Postcentral gyrus infarction with spared proprioceptive sensation

The involvement of spontaneous brain activity in natural recovery from internet gaming disorder: A resting-state fMRI study

OBJECTIVE

Internet gaming disorder (IGD) can seriously impair an individual's physical and mental health. However, unlike the majority of those suffering from substance addiction, individuals with IGD may recover without any professional intervention. Understanding the brain mechanisms of natural recovery from IGD may provide new insight into how to prevent addiction and implement more targeted interventions.

METHODS

Sixty individuals with IGD were scanned by using a resting-state fMRI to assess brain region changes associated with IGD. After 1 year, 19 individuals with IGD no longer met the IGD criteria and were considered recovered (RE-IGD), 23 individuals still met the IGD criteria (PER-IGD), and 18 individuals left the study. The brain activity in resting state between 19 RE-IGD individuals and 23 PER-IGD individuals was compared by using regional homogeneity (ReHo). Additionally, brain structure and cue-craving functional MRIs were collected to further support the results in the resting-state.

RESULTS

The resting-state fMRI results revealed that activity in brain regions responsible for reward and inhibitory control [including the orbitofrontal cortex (OFC), the precuneus and the dorsolateral prefrontal cortex (DLPFC)] was decreased in the PER-IGD individuals compared to RE-IGD individuals. In addition, significant positive correlations were found between mean ReHo values in the precuneus and self-reported craving scores for gaming, whether among the PER-IGD individuals or the RE-IGD individuals. Furthermore, we found similar results in that brain structure and cue-craving differences exist between the PER-IGD individuals and RE-IGD individuals, specifically in the brain regions associated with reward processing and inhibitory control (including the DLPFC, anterior cingulate gyrus, insula, OFC, precuneus, and superior frontal gyrus).

CONCLUSION

These findings indicate that the brain regions responsible for reward processing and inhibitory control are different in PER-IGD individuals, which may have consequences on natural recovery. Our present study provides neuroimaging evidence that spontaneous brain activity may influence natural recovery from IGD.

Dissociative pseudo-ulnar sensory loss in a patient with a focal haemorrhage secondary to cerebral venous thrombosis - A case report

INTRODUCTION

Small cortical strokes can mimic weakness of peripheral nerve lesions. However, isolated sensory deficits involving the fingers due to cortical lesions are rare.

METHODS

We present a case of a 46 year old man with cerebral venous thrombosis, and a haemorrhage restricted to the postcentral gyrus, who reported numbness in an ulnar neuropathy-like distribution. Testing of somatosensory (SSEP) and pain-related evoked potential (PREP) was done, and the lesion location was mapped to the template brain.

RESULTS

The patient had impaired touch and pain but preserved proprioception. He had a normal SSEP response but a prolonged PREP. The lesion was mapped to Broadmann areas 1 and 3b of the postcentral gyrus.

DISCUSSION

Sensory cortical representation is such that, the ulnar fingers are medial, and the radial ones are lateral. Also, modality-specific organization is noted with tactile sensation being mapped to areas 1 and 3b, and proprioceptive sensation to area 3a and 2. Thus focal lesions involving the post central gyrus can have selective sensory loss over some fingers and can have selective impairment of some modalities.

CONCLUSIONS

We highlight the rare finding of an ulnar-like sensory loss in a patient with cerebral venous thrombosis and the dissociate nature of the sensory loss in isolated cortical lesions.