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Ecchymosis: a blue-purple discoloration of the skin due to passage of blood from ruptured blood vessels into subcutaneous tissue
Echographia: A form of agraphia in which one cannot express his/her thoughts in writing, but can accurately copy written material or from dictation; pathological copying of words or phrases in written form
Echoic memory: Form of sensory memory for auditory information - limited duration (2-3 seconds), but large capacity
Echopraxia: Involuntary (pathological) imitation of the movements or gestures of another person.
Damage to what area of the brain may result in echopraxia?: frontal lobe
ECoG: abbreviation for electrocorticography or electrocorticogram; activity (brain waves) recorded directly from the cortical surface of the brain
Ecological validity: One type of external validity that pertains to how well a test (or the methods, materials, setting of a study) predicts behavior in real situations or everyday life
Ecphory: pertaining to episodic memory retrieval - interaction between retrieval cues and stored information that lead to reconstruction of information into memory (described by Tulving)
Electrocerebral Silence (ECS): electrocerebral inactivity - associated with brain death
Edema: Tissue swelling and intracranial pressure increase that result from water accumulation in the brain
What is the difference between vasogenic edema and cytotoxic edema?: vasogenic edema- accumulation of water in the extracellular space

cytotoxic edema - diffusion of water into cells due to neural or glial membrane impairment
Effective visual field: portion of the visual field where recognition of letters is possible
Efferent: conduction of neural messages AWAY from the CNS (think E for Exit)
Elaboration: Pertains to memory processing - information that was initially encoded into memory is enriched through additional processing of the information
Electrical stimulation mapping: electrical current is applied directly to the brain in order to identify eloquent areas (i.e., sensory, motor, language).
ECT: Electroconvulsive Therapy - Treatment in which seizure is produced by passing electrical current through brain; commonly used to treat psychiatric disorders (e.g., depression, schizophrnia)
How should ECT be administered to obtain the fewest cognitive side effects?: Unilateral ECT generally results in less cognitive impairment than bilateral ECT; Cognitive impairment is also less frequently observed when unilateral stimulation is applied to the nondominant hemisphere (although dominant hemisphere stimulation may be more therapeutic)
Electrodermal response (EDR): a change in the electrical properties of the skin in response to physical or psychological stimuli (e.g., stress, anxiety); same as Galvanic skin response (GSR)
Electroencephalogram (EEG): Recording of brain waves using scalp or depth electrodes (commonly used to diagnose epilepsy, encephalitis or encephalopathies, dementia; also used to evaluate brain death and coma); recordings directly from the cortical surface during surgery are usually referred to as ECog (electrocorticogram)
Electrolyte imbalance: When electrolytes (e.g., sodium, potassium) become disturbed due to dehydration or dietary insufficiency. Can cause confusional state, particularly in elderly.
ELISA: Enzyme-Linked Immunosorbent Assay - this is a test that is very sensitive at detecting antibodies in the blood or CSF; Often used to diagnose infection agents that are not easily cultured (e.g., lyme disease, AIDS)
Eloquent cortex: Ares of the brain that would result in significant functional impairment if they were surgically resected (e.g., language, motor, and sensory areas)
Embedded Figures Tests: This test includes a number of complex designs, each which contain a more simple geometric figure. Subject must locate the simple geometric figure and trace the shape of it
Embolism: blockage of a blood vessel that disrupts blood flow (may be due to thrombus fragment or other intra-arterial or cardiac material); has been thought to be most common cause of TIAs and cerebral infarction
What is the most common embolic source?: the heart
Where do emobli most frequently lodge?: bifurcations, branchings and curvatures in the blood vessels (e.g., bifurcations of common carotid artery, internal carotid artery, and middle cerebral artery)
Embolization: Method used to close vessels feeding AVMs (e.g., metal pellets, thrombogenic coils, balloons, glues)
What are some common conditions that require embolization?: 1) reduce size of AVM before resection; 2)to treat aneurysms and cavernous fistulas that cannot be resected; 3) to stop uncontrollable bleeding of an artery following head or neck injury
Emotional lability: Rapid and repetitive shifts in affect
