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Word of the Week
HYPERMNESIA
abnormally vivid or complete memory or recall of the past
TELEMEDICINE
use of medical information exchanged from one site to another via electronic communications to improve patient’s health status. Telemedicine can be used as a teaching tool, by which experienced medical staff can observe, show and instruct medical staff in another location, more effective or faster examination techniques.
PERCENT ALPHA VARIABILITY (PAV)
Quantitative EEG parameter of alpha activity; decreased PAV indicates a poorer prognosis; PAV can help monitor cerebral blood flow and to predict blood flow abnormalities
NONEPILEPTIC PHYSIOLOGIC SEIZURES
sudden alterations in movement, sensations, or consciousness without any neurophysiological features of epileptic seizures. Examples of nonepileptic physiologic seizures include syncope, parasomnias, paroxysmal movement disorders, migraine, and drug and alcohol withdrawal states.
PRIVADEMIC
The “privademic” model is the safe and effective practice of academic medicine within a private practice setting. This is an increasingly popular form of medical practice that involves a physician’s participation in cutting edge research outside the spectrum of a university.
DECOMPRESSIVE HEMICRANIECTOMY
surgical technique used to relieve the increased intracranial pressure and brain tissue shifts that occur in the setting of large cerebral hemisphere mass, or space-occupying, lesions. In general, the technique involves removal of bone tissue (skull) and incision of the restrictive dura mater covering the brain, allowing swollen brain tissue to herniate upwards through the surgical defect rather than downwards to compress the brainstem. Hemicraniectomy has been used to treat brain swelling and mass effect secondary to a middle cerebral artery (MCA) territory infarction, hemispheric encephalitis, and large parenchymal intracerebral hemorrhage in subarachnoid hemorrhage.
PANDEMIC
An epidemic (a sudden outbreak) that becomes very widespread and affects a whole region, a continent, or the world.
SENSITIVITY AND SPECIFICITY
Sensitivity is how often a test will be positive in patients who have the disease; the proportion of actual positives which are correctly identified. Specificity is the number of normal or negative results obtained from a population of patients without the disease; the proportion of negatives which are correctly identified.
JACTITATION
extreme restlessness or tossing in bed, seen with acute infections and some psychiatric disorders.
ELECTROCLINICAL UNCOUPLING
after treatment with antiepileptic medications, the clinical signs of seizures vanish despite persistence of electrographic seizures.
POSTMENSTRUAL AGE
the time elapsed between the first day of the last menstrual period and birth (gestational age) plus the time elapsed after birth (chronological age). The American Academy of Pediatrics recommends using postmenstrual age in place of conceptional age. http://pediatrics.aappublications.org/content/114/5/1362.full.pdf+html
HYPNOPOMPIC HYPERSYNCHRONY
generalized, paroxysmal, synchronous, rhythmic, high voltage, 3 to 4.5 Hz activity that appears during arousal. Most prominent in ages 1 to 5 years and tends to disappear after adolescence.
DOOR-TO-NEEDLE-TIME
when treating a patient with acute ischemic stroke, the time from the patient’s arrival in the Emergency Department to the initiation of intravenous (IV) recombinant tissue plasminogen activator/alteplase (tPA) therapy.
FEVER INDUCED REFRACTORY EPILEPTIC ENCEPHALOPATHY (FIRES)
a devastating condition initiated by prolonged perisylvian refractory status epilepticus (SE) triggered by fever of unknown cause. SE may last more than 1 month, and this condition may evolve into pharmacoresistant epilepsy associated with severe cognitive impairment.
PRURITUS
the unpleasant sensation that elicits the desire to itch. Pruritus is a distressing symptom that can cause discomfort and threaten the effectiveness of the skin as a major protective barrier.
RENAL OSTEODYSTROPHY
bone disease due to kidney failure that occurs in both children and adults. The bones become thin, weak, brittle, and break easily.
SOMNILOQUY
also known as “sleep-talking” it is a parasomnia that refers to talking aloud while asleep. It can be quite loud, ranging from simple sounds to long speeches, and can occur many times during sleep. Listeners may or may not be able to understand what the person is saying.
ENDEMIC
Endemic means a disease occurs frequently and at a predictable rate in a specific location or population. For example, chicken pox occurs at a high and predictable rate among American school children.
ELECTROCAUTERY
an apparatus for surgical dissection and hemostatis using heat generated by a high-voltage, high-frequency alternating current passing through an electrode.
SIGMA
the Greek Letter S. The symbol is Σ. Used to indicate summation of data, such as EMG potentials. In evoked potentials, it is often used to signify the number of trials constituting the average potential.
ISOGROUND
a connection used for safety purposes which limits any current in the grounding electrode to a safe level in the event of equipment failure.
ASYNERGIA
lack of cooperation or working together of parts that normally act in unison or reciprocally.
FORNIX
a C-shaped bundle of fibers that is the efