ABSTRACT: Cognitive deficits are core features in schizophrenia. Disruption in cholinergic neurotransmission has been associated with executive dysfunction in animals and humans. The objective of this study was to evaluate the impact of compromised cholinergic pathways on executive versus non-executive cognitive functions of patients with schizophrenia.
62 patients with schizophrenia and 62 age- and sex-matched non-psychiatric control subjects ("controls") were assessed and compared using: clinical measures, cognitive measures of global cognition, executive function, and memory; and an MRI-based visual rating scale that assesses damage strategically localized within the cholinergic pathways.
11 of the 62 patients with schizophrenia (17.7%) and 6 of the 62 controls (9.7%) had compromised cholinergic pathways. These proportions were not statistically significant. Patients and controls with compromised cholinergic pathways were more impaired on measures related to executive function than patients or controls without compromised pathways.
Patients with schizophrenia have worse executive function than controls. Compromised cholinergic pathways appear to worsen the executive dysfunction observed in schizophrenia. If these preliminary findings are replicated, they could lead to the identification of a subgroup of patients with schizophrenia who could specifically benefit from interventions enhancing cholinergic neurotransmission.
Biological Psychiatry 06/2012; 139(1-3):46-52. · 8.28 Impact Factor
ABSTRACT: Objective: To study the effect of memantine on apathy, a common symptom of behavioral variant frontotemporal dementia (bvFTD). Design: The patient underwent an off-label trial of memantine with behavioral inventories and [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) scans performed at baseline, 7 weeks and 6 months. Subject: The patient was a 66-year-old male whose main manifestation of bvFTD was affective, behavioral and cognitive apathy. Intervention: The patient began memantine at an oral dose of 5 mg per morning and titrated up by 5 mg per week to the maintenance dose of 10 mg PO bid. Results: Informants reported reduction of the apathy. The insula and cerebellum, both involved in the salience network, showed improved metabolism. Conclusion: Further study to correlate the effects of memantine on apathy and the salience network in bvFTD are warranted.
Neurocase 04/2012; · 1.11 Impact Factor
ABSTRACT: To determine whether basal ganglia atrophy, known to be associated with apathy in nondementia populations, was associated with presence of apathy in patients with frontotemporal dementia (FTD).
A cross-sectional case study was conducted at two tertiary dementia care clinics in Toronto, Ontario, Canada. Striatal and thalamic gray matter volumes and apathy measures were collected from 21 subjects with FTD, 6 of whom did not show apathy on the Neuropsychiatric Inventory.
No significant differences in gray matter volumes were found between apathetic and nonapathetic groups for the striatum or the thalamus.
Our findings imply that the etiology of apathy seen in patients with FTD differs from that of patients with apathy after acquired injuries to the basal ganglia. Further study is needed to determine whether posterior thalamic atrophy correlates with apathy in FTD or functional imaging techniques might successfully find a relationship between basal ganglia dysfunction and apathy.
The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 10/2009; 17(9):819-21. · 3.35 Impact Factor