 adults, 46 healthy participants (37 female; mean ± SD age = 37.48 ± 12.45 years) and 34 multiple sclerosis patients (28 female; mean ± SD age = 38.58 ± 10.02 years). First, we assessed the heartbeat evoked potential, a key signature of the neural dynamics of interoception during a heartbeat detection task (including an exteroceptive and interoceptive condition). Also, to examine possible anatomical abnormalities related to this process, we measured the patients? atrophy of main interoceptive hubs: insula, anterior cingulated cortex and somatosensory cortex. Then we correlated the electrophysiological results to gray matter of interoceptive hubs. Second, we evaluated the functional connectivity and related network properties of the interoceptive network during two resting state conditions (mind-wandering and interoception). Our results show that in controls the heartbeat evoked potential exhibit, as expected, a more negative modulation in the interoceptive condition than in the exteroceptive condition, Conversely, no systematic differences between conditions emerged in patients. Patients showed significant atrophy only in bilateral insula the left anterior cingulated cortex. Correlation analyses revealed that the volume of bilateral insula (R = 0.37, p =.04) and the right anterior cingulated cortex (R = 0.43, p = .01) were significantly associated with to the results of the subtraction of both heartbeat detection task conditions in the control sample.On the other hand, patients only presented significant correlations to bilateral somatosensory cortex (R = 0.41, p = .03). Within the connectivity results, during mind wandering condition, patients presented greater inter-regional connectivity. Although when subtracting the interoceptive condition to the mind-wandering condition, the controls presented a greater inter-regional connectivity, but patients presented no differences. To the extent of our knowledge, this report is the first multidimensional approach to show an altered interoceptive processing in multiple sclerosis patients. Our results suggest that these patients would have an altered interoceptive processing, marked by a hyperactivation of the interoceptive network, but including the absence of a differential HEP modulation and functional connectivity.