Etiology of Frontal Network Syndromes in Isolated Subtentorial Stroke

Abstract

Abstract. Background:The neurobiology of the frontal network syndrome (FNS) that may occur with isolated subtentorial stroke is unknown. Aim: Evaluate for frontal network syndromes in young people post subtentorial stroke who have recovered neurologically and compare to a stroke lesion group least likely to manifest frontal network syndromes Methods: Young people (18-49 years) with isolated cerebellar or brainstem subtentorial stroke (ST) that had recovered to independency (Rankin score 2) with minimal or no residual neurological deficit (NIHSS 4) with neurological recovery enabling resumption of former employment. Comparison was made to age and education matched young people with posterior circulation territory parieto occipital lobe infarcts (PO). Depression, anxiety, systemic disease, autoimmune disease, neurodegenerative disease and substance abuse were specific exclusions. A battery of frontal tests surveying the principal frontal network syndromes (apathy, disinhibition, executive dysfunction, emotional intelligence quotient) was used. Neurological deficit and long tract signs were measured by the NIH stroke score (NIHSS). Results: From the cognitive stroke registry of young stroke patients (n = 511), analysis for isolated subtentorial infarction yielded cerebellar infarcts (n = 43, 8.4%) and brainstem infarcts (n = 36, 7.0%). After exclusions, 16 patients (cerebellum, n = 10, pons, n = 6) were compared to 10 PO infarct patients controlled for mean age, gender and NIH stroke scores. Overall 11/16 (69%) patients in the ST and 5/10 (50%) in the PO group manifested one or more of the principal FNS syndromes. Mean T scores for apathy, disinhibition, executive function and emotional intelligence standard scores were significantly more impaired in the ST group, but not for WCST error percentage scores. Conclusions: The mismatch of scant neurological deficit manifested by low NIHSS but with FNS in the majority of isolated ST stroke and more so than with PO stroke, gives support for a state dependent or neurotransmitter perturbation. The clinical impact is that such syndromes may be amenable to neuropharmacological intervention.

The Cerebellar Cognitive Affective/Schmahmann Syndrome: a Task Force Paper

“…& Thirty-seven patients with isolated CB infarcts had elevated scores on a frontal systems impairment index, delayed recall of verbal or visual information, anomic aphasia, limb kinetic apraxia, and acquired dyslexia [181]. Another 43 with isolated CB or brainstem infarcts were impaired on tests of apathy, disinhibition, executive function, and emotional intelligence [182]. & Twenty-two (88%) of 25 Russian patients with isolated CB infarcts showed impaired attention, cognitive control, and mental flexibility [183].…”

Neural Correlates for Apathy: Frontal-Prefrontal and Parietal Cortical- Subcortical Circuits

“…Within a study focusing apathy due to subcortical lesions, regional changes at a distal location from the lesion site were reported, namely in the posterior cingulate cortex (Tatemichi et al, 1992; Deguchi et al, 2013; Matsuoka et al, 2015), bilateral basal ganglia damage (Levy et al, 1998; Moretti et al, 2013), isolated pontine or cerebellar infarcts (Piamarta et al, 2004; Hoffmann and Cases, 2008; Onoda et al, 2011). …”

“…Ample epidemiological data indicate, on the other hand, that in AD, individual NPS rarely occur alone (Hoffmann and Cases, 2008). While, these groupings have been supported by limited studies (Jonsson et al, 2010; Geda et al, 2013) others do not support this approach (Jeste and Finkel, 2000; Olin et al, 2002; Robert et al, 2009; Trzepacz et al, 2013; Cummings et al, 2015a,b).…”

Disfunção Cognitiva em Acidente Vascular Cerebral Isolado do Tronco Cerebral

“…Os 16 doentes que conseguiram retomar a profissão tinham queixas subjetivas de dificuldade. 6 Uma revisão de 75 doentes com AVC do tronco cerebral reportou disfunção executiva e défices atencionais como os fenómenos cognitivos mais típicos. 3 Só foram analisados doentes com lesão vascular isolada.…”