Midterm Pathologies Flashcards
Anencephaly
Clinical Presentation: absence of brain and skull; elevated AFP in amniotic fluid and maternal blood; frog-like appearance of fetus; polyhydramnios
MOA: cranial end of the neural tube fails to close leading to no forebrain and calvaria
*associated with maternal T1DM
*folate will decrease risk
Spina Bifida
Clinical Presentation: elevated AFP; occulta: dimple or patch of hair over the vertebral defect; meningocele: protrusion of meninges; meningomyelocele: protrusion of meninges and spinal cord
MOA: caudal neuropore fails to close, but neural tissue continues to develop normally; closed neural tube necessary to induce formation of vertebral arches
Craniosynostosis
Clinical Presentation: scaphocephaly or oxycephaly/turricephaly
MOA: premature closure of sagittal, lambdoid, and coronal sutures leading to deformities of the head which inhibit proper brain development
*scaphocephaly = early closure of sagittal suture
*oxycephaly or turricephaly = early closure of coronal suture
Amyotrophic Lateral Sclerosis (ALS)
Clinical Presentation:
lower signs - flaccid paralysis with muscle atrophy, fasciculations, weakness with decresed muscle tone, impaired reflexes, negative Babinski sign
upper signs - spastic paralysis with hyperreflexia, increased muscle tone, positive Babinski sign
MOA: degeneration of upper and lower motor neurons of the corticospinal tract; anterior motor horn degeneration leads to lower motor neuron signs; lateral corticospinal tract degeneration leads to upper motor neuron signs
*SOD1 mutation present in some familial cases (leads to free radical injury in neurons)
*atrophy and weakness of hands is early sign
Corticospinal lesions
Clinical Presentation: weakness or paralysis on the contralateral side of the body
MOA: rostral to decussation at pyramids - lesions to upper motor neuron in pyramidal tract, brainstem, or forebrain
Clinical Presentation: weakness of paralysis on the ipsilateral side of the body
MOA: caudal to decussation at pyramids - lesions to lateral corticospinal tract, ventral horn, ventral root of the spinal cord, or peripheral alpha motor neuron.
DC/ML Lesions
Clinical Presentation: Sensory (vibration, proprioception, discriminative touch) deficits on the contralateral side of the body
MOA: rostral to decussation at Dorsal Column Nucleus lesions to medial lemniscus, thalamus, thalamic radiation, or forebrain
Clinical Presentation: Sensory (vibration, proprioception, discriminative touch) deficits on the ipsilateral side of the body
MOA: caudal to decussation at Dorsal Column Nucleus - lesions to gracile/cuneate fasciculi, dorsal root, and peripheral nerve
AL Lesions
Clinical Presentation: Sensory (pain and temperature) deficits on the contralateral side of the body
MOA: Rostral to decussation at anterior white commissure - lesions to spinothalamic/Lissauer’s tract, thalamus VPL, thalamic radiation, or forebrain
Clinical Presentation: Sensory (pain and temperature) deficits on the ipsilateral side of the body
MOA: Caudal to decussation at anterior white commissure - lesions to substantia gelatinosa in dorsal horn, dorsal root, and peripheral nerve
Epidural Hematoma
Clinical Presentation: cranial nerve III palsy
MOA: Collection of arterial blood between dura and the skull; classically due to fracture of the temporal bone with rupture of middle meningeal artery
*lens shaped (biconvex) lesion of CT; not crossing suture lines
*herniation is a lethal complication
Subdural Hematoma
Clinical Presentation: progressive neurologic signs; increased occurrence in elderly due to age-related cerebral atrophy
MOA: Venous blood pooling underneath dura and covers the surface of the brain. Due to tearing of bridging veins that lie underneath the dura and arachnoid usually because of trauma
*crescent-shaped lesion of CT that crosses suture lines
*herniation is a lethal complication
Subarachnoid hemorrhage
Clinical Presentation: sudden SEVERE headache. produces blood in the CSF; causes severe headache, stiff neck, loss of consciousness
MOA: typically due to rupture of an aneurysm as arteries pass within the subarachnoid space
Tentorial Hernia
Increase in intracranial pressure above the tentorium cerebelli (i.e. epi or subdural hematoma) or decreased pressure below (i.e. CSF leak) brain may herniate through tentorial incisure
Scalping
hair is caught in piece of machinery - hair, skin, connective tissue, and epicranial aponeurosis pulled away as a unit; skull with its periosteal connective tissue layer is left exposed.
Whiplash
Clinical Presentation: anterior longitudinal ligament or anterior neck muscles are stretched and/or torn; may rupture intervertebral discs, break posterior arch of atlas or dens of axis
MOA: hyperextension (or flexion) of neck due to sudden forward acceleration of the body
Hangman Fracture
Breakage of the posterior arch of the axis with atlas, odontoid process, and body of C2 staying with the head; rest of the vertebral column breaks inferiorly.
