Midterm Pathologies Flashcards
(146 cards)
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