Neuro pathology Flashcards
Dandy-Walker malformation
Congenital failure of the cerebellar vermis to develop
Presents with a massively dilated 4th ventricle and an absent cerebellum
Syringomyelia
Cystic degeneration of the spinal cord, arising with trauma or in associated with type 1 Arnold-Chiari malformation; usually presents at C8-T1
Initially presents with “cape-like” loss of pain and T sensation with sparing of fine touch and position sense (due to damage to anterior white commissure)
Syprinx expansion may result in muscle atrophy and weakness (damage to anterior horns) and horner syndrome (damage to lateral horns)
Poliomyelitis
Damage to anterior motor horn due to Poliovirus
Presents with LMN signs
Werdnig-Hoffman disease
Inherited degeneration of anterior motor horns
Presents as “floppy baby”
Amyotropic Lateral Sclerosis (ALS)
Degenerative disorder of UMN and LMN Initially presents as atrophy and weakness of hands.
Lack of sensory impairment distinguishes ALS from syringomyelia.
May be caused by zinc-copper superoxide disputes mutation (SOD1)
Friedreich ataxia
Autosomal recessive degenerative disorder of the cerebellum and spinal cord, caused by expansion of GAA in the frataxin gene (mitochondrial iron regulation) on chromosome 9
Presents with ataxia, loss of vibratory sense and proprioception, muscle weakness in the LEs, loss of DTRs, and hammertoes.
Associated with HOCM
Closely resembles severe Vitamin E deficiency
Subfalcine hernation
Displacement of the cingulate gyrus under the falx cerebri
Compression of the ACA
Uncal herniation
Displacement of the temporal lobe uncus under the tentorium cerebelli
- Compression of CNIII –> down and out eye with dilated pupil
- Compression of PCA –> contralateral homonymous hemianopsia with macula sparing
- Rupture of paramedian artery –> Duret (brainstem) hemorrhage
Metachromatic leukodystrophy
Demyelinating disorder caused by deficiency of arylsulfatase. Sulfatides accumulate in the lysosomes of oligodendrocytes (lysosomal storage disease)
Krabbe disease
Demyelinating disorder caused by deficiency of galactocerebrosidase. Galactocerebroside accumulates in macrophages.
Adrenoleukodystrophy
Demyelinating disorder caused by impaired addition of coenzyme A to long-chain fatty acids (X-linked).
Accumulation of fatty acids damages adrenal glands and white matter of the brain.
Multiple sclerosis
Demyelinating disorder caused by autoimmune destruction of CNS myelin and oligodendrocytes. Associated with HLA-DR2.
Relapsing and remitting neurologic deficits (e.g. scanning speech and internuclear opthalmoplegia)
MRI reveals plaques (white matter demyelination)
LP shows lymphocytes, increased Ig’s with oligoclonal IgG bands, and myelin basic protein
Subacute sclerosing panencephalitis
Demyelinating disorder caused by measles virus. Infection in infancy, slow progression, symptoms in childhood.
Progressive multifocal leukoencephalopathy
Demyelinating disorder caused by JC virus of oligodendrocytes. Reactivation of latent virus can occur with AIDS or leukemia
Central pontine myelinolysis
Demyelinating disorder caused by rapid IV correction of hyponatremia. Causes “locked in” syndrome.
Morphological features of Alzheimer disease
1) Cerebral atrophy with hydrocephalus ex vacuo
2) Extracellular neuritic plaques, composed of AB amyloid and entangled neuritic processes
3) Intracellular neurofibrillary tangles, composed of hyperphosphorylated tau protein
- unlike in Pick disease, where tau proteins form round aggregates
Histology of Parkinson disease
Loss of pigmented neurons in the SNc
Lewy bodies - round eosinophilic inclusions of alpha-synuclein in affected neurons; Lewy bodies of Lewy body dementia are located in the cortex (alpha-synuclein defect)
Glioblastoma multiforme
Malignant high grade tumor of astrocytes in adults; most common primary CNS malignancy in adults
Arises in cerebrum and crosses corpus collosum to form “butterfly lesion”; characterized by regions of necrosis surrounded by “pseudopallisading” tumor cells.
Stain astrocytes for GFAP (intermediate filament in glial cells)
Meningioma
Benign tumor of arachnoid cells in adults (females>males)
Tumor compresses but does not invade cortex.
May present with seizures.
Characterized by spidle cells arranged in a “whorled pattern”; psammoma bodies may be present
Schwannoma
Benign tumor of schwann cells in adults
Usually arises at cerebellopontine angle and affects CNVIII
Tumor cells are S-100 positive.
Bilateral schwannomas are seen in NF type 2
Oligodendroglioma
Malignant tumor of oligodendrocytes in adults, usually affecting frontal lobe.
Oligodendrocytes have a “fried-egg” appearance
Pilocytic astrocytoma
Benign low-grade tumor of astrocytes in children; most common primary CNS malignance in children
Usually arises in cerebellum.