Huntington Disease
Clinical Presentation: chorea that can progress to dementia and depression; aggression; average age of presentation is 40 y.o.
MOA: degeneration of the GABA neurons in the caudate nucleus of basal ganglia; AD inheritance (expanded CAG trinucleotide repeats in the Huntington gene)
*SSRI or ampakine treatment increases BDNF production in patients
*inheritance shows anticipation; suicide is common cause of death
Peripheral Neuropathy
Clinical Presentation: affects sensation, movement, gland, and organ function
MOA: damage or disease affecting peripheral nerves due to diabetes, metabolic disorder, traumatic injury, etc.
Bell’s Palsy
Clinical Presentation: Ipsilateral paralysis of upper and lower muscles of facial expression
MOA: Idiopathic cause of facial nerve palsy
Tx: corticosteroids, acyclovir; most pts have gradual recovery of function
Facial Nerve Palsy
Clinical Presentation: Ipsilateral paralysis of upper and lower muscles of facial expression
MOA: Peripheral CN VII/Facial (LMN) lesion
Tx: corticosteroids, acyclovir; most pts have gradual recovery of function
*can be caused by Lyme disease, HSV, Herpes Zoster, Sarcoidosis, and tumors
Cutting of Facial Nerve
Clinical Presentation: Paralysis of single or group of muscles of facial expression
MOA: Deep facial lacerations may cut branches of the facial nerve
Tx: laceration medial to lateral canthus of the eye then cut branches will re-innervate their target muscles and fx will be restored over time
Congenital Insensitivity to Pain with Anhidrosis (CIPA)
Clinical Presentation: devoid of all pain and thermal sensations but with normal touch, vibration, and proprioception; variable degrees of mental retardation, learning deficits, and emotional distrubances
MOA: Loss of function mutation of NTRK1 that results in developmental apoptosis of a specific neuronal population; loss of NGF-dependent primary sensory neurons and postganglionic SYMP neurons
*Lissauer’s and Spinothalamic tracts can’t be distinguished at autopsy
Tx: management of Sx and prevention of injury and infection; removal of baby teeth in young pts
*most pts don’t live past 3 y.o. due to hyperthermia
Arachnoid Granulations
hypertrophy of the arachnoid villi results in arachnoid granulations which may form pits on the inner table of cranial bones along the superior sagittal sinus
Brown-Sequard Syndrome
Clinical Presentation: Ipsilateral UMN signs and loss of tactile, vibration, and proprioception sense and contralateral pain/temp loss below the level of the lesion; ipsilateral sensation loss and LMN signs at level of lesion
MOA: hemi-section of the spinal cord
Acute Inflammatory Demyelinating Polyraduculopathy (Guillian-Barre syndrome)
Clinical Presentation: symmetric ascending muscle weakness/paralysis starting in the lower extremities; autonomic dysregulation; 2/3 have antecedent flu illness; peak in 60y.o.
MOA: autoimmune destruction of Schwann cells causing inflammation and demyelination of peripheral nerves and motor fibers
Tx: supportive care, IVIG, and plasmapharesis
*assc with infections
*increased CSF protein with normal cell count
*almost all pts survive and most recover completely in weeks to months
Charcot-Marie-Tooth Disease
Clinical Presentation: lower extremity weakness, sensory deficits, wasting, decreased reflexes pes cavus, hammertoe; onset usually by 20 y.o,
MOA: hereditary nerve disorder related to defective production of protein involved in structure and function of peripheral nerves or myelin sheath; due to segmental duplication of PMP22 gene (70% of cases)
Histo: large onion bulbs; hypertrophy of neurons
*usually AD inheritance; associated with foot deformaties
Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP)
Clinical Presentation: proximal and distal weakness, sensory change, hyporeflexia over 2 months or more; may be progressive or relapsing/remitting
MOA: autoimmune destruction of Schwann cells causing inflammation and demyelination of peripheral nerves and motor fibers
Histo: lymphocyte infiltrate of the nerve itself, thinly myelinated axons, macrophages, onion bulbs
Tx: corticosteroids, IVIG, plasma exchange
Lepromatous Leprosy
Clinical Presentation: symmetric polyneuropathy with loss of pain; generalized fatigue, numbness of ears, forehead, toes, and fingers.
