Dementia with Lewy Bodies
Dementia with Lewy bodies (DLB) is characterized by some difficulties to initiate actions and to plan daily activities, by a loss of spatial references, by some hallucinations (mostly visual) and some parkinsonian symptoms (rigid bearing and glance, arched posture, small step walk).
Memory disorders are generally secondary.
Cognitive impairments and waking state of the patient can be very variable from one time to another which is very characteristic of the disease. Other clinical signs frequently found are sleep disorders (corresponding to the dreams experienced), nightmares, repetitive falls, faintness with loss of consciousness, depression (one mode of onset), an acute reaction to some drugs (especially neuroleptics) making them contraindicated for this pathology (Ballard Drugs aging 2013)
The dementia with Lewy bodies is related to the deposition (called Lewy bodies) inside the neurons of the alpha Synucléine protein, leading to the neural degeneration.
Like the AD, the diagnosis of DLB is based on a neurologic examination, a neuropsychological screening and some brain imaging analyses (brain MRI, +/- brain sintigraphy, Dat-Scan Sintigraphy)
The hereditary forms of the DLB are extremely rare.
There is in Dementia with Lewy Bodies, like in Alzhaimer Disease, a defective production of acetylcholine which is involved in the memory process. Inhibitors of acetylcholine esterase can also be used in DLB, this especially as the DLB lesions are often associated closely with the AD lesions. Rivastigamine drug has a marketing authorization for Parkinson dementia which is related to DLB.
Anti-cholinergic treatments must be avoided. Neuroleptic drugs are contraindicated and new anti-psychotic drugs such as Clozapine, must be used with extreme care.
To fight extrapyramidal symptoms, Levodopa can be recommended but with a very careful implementation as there is a risk to increase hallucinations and delirious thoughts. It is not recommended to give a dose over 3*250 mg/day.
DLB Patient’s prognosis is less favourable than AD patient’s prognosis as DLB cognitive impairments are associated with motor disorders and movements disabilities, psycho-behavioral disorders which make the patient more difficult to manage for the caregiver, inducing the use of psychotropic drugs and accelerating his/her hospitalization.
