Neuro: Pathology Flashcards
- Failure of Rostral Neuropore closure
- Characherized by the absence of the Scalp, Skull, and Large portions of the Cortex
- Anterior neuropore closure @ day 25
- Posterior neuropore closure @ day 27
- Increased levels of AFP and ACh
Anencephaly
- Failure of Caudal neopore closure
- Severity depends on the degree of closure as well as the location of the Fusion defect
- Elevated AFP in Maternal serum or Amniotic fluid
Spina Bifida
- Small Tuft of hair overlying the defect without any visible Herniate contents
- Asymptomatic
- Missing Lumbar or Sacral processes
- Failure of the Vertebral arches to close w/out Herniation of Intraspinal contents
Spina Bifida Occulta
- Protrusion of the Dura mater and Arachnoid, forming a Lumbosacral cyst
- Failure of Vertebral arches to close w/ Herniation of Meninges but NOT the Spinal cord
Spina Bifida Meningocele
- Herniated Lumbosacral sac
- Depending on the location: Paralysis and Loss of Deep Tendon reflexes and Sensation in the lower extremities as well as Incontinence
- A/w Type II Arnold-Chiari syndrome
Spina Bifida Meningomyelocele
- Mental Retardation
- Herniation of Meninges and Brain
Spina Bifida Meningoencephalocele
- Herniation of Meninges, Brain, and CSF-containing Ventricles
Spina Bifida Meningohydroencephalocele
- Most severe form of Spina Bifida w/ Myelomeningocele
- Flattened plate like mass of nervous tissue w/ no overlying membrane
- More prone to life threatening Infections and Meningitis
- Split Brain
Spina Bifida w/ Myeloshisis
- Neural tube Birth defect
- Posterior Neural tube fails to close by the 27th day
- Vertebrae over defect fail to form and remain Unfused and Open
- Spinal cord remains exposed
- Motor and Sensory defects
- Chronic Infections
- Bladder disfunction
- A/w Anencephaly
Rachischisis
- Enlarging Head circumference
- Dilation of the ventricles (Cranial suture lines not fused)
- Congenital Stenosis between 3rd and 4th Ventricle
- Accumulation of CSF
- Common in Newborns
Cerebral Aqueduct Stenosis
- Agenesis / Congenital failure of the Cerebellar Vermis Hypoplasia and Splenium of Corpus Callosum
- **Failure ** to Open of the Foramina of Luschka and Foramina of Magendie
- Massively dilatated 4th Ventricle (Posterior fossa) w/out Cerebellum
- Accompanied by Hydrocephalus
Dandy-Walker Malformation
- Herniation of the Cerebellar Tonsils ONLY
- May not show neurologic symptoms until Adolescens or Adult life
- Cerebellar Ataxia
- Obstructive Hydrocephalus
- Brain stem compression
- Syringomyelia
- Large Foramen magnum
Arnold-Chiari Type I
- Congenital downward displacement of Cerebellar vermis and Tonsils through the Foramen magnum
- A/w obstruction of CSF and Hydrocephalus and Meningomyelocele
- Difficulty swallowing (compression of the Nucleus Ambiduus)
- Loss of Pain / Temperature sensation along the Back of the Neck and Shoulders
- Cranial Nerve and Brain stem dysfunction results in Respiratory failure and Death
Arnold-Chiari Type II
- Cystic degeneration of the Spinal cord
- Arises w/ Trauma and A/w Type I Arnold-Chiari malformation, Usually C8 – T1