MOA: Schwann cells infected by M. Leprae (a mycobacterium)
Histo: demyelination and remyelination
Diptheria
Clinical Presentation: weakness and paresthesias
MOA: Exotoxin infection causing demyelination
Varicella-Zoster Virus infection
Latent virus travels to sensory nerves of the skin causing sensory ganglia neuronal degeneration and axonal degeneration
Glioblastoma Multiforme (GBM)
Clinical Presentation: nausea, vomiting, headache
MOA: malignant tumor of astrocytes usually in the cerebral hemisphere and crosses corpus callosum
Histo: Regions of necrosis surrounded by tumor cells and endothelial cell proliferation; tumor cells GFAP positive; vascular proliferation
*most common malignant CNS tumor in adults; poor prognosis
Meningioma
Clinical Presentation: seen more in women; presents as seizures
MOA: benign tumor of arachnoid cells; often near surfaces of brain and parasaggital region
CT/MRI: round mass attached to the dura
Histo: Whirled pattern, psammoma bodies may be present; progesterone receptors frequent
Tx: resection and/or radiosurgery
*most common adult benign CNS tumor; rare in children
Hemangioblastoma
Clinical Presentation: Can cause secondary polycythemia (b/c makes EPO)
MOA: most often cerebellar, brain stem, or spinal; associated with VHL syndrome
Histo: closely arranged thin-walled capillaries, minimal intervening parenchyma; often rich in lipids
Tx: surgery
*benign slow growing tumor
Schwannoma
MOA: benign tumor of Schwann cells; involves cranial or spinal nerves most commonly cranial VIII (abducens); compresses nerve but doesn’t infiltrate
*NF2 association
Histo: encapsulated, verocay bodies, hyalinized blood vessels; tumor cells are S-100 positive
Tx: resection or steriotactic radiosurgery
Oligodendroglioma
Clinical Presentation: may present with seizures
MOA: malignant tumor of oligodendrocytes usually involving frontal lobe
CT/MRI: calcified tumor in white matter; fried-egg appearance of cells, chicken wire capillary pattern; calcifications, perinuclear halos
*relatively rage, slow growing; IDH-1 mutation frequent
Pituitary Adenoma
Clinical Presentation: bitemporal hemianopia due to pressure on optic chiasm; hypo or hyperpituitarism
MOA: hyperplasia or single type of cell in the pituitary; most often prolactinoma
Pilocytic Astrocytoma
MOA: benign astrocyte tumor often in cerebellum, 3rd ventricle, and optic nerves
Histo: cystic lesion with mural nodule; Rosenthal fibers and eosinophilic granular bodies; GFAP positive tumor cells
Medulloblastoma
Clinical Presentation: usually arises in small children; can compress 4th ventricle and cause non-communicating hydrocephalus
MOA: malignant tumor derived from granular cells of the cerebellum
Histo: small, round, blue cells; rosettes may be present
Tx: surgery, adjuvant therapy
*poor prognosis; tumor grows rapidly and spreads via CSF
Ganglioglioma
Clinical Presentation: found in temporal lobe of children/YA with early onset epilepsy
MOA: glioneuronal neoplasm with dysplastic ganglion cells and neoplastic glial cells
Histo: cystic; well differentiated
Genetics: BRAF of V600E mutation
*good prognosis
Ependymoma
Clinical Presentation: hydrocephalus; usually in children
MOA: Ependymal cells, malignant; most commonly in the 4th ventricle
Histo: perivascular pseudo-rosettes and acellular regions, ependymal canals
Tx: surgery and radiation
*poorer prognosis for children
Meningeal Carcinomatosis
MOA: malignant tumor cells found in the subarachnoid space, often from small cells carcinomas or adenocarcinomas (esp breast and lung)
*can’t resect = bad prognosis
Central Neurocytoma
Clinical Presentation: seen in young adults
MOA: tumor found intraventricularly usually attached to the septum pellucidum in region of foramen of Monro
Histo: neuronal cells
*favorable prognosis
Pleomorphic Xanthoastrocytoma
Histo: large, bizarre cells; chronic inflammation, eosinophilic granular bodies, mural nodule with a cyst
Tx: surgery
*better prognosis than diffuse astrocytomas
Lymphoma
Clinical Presentation: 2-3% of all brain tumors; single or multiple lesions
MOA: Diffuse large B-cell lymphoma of the CNS; associated with immune deficiency
Tx: surgery (steriotactic biopsy), steroids (avoid pre-op), radiation, chemo
*MRI is most sensitive technique to detect
Atypical Teratoid Rhabdoid Tumor (ATRT)
Clinical Presentation: Found in young children (<5y.o.); found in posterior fossa or supratentorial location
MOA: high frequency of SMARCB1 inactivation
Histo: rhabdoid cells that are polyphenotypic
*poor prognosis
Myxopapillary Ependymoma
MOA: form of ependymoma
Histo: little blue ependymal cells, degenerative changes, pink hyalinized blood vessels, mucin
*slow growing, low grade tumor with good prognosis
Neurofibroma
Clinical Presentation: can be cutaneous
MOA: tumor that arises most commonly on solitary nerve section
Histo: low cellularity, fibroblasts and Schwann cells, lots of collagen
Tx: have to remove the nerve when you resect the tumor
Malignant Peripheral Neve Sheath Tumor (MPNST)
MOA: can arise de novo or from a plexiform neurofibroma
Histo: very cellular, large ugly nuclei with prominent, mitotic figures, necrosis
Myoclonus/ Clonus
sudden, brief, uncontrolled muscle contraction
Hypotonia/Hyporeflexia
diminished deep tendon reflexes; flaccid muscle
MOA: early stage spinal cord transection (2-3) weeks where alpha motoneuron excitability is diminished; following peripheral nerve or ventral horn injury (LMN/alphaMN)
Hypertonia/Hyperreflexia
heightened deep tendon reflexes, muscle rigidity (spasticity, clonus)
MOA: upper motor neuron lesion
Rigidity
sustained muscle contraction at rest (in the absence of any voluntary movement)
Spasticity
little of no contraction at rest
MOA: late phase of spinal cord transection; corticospinal lesions
Open angle glaucoma
Clinical Presentation: painless; elevated IOP, progressive peripheral visual field loss.
MOA: primary cause is unclear; associated with age, AA race, family history; secondary causes: blocked trabecular meshwork from WBCs, RBCs, retinal elements
Histo: optic disc atrophy; thinning of outer rim of optic nerve head
Tx: pharmacological or surgical lowering of IOP
Closed/narrow angle glaucoma
Clinical Presentation: Elevated IOP, progressive peripheral visual field loss. conjunctival infection, fixed mid-dilated pupil. “steamy” or edematous cornea.
MOA: enlargement or forward movement of lens against the central iris obstructing normal aqueous flow through pupil and peripheral iris gets pushed against cornea
Histo/Radiology: optic disc atrophy; thinning of outer rim of optic nerve head
Tx: IV Diamox, laser iridotomy, topical glaucoma medications
Conjunctivitis
Clinical Presentation: red eye; allergic = itchy, viral = watery discharge, bacterial = grittiness, irritation, mucopurulent discharge
MOA: inflammation of the conjuctiva from virus, bacterial, or allergic reaction
Papilledema
MOA: optic disc swelling due to increased ICP from excessive CSF; blood, esp venous blood, pools in the veins on the surface or the retina
*enlarged blind spot and elevated optic disc with blurred margins
Sty (hordeolum)
Clinical Symptoms:
Internal sty - inflammation of meibomian/tarsal gland just under conjunctival side of the eyelid
External sty - inflammation of eyelash follicle or lid-margin glands
MOA: acute purulent inflammation of the eyelid, generally caused by staph aureus
Chalazion
Clinical Symptoms: normally not infected or painful
MOA: lump in the eyelid as a result of the chronic blockage of one of the meiboinan/tarsal glands
Tx; hot compresses 4x daily or lancing the inner surface of the eyelid
Exopthalmos
Clinical Presentation: eyes that protrude slightly; seen in patients with Grave’s disease
MOA: increased size of the extraocular muscles and edema in the orbit due to autoimmune rxn to TSH receptor antigen which is expressed in retroorbital tissues including extraoccular muscles
Strabismus
Clinical Presentation: 2-3% of the population (more common in Caucasians and females)
MOA: pathological misalignment of the visual axis that cause a loss of depth perception and binocular vision
Esotropia
one or both eyes turn inward; more common form of strabismus
*form of strabismus
Exotropia
one eye deviates outward; rare
*form of strabismus
Presbyopia
trouble seeing up close
MOA: with increased age, lens becomes less elastic and can’t round up as much when ciliary muscle contracts
Venous Nicking
during HTN the arteries become swollen and tend to restrict venous return as arteries cross the veins of the fundus
CN IV Damage
(trochlear)
eye moves up (especially with contralateral gaze), head tilt toward unaffected side
CN VI Damage (Abducens Nerve Palsy)
Clinical Presentation: double vision in which two images appear side by side
MOA: medially directed eye that can’t abduct (turn outward): often due to conditions that increase intracranial pressure and stretch abducens nerve
CN VII Damage
MOA: damage to zygomatic/temporal branch of facial nerve (CN VII) leads to dysfunction of orbicularis oculi muscle so can’t close eyes properly
Tx: place gold weights in the upper lid to aid closing to protect the cornea from drying
Von Hippel-Lindau Disease
Clinical Presentation: hemangioblastomas in the retina, brain stem, cerebellum, spine; angiomatosis, bilateral renal cell carcinoma, pheochromocytomas
MOA: AD inheritance, inactivation of the VHL tumor suppressor gene
NF2 (Neurofibromatosis Type 2)
Clinical Presentation: bilateral acoustic schwannomas, multiple meningiomas, gliomas, hamartomas
MOA: autosomal dominant; mutation in the protein merlin
Dislocated Jaw
Clinical Presentation: pain locking of the jaw
MOA: dislocation of temporomandibular joint; occurs when mouth is opened too wide or when mouth is bumped when open, head of mandible slides too far anteriorly over the articular tubercle, locking the jaw open
Tx: place was of material on the occlusal surface of teeth while applying downward pressure with fingers placed in the vestibule of the oral cavity
Mandibular Tori