What conditions may result in emotional lability?: common in mania and delirium; may also result from damage to the orbitofrontal regions
Empty speech: Speech is fluent, but lacking in content often because of significant word-finding difficulties; characteristic of anomic aphasia
Empyema: presence of pus in a body cavity (can be epidural or subdural)
Encapsulated: encased or enclosed
Encephalitis: brain inflammation that results from infection (usually viral)
What is the most common type of viral encephalitis and what areas of the brain are affected by it?: herpes simplex encephalitis -damages inferior surface of frontal and temporal lobes
Encephalocele: congenital skull defect that usually results in a protrusion of brain tissue through the defect
Encephalomalacia: softening of brain tissue, usually caused by vascular insufficiency, degenerative changes, or trauma
Encephalopathy: Diffuse brain imparment - often due to some systemic condition. Often accompanied by a confusional state
Encoding: Process by which a stimulus representation gets into memory
Encoding specificity principle: memory retrieval is a function of the overlap between the context of learning and that of the retrieval; when information available at encoding is present during retrieval, memory is facilitated
Endarterectomy: surgical excision of the inner lining (plaque) of an artery (often carotid artery) that is clogged with atherosclerotic buildup; this procedure decreases risk of ischemic stroke in patients with significant stenosis
Endorphins: compounds (peptide hormones) synthesized in the brain that bind to opiate receptors; they reduce the sensation of pain and affect emotions
Where are endorphins found within the brain?: endorphins are primarily in the pituitary; lesser amounts are also present in the hypothalamus and other regions of the brain involved in pain perception
Entorhinal cortex: anterior portion of the parahippocampal gyrus in the medial temporal lobe; relay area between hippocampus and association cortex; involved in odor processing and memory
Environmental dependency syndrome: syndrome marked by imitation and utilization behavior - patients are excessively responsive to stimuli in their environment
What area of the brain is usually damaged in environmental dependency syndrome?: this syndrome has been associated with bilateral orbitofrontal lesions
EOMI: "Extra-ocular movements intact" - includes up, down, medial and lateral movements of the eyes.
If a patient's extra-ocular movements are intact, what cranial nerves are functioning normally?: 3rd - oculomotor
4th - trochlear
6th - abducens
Ependyma: epithelial membrane that lines the central canal of the spinal cord and the ventricles of the brain
Ependymoma: A CNS neoplasm made up of relatively undifferentiated ependymal cells (usually from central canal of spinal cord); most are benign and slow growing, although they can be malignant
Epicritic: pertains to sensory nerve fibers that enable the perception of slight differences in the intensity of stimuli, especially touch (light or localized touch) or temperature; also light pressure and sharp pain
Epidural hematoma: an extradural hematoma - blood accumulates between dura and calvaria (skull)
What is a common cause of epidural hematoma?: often results from skull fracture when meningeal artery is damaged by bony skull groove
Epigastric: upper middle region of the abdomen (above the stomach)
Epilepsy: brain disorder characterized by recurrent seizures (usually defined as...at least 2 spontaneous, unprovoked seizures)
Epilepsy - Centrencephalic Epilepsy: historical term used to refer to the hypothesis that generalized epilepsy is triggered by a subcortical pacemaker
Epilepsy - Psychomotor Epilepsy: epilepsy with prominent ictal motor automatisms (e.g., lipsmacking) and seizures arising from temporal lobe region (now called complex partial epilepsy)
Epilepsy - Reflect Epilepsy: epilepsy in which seizures are provoked by specific stimuli in the enviroment (internal or external) (e.g., flashing lights)
Epilepsy - Rolandic Epilepsy: this type of epilepsy occurs in childhood; it is a benign focal motor epilepsy that is assocaited with central-temporal spikes on EEG
Epilepsy Surgery: neurosurgical intervention for the treatment of medically intractable epilepsy (doesn't respond to anti-epileptic drugs); epileptogenic region is resected to eliminate seizures
Epinephrine: neurotransmitter associated with the sympathetic nervous system - released by adrenal gland
Episodic Dyscontrol Syndrome: involves intermittent explosive behavior in reaction to frustration; individual seems ot lose self-control and strike out in rage that is disproportionate to the stimulus (pts often diagnosed with DSM-IV - intermittent explosive disorder)