- Sensory (Pain, Temp. Loss) w/ sparing of Fine touch w/ “Cape-like” distribution – Anterior white commissure of the Spinothalamic Tract w/ sparing of the Dorsal column
- Muscle atrophy and Weakness – dmg to lower motor neurons of Ant. Horn
- A/w Horner Syndrome w/ Ptosis, Miosis, and Anhydrosis
Syringomyelia
- Sympathetic trunk nerves get damaged, same side
- Miosis (constricted pupil)
- Ptosis (droopy eyelid)
- Anhidrosis (decreased sweating)
- A/ diseases may be Congential or Acquired
Horner Syndrome
- Dmg to Anterior Motor Horn due to Poliovirus Infection (Piconaviridae Enterovirus)
- Fecal-oral transmission
- Sore throat, malaise
- Lower motor neuron – Flaccid paralysis w/ Muscle atrophy
- Fasciculations - small uncontrolled muscle twitch
- Weaness w/ decreased Muscle tone
- Impaired reflexes
- Negative Babinski sign (downgoing toes)
Poliomyelitis
- Inherited degeneration of the Anterior Motor Horn
- Autosomal recessive
- “Floppy baby”
- Death occurs w/in a few years after birth
Werding-Hoffman Disease
- Degenerative disorder of the Upper and Lower motor neurons of the Corticospinal tract - Anterior Horns
- Zinc-copper Superoxide Dismutase mutation (SOD1) w/ Familial cases (chrom 21) – free radical injury in neurons
- Anterior motor horn degn. – Lower motor neuron signs, Flaccid paralysis w/ muscle atrophy, Fascicultations, Weakness, Impared reflexes, Negative Babinski
- Lateral corticospinal tract degn. – Upper motor neuron signs, Spastic paralysis w/ Hyperreflexia, Increased tone, Positive Babinski
Amyotrophic Lateral Sclerosis (ALS)
- Degn. disorder of Cerebellum (Ataxia) and Spinal cord (Loss of Vibratory sense and Proprioception, Muscle weakness in Lower extremities, and loss of Deep tendon reflexes)
- Autosomal Recessive – unstable trinucleotide repeat (GAA) in Frataxin gene
- Presents in early childhood
- Pts. are wheelchair bound w/in a few years
- A/w Hypertrophic cardiomyopathy (HCM)
- Frataxin – essential for Mitochondrial iron regulation – Free radical damage via Fenton reaction
Friedreich Ataxia
- Group B Streptococci (Streptococcus agalactia)
- Listeria monocytogenes
- E. coli (Escherichia coli)
Neonatal Meningitis
- Pneumococci (Streptococcus pneumonia)
- Meningococci (Neisseria meningitidis)
- Influenzae Type B (Haemophilus influenza Type B) (non-vaccinated kids)
Meningitis (6 mos. – 6 yrs.)
- Meningococci (Neisseria meningitidis)
- Polio (Picornavirdae enterovirus)
- Pneumococci (Streptococcus pneumonia)
Meningitis (6 yrs. 60 yrs)
- Cryptococcosis (Cryptococcus neoformans)
Fungal Meningitis
- Coxsackie A & B (Picornaviridae enterovirus)
- Echovirus (Picornaviridae enterovirus B)
- Mumps (Paramyxoviridae rubulavirus)
- Polio (Picornavirdae enterovirus)
Aseptic Meningitis
Bacterial Profile of Meningitis?
- Protein: ↑ ↑
- Glucose: ↓ ↓
- Cell Infiltration: Neutrophils and PMNs
- Pressure: ↑
- Gram stain and Culture often Identify causative agent
Viral Profile of Meningitis?
- Protein: ↑ or Normal
- Glucose: Normal
- Cell Infiltration: Lymphocytes w/ normal CSF
- Pressure: Normal
Fungal Profile of Meningitis?
- Protein: ↑
- Glucose: ↓
- Cell Infiltration:Lymphocytes
- Pressure: ↑
Two Basic Types of Cerebrovascular Disease?