Clinical Presentation: 90% bilaterally; more common in Asian and Inuit populations
MOA: benign bony protrusions form the medial wall of the mandible towards the oral cavity
Tooth Cavity
acids released form bacteria erode through the enamel into the sodter dentine
Root Canal
cavity extends to the pulp of the tooth
*pulp material is removed, destroying the internal blood supply and innervation and packed with antibiotics, then sealed
Uvular Deviation
Clinical Presentation: uvula is not midline
MOA: can indicate a lower motor neuron lesion of CN X which innervates most of the muscles of the soft palate
*uvula will deviate away from the affected side
Uvulitis
Clinical Presentation: uvula is the most inflamed structure in the posterior pharynx of a febrile patient
MOA: inflammation of the uvula often from infection (group A strep most common)
Bifid Uvula
Clinical Presentation: mildest form of cleft palate
MOA: associated with Loeys-Dietz syndrome, an AD genetic condition similar to Ehlers-Danlos and Marfans
Torticollis
Clinical Presentation: holding head tilted to one side; difficulty turning the head
MOA: tearing of the sternocleidomastoid muscle during passage through the birth canal - muscle shortens in response to being torn
Spasmodic Torticollis
*rare, sudden contraction of the sternocleidomastoid muscle
Hiccups
diaphragmatic spasm which causes sudden inhalation of air which interrupted by reflex closure of the glottis
Laryngeal Cancer
25% of head and neck cancers
MOA: vocal cords are area of transition from on epithelial type to another, so they are susceptible to cancer
*95% arise from squamous epithelial cells
Epiglottitis
Clinical Presentation: can have excessive swelling which can interfere with breathing
MOA: inflammation of the epiglottis; often due to strep pneumonia or staph aureus
Tx: hospitalization, IV antibiotics, intubation
Laryngitis
inflammation of vocal cords due to viral infection (usually) of respiratory epithelium within the larynx; can also be due to acid reflux
*true vocal cords turn from white to red and thicken due to edema; increased mass of vocal cord limiting their vibration
Superior Laryngeal Nerve Damage
Clinical Presentation: weak, rough, easily fatiguing voice; can’t sing high pitches
MOA: unilateral paralysis of cricothyroid muscle
*touch supraglottic mucosa to see if causes cough reflex to test this nerve function
Vocal Cord Paralysis
loss of innervation (recurrent laryngeal from vagus: CNX) to laryngeal muscles causes passive closure of the glottis
Tx: intubation
C6 Radiculopathy
decreased bicep, triceps, and brachioradialis reflex; weakness of biceps, triceps, and flexor carpi radialis. Numbness in first two fingers
C7 Radiculopathy
hand numbness and weakness just of the middle finger, weakness of triceps and decreased triceps tendon reflex
Radial Neuropathy
weakness of arm affecting elbow, wrist, and finger extension
Median Neuropathy
decreased radial flexion of hand, flexion of distal phalanx and digits 2/3, abduction of thumb
Ulnar Neuropathy
decreased abduction of digits 2-5; decreased ulnar flexion of hand and of distal phalanx 4/5
L4 Radiculopathy
weak knee extension and ankle dorsiflexion
S1 Radiculopathy
weakness of plantar flexion, tow flexion, to extension, and foot eversion
Femoral Neuropathy
decreased sensation to lateral thigh, episodic burning and numbness to lateral thigh
Peroneal (Fibular) Neuropathy
weakness of ankle dorsiflexion, ankle eversion, and toe extensors
Cryptogenic Sensory Polyneuropathy (CSPN)
Type of distal symmetric peripheral neuropathy
Clinical Presentation: “stocking and glove” sensory loss
MOA: chronic distal symmetric neuropathy. selective vulnerability of the longest neurons
Tx: symptom control
Diabetic Peripheral Neuropathy
Type of distal symmetric peripheral neuropathy
Clinical Presentation: “stocking and glove” sensory loss
MOA: elevated fasting blood sugar leads to NEG of neurons and neuropathy. selective vulnerability of the longest neurons
Tx: symptom control
Thyroglossal Duct Cyst
Clinical Presentation: midline masses below the hyoid bone. May interfere with swallowing.