Where is the lesion likely to be found in neurologic patients who demonstrate dyscontrol episodes?: often lesions in ventromedial structures, including frontal cortex, hypothalamus, septal nuclei, and amygdala
Episodic Memory: context-specific memory that is typically autobiographical (a type of explicit memory)
Equipotentiality: posits that memory impairment depends on amount of tissue damaged rather than on localization of the lesion - proposed by Karl Lashley
Errorless Learning: all errors are prevented during training process - believed to be more efficient than trial and error learning in neurological populations (especially those with anterograde amnesia)
Errors of Action: problems with perception-action cycle (often includes sequencing deficits or misuse of objects)
Erythemia: Redness of the skin or mucous tissues caused by dilatation and congestion of the capillaries, often a sign of inflammation or infection
Essential Tremor: a common usually hereditary or familial disorder of movement; characterized by benign resting tremor of the hands, head or voice - typically exacerbated by anxiety and by activity; not symptomatic of Parkinson's disease
How is essential tremor typically treated: beta-blockers
Etat Lacunaire: mutliple small infarcts often associated with chronic high blood pressure
Evoked Potentials: an electrical response in the cerebral cortex as recorded following stimulation of a peripheral sense receptor
What are the two broad categories of evoked potentials?: 1) Exogenous sensory potentials - modality-specific responses reflecting processing of sensory info in afferent pathways; 2) Endogenous potentials - not specific to a sensory modality and reflect task that subject is asked to perform (aka event-related potentials)
Auditory Evoked Potentials: recorded in response to auditory stimuli; range from brainstem auditory evoked respones (reflect integrity of brainstem auditory pathway and occur in first 10 milliseconds post-stimulation) to long-latency evoked potentials that are generated in neocortex and reflect processing speed
Motor Evoked Potentials: activity recorded in relation to motor response; includes activities before movement or shortly after movement
Somatosensory Evoked Potentials: recorded in response to brief somatosensory stimulation (e.g., electric shock); used to assess integrity of sensory functioning
Visual Evoked Potentials: recorded in response to visual stimuli (e.g., strobe light); used to assess integrity of visual function; long-latency VEPs are generated in neocortex and reflect processing speed
Executive Function: cognitive abilities needed to accomplish comlex goal-directed behaviro and adaptation in response to environmental demands; includes planning, cognitive flexibility, direction of attentional resources; also involved in self-awareness and monitoring
Exner's Area: posited to be center for motor graphic images needed for successful writing; located in the poterior portion of the second frontal convolution; not supported by research
Exploratory Factor Analysis: a multivariate statistical method for characterizing the relationships between a set of observed variable in terms of their relation to a smaller set of common underlying variables referred to as factors.
Extensor: when this type of muscle is contracted, it causes the limb to extend or straighten (opposite of flexor)
External Validity: extent to which results from a measure can generalize beyond that measure
Extinction: two definitions: 1) failure to detect a stimulus contralateral to a lesion during bilateral simultaneous stimulation, but detection to affected side is intact with unilateral stimulation; 2) in classical conditioning, animal stops producing learned response when it is no longer reinforced
Motor Extinction: akinesia in contralateral limb increase when person simultaneously uses extremities ipsilateral to lesion
Sensory Extinction: Most often observed in tactile modality; often observed during resolution of hemispatial inattention with right cerebral injuries
Extinction Burst: increase in frequency of response following withdrawal of reinforcer
Extrapyramidal Motor System: functional unit of structures that are physiologically similar, including basal ganglia, subtahalmic nucleas, substantia nigra and their interconnections and connections with the thalaums
Extrapyramidal Syndrome (EPS): includes akinesia, rigidity, temor akathisia, and buccolingual dyskinesia - often experienced as side effects of neuroleptic medications; different from tardive disorders in that movement abnormalities develop acutely rather than following long-term medication use
Extubation: removal of endotracheal or tracheostomy tube

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