Neuroscientists at the Institute of Cognitive Neuroscience, London, UK report the case of a 38-year-old male with severe deficits in arousal and sustained attention, associated with hemispatial neglect, secondary to acute disseminated encephalomyelitis. Treatment with the noradrenergic agonist guanfacine was associated with significant improvements in both sustained attention and spatial neglect. Presenting with a right hemiparesis following a prodrome of headache and fever, he developed tonic-clonic seizures soon after admission. MRI revealed signal changes in the thalamus, cerebellum, and temporal and occipital lobes. CSF was normal, and EEG was consistent with encephalopathy and ADEM. Following courses of iv methylprednisole, immunoglobulin, plasma exchange and antibiotics, seizures at first refractory to AEDs were stabilized after 4 months. Neuropsychological testing revealed severe cognitive impairments and left-sided neglect. At a 2-year follow-up, he had persistent left hemiparesis with severe left hemispatial negect, and impairments in sustained attention and arousal. MRI showed lesions localized to the right thalamus and pulvinar, areas linked to the mechanism of neglect. This is the first demonstration of a persistent amelioration of spatial neglect following treatment with guanfacine. General level of alertness and arousal also improved. [1]

COMMENT. Impairments of arousal or maintained alertness are considered a component of the neglect syndrome, and arousal is dependent on noradrenergic input, responsive to guanfacine. Guanfacine, as a sustained release formulation, Intuniv, is effective in the treatment of ADHD. [2]

Hemispatial neglect is usually reported following stroke involving the medial thalamus and pulvinar in the right hemisphere. ADEM is a rare cause of neglect but is associated with impaired arousal and sustained attention, components of the neglect syndrome. A study comparing cognitive profiles of children aged 7-16 years with MS (n=9) to those with ADEM (n=9) found impairments across all cognitive domains with differences in severity and spread. The transient white matter disruption in ADEM results in subtle cognitive impairments, while the multiple white matter insults in childhood MS are associated with more severe cognitive sequelae. [3]