Dopamine agonists reorient visual exploration away from the neglected hemispace

Abstract

Our results show that bromocriptine may worsen some aspects of hemispatial neglect in patients with lesions that include the postsynaptic components of ascending dopaminergic pathways.

Anatomical Correlates of Directional Hypokinesia in Patients with Hemispatial Neglect

“…In another single case study, treatment with bromocriptine of a patient with motor intentional neglect and a putamen lesion increased the motor bias toward the ipsilesional field (Barrett et al, 1999). The authors suggested that the right side putamen lesion might have prevented the positive effect of bromocriptine on the right hemisphere, while at the same time stimulating the intact left putamen, which in turn caused increased motor bias (for a group study with similar results, see also Grujic et al, 1998). Overall, these studies strongly support the involvement of the dopamine system in neglect and in particular the involvement of the putamen in mediating the motor bias in neglect.…”

Recovery from Aphasia and Neglect

“…Bromocriptine (15 mg/day) was found to improve neglect by some authors [201][202][203] but not by others [204]. Grujic et al [205] showed in 7 patients that bromocriptine may worsen the exploratory motor component of directed attention. Hurford et al [203] reported more improvement with bromocriptine than with methylphenidate in a single case, although methylphenidate was nevertheless better than no drug.…”

Cognitive Rehabilitation Interventions for Neglect and Related Disorders: Moving from Bench to Bedside in Stroke Patients

“…Most pharmacological interventions for neglect have centered on the use of dopaminergic and noradrenergic agents. Dopaminergic treatments such as bromocriptine (Barrett, Crucian, Schwartz, et al, 1999;Grujic et al, 1998;Hurford, Stringer, & Jann, 1998;Fleet, Valenstein, Watson, & Heilman, 1987), apomorphine (Geminiani, Bottini, & Sterzi, 1998), carbidopa/levodopa (Mukand et al, 2001), and amantadine (Buxbaum, Ferraro, Whyte, Gershkoff, & Coslett, in press) are based on the observation that unilateral dopaminergic ablation in animals produces a syndrome comparable to human neglect (Schwarting & Huston, 1996). Noradrenergic treatments are based on observed abnormal arousal in neglect and reported benefit of stimulants in motor and language rehabilitation (e.g., Walker-Batson, Curtis, et al, 2001;e.g., Walker-Batson, Smith, Curtis, Unwin, & Greenlee, 1995).…”