Bilateral Hemispheric Activation in the Early Recovery of Motor Function After Stroke

Abstract

Background and Purpose-Functional recovery after cerebral infarction is a complex phenomenon that depends on various factors. The aim of this study was to investigate changes in cerebral perfusion during motor activity in stroke patients with very early recovery of motor function. Methods-We included 9 consecutive patients hospitalized for acute-onset hemiparesis who showed complete functional recovery within 24 hours. CT of the brain showed an ischemic or hemorrhagic cerebral lesion in areas compatible with the symptomatology. Within 36 hours (range, 28 to 36) all patients were examined for the effects of a thumb-to-finger opposition task on cerebral blood flow in the middle cerebral arteries, evaluated by means of bilateral transcranial Doppler ultrasonography. Data were compared with those of 9 healthy subjects matched for age and sex. In patients, the evaluation was repeated 2 to 4 months later. Results-A comparable increase in flow velocity (% meanϮSD) was observed with respect to baseline in the contralateral middle cerebral artery during motor activity with patients' normal (8.8Ϯ2.0%) and recovered hand (9.7Ϯ4.1%) and with both hands of control subjects (10.6Ϯ1.4%). In the middle cerebral artery ipsilateral to the hand performing the motor task, the increase in flow velocity was significantly higher (PϽ0.0001) during movement of the recovered hand in patients (8.6Ϯ2.7%) than during movement of the normal hand in both patients (2.6Ϯ1.6%) and control subjects (1.4Ϯ0.7%). In patients, pattern of changes in flow velocity during motor performance remained the same in the second evaluation. Conclusions-These observations suggest that areas of the healthy hemisphere can be activated soon after a focal injury and contribute to the positive evolution of a functional deficit in some patients. This phenomenon of ipsilateral activation cannot be considered transient because it is evident months after stroke onset. (Stroke. 1998;29:1305-1310.)

Evolution of Cortical Activation During Recovery From Corticospinal Tract Infarction

“…Ipsilateral increases in blood flow velocity during movement of the paretic hand have been shown as early as 36 hours after stroke onset by transcranial Doppler. 20 Focal ipsilateral CBF increases have been shown in response to passive movement of a paretic limb 19 hours after stroke onset by positron emission tomography imaging. 21 One conclusion drawn from such data is that the role of the contralesional hemisphere is to provide ipsilateral motor pathways originating in the contralesional SMC.…”

Detecting peripersonal space: The promising role of ultrasonics

“…We may propose TCD as a rapid and easy approach to furnish new information concerning brain responses when perturbing PPS. The understanding of CBF changes related to PPS perturbation can contribute to understanding the results of psychophysical and behavioral trials in either healthy or neurologic/neuropsychiatry conditions (e.g., poststroke neglect) (Cuadrado, Egido, Gonzalez‐Gutierrez, & Varela‐de‐Seijas, 1999; Halligan & Marshall, 1991; Holt et al., 2015; Riestra & Barrett, 2013; Silvestrini, Cupini, Placidi, Diomedi, & Bernardi, 1998). …”

Aggravation of Poststroke Sensory Symptoms after a Second Stroke on the Opposite Side

“…The most plausible explanation for this phenomenon has been that there are uncrossed motor pathways accounting for approximately 25% of the fibers in the corticospinal tract of human beings and primates [9]. If these fibers have a role in the recovery of muscle strength [10, 11, 12], a second stroke affecting the contralateral hemisphere would not only produce a hemiparesis on the side contralateral to the new lesion, but also worsen the previous motor symptoms. Similarly, it has been shown that a considerable portion of the spinothalamic tract ascends ipsilaterally [13].…”