- Ischemia
- Focal
- Thrombotic stroke
- Embolic stroke
- Lacunar stoke
- Global
- Focal
- Hemorrhage
- Intracerebral
- Subarachnoid
- Low perfusion (atherosclerosis)
- Acute decrease in blood flow (Cardiogenic shock, Overall decrease) - Chronic hypoxia (anemia)
- Repeated episodes of Hypoglycemia (Insulinoma)
- Mild – Transient confusion w/ prompt recovery
-
Moderate – Infarcts in watershed areas
- Pyramidal neurons of Cerebral cortex – Laminar necrosis
- Pyramidal neurons of Hippocampus (Temporal lobe) – long term memory
- Severe – Diffuse necrosis w/ ‘vegetative state’
Global Cerebral Ischemia
- Rupture of an Atherosclerotic plaque
- Pale infarct at the periphery of the Cortex
- Atherosclerosis usually develops at Branch points (Bifurcation of Internal Carotid and Middle cerebral artery, in Circle of Willis)
Thrombotic Stroke
- Due to Thromboemboli
- Commonly arising from the Left side of the Heart (Atrial fibrillation)
- Usually involves the Middle Cerebral artery
- After lysis of Emboli - Hemorrhagic infarct at the Periphery of the Cortex
Embolic Stroke
- Occurs secondary to Hyaline arteriolosclerosis
- Complication of Benign HTN, Diabetes mellitus
- Most commonly involves Lenticulostriate vessels, resulting in small cystic areas of infarction
- Involvement of the Internal capsule leads to a pure Motor stroke
- Involvement of the Thalamus leads to a pure Sensory Stroke
Lacunar Stroke
Progression of Ischemic Stroke?
- 12 hrs after Infarction: Eosinophilic change in the cytoplasm of neurons (“Red neurons”) is an early microscopic finding
-
24 hrs after infarction:
- Neutrophils (days 1 - 3)
- Microglial cells (days 4 – 7)
- Gliosis (weeks 2 – 3)
- Formation of Fluid-filled cystic space surrounded by Gliosis – Caseating necrosis and Liquefactive necrosis
- Bleeding into the Brain parenchyma
- Rupture of Charcot-Bouchard microaneurysms of Lenticulostriate vessels – Deep bleeding in Paranchyma of Brain
- A/w HTN, reduced HTN decreases incidence by half
- Severe Headache, Nausea, Vomiting, and eventual Coma
Intracerebral Hemorrhage
- Bleeding into the Subarachnoid space
- Sudden Headache “Worse Headache of my Life” w/ Nuchal rigidity
- Lumbar puncture shows Xanthochromia (yellow hue due to Bilirubin breakdwon)
- A/w Berry aneurysm – Saccular (aneurysm) outpouchings that lack media layer, esp. Anterior Circle of Willis @ branch points of the Anterior communicating artery
- A/w Marfan syndrome (FBN1 on Chr. 15 misfolding of Fibrillin-1 – connective tissue weakness) and ADPKD (MVP, Hepatic cysts)
- Other causes AV malformations and an Anticoagulated state
Subarachnoid Hemorrhage
- Blood between Dura mater and Skull – bleeding seperates
- Fracture of the Temporal bone w/ rupture of the Middle meningeal artery
- A/w a blow to the head, head trauma
- “Lucid interval” may precede Neurologic signs
- Lens-shaped lesion on CT scan
- Herniation – a lethal complication, pushes brain to other side
Epidural Hematoma
- Blood under the Dura mater, covering the surface of the brain
- Tearing of Bridging veins that lie between the Dura and Arachnoid
- Trauma
- Crescent-shaped on CT
- Progressive neurologic signs – leading toward Herniation (lethal)
- Increased rate in Elderly due to age-related cerebral atrophy, stretching the veins
Subdural Hematoma
- Displacement of the cerebellar tonsils into the Foramen magnum
- Compression of the Brain stem leads to Cardiopulmonary arrest
Tonsillar Herniation
- Displacement of the Cingulate gyrus under the Falx cerebri
- Compression of the Anterior cerebral artery leads to infarction
Subfalcine Herniation
