Classification of DBS microelectrode recordings using a residual neural network with attention in the temporal domain.

During the Deep Brain Stimulation (DBS) surgery for Parkinson's disease (PD), the main goal is to place the permanent stimulating electrode into an area of the brain that becomes pathologically hyperactive. This area, called Subthalamic Nucleus (STN), is small and located deep within the brain. Therefore, the main challenge is the precise localization of the STN region, considering various measurement errors and artifacts. In this paper, we have designed and developed a computer-aided decision support system for neurosurgical DBS surgery. The implementation of this system provides a novel method for calculating the expected position of the stimulating electrode based on the recordings of the electrical activity of brain tissue. The artificial neural network with attention is used to classify the microelectrode recordings and determine the final position of the stimulating electrode within the STN area. Experiments have verified the utility and efficiency of our system. The tests were carried out on many recordings collected during DBS surgeries, giving encouraging results. The experimental results demonstrate that deep learning methods extended with self-attention blocks compete with the other solutions. They provide significant robustness to recording artifacts and improve the accuracy of the stimulating electrode placement.

Visual hemineglect and hemihallucinations in a patient with a subcortical infarction.

An alcoholic patient with a mainly right subcortical infarction developed contralateral left-sided neglect and then, in the context of alcohol withdrawal, unilateral hallucinations in the non-neglected right hemispace. It is hypothesized that an interruption of the striatocortical pathways could prevent the right hemisphere from representing appropriately internally produced stimuli.

Left hemiparalexia.

Three patients with left splenial lesions made paralexic errors restricted to the left end of words. Errors appeared more frequently when a correct response was highly dependent on the initial letter of the stimulus. One patient had full visual fields with hemialexia affecting the left visual field. The other two patients had complete right hemianopia. We attribute left-sided reading errors in the hemianopic patients to a retinotopically restricted disconnection pattern that selectively disrupts transfer of information originating from the peripheral left visual field. Functional resistance of the more numerous transcallosal projections representing visual field adjacent to the vertical meridian may account for such a pattern. The emergence of positional reading errors from retinotopically restricted left hemifield disconnection suggests that callosal information transfer during normal reading may primarily involve elemental sensory rather than lexical/semantic information.