What could be causing my memory loss, difficulty finding words, sudden blank brain, and leg weakness?

Urgent Neurological Evaluation Required

Your symptoms—memory loss, word-finding difficulty, sudden mental blanking, and leg weakness—require immediate medical evaluation as they suggest a potentially serious neurological condition that could represent stroke, dementia, or another progressive brain disorder. 1

Critical Warning Signs Present

Your symptom cluster raises concern for several urgent conditions:

• Memory impairment with word-finding difficulty (anomia) suggests involvement of language and memory networks, which can indicate Alzheimer's disease, vascular cognitive impairment, or progressive aphasia 1
• Sudden "brain blanking" may represent transient cognitive episodes that warrant stroke evaluation 1
• Leg weakness combined with cognitive symptoms is particularly concerning for vascular disease, normal pressure hydrocephalus, or a progressive neurodegenerative disorder with motor involvement 1

Immediate Actions Required

1. Rule Out Stroke/TIA First

Seek emergency evaluation if leg weakness developed suddenly (within hours to days), as this combined with cognitive symptoms could represent an acute stroke or transient ischemic attack requiring immediate intervention 1. Time-sensitive treatments exist for stroke.

2. Comprehensive Cognitive Assessment Needed

If symptoms developed gradually (weeks to months), you need:

• Detailed history from someone who knows you well about when symptoms started, how they've progressed, and impact on daily activities like managing finances, medications, appointments, cooking, or driving 1
• Objective cognitive testing using validated tools like the Montreal Cognitive Assessment (MoCA) or Mini-Mental State Examination (MMSE) to quantify impairment 1, 2
• Functional assessment to determine if symptoms interfere with instrumental activities of daily living (paying bills, medication management, transportation) 1

3. Essential Medical Workup

Laboratory testing is mandatory to identify reversible causes: 1, 2

• Thyroid function (TSH, free T4)—hypothyroidism causes memory problems and weakness
• Vitamin B12 and folate levels—deficiency causes cognitive impairment and leg weakness/neuropathy
• Complete blood count—anemia impairs cognition
• Comprehensive metabolic panel—electrolyte abnormalities affect mental status
• Hemoglobin A1c—diabetes contributes to vascular cognitive impairment

Brain MRI is strongly preferred over CT to evaluate for: 2

• Stroke or vascular disease (white matter lesions)
• Brain tumors or masses
• Normal pressure hydrocephalus (enlarged ventricles with gait disorder)
• Neurodegenerative changes
• Structural abnormalities

4. Critical Conditions to Exclude

Your physician must specifically assess for: 1

• Vascular cognitive impairment: Executive dysfunction and slowed processing with leg weakness suggests cerebrovascular disease 3
• Medication toxicity: Review all medications, especially antiepileptics, sedatives, or anticholinergics that impair cognition 1
• Depression: Can mimic dementia ("pseudodementia") and cause subjective cognitive complaints 1
• Sleep apnea: Causes cognitive impairment and should be evaluated 1, 2
• Hearing/vision loss: Sensory deficits worsen apparent cognitive function 1
• Pain: Undiagnosed or undertreated pain impairs cognition 1
• Cervical spine disorders: Can cause leg weakness with cognitive symptoms, especially in certain populations 1

Specific Syndrome Patterns to Consider

Progressive Aphasia Pattern

Word-finding difficulty as a prominent feature suggests primary progressive aphasia, which requires specialized evaluation: 1

• Logopenic variant (most common) typically due to Alzheimer's disease
• Semantic variant due to frontotemporal dementia
• Non-fluent variant due to frontotemporal degeneration

Vascular Pattern

Executive dysfunction, processing speed problems, and leg weakness characteristically indicate vascular cognitive impairment rather than Alzheimer's disease: 3

• Requires aggressive vascular risk factor management
• Blood pressure control is critical (target <140/90 mmHg, potentially <120 mmHg systolic if multiple vascular risk factors) 1

Motor-Cognitive Syndrome

Combined cognitive and motor symptoms raise concern for: 1

• Dementia with Lewy bodies (fluctuating cognition, visual hallucinations, REM sleep behavior disorder)
• Parkinson's disease dementia
• Progressive supranuclear palsy
• Corticobasal degeneration
• Normal pressure hydrocephalus (classic triad: gait disorder, cognitive impairment, urinary incontinence)

Common Pitfalls to Avoid

• Do not accept "normal aging" as explanation—these symptoms warrant full evaluation 1
• Do not delay evaluation—early diagnosis allows treatment of reversible causes and planning for progressive conditions 1, 2
• Do not skip informant interview—patient self-report is unreliable due to lack of insight (anosognosia) 1
• Do not attribute everything to one diagnosis—multiple conditions often coexist (e.g., Alzheimer's plus vascular disease plus medication effects) 1, 2

What Happens Next

After initial evaluation establishes whether cognitive impairment exists and rules out reversible causes, you may need: 2, 4

• Neuropsychological testing to characterize the pattern and severity of deficits
• Specialty referral to neurology or geriatric psychiatry for complex cases
• Longitudinal monitoring every 6-12 months to track progression 2
• Safety assessment including driving evaluation, fall risk, and home safety 1

Do not wait—schedule an appointment with your primary care physician immediately, or go to an emergency department if leg weakness is acute or worsening. 1