- Displacement of the Temporal lobe uncus under the Tentorium cerebelli
- Compression of CN III (oculomotor) leads to the eye moving “down and out” and a Dilated pupil
- Compression of Posterior cerebral artery leads to Infarction of Occipital lobe (Contralateral homonymous hemianopsia)
- Rupture of the Paramedian artery leads to Duret (brainstem) hemorrhage
Uncal Herniation
- Autosomal recessive lysosomal storage disease
- Arylsulfatase A Deficiency (Autosomal recessive)
- Most common Leukodystrophy
- Sulfatides cannot be degraded and Accumulate in the Lysosome of Oligodendrocytes (lysosomal storage disease) -> impaired production of myelin sheath
- Central and Peripheral Demyelination w/ Ataxia and Dementia
- Accumulation of Sulfatides
Metachromatic Leukodystrophies
- Autosomal recessive Lysosomal Storage dieseae
- Deficiency of Galactocerebrosidase
- Galactocerebroside and Psychosine destroy myelin sheath, accumulates in Macrophages
- Peripheral neuropathy
- Developmental delay
- Optic atrophy
- Globoid cells
Krabbe disease
- Mostly Males
- Impaired Metabolism and addition of Coenzyme A to Long-chain Fatty-acids (X-linked defect)
- Accumulation of Fatty-acids damages Adrenal glands (Adrenal gland crisis) and White matter of the Brain
- **Long-term progression **-> Death
Adrenoleukodystrophy
- Autoimmune inflammation / destruction of CNS myelin and Oligodendrocytes (demyelination)
- Chronic CNS disease of Young Women (20 – 30 yrs old) (F > M) - Brain and Spinal cord
- A/w HLA-DR2
- Regions away from Equator
- Blurred vision in ONE eye (optic nerve) (Marcus Gunn pupils)
- Vertigo and Scanning speech mimicking Alcohol intoxication (Brain stem)
- Internuclear ophthalmoplegia (medial longitudinal fasciculus)
- Hemiparesis or Unilateral loss of sensation (cerebral white matter)
- Lower extremeity loss of sensation (spinal cord)
- Bowel, Bladder, and Sexual dysfunction (ANS)
- Dx: MRI and Lumbar puncture (increased Lymphocytes, Immunoglobulins w/ Oligoclonal IgG bands, Myelin basic protein)
- Gray appearing plaques in White matter
- Tx: Acute: IV Solumedrol, Chronic: High-dose steroids, and Long-term β-INF
Multiple Sclerosis
Charcot classic triad of MS is a SIN
- Scanning speech
- Intention tremor (also Incontinence and Internuclear ophthalmoplegia)
- Nystagmus (involuntary eye movement)
- Progressive, Debilitating encephalitis – Leads to Death
- Slowly progressive
- Persistent infection of the Brain by Measles virus (Paramyxoviridae Morbillivirus – Rubeola, Togaviridae Rubivirus – German Measles - Rubella)
- Infection occurs in Infancy – Neurologic signs arise years later (during childhood)
- Viral inclusions w/in Neurons (gray matter) and Oligodendrocytes (white matter)
Subacute Sclerosisng Panencephalitis
- JC virus infection of Oligodendrocytes (white matter) at multiple foci (Papovaviridae Polyomavirus)
- Immunosuppression (AIDS or Leukemia) leads to reactivation of the Latent virus
- Demyelination of CNS due to destruction of Oligodendrocytes
- Presents w/ Rapidly progressive neurologic signs (visual loss, Weakness, Dementia) which leads to Death
Progressive Multifocal Leukoencephalopathy
- Focal demyelination of the Pons (Anterior Brain stem)
- Due to rapid intravenous correction of Hyponatremia (alcoholic)
- Severly malnourished pts. (Liver disease)
- Presents as Acute bilateral paralysis “Locked-In” Syndrome
- Loss of voluntary movement from head to toe, but can still move eyes
Central Pontine Myelinolysis
- Degenerative disease of Cortex, ↓ ACh
- Widespread cortical atrophy
- Narrowing Gyri and Widening Sulci
