The Intersection between Ocular and Manual Motor Control: Eye–Hand Coordination in Acquired Brain Injury

Abstract

Acute and chronic disease processes that lead to cerebral injury can often be clinically challenging diagnostically, prognostically, and therapeutically. Neurodegenerative processes are one such elusive diagnostic group, given their often diffuse and indolent nature, creating difficulties in pinpointing specific structural abnormalities that relate to functional limitations. A number of studies in recent years have focused on eye–hand coordination (EHC) in the setting of acquired brain injury (ABI), highlighting the important set of interconnected functions of the eye and hand and their relevance in neurological conditions. These experiments, which have concentrated on focal lesion-based models, have significantly improved our understanding of neurophysiology and underscored the sensitivity of biomarkers in acute and chronic neurological disease processes, especially when such biomarkers are combined synergistically. To better understand EHC and its connection with ABI, there is a need to clarify its definition and to delineate its neuroanatomical and computational underpinnings. Successful EHC relies on the complex feedback- and prediction-mediated relationship between the visual, ocular motor, and manual motor systems and takes advantage of finely orchestrated synergies between these systems in both the spatial and temporal domains. Interactions of this type are representative of functional sensorimotor control, and their disruption constitutes one of the most frequent deficits secondary to brain injury. The present review describes the visually mediated planning and control of eye movements, hand movements, and their coordination, with a particular focus on deficits that occur following neurovascular, neurotraumatic, and neurodegenerative conditions. Following this review, we also discuss potential future research directions, highlighting objective EHC as a sensitive biomarker complement within acute and chronic neurological disease processes.

Optic tract injury after closed head traumatic brain injury in mice: A model of indirect traumatic optic neuropathy

“…Visual changes are common after TBI of all severities, and include damage to multiple functions including oculomotor, visual acuity, eye-hand coordination, visual attention, and visual memory [ 32 , 33 ]. In a subset of patients with traumatic vision loss after head trauma, the cause is injury to the optic nerve and its projections [ 34 ].…”

Motor and Perceptual Recovery in Adult Patients with Mild Intellectual Disability

“…This system is of crucial importance for the normal child development, but it is also relevant for activities of daily living in adult people. Indeed, deficit of ocular or manual control has been studied also after an acquired brain injury [ 38 ].…”

The importance of visuo-motor coordination in upper limb rehabilitation after ischemic stroke by robotic therapy

“…This solution restores visual control of the complex motor function of the upper limb into the space. The roboticarm-eye connection via functional electrical stimulation actually reinforce the lost functional connection between eye and hand which is essential for movement coordination (30). If eye-hand coordination recovers through sensors and functional electrical stimulation, there is possibility for a more rapid progress in neurorehabilitation.…”

“…There can be a change in latency of saccades initialization for a target pursuing, comparing with control subjects (saccades occurs earlier). This can be due to upper-motor-neuron-like desinhibition phenomenon, in which, patients with cerebrovascular lesions anticipate the movement in spite of the instruction to the contrary (30).This phenomenon has as an explanation the inability to suppress saccades, that are maintained as a reflexively, in response to a target (initialization of saccades takes about 60 ms that are needed for the information to travel from the retina to brainstem where the command for extraocular muscle is made in order to initialize saccades ; the saccades are onset after 200 ms, the differences being attributed to the cognitive process to analyze these information and make a decision) (47). In stroke patients there is an anticipation of saccades which occur earlier than 60 ms (47).…”

“…There is also an alteration of predictive control which is essential for planning a visuomotor action. After stroke, the patients can experience the inability to program motor action sequences in space and time (51,30).…”