Neurology Flashcards
Posterior fossa malformations - Agenesis of cerebellar vermis with cystic enlargement of 4th ventricle (fills the enlarged posterior fossa). Associated with hydrocephalus, spina bifida. -absent cerebellum
Dandy-Walker malformation (midline sagittal MRI shows large cystic 4th ventricle)
These cells give physical support, repair, K+ metabolism, removal of excess neurotransmitter, component of blood-brain barrier, glycogen fuel reserve buffer. Reactive gliosis in response to neural injury. Specific marker: GFAP. Derived from neuroectoderm.
Astrocytes
These phagocytic scavenger cells of CNS (mesodermal, mononuclear origin). Activated in response to tissue damage. Not readily discernible by Nissl stain. Infected cells fuse to form multi nucleated giant cells in CNS.
Microglia
These cells increase their conduction velocity of signals transmitted down axons –> Saltatory conduction of action potential at the nodes of Ranvier, where there are high concentrations of Na+ channels. CNS-oligodendrocytes; PNS-Schwann cells. Wraps and insulates axons: increase space constant and increases conduction velocity.
Myelin
Sensory Receptors - Free nerve endings: These fibers are located on the skin, epidermis, and some viscera. Detect pain and temperature. –> Slow, un myelinated fibers.
C Fibers
Sensory Receptors - Free nerve endings: These fibers are located on the skin, epidermis, and some viscera. Detect pain and temperature. –> Fast, myelinated fibers.
A sigma
Large, myelinated fibers; adapt quickly. Location: Glabrous (hairless) skin. Senses: Dynamic, fine/light touch, position sense.
Meissner corpuscles
Large, myelinated fibers; adapt quickly. Location: Deep skin layers, ligaments, joints. Senses: Vibration, Pressure.
Pacinian corpuscles
Large, myelinated fibers; adapt slowly. Location: Finger tips, superficial skin. Senses: Pressure, deep static touch (e.g., shapes, edges), position sense.
Merkel disks
Dendritic endings with capsule; adapt slowly. Location: Finger tips, joints. Senses: Pressure, slippage of objects along surface of skin, joint angle change.
Ruffini corpuscles
Phagocytic scavenger cells of CNS (mesodermal, mononuclear origin). Activated in response to tissue damage. Not readily discernible by Nissl stain. HIV-infected cells fuse to form multinucleated giant cells in CNS.
Microglia
Physical support, repair, K+ metabolism, removal of excess neurotransmitter, component of blood-brain barrier, glycogen fuel reserve buffer. Reactive gliosis in response to Euronav injury. Marker: GFAP. Derived from neuroectoderm.
Astrocytes
Posterior fossa malformations - significant herniation of cerebellar tonsils and vermis through foramen magnum with aqueductal stenosis and hydrocephalus. Often presents with lumbosacral meningomyelocele, paralysis below the defect.
Chiari II
What pathology is being described: elevated CSF pressure (>200mmHg in non obese, and >250mmHg in obese patients)
CT scan: Absence of ventricular dilation, no tumor or mass
Papilledema, and vision loss, headaches - daily worse in mornings, pulsitile, possible nausea/vomiting, and retro ocular pain.
Pseudotumor cerebri
Glial cells with a ciliated simple columnar form that line the ventricles and central canal of the spinal cord. Apical surfaces are covered in cilia (which circulate CSF) and microvilli (which help in CSF absorption).
Ependymal cells
This system is comprised of the hippocampus, amygdalae, mammillary bodies, anterior thalamic nuclei, cingulate gyrus, and entorhinal cortex. What is being described, and what is its function?
Limbic system - reponsable for feeding, fleeing, fighting, feeling, and sex.
5Fs!
Which spinal tract conveys the following information: touch, vibration, and pressure sensation.
Dorsal columns
Includes fasciculus gracilus and fasiculus cuneatus
Which spinal tract conveys the following information:
Voluntary motor command from motor cortex to body
Lateral and ventral corticospinal tracts
Which spinal tract conveys the following information:
Voluntary motor command from motor cortex to head/neck
Corticobulbar tract
Which spinal tract conveys the following information:
Alternate routes for the mediation of voluntary movement
Reticulospinal and rubrospinal tracts
Which spinal tract conveys the following information:
Pain and temperature sensation
Lateral spinothalamic tract
Which spinal tract conveys the following information:
Important for postural adjustments and head movements
Vestibulospinal tract
Which spinal tract conveys the following information:
Proprioceptive information for the cerebellum
Dorsal and ventral spinocerebellar tracts
What is Being described:
Scanning speech, intention tremor, and nystagmus
Charcot’s Triad of Multiple Sclerosis
What hallmark is being described:
Alternating syndromes - long tract symptoms on one side (i.e. hemiparalysis, motor or sensory) and cranial nerve symptoms on the other
General brain-stem lesion
What CNs are found in the:
Midbrain
CN 3 and 4
What CNs are found in the:
Medulla
CNs 9, 10, and 12
What CNs are found in the:
Pons
CNs 5, 6, 7, and 8
What CNs are found in the:
Spinal Cord
CN 11 - Accessory (Spinal Accessory) Nerve
Patient presents with bilateral loss of pain and temp sensation, with weakness and atrophy of the hand muscles. What pathology is at hand and the associated disease?
Syringomyelia - Chiari Malformation