- Slow-onset memory loss and Progressive disorientation
- Loss of learned Motor skills and Language
- Changes in Behaviour and Personality
- Patients become Mute and Bedridden
- Infection is common cause of Death
- Risk increases w/ Age
- E4 allele of Apolipoprotein E (ApoE4) a/w increased Risk on Chrom 19, ApoE2 on Chr. 19 is protective
- E2 allele w/ decreased Risk
- Familial cases a/w Presenilin 1 (Chrom 14) and Presenilin 2 (Chrom 1) mutations
- A/w Down syndrome by age 40 due to p-APP on Chrom 21
- Cerebral atrophy, Neuritic ‘Senile’ plaques, AB amyloid (APP) chromosome 21
- Neurofibrillary tangles – aggregates of fibers Hyperphosphorylated Tau Protein
- Loss of Cholinergic neurons in the Nucleus Basalis of Meynert
- Senile plaques: extracellular β-amyloid core; may cause amyloid angiography → Intracranial hemorrhage
- αβ-amyloid syn. by cleaving the precursor APP
Alzheimer Disease (AD)
- Consequene of Moderate Global Ischemia
- Multifocal infarction and Injury due to Hypertension, Atherosclerosis, or Vasculitis
- 2nd most common cause of dementia
Vascular Dementia
- Frontotemporal atrophy
- Dementia, Aphasia, Parkinsonian aspects, Change in personality
- Degenerative disease of the Frontal and Temporal Cortex
- Spares the Parietal and Occipital lobes and Posterior 2/3 of Superior temporal gyrus
- Round aggregates of Tau protein (Pick bodies) in neurons of the Cortex
- Behavioral and Language symptoms aries early; progress to dementia
Pick Disease
(frontotemporal dementia)
- Degenerative loss of Dopaminergic neurons (Dopamine-secreting) pigmented neurons in the Substantia nigra of the Basal ganglia (Midbrain)
- Nigrostriatal pathway of Basal ganglia uses Dopamine to initiate movement
- α-synuclein, parkin, DJ-1, and PINK1 genes and proteins
- Aging, rare cases a/w MPTP exposure
- “TRAPS” – Tremor, Rigidity, Akinesia/bradykinesia (exp.less face), Postural instability, Shuffling gait
- Pigmented neurons in the Substantia nigra and Round, Eosinophilic inclusions of alpha-synucleain (Lewy bodies – Hallucinations)
- ‘Pill-rolling’ tremor
Parkinson Disease
- Degeneration of GABAergic neurons in the Caudate nucleus of the Basal ganglia – Inhibitory neural transmitter
- Loss of Spiny striated neurons that normally dampen motor activity
- Autosomal Dominant disorder (Chromsome 4p16)
- Trinucleotide repeat (CAG) in huntingtin gene (40 - 55, 70+), Normal (6 - 34 repeats)
- Repeats during Spermatogenesis leads to Anticipation
- Chorea (snake-like) movements progress to Dementia and Depression
- ~40 years old
- Suicide is common cause of death
Huntington Disease
- Increased CSF – Dilated Ventricles
- Dementia in Adults (Idopathic)
- Triad – Urinary incontinence, Gait instability, Dementia (“Wet, Wobbly, Wacky”)
- Lumbar puncture improves symptoms
- Tx: Ventriculoperitoneal shunting
Normal Pressure Hydrocephalus
- Degenerative Prion protein disease
- PrPC -> PrPSC (Beta pleated sheet)
- Sporadic conversion
- Inherited Familial forms
- Transmitted
- Pathologic protein not degradable
- Intracellular vacuoles dmgs. Neurons and Glial cells
Spongiform Encephalopathy
- Rapidly progressive Dementia (weeks to months) w/ Myoclonus (“startle myoclonus”)
- Most common spongiform encephalopathy
- Sporadis, rarely arises due to exposure
- Rapidly progressive Dementia a/w Ataxia (cerebellar involvement) and Startle myoclonus (involuntary contractile w/ sensation)
- Hallucinations followed by Parkinsonian features
- Sharp waves seen on EEG
- Death w/in 1 year
Creutzfeldt-Jakob disease (CJD)
- An inherited form of prion disease characterized by:
- Severe Insomnia
