03/11/2025
Ch. 94
Neurodegenerative Disease
Alzheimer's disease is a neurodegenerative disorder characterized primarily by memory loss and cognitive decline, most commonly affecting people over the age of 65. The disease is caused by abnormal build-up of beta-amyloid plaques and tau tangles in the brain, which interfere with neuron communication and function.
Causes
Alzheimer's disease results from a complex interplay of genetic, environmental, and lifestyle factors leading to brain cell damage and death. Key pathological features include accumulations of beta-amyloid protein plaques and tau protein tangles in the brain.
Symptoms
The core symptom is memory loss, especially difficulty remembering recent events. Other symptoms include confusion, trouble planning or solving problems, difficulty completing familiar tasks, changes in mood and personality, and impaired judgment. Symptoms worsen gradually over time.
Management
There is no cure for Alzheimer's disease, but treatment focuses on symptom management and maintaining quality of life. Medications commonly used include:
Acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) to increase acetylcholine levels and help cognitive function in mild to moderate stages.
Memantine, an NMDA receptor antagonist, used for moderate to severe stages.
Newer immunotherapies like lecanemab and donanemab target amyloid plaques to slow progression, mainly in early stages.
Supportive care involves regular exercise, healthy nutrition, social engagement, and creating a safe environment. Nonpharmacologic strategies include cognitive stimulation and behavioral interventions.
Pathological Tests
Diagnosis involves a combination of:
Clinical evaluation including medical history and cognitive tests.
Neurological examination.
Blood tests to exclude other causes of dementia symptoms.
Brain imaging (MRI, CT, PET scans) to look for brain changes.
Biomarker tests measuring beta-amyloid and tau proteins in cerebrospinal fluid or blood to confirm Alzheimer's pathology.
Mental status and neuropsychological tests assess memory and cognitive function to track disease progression.
In summary, Alzheimer's disease is diagnosed through clinical assessment complemented by neurological and biomarker tests. Management is symptomatic with medications and lifestyle modifications aimed at maintaining quality of life and function.
This comprehensive overview addresses the cause, symptoms, management, and pathological tests for Alzheimer's disease according to latest available information. If detailed protocols or treatment options are required, consultation with specialized healthcare providers is recommended. Required Pathology Tests to Find Alzheimer's Disease1. Cerebrospinal Fluid (CSF) BiomarkersCSF testing, obtained via a lumbar puncture (spinal tap), is considered the gold standard for biological confirmation and is currently used by memory specialists.BiomarkerWhat it MeasuresSignificance in Alzheimer's DiseaseAmyloid Beta 42 (Aβ42)The long form of the amyloid protein.Decreased levels in CSF, as the protein is clumping together to form plaques in the brain tissue instead of staying in the fluid.Total Tau (T-Tau)A general marker of neuronal/axonal damage.Increased levels in CSF, indicating significant brain cell injury and degeneration.Phosphorylated Tau (P-Tau)Tau protein with extra phosphate groups, which form neurofibrillary tangles.Increased levels in CSF, providing highly specific evidence of Alzheimer's pathology.Aβ42/Aβ40 RatioThe ratio of the two most common forms of Amyloid-beta.Used to improve diagnostic accuracy; a lower ratio is a strong indicator of AD pathology.2. Blood-Based Biomarkers (BBMs)These are newer, less invasive, and increasingly accurate tests that are gaining clinical acceptance, especially for initial screening.BiomarkerWhat it MeasuresSignificance in Alzheimer's Diseasep-Tau217 or p-Tau181Specific phosphorylated forms of the Tau protein in the blood plasma.Elevated levels correlate highly with brain amyloid plaques and are a strong indicator of AD, often used to determine who should receive confirmatory testing.Aβ42/Aβ40 RatioMeasured in blood plasma.Used as a screening tool to assess the likelihood of cerebral amyloidosis.3. Tests to Rule Out Other ConditionsBefore an Alzheimer’s diagnosis can be made, other potential causes of cognitive decline must be excluded. These are often ordered by the primary care physician:Complete Blood Count (CBC): To check for infections or anemia.Thyroid Function Tests (TFTs) (TSH, T3, T4): To rule out Hypothyroidism, which can mimic dementia symptoms.Vitamin B12 and Folate Levels: Deficiency in these vitamins can cause reversible cognitive impairment.Comprehensive Metabolic Panel (CMP) / Kidney and Liver Function Tests: To check for organ failure, electrolyte imbalance, or medication side effects.
Ayodhya Healthcare Services Jiksha Healthcare Pathology Jiksha Pathology Jiksha Pathology Jiksha Healthcare Pathology Jiksha Pathology Jiksha Pathology {A Group of World most renowned & Best Labs Under one roof
063909 90002