MOA: thyroid tissue that did not fully migrate out of the thyroglossal duct. Generally runs posterior to the hyoid bone
Tx: surgery
*common in children 2-10y.o,
Holoprosencephaly
Clinical Presentation: moderate - cleft lip/palate; severe - cyclopia
MOA: failure of the left and right hemispheres of the brain to separate; may be related to SHH pathway mutation
*can be seen in Patau syndrome and fetal alcohol syndrome
Fetal Alcohol Syndrome
Clinical Presentation: craniofacial defects
MOA: alcohol causes apoptosis of pre-migratory neural crest cells during the first month of development when midline structures are established
Treacher Collins Syndrome (TCS)
Clinical Presentation: maral hypoplasia (underdevelopment of zygomatic bones); underdeveloped mandible, malformed or missing ears, down-slanting palpebral fissures
MOA: Autosomal dominant inheritance; due to not enough neural crest cells proliferating and migrating to branchial arches.
Pierre Robin Sequence (PRS)
Clinical Presentation: micrognathia of mandible, cleft palate, glossoptosis (posteriorly placed tongue)
MOA: defect in neural crest cell affecting mandible development; environmental and genetic factors.
DiGeorge anomaly
Clinical Presentation: CATCH-22: cardiac outflow tract anomalies, abnormal facies, thymic aplasia, cleft palate, hypoparathyroidism
MOA: deletion of the long arm of chromosome 22 (22q11) causing errors in the development of the branchial arches (3 and 4)
Global Cerebral Ischemia
Clinical Presentation: mild - transient confusion; severe - diffuse necrosis, vegetative state
MOA: global ischemia to the brain - low perfusion, acute decrease in blood flow, chronic hypoxia, repeated hypoglycemia
Ischemic Stroke
Thrombotic - rupture of atherosclerotic plaque, often at a branch point
Embolic - thromboemboli (often from left side of the heart blocking the MCA); hemorrhagic infarct at periphery of cortex
Lacunar - secondary to hyaline arteriosclerosis; involves lenticulostriate vessels causing small cystic infarcts
Intracerebral hemorrhage
Clinical Presentation: severe headache, nausea, vomiting, eventual coma
MOA: bleeding into the brain parenchyma (due to rupture of Charcot-Bouchard microaneurysm of lenticulostriate vessels)
*HTN complication; most common at basal ganglia
Multiple Sclerosis
Clinical Presentation: neuro deficits with periods of remission; blurred vision in one eye, vertigo, scanning speech, hemiparesis; internuclear opthalmoplegia; lower extremity loss of sensation or weakness
MOA: autoimmune destruction of CNS myelin and oligodendrocytes; associated with HLA-DR2
MRI: periventricular plaques (areas of white matter de-myelination);
Lumbar Puncture: increased lymphocytes, increased Ig and MBP (myelin basic protein)
Tx: high dose steroids for acute attacks, interferon beta for long term- slows progression of Dz
Parkinson Disease
Clinical Presentation: TRAP - Tremor at rest, Rigidity in extremities, Akinesia/bradykinesia, Postural instability and shuffling gait
MOA: loss of dopaminergic neurons in the substantia nigra of the basal ganglia; related to aging; unknown etiology
Histo: loss of pigmented neurons in substantia nigra and round eosinphilic inclusions of alpha-synuclein (Lewy bodies)
Acoustic Neuroma
Clinical Presentation: disrupted vestibular and acoustic function; affected movement of muscles of facial expression taste and salivary gland secretion and anterior 2/3 of tongue
MOA: Schwann cell tumor of the vestibular nerve; can also affect function of the facial cranial nerve
*Associated with NF-2
Facial Nerve Upper Motor Neuron Lesion
Clinical Presentation: contralateral paralysis of lower muscles of facial expression - forehead spared (frontalis)
MOA: destruction of the motor cortex or connection between motor cortex and facial nucleus in pons
Facial Nerve Lower Motor Neuron Lesion
Clinical Presentation: Ipsilater paralysis of the upper and lower muscles of facial expression, hyperacusis, loss of taste sensation to anterior 2/3 of tongue
MOA: destruction of facial nucleus of CN VII
Trigeminal Neuralgia
Clinical Presentation: sudden, severe pain in the regions covered by the trigeminal nerve
MOA: generally due to aberrant (redundant) cerebral arteries that compress the foot of the trigeminal nerve; most often only affects one of the branches. Causes focal area of demyelination with “cross talk” between bare axons
Tx: carbamezapine
Vagus Nerve Lesions
Clinical Presentation: unilateral - hoarseness; difficulties swallowing; uvula deviates to the unaffected side
MOA: lesions causes loss of function of the intrinsic muscles of the larynx; inability to elevate the soft palate and contract the pharynx muscles necessary for swallowing
CN XII LMN Lesion
Clinical Presentation: Tongue deviation to the same side as the lesion
MOA: lesions causes loss of function of the muscles of the tongue (except palatoglossus)
Cataracts