- Exaggerated Startle Response
Familial Fatal Insomnia
- Malignant, high-grade Tumor of Astocytes
- Most common CNS tumor in Adults
- Cerebral Hemisphere, Crosses the Corpus callosum
- “Butterfly” lesion
- Regions of necrosis surrounded by tumor cells ‘pseudopalisading’ and Endothelial cell proliferation
- Pleomorphic Tumor cells (astrocytes) are GFAP positive
- Poor prognosis (~1 year survival)
Glioblastoma Multiforme (GBM)
- Bening 1• tumor of Arachnoid cells, Brain Tumor
- Most common benign CNS tumor in adults
- More commonly seen in Women (presents w/ Estrogen receptors), and rare in children
- Seizures; tumor compresses but DOES NOT invade the Cortex
- Convexities of Hemispheres, near Brain surface
- May have Dural attachment “Dural Tail”
- Round mass attached to the Dura on imaging -> presses on the Cortex -> causes seizures
- ‘Whorled pattern’ w/ Psammoma bodies on histology w/ Pink cytoplasm
Meningioma
- Bening tumor of Schwann cells (PNS)
- Involves Cranial or Spinal nerves; w/in the Cranium
- Most commonly seen in CN VIII at the Cerebellopontine angle
- Loss of hearing and Tinnitus – ‘ringing in the ears’ -> Acoustic schwannoma (aka acoustic neuroma)
- Tumor cells are S-100 positive
- Multiple pigminted skin lesions and Optic nerve glioma a/w Neurofibromatosis Type 1
- Bilat. Tumor cells seen in Neurofibromatosis Type 2 (NF-2)
- Tx: Stereotactic radiosurgery
Schwannoma
- Malignant tumor of Oligodendrocytes
- Imaging reveals a Calcified tumor in the White matter
- Usually involving the Frontal lobe
- May present w/ Seizures
- ‘Chicken-wire’ capillary pattern
- ‘Fried-egg’ apperance of cells on biopsy - round nuclei w/ clear cytoplasm
Oligodendroglioma
- **Benign tumor of Astrocytes, **good prognosis
- Most common CNS tumor in Children
- Usually arises in the Cerebellum (Posterior Fossa)
- Cystic lesion w/ Mural nodule on imaging, **Well circumscribed **(Cystic + solid (gross))
- GFAP positive
- Rosenthal fibers (thick corkscrew Eosinophilic processes of Astrocytes) on Biopsy
Pilocytic Astrocytoma
- Malignant tumor derived from the Granular cells of the Cerebellum midline (Neuroectoderm)
- Usually arises in Children
- Small, Round Blue cells; Homer-Wright rosettes may be present: small cells wrap around neurotic proccess
- Tumor grows Rapidly and spreads via CSF
- Metastasis to the Cauda equina is termed ‘Drop metastasis’ -> Spinal cord
- Can compress 4th ventricle -> Hydrocephalus
- Poor prognosis
Medulloblastoma
- Malignant tumor of Ependymal cells
- Usually seen in Children
- Most commonly arises in the 4th Ventricle
- May present w/ Hydrocephalus -> beneath the Tentorium – blocking CSF flow in CNS
- Perivascular Pseudorosettes are characteristic finding on biopsy
- Calcification is common (Tooth enamel-like)
Ependymoma
- Benign Childhood tumor arises from Epithelial remnants of Rathke’s pouch (Surface ectoderm Anterior pituitary)
- Supratentorial tumor mass in Children and Young Adult
- Compress the Optic chiasm -> Bitemporal hemianopsia (a/w tumors of pituitary)
- ‘Tooth-like’ Calcifications
- Tends to recur after Resection
Craniopharyngioma
- Initially dementia and Visual hallucinations followed by Parkinsonian features
- Progressive Cognitive decline similar to Alzheimer disease
- α-synuclein defect
Lewy Body Dementia
- Most common varieant of Guillain-Barre syndrome
- Autoimmune against Schwann cells -> Inflammation and Demyelination of PNS and motor fibers
- Ascending muscle weakness / paralysis beginning in the lower extremities
- Facial paralyis (50%)
- Increased CSF protein w/ normal cell count (albuminocytologic dissociation)
