Neuropathology: High-Yield Pathology

Neuroaxonal Dystrophies

Neurodegeneration with Brain Iron Accumulation Type 1 (NBIA 1) Definition Progressive neurodegenerative disease characterized clinically by extrapyramidal symptoms with dementia and by the presence of iron accumulation and axonal spheroids within the globus pallidus and substantia nigra histologically Previously called:…

Triple-Repeat Inherited Neurodegenerations

Huntington Disease Definition Autosomal dominant neurodegenerative disease characterized clinically by choreiform movements, psychiatric symptoms, and dementia and genetically by expansion of the trinucleotide (CAG) repeat in the HD gene Clinical Features Epidemiology Age range: 2 to 85 years (mean age:…

Amyotrophic Lateral Sclerosis (ALS)

Definition Progressive neuromuscular disease characterized by degeneration of upper and lower motor neurons resulting in progressive skeletal muscle wasting and weakness leading to respiratory failure and death; ALS subtypes: primary lateral sclerosis (mainly upper motor disease) and progressive muscular atrophy…

Parkinson’s Disease and Related Alpha-Synucleinopathies

Parkinson's Disease Definition Progressive neurodegenerative disease characterized clinically by movement abnormalities including the triad of resting tremor, bradykinesia, and cogwheel rigidity with histologic findings of pigmented neuron loss within the substantia nigra and elsewhere Presence of α-synuclein immunoreactive Lewy bodies…

Frontotemporal Lobar Degenerations and Related Tauopathies

Corticobasal Degeneration (Rebeiz Disease) Definition Sporadic neurodegenerative disease characterized clinically by progressive asymmetrical involuntary movements, akinetic-rigid parkinsonism, symptoms of upper motor neuron dysfunction (dysarthria, aphasia), and variable dementia; pathologic findings are atrophy of superior frontal lobes, rostral parietal lobes, basal…

Alzheimer’s Disease

Definition A neurodegenerative disorder; most frequent cause of dementia in adults—pathologically characterized by variable cerebral atrophy with neuritic (“senile”) plaques and neurofibrillary tangles Clinical Features Epidemiology Majority of Alzheimer's disease (AD) cases are sporadic, affecting adults usually older than 60…

Prion Diseases

Prion-Related Diseases (Overview) Definition Transmissible spongiform encephalopathies caused by misfolded prion proteins Clinical Features Epidemiology Prion disease: first identified in sheep (scrapie) Later identified in elk, deer, mink, large felines Cellular PrP glycoprotein (PrPc—normal protein of unknown function) PRNP gene:…

Neuropathology of AIDS

Primary Central Nervous System HIV Infection Definition Neurologic complications directly attributable to primary infection of the CNS by human immunodeficiency virus-1 (HIV-1) Clinical Features Epidemiology Virus enters CNS early, may remain subclinical Neurologic complications develop in up to 50% of…

Viral Infections

General Viral Effects on the Central Nervous System Definition CNS viral infection associated with clinical or laboratory evidence of neurologic dysfunction based on viral tropism Clinical Features Epidemiology Viruses: number one cause of encephalitis and meningitis Most cases: acute, self-limited…