Senile cognitive claudication

Specialty: Geriatrics.

• bradypsychia due to attentional exhaustion
• cognitive fatigue of the elderly
• senile mental claudication
• cognitive fatigue in dementia

Why it occurs

• Accelerated neuronal fatigue in the context of underlying neurodegenerative dementia (Alzheimer's disease in mild to moderate phases)
• Sensory overload in noisy or poorly structured environments with impossibility of effective filtering of stimuli
• Chronic sleep disorder or untreated obstructive sleep apnea-hypopnea syndrome (OSAS)
• Late-onset major depressive episode characterized by marked attentional dysfunction (depressive pseudodementia)
• Chronic cerebral vascular insufficiency secondary to deep ischemic microangiopathy (multifocal leukoaraiosis)

Initial workup

Comprehensive cognitive assessment using dual-task testing (Dual-Task, for example, timing normal walking versus walking while counting down); nocturnal polysomnography or ambulatory respiratory polygraphy; Brain MRI to quantify white matter lesions (Fazekas scale) and hippocampal atrophy (Scheltens scale); laboratory analysis that includes thyroid profile, serum levels of vitamin B12, folic acid and plasma cortisol.

Standard management

• Donepezil — 5 mg to 10 mg orally at night, indicated if there is a formal diagnosis of Alzheimer's disease, monitoring the appearance of sinus bradycardia, nausea, diarrhea or muscle cramps
• Memantine — 5 mg orally per day, increasing weekly up to 20 mg per day if moderate-severe dementia coexists, to regulate glutamatergic transmission and reduce attentional fatigue
• Strictly avoid medications with a central sedative effect during daylight hours (such as intermediate or long-acting benzodiazepines, antihistamines or codeine).