- Increased protein -> Papilledema
- A/w Campylobacter jejuni and CMV -> autoimmune attack of peripheral myelin due to molecular mimicry inoculations, and stress
- No definitive link to pathogens
Acute Inflammatory Demyelinating Polyradiculopathy
- Multifocal perivenular Inflammation and Demyelination after infection (commonly Measles or VZV) or certain vaccines (e.g. Rabies, Smallpox)
Acute Disseminated (Post-infectious) Encephalomyelitis
- a.k.a Hereditary Motor and Sensory neuropathy (HMSN)
- Group of progressive hereditary nerve disorders related to the defective production of Proteins involved in the Structure and Function of Peripheral nerves of the Myelin Sheath
- Typically Autosomal dominant pattern
- A/w Scoliosis and Foot deformities (High and Flat arches)
Charcot-Marie-Tooth Disease
- Affect 1 area of the Brain
- Most commonly originate in Medial Temporal Lobe
- Often preceded by Seizure aura
- Simple, Partial - (consciousness intact) - motor sensory, autonomic, psychic
- Complex, Partial - (impaired consciousness)
Partial (focal) Seizures
- Absence (petit mal) - 3 Hz, no postictal confusion, blank stare
- Myoclonic - quick, repetitive jerks
- Tonic-clonic - (grand mal) - alternating stiffening and movement
- Tonic - stiffening
- Atonic - “drop” seizures (falls to floor); commonly mistaken for fainting
Generalized Seizures
- Most often composed of Stromal cells in small blood vessels w/in Cerebellum, Brain Stem, and Spinal cord
- A/w von Hippel-Lindau Syndrome when found w/ Retinal agiomas
- Due to ectopic production of Erythropoietin can lead to -> A/w 2• Polycythemia (paraneoplastic syndrome = increased RBC count)
- Closely arranged
- Thin walled capillariey w/ minimal Paranchyma composed of Endothelial cells, Pericytes, and Stromal cells
Hemangioblastoma
- Most commonly Prolactinoma
- Bitemporal Hemianopia (decreased vision or blindness), Vertigo, Nausea, Vomiting
- Amenorrhea, Galactorrhea (Increased milk production - women)
- Sexual dysfunction, Hypogonadism, Gynocomastia (men)
- Shows normal visual field above, patient’s perspective below) due to Pressure on Optic Chiasm
- Hyper- or Hypo-Pituitarism are sequelae
Pituitary Adenoma
- Vitamin B1 (Thiamine) deficiency
- Uncommon in individuals w/ varied diet
- A/w Chronic alcoholism
- Capillary proliferation, Hemorrhage, Necrosis, and Hemosiderin deposition are often found in the Mammillary bodies and the Periaqueductal gray matter
- Results in Paralysis of Extraocular muscles
Wernicke-Korsakoff disease
- Diverticulum of malformed brain tissue extending through a defect in the Cranium
- Most often occurs in the Posterior Fossa
- Comparable extensions of brain occur through the Cribiform plate in the Anterior Fossa (“sometimes misleadingly referred to as a “Nasal Glioma”)
Encephalocele
- Abnormal generation and migration of Neurons results in malformations of the Forebrain that may be focal or involve entire structures
- Small Head Circumferance
- A/w Chromosome abnormalities, Fetal Alcohol syndrome, HIV-1 infection in utero
- Reduction in the number of neurons that reach the Neocortex leads to a Simplification of the Gyral Folding
Microcephaly
- Bilateral optic neuritis and Spinal cord demyelination
- Anti-bodies (Ab) against Aquaporin-4, the major protein in Astrocytes and areas of demyelination
- Loss of Aquaporin-4
- Ab injure through Complement-dependent mechanisms
- White cells are common in CSF (including Neutrophils)
- Vascular deposition of Immunoglobulin and Complement
- Tx: reduce Ab burden, Plasmapheresis, Depletion of B cells w/ anti-CD20 Ab
