NeuroPathology - Lecture Eight Objectives - ALS and Neoplasms Flashcards
What is Amyotrophic Lateral Sclerosis?
a degenerative terminal disease affecting BOTH upper and lower motor neurons
What clinically occurs with ALS?
muscle wasting and gliotic hardening of the anterior/lateral corticospinal tracts
What percentage of ALS patients inherited it from family?
5-10% // familial ALS
What structures are affected in ALS?
the cortex, corticospinal tract, brainstem nuclei of CN V, VII, IX, X, and XII, and anterior horn cells in spinal cord
What are some possible causes of ALS?
excess glutamate, oxidative stress, impaired axonal transportation, protein aggregation, apoptosis, and lifestyle factors
How is strength preserved early in ALS?
healthy, intact surrounding axons can sprout and re-innervate the partially denervated muscle
How long can re-innervation occur/compensate in ALS?
Only up until motor unit loss is at about 50%. After that re-innervation cannot compensate faster than the rate of degeneration
How is ALS diagnosed?
LMN and UMN lesions found by clinical examination + progression of disease within a region(s) AND an absence of any evidence that may indicate another disease
What is the rarest form of ALS, and how is it characterized?
Primary Lateral Sclerosis // neuronal loss in cortex, hyperreflexia+spasticity, NO muscle atrophy or fasciculation(twitching)
What are the two subtypes of ALS, and what % of the population do they affect?
Limb onset - 70-80% // Bulbar onset - 20-30%
What are the clinical features of ALS Limb Onset?
extremities affected first, insidious LMN lesion onset, asymmetric weakness, distal to proximal, extensors weaker than flexors, head drooping, increased lumbar lordosis, clawhand, fasciculation, cramping/stiffness
What are the clinical features of ALS Bulbar Onset?
voice/swallowing affected first, cognitive/executive function impairment, decreased verbal fluency, weakness in articulation, swallowing, facial muscle weakness, decreased tongue movements, and change in voice quality(hoarseness)
What affects general prognosis of ALS survival rates?
younger age = better/longer survival rate, limb-onset has better prognosis, psychological well being, and less severe involvement/longer duration between onset and diagnosis/no dyspnea at onset
What classifies a Primary brain tumor?
developed within the CNS
What classifies a Secondary brain tumor?
metastasis of a cancer started elsewhere **commonly breast/lung cancer that metastasizes to brain
How does the WHO classify a Grade I Tumor?
slow growing, cells almost look normal, rarely spreads and may be cured if completely removed
How does the WHO classify a Grade II Tumor?
slow growing but may spready to nearby tissue and may recur/progress
How does the WHO classify a Grade III Tumor?
quickly growing, likely to spread, looks very different from normal cells
How does the WHO classify a Grade IV Tumor?
grows and spreads quickly and cells do not look normal at all, may have some dead cells and this tumor cannot be cured
What are the symptoms of a brain tumor?
Depends on where in the brain it is / which lobe
What are the brain tumor types?
Glioma, Meningioma, and Neurioma
What are Gliomas subdivided into?
astrocytomas, oligodendrogliomas, and ependymomas
What is the most common type of brain tumor?
Gliomas - 40-45% of all brain tumors
What is a Glioblastoma?
A high grade astrocytoma that is rapidly growing, aggressive, and highly infiltrative that tends to invade both hemispheres via corpus callosum
What percentage of oligodendrogliomas make up overall glioma cases?
2-3%
What are the clinical characeristics of an oligodendroglioma?
solid and slow growing, predominantly located in cerebral hemispheres(often in frontal lobe), bleeds spontaneously and may manifest with stroke like symptoms
What percentage of Ependymomas make up overall gliomas?
Low, only about 2% and arises from ependymal cells
What are the characteristics of a Meningioma?
slow growing and usually benign in dural folds, cerebral convexities, spinal cord. Accounts for 27% of all intracranial neoplasms and second most common tumor
What type of glioma arises from Schwann cells?
Neurinoma
What are the characteristics of a Neurinoma?
unilateral sensorineural hearing loss, tinnitus, vertigo, unsteadiness
