Increased Connectivity of Thalamocortical Tract/Occipital Cortex Concurrent with Recovery of Impaired Consciousness in a Stroke Patient: A Diffusion Tensor Tractography Study: A Case Report

Background: Little has been reported about the role of the occipital cortex in the recovery from impaired consciousness. In this case report, we report on a stroke patient who showed increased connectivity of the thalamocortical tract (TCT), including the occipital cortex, on follow-up diffusion tensor tractography (DTT) that was concurrent with recovery of impaired consciousness. Case presentation: A 64-year-old male patient underwent craniectomy and hematoma removal for spontaneous intracerebral hemorrhage (ICH) in the left fronto-parieto-temporal lobes and extraventricular catheterization for intraventricular hemorrhage (IVH). When he started rehabilitation eight weeks after onset, he was in a minimally conscious state with a Coma Recovery Scale-Revised (CRS-R) score of 14. On 8-week DTT, decreased connectivity of the TCT between the thalamic intralaminar nuclei and the cerebral cortex was observed in both medial prefrontal cortices (mPFCs), the occipital cortex, and the left parietal cortex. By contrast, on 12-week DTT, TCT connectivity had increased to include both medial prefrontal cortices and the right occipital cortex. Conclusion: Increased neural connectivity of the TCT to the mPFC and the occipital cortex, as shown by DTT, contributed to the recovery of impaired consciousness in a stroke patient. The results suggest that increased neural connectivity to the occipital cortex might contribute to the recovery of impaired consciousness in stroke patients.