Imaging reveals cystic lesion with a mural nodule
Biopsy shows Rosenthal fibers (thick eosinophilic procesees). Astrocytes are GFAP positive
Medulloblastoma
Highly malignant tumor of neuroectoderm of cerebellum in children.
Tumor grows rapidly and spreads via CSF
Histology reveals small blue cells and Homer Wright rosettes
Ependymoma
Malignant tumor of ependymal cells in children.
Most commonly arises in 4th ventricle and may present with hydrocephalus.
Characteristic perivascular pseudorosettes
Craniopharyngioma
Benign childhood tumor arising from epithelial remants of Rathke’s pouch
May present with bitemporal hemianopsia
Charcot-Marie-Tooth disease
Progressive hereditary nerve disorder caused by the defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath.
Associated with scoliosis and foot deformities
Sturge-Weber syndrome
Congenital somatic developmental anomaly of neural crest derivatives due to activating mutation of GNAQ gene.
Characterized by port-wine stain, retardation, early-onset glaucoma, and epilepsy.
NF Type 1 (von Recklinghausen disaese)
Caused by mutated NF1 gene on chromosome 17 (negative regular of RAS).
Characterized by cafe-au-lait spots, Lisch nodules, pheochromocytomas, and neurofibromas (derived from neural crest cells)
von Hippel-Lindau disease
AD, caused by mutated VHL on chromosome 3 (negative regulator of HIF and angiogenic growth factors).
Characterized by cavernous hemangiomas, bilateral renal cell carcinomas, hemangioblastomas, and pheochromocytomas
Neurotransmitter changes with Alzheimer disease
Decreased ACh
Neurotransmitter changes with anxiety
Increased norepinephrine
Decreased GABA and 5-HT
Neurotransmitter changes with Huntington disease
Decreased norepinephrine and 5-HT
Increased dopamine
Neurotransmitter changes with Parkinson disease
Decreased dopamine
Increased ACh and 5-HT
Neurotransmitter changes with Schizophrenia
Increased dopamine
Neurological manifestations of Vit B12 deficiency
Subacute combined degeneration. Degeneration of dorsal columns, lateral corticospinal tracts, and peripheral nerves.
Characterized by loss of position and vibration sense, ataxia, and spastic paresis.
Medial medullary syndrome
Occlusion of anterior spinal artery (branch of veretebral artery)
- Pyramid - contralateral spastic paresis
- Medial lemniscus -contralateral loss of tactile, vibration and conscious proprioception
- XII nucleus - ipsilateral flaccid paralysis of tongue
Lateral medullary (Wallenberg) syndrome
Occlusion of posterior inferior cerebellar artery (PICA; a branch of veretebral artery)
- Inferior cerebellar peduncle - ipsilateral limb ataxia
- Vestibular nuclei - vertigo, contralateral nystagmus
- Nucleus ambiguus (IX, X) - ipsilateral paralysis of larynx, pharynx, palate (dysarthria, dysphagia, loss of gag reflex)
- Spinal V (V) - ipsilateral facial pain/T loss
- Spinothalamic tract - contralateral body pain/T loss
- Descending hypothalamics - ipsilateral Horner syndrome
Medial pontine syndrome
Occlusion of paramedian artery (branch of basilar)
- Corticospinal tract - contralateral spastic hemiparesis
- Medial lemniscus - contralateral loss of tactile/position/vibration sensation
- Fibers of VI - medial strabismus (diplopia on lateral gaze to affected side)
Lateral pontine syndrome
Occlusion of anterior inferior cerebellar artery (branch of basilar)
- Middle cerebellar peduncle - ipsilateral ataxia
- Vestibular nuclei - vertigo, nausea, contralateral nystagmus
- Facial nucleus - ipsilateral facial paralysis, loss of taste in anterior 2/3 tongue, lacrimation, salivation, corneal reflex, hyperacusis
- Spinal trigeminal nucleus - ipsilateral facial pain/T loss
- Spinothalamic tract - contralateral body pain/T loss
- Cochlear nucleus - ipsilateral hearing loss
- Descending hypothalamus - ipsilateral Horner syndrome
Pontocerebellar angle syndrome
Usually caused by acoustic neuroma (schwannoma) of CN VIII
May involves CN VII and V
Medial midbrain (Weber) syndrome
Occlusion of posterior cerebral artery
- CN III - ipsilateral ocluomotor palsy (lateral strabismus, dilated pupil, ptosis, no accomodation or convergence)
- Corticospinal tract - contralateral spastic hemiparesis
- Corticobulbar tract - contralateral hemiparesis of lower face (upper face is innervated bilaterally)
Dorsal midbrain (Parinaud) syndrome
Usually caused by pineal tumor compressing superior colliculi
- **Superior colliculus/pretectal area - **paralysis of upward gaze
- Cerebral aqueduct - noncommunicating hydrocephalus
