High Risk of Dementia in Ventricular Enlargement with Normal Pressure Hydrocephalus Related Symptoms¹

Article type: Research Article

Authors: Koivisto, Anne M.^{a; b} | Kurki, Mitja I.^c | Alafuzoff, Irina^d | Sutela, Anna^e | Rummukainen, Jaana^f | Savolainen, Sakari^c | Vanninen, Ritva^{e; g} | Jääskeläinen, Juha E.^{c; h} | Soininen, Hilkka^{a; b} | Leinonen, Ville^{c; h; *}

Affiliations: [a] Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland | [b] Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland | [c] Neurosurgery of NeuroCenter, Kuopio University Hospital, Kuopio, Finland | [d] Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University and Department of Pathology and Cytology, Uppsala University Hospital, Uppsala, Sweden | [e] Department of Radiology, Kuopio University Hospital, Kuopio, Finland | [f] Department of Pathology, Kuopio University Hospital, Kuopio, Finland | [g] Unit of Clinical Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland | [h] Unit of Neurosurgery, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland

Correspondence: [*] Correspondence to: Ville Leinonen, MD, PhD, Department of Neurosurgery, Kuopio University Hospital, P.O. Box 100, FI-70029 KYS, Finland. Tel.: +358 40 514 7320, +358 44 717 2303; Fax: +358 17 173 916; E-mail: [email protected]; http://www.uef.fi/nph.

Note: [1] Kuopio NPH Registry (http://www.uef.fi/nph).

Abstract: Background: Differential diagnosis of ventricular enlargement with normal pressure hydrocephalus (NPH) related symptoms is challenging. Patients with enlarged ventricles often manifest cognitive deterioration but their long-term outcome is not well known. Objectives: We aim to evaluate long-term cognitive outcome in patients with enlarged ventricles and clinically suspected NPH. Methods: A neurologist and a neurosurgeon clinically evaluated 468 patients with enlarged ventricles and suspected NPH using radiological methods, intraventricular pressure monitoring, and frontal cortical brain biopsy. The neurologist confirmed final diagnoses after a median follow-up interval of 4.8 years. Results: Altogether, 232 patients (50%) with enlarged ventricles did not fulfill the criteria for shunt surgery. The incidence of dementia among patients with enlarged ventricles, and at least one NPH-related symptom with adequate follow-up data (n = 446) was high, varying from 77 (iNPH, shunt responders) to 141/1000 person-years (non-shunted patients with enlarged ventricles). At the end of the follow-up, 59% of all these patients were demented. The demented population comprised 73% of non-shunted patients with enlarged ventricles, 63% of shunted iNPH patients that did not respond to treatment, and 46% of iNPH patients that were initially responsive to shunting. The most common cause of dementia was Alzheimer’s disease (n = 94, 36%), followed by vascular dementia (n = 68, 26%). Conclusions: One-half of patients with enlarged ventricles and clinically suspected NPH were not shunted after intraventricular pressure monitoring. Dementia caused by various neurodegenerative diseases was frequently seen in patients with ventricular enlargement. Thus, careful diagnostic evaluation in collaboration with neurologists and neurosurgeons is emphasized.

Keywords: Alzheimer’s disease, cognition, dementia, memory, normal pressure hydrocephalus, prognosis, vascular dementia, ventricular enlargement

DOI: 10.3233/JAD-150909

Journal: Journal of Alzheimer's Disease, vol. 52, no. 2, pp. 497-507, 2016