Clinical Presentation: painless, often bilateral opacification of the lens often decreasing vision
MOA: congenital (galactosemia, galactokinase deficiency, trisomies, Marfan, Alport) and acquired (age, smoking, alcohol, excessive sunlight, DM, trauma) risk factors
Uveitis
Clinical Presentation: may have hypopyon (leukocytic exudate and anterior chamber) or conjunctival redness
MOA: inflammation of uveal tract (iris + choroid + ciliary body)
Age-related Macular Degeneration
Clinical Presentation:
Dry - deposition of yellowish extracellular material in and between Bruch’s membrane and retinal pigment epithelium
Tx: multivitamin and antioxidant supplements
Wet - rapid loss of vision due to bleeding secondary to choroidal neovascularization
Tx: anti-VEGF injections
MOA: degeneration of macula causing distortion and loss of central vision
Diabetic Retinopathy
Clinical Presentation: Retinal damage
MOA:
Non-proliferative - damaged capillaries leak blood; fluids and lipids seep into retina causing hemorrhages and macular edema
Fundoscopic: cotton wool spots, venous nicking, intraretinal microvascular abnormalities
Proliferative - chronic hypoxia results in new blood vessels forming with resultant traction of retina
Fundoscopic: neovascularization of iris and disc; vitreous hemorrhage
Retinal Detachment
Clinical Presentation: visual loss
MOA: separation of neurosensory layer of the retina from the outermost pigmented epithelium leading to degeneration of photoreceptors
Fundoscopic: crinkling of retinal tissue and changes in vessel direction
*more common in pts with high myopia and history of head trauma
*surgical emergency
Retinitis
MOA: retinal edema and necrosis often due to virus (can be bacterial or parasitic)
*may be associated with immunosuppression
Horner Syndrome
Clinical Presentation: ptosis, anhidrosis, and flushing of affected side of face, miosis (pupillary constriction)
MOA: sympathetic denervation of the face
*associated with spinal cord lesion above T1 and pancoast lung tumor compression of superior cervical ganglia
Bitemporal Hemianopsia (Tunnel Vision)
Clinical Presentation: loss of temporal vision
MOA: lesion within the optic chiasm (often due to pituitary tumor)
Anton’s Syndrome
Clinical Presentation: blindness but the patient doesn’t realize they are blind
MOA: damage to the visual cortex and the visual association cortex
Pterygium
Clinical Presentation: obscured vision; common in elderly
MOA: vascularized conjunctival tissue may grow over the iris obscuring vision
Tx: surgical excision; may recur
Corneal Abrasion
Extremely common; pt has a scratch of the cornea and feels like there is something in there eye, but has conjunctivitis
Uveal Tract Melanoma
Arises from melanocytes of nevi in the uvea; hematogenous metastasis usually to liver
Histo: spindle cells that are fusiform in shape; epithelioid spheroid cells with cytoplasmic irregularity
Tx: enucleation or radiation; good prognosis if found early
CN III Damage
Clinical Presentation:
Motor - ptosis, down and out gaze
Parasympathetic - diminished or absent pupillary light reflex, blown pupil, often with down and out gaze
MOA:
Motor - decreased diffusion of O2 and nutrients to interior fibers from compromised vasculature on the outside of the nerve
Parasympathetic - compression of the nerve (i.e. form aneurysm to PCA or superior cerebellar artery, or uncal herniation); affects fiber s on the periphery first
Post Herpetic Neuralgia
Clinical Presentation: persistent pain despite resolution of active infection; association with numbness
MOA: presumed secondary to decreased modulation from de-afferentiation of A-beta fibers allowing C fibers to be sensed more
*risk reduced with early use of antivirals
Anosmnia
Clinical Presentation: loss of sense of smell, can be temporary or permanent
MOA: head trauma can cause shearing of olfactory nerves as they pass through the cribiform plate
*association with early Parkinson’s, Alzheimer’s, MS, and Huntington’s
CSF Rhinorrhea
Fracture of the cribiform plate can cause leakage of CSF into the nose
Sinusitis
Clinical Presentation: tapping on bone superficial to sinus will elicit pain
MOA: inflammation of one or more of the paranasal sinuses usually due to bacterial infection secondary to virus or allergies
PTSD
Clinical Presentation: avoidance of triggers, emotional numbness, persistent arousal; duration of longer than 1 month
MOA: exposure to a traumatic event that is relived and re-activates the anxiety/stress response
Tx: CBT (cognitive behavioral therapy), SSRI, vanlafaxine (SNRI)
Acute Stress Disorder
Clinical Presentation: avoidance of triggers, emotional numbness, persistent arousal; duration of less than 1 month
MOA: exposure to a traumatic event that is relived and re-activates the anxiety/stress response
Tx: CBT (cognitive behavioral therapy)
OCD
Clinical Presentation: compulsive behaviors, obsessions that are irrational/excessive; produces dysfunction
MOA: Obsessions - recurrent thoughts, impulses, and/or images
Compulsions - repetitive behaviors that one feels drive to perform
Tx: CBT, SSRI, clomipramine
Panic Disorder
Clinical Presentation: concern, worry, or change in behavior due to fear of additional attacks for 1 month or longer
MOA: recurrent non-triggered panic attacks with rapid experience of anxiety and physical manifestations
*Has at least 4 of the following: palpitations, paresthesia, depersonalization, abdominal distress, nausea, intense fear, chest pain, choking, chills, sweating, SOA
Generalized Anxiety Disorder
Clinical Presentation: restlessness, easily fatigues, difficulty concentrating, irritability, sleep disturbances
MOA: excessive worry about multiple events or activities; subjective difficulty redirecting worry
Tx: CBT, SSRI, SNRI, Buspirone, TCA, Benzodiazepines
Social Anxiety Disorder
Clinical Presentation: exposure provokes immediate anxiety and those situations are endured with distress; is excessive or unreasonable
MOA: fear of one or more social/performance situations; perception of scrutiny by others
Insomnia
Often a learned behavior component; trouble with the initiation and maintenance of sleep
- Anxiety can be associated with initiation of sleep
- Depression can be associated with the maintenance of sleep
Parasomnia
Clinical Presentation:
- Sleep inertia - difficult transition from sleep to wakefullness
- Slow wave sleep behaviors - sleep: walking, talking, eating, terrors, periodic leg movements while asleep
- REM sleep disorder - failure of REM paralysis mechanism
Narcolepsy
Clinical Presentation: daytime sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations may accompany sleep paralysis
MOA: abnormality in brain systems that produce atonia during REM; may involve immune system attack; immediately enter REM when first going to sleep
*cataplexy = abrupt and reversible loss of muscle tone elicited by strong emotion
Ramsay Hunt Syndrome (Herpes Zoster Oticus)
Clinical Presentation: painful vesicles within the auditory canal, ear drum, and anterior 2/3 of tongue; paralysis of facial muscles and alters taste
MOA: herpes zoster virus reactivation and infection of geniculate ganglia of the facial nerve
Tx: antiviral medications, steroid, pain medications
Epilepsy
Clinical Presentation: An intrinsic tendency of the brain to have seizures. Defined by two or more unprovoked seizures
MOA: Focal (localization related) - localized EEG abnormalities, structural lesion (often cryptogenic)
Generalized (non-localization related) - often genetic
*anti-epileptic drugs, epilepsy surgery, electrical stimulation of nervous system
“Reflex Sympathetic” Dystrophy
Clinical Presentation: excessive hyperpathia/allodynia after an injury
MOA: associated with vasomotor changes after an injury. Usually after a period of immobilization. Extreme abnormal sensitization.
*also called Complex Regional Pain Disorder and Causalgia (if associated with a nerve injury)
Tx: aggressive mobilization and pain control
Cerebral Palsy
Clinical Presentation: Disorder of movement or posture. Brain lesions do not progress, but clinical manifestations can MOA: Encephalopathy (brain lesion), acquired early Sub-classifications: - Spastic CP (UMN) - Ataxic CP (Cerebellar systems) - Dyskinetic CP (Basal Ganglia) - Hypotonic CP (LMN) *Diagnosed before age 3
Autism
Clinical Presentation: Impaired socialization. More than half associated with intellectual disability. Lack of mutual attention, lack of understanding the mental state of others
MOA: Not known, but strong genetic component. More common in males so possibly X linked
Brain changes in: orbitofrontal cortex, anterior cingulate cortex, amygdyla
*Diagnosed before age 3
Intellectual Disability
Clinical Presentation: Intelligence substantially below average (< 70)
MOA: 33% from unknown causes. Known causes include down’s syndrome, fragile X syndrome, Rett Syndrome, malnutrition, toxin exposure (lead), neonatal injury
*Diagnosed before age 18
Autism Spectrum Disorder
Impaired socialization that can either be mild with no intellectual disability (Asperger Syndrome) or with severe intellectual disability
*Diagnosed after age 3
Convulsion
Involuntary, coarse, usually semi-rhythmic, synchronous movements of the limbs. Can be tonic or clonic. Often associated with loss of consciousness.
Seizure
Clinical manifestations of abnormal synchronous discharge of (cerebral cortical) neurons. Can be focal onset (old term: partial) or general onset (old term: primary generalized).
Focal Categories:
1. Aware (simple partial)
2. Impaired Awareness (complex partial)
a. both 1 and 2 can be
motor or non-motor
3. Focal to Bilateral Tonic-Clonic (secondary generalized)
Generalized Categories:
1. Motor
a. tonic-clonic ("grand mal")
b. other motor
2. Non-motor (absence, "petit mal")
*Often manifested by convulsions