Neuromyelitis Optica
- gene 178 of PrPc
- gene 129 of PrPc
- homozygotes Met/Met at gene 129 of PrPc
Prion Proteins
- gene 178 of PrPc = Fatal Familial Insomnia (Asp) –> results in encoding Metionine at 129
- gene 129 of PrPc = Famiial Forms (Met or Val)
- Homozygous Met/Met = Creuzfeldt-Jakob Varient
- Degeneration of Frontal and/or Temporal Lobes
- Alterations in personality, behavior and language (aphasias) precede memory loss
- Global dementia and Early onset Dementia
- A/w Cellular Inclusions of FTLD-tau and w/ TDP43 (FTLD-TDP) found in the nucleus (phosphorylated and ubiquitinated)
Frontaltemporal Lobe Dementia
- Accumulation of Storage Material w/in Neurons –> followed by death of the Neurons
- Seizures, Generalized loss of Neurologic function
Neuronal Storage Disease
- Gm2 gangliosidoses a lysosomal storage diseases caused by an inability to Catabolize Gm2 gangliosides
- Accumulates in the Heart, Liver, Spleen, Nervous System
- Central and Autonomic nervous systems and Retina dominate the clinical picture
- Cherry-red spot thus appears in the Macula
- Cytoplasmic inclusions w/ Onion-skin layers
- Mutations in the α-subunit locus on chromosome 15 causes a severe deficiency of Hexosaminidase A
- Ashkenazic Jews (1:30)
Tay Sachs Disease
- Rare disorder in which Lipid pigments accumulate in Neurons
- Neuronal dysfunction leads to a combination of Blindness, Cognitive, and Motor Deterioration and Seizures.
Ceroid Lipofuscinosis
- Impared oxygen-carrying capacity of Hemoglobin
- CO interactions w/ Cytochrome C oxidase inhibiting electron transport in mitochondria
- Selective injury to layers III and V of Cerebral cortex, Sommer center of the Hippocampus, and Purkinje cells
- Bilateral necrosis of the Globus Pallidus
- Demyelination of White matter tracts as Late event
Carbon Monoxide Poisoning (CO)
- Preferentially affects the Retina; degeneration of Retinal Ganglion cells causes Blindness
- Bilateral necrosis of the Putamen and Focal White-matter necrosis also occur when the exposure is severe
- Disruption of Oxidative phosphorylation and Nonenzymatic protein modification
- Ingestion of illicit liquor (moonshine)
Methanol Poisoning
- Degeneration of both Ascending and Descending Spinal tracts
- Defect in Myelin formation
- Bilateral symmetrical Numbness, Tingling, and slight Ataxia in the Lower Extremities
- Complete Paraplegia may occur
- Starts in the Mid-Thoracic level
- Swelling in Myelin layers produces vacuoles, with eventual Axon degeneration
Vitamin B12 Defeciency
- Wernicke Encephalopathy - acute appearance of a combination of psychotic symptoms and Opthalmoplegia
- Acute symptoms are reversible when treated w/ Thiamine –> if untreated results in Korsakoff syndrome
- Disturbances in Short-term memory (MedialDorsal Lesions in Thalamus) and Confabulation
- Common in Chronic Alcoholism
- Focal hemorhage and necrosis in the Mamillary bodies and the walls of the 3rd and 4th Ventricles
- Development of Cystic space w/ Hemosiderin-laden Macrophages
Thiamine Deficiency
Aβ Protein
Alzheimer Disease
Tau Protein
- Alzheimer Disease
- Frontotemporal lobar degeneration
- Parkinson Disease w/ LRRX2 mutations
- Progressive supranuclear palsy
- Corticobasal degeneration
TDP-43 Protein
- Frontotemporal lobar degeneration
- Amyotrophic lateral sclerosis (ALS)
FUS protein
- Frontotemporal lobar degeneration
- Amyotrophic lateral sclerosis
α - synuclein Protein
- Parkinson Disease
- Multiple system atrophy
Polyglutamine Aggregates
- Huntington Disease
- Spinocerebellar Ataxia (some forms)
- Spinal Bulbar Muscular Atrophy