Neurology - Pathology Flashcards
1
Q
Dementia
- Description
- Most common causes
- Other causes
A
- Description
- A decrease in cognitive ability, memory, or function with intact consciousness.
- Most common causes
- Alzheimer disease
- Pick disease (frontotemporal dementia)
- Lewy body dementia
- Creutzfeldt-Jakob disease
- Other causes
- Multi-infarct (2nd most common cause of dementia in elderly)
- Syphilis
- HIV
- Vitamins B1, B3, or B12 deficiency
- Wilson disease
- NPH.
2
Q
Alzheimer disease
- Type of condition
- Description
- Histologic / gross findings
A
- Type of condition
- Dementia
- Description
- Most common cause in elderly.
- Down syndrome patients have an increased risk of developing Alzheimer.
- Familial form (10%) associated with the following altered proteins (respective chromosomes in parentheses):
- Early onset: APP (Chr 21), presenilin-1 (Chr 14), presenilin-2 (Chr 1)
- Late onset: ApoE4 (Chr 19)
- ApoE2 (Chr 19) is protective.
- Histologic / gross findings
- Widespread cortical atrophy.
- Narrowing of gyri and widening of sulci
- Decreased ACh
- Senile plaques [A]
- Extracellular β-amyloid core
- May cause amyloid angiopathy –> intracranial hemorrhage
- Aβ (amyloid-β) synthesized by cleaving amyloid precursor protein (APP)
- Neurofibrillary tangles
- Intracellular, hyperphosphorylated tau protein = insoluble cytoskeletal elements
- Tangles correlate with degree of dementia
3
Q
Pick disease (frontotemporal dementia)
- Type of condition
- Description
- Histologic / gross findings
A
- Type of condition
- Dementia
- Description
- Dementia, aphasia, parkinsonian aspects, change in personality.
- Spares parietal lobe and posterior 2 ⁄3 of superior temporal gyrus.
- Histologic / gross findings
- Pick bodies: spherical tau protein aggregates
- Frontotemporal atrophy
4
Q
Lewy body dementia
- Type of condition
- Description
- Histologic / gross findings
A
- Type of condition
- Dementia
- Description
- Initially dementia and visual hallucinations followed by parkinsonian features.
- Histologic / gross findings
- α-synuclein defect
5
Q
Creutzfeldt-Jakob disease
- Type of condition
- Description
- Histologic / gross findings
A
- Type of condition
- Dementia
- Description
- Rapidly progressive (weeks to months) dementia with myoclonus (“startle myoclonus”).
- Histologic / gross findings
- Spongiform cortex
- Prions (PrPc –> PrPsc sheet [beta-pleated sheet resistant to proteases])
6
Q
Multiple sclerosis
- Definition
- Presentation
- Findings
- Treatment
A
- Definition
- Autoimmune inflammation and demyelination of CNS (brain and spinal cord).
- Relapsing and remitting course.
- Most often affects women in their 20s and 30s
- More common in whites.
- Presentation
- Patients can present with:
- Optic neuritis (sudden loss of vision resulting in Marcus Gunn pupils)
- Internuclear ophthalmoplegia
- Hemiparesis
- Hemisensory symptoms
- Bladder/bowel incontinence
- Charcot classic triad of MS is a SIN:
- Scanning speech
- Intention tremor (also Incontinence and Internuclear ophthalmoplegia)
- Nystagmus
- Patients can present with:
- Findings
- Increased protein (IgG) in CSF.
- Oligoclonal bands are diagnostic.
- MRI is gold standard.
- Periventricular plaques [A] (areas of oligodendrocyte loss and reactive gliosis) with destruction of axons.
- Multiple white matter lesions separated in space and time.
- Treatment
- β-interferon, immunosuppression, natalizumab.
- Symptomatic treatment for neurogenic bladder (catheterization, muscarinic antagonists), spasticity (baclofen, GABA receptor agonist), pain (opioids).
7
Q
Acute inflammatory demyelinating polyradiculopathy
- Definition
- Findings
- Associated with…
- Treatment
A
- Definition
- Most common variant of Guillain-Barré syndrome.
- Autoimmune condition that destroys Schwann cells –> inflammation and demyelination of peripheral nerves and motor fibers.
- Autonomic function may be severely affected (e.g., cardiac irregularities, hypertension, or hypotension).
- Almost all patients survive
- The majority recover completely after weeks to months.
- Findings
- Results in symmetric ascending muscle weakness/paralysis beginning in lower extremities
- Facial paralysis in 50% of cases
- Increased CSF protein with normal cell count (albuminocytologic dissociation).
- Increased protein –> papilledema.
- Associated with…
- Infections (Campylobacter jejuni and CMV)
- –> autoimmune attack of peripheral myelin due to molecular mimicry, inoculations, and stress, but no definitive link to pathogens.
- Treatment
- Respiratory support is critical until recovery.
- Additional treatment: plasmapheresis, IV immune globulins.
8
Q
Other demyelinating and dysmyelinating diseases
- Progressive multifocal leukoencephalopathy
- Acute disseminated (postinfectious) encephalomyelitis
- Metachromatic leukodystrophy
A
- Progressive multifocal leukoencephalopathy
- Demyelination of CNS due to destruction of oligodendrocytes.
- Associated with JC virus.
- Seen in 2–4% of AIDS patients (reactivation of latent viral infection).
- Rapidly progressive, usually fatal.
- Increased risk associated wtih natalizumab.
- Acute disseminated (postinfectious) encephalomyelitis
- Multifocal perivenular inflammation and demyelination after infection (commonly measles or VZV) or certain vaccinations (e.g., rabies, smallpox).
- Metachromatic leukodystrophy
- Autosomal recessive lysosomal storage disease, most commonly due to arylsulfatase A deficiency.
- Buildup of sulfatides –> impaired production of myelin sheath.
- Findings: central and peripheral demyelination with ataxia, dementia.
9
Q
Other demyelinating and dysmyelinating diseases
- Charcot-Marie-Tooth disease
- Krabbe disease
A
- Charcot-Marie-Tooth disease
- Also known as 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 or the myelin sheath.
- Typically autosomal dominant inheritance pattern and associated with scoliosis and foot deformities (high or flat arches).
- Krabbe disease
- Autosomal recessive lysosomal storage disease due to deficiency of galactocerebrosidase.
- Buildup of galactocerebroside and psychosine destroys myelin sheath.
- Findings: peripheral neuropathy, developmental delay, optic atrophy, globoid cells.
10
Q
Adrenoleukodystrophy
A
- X-linked genetic disorder typically affecting males.
- Disrupts metabolism of very-long-chain fatty acids –> excessive buildup in nervous system, adrenal gland, and testes.
- Progressive disease that can lead to long-term coma/death and adrenal gland crisis.
11
Q
Seizures
- Definition
- Partial (focal) seizures
- Definition
- Types
- Generalized seizures
- Absence
- Myoclonic
- Tonic-clonic
- Tonic
- Atonic
- Epilepsy
- Status epilepticus
- Causes of seizures by age
- Children
- Adults
- Elderly
A
- Definition
- Characterized by synchronized, high-frequency neuronal firing.
- Variety of forms.
- Partial (focal) seizures
- Definition
- Affect 1 area of the brain.
- Most commonly originate in medial temporal lobe.
- Often preceded by seizure aura
- Can secondarily generalize.
- Types
- Simple partial (consciousness intact)— motor, sensory, autonomic, psychic
- Complex partial (impaired consciousness)
- Definition
- Generalized seizures (diffuse)
- 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
-
Epilepsy
- A disorder of recurrent seizures (febrile seizures are not epilepsy).
-
Status epilepticus
- Continuous seizure for > 30 min or recurrent seizures without regaining consciousness between seizures for > 30 min.
- Medical emergency.
- Causes of seizures by age
- Children—genetic, infection (febrile), trauma, congenital, metabolic
- Adults—tumors, trauma, stroke, infection
- Elderly—stroke, tumor, trauma, metabolic, infection
12
Q
Headaches
- Definition
- Main causes
- Other causes
- Cluster headaches vs. trigeminal neuralgia
A
- Definition
- Pain due to irritation of structures such as the dura, cranial nerves, or extracranial structures.
- Main causes
- Cluster
- Tension
- Migraine
- Other causes
- Subarachnoid hemorrhage (“worst headache of life”)
- Meningitis
- Hdrocephalus
- Neoplasia
- Arteritis.
- Cluster headaches can be differentiated from trigeminal neuralgia based on duration.
- Trigeminal neuralgia produces repetitive shooting pain in the distribution of CN V that lasts (typically) for < 1 minute.
- The pain from cluster headaches lasts considerably longer (> 15 minutes).
13
Q
Cluster headache
- Localization
- Duration
- Description
- Treatment
A
- Localization
- Unilateral
- Duration
- 15 min–3 hr
- Repetitive
- Description
- Repetitive brief headaches.
- Excruciating periorbital pain with lacrimation and rhinorrhea.
- May induce Horner syndrome.
- More common in males.
- Treatment
- Inhaled oxygen, sumatriptan
14
Q
Tension headache
- Localization
- Duration
- Description
- Treatment
A
- Localization
- Bilateral
- Duration
- > 30 min (typically 4–6 hr)
- Constant
- Description
- Steady pain.
- No photophobia or phonophobia.
- No aura.
- Treatment
- Analgesics, NSAIDs, acetaminophen
- Amitriptyline for chronic pain
15
Q
Migraine headache
- Localization
- Duration
- Description
- Treatment
A
- Localization
- Unilateral
- Duration
- 4–72 hr
- Description
- Pulsating pain with nausea, photophobia, or phonophobia.
- May have “aura.”
- Due to irritation of CN V, meninges, or blood vessels (release of substance P, CGRP, vasoactive peptides).
- Treatment
- Abortive therapies (e.g., triptans, NSAIDs) and prophylactic (propranolol, topiramate, calcium channel blockers, amitriptyline).
- POUND–Pulsatile, One-day duration, Unilateral, Nausea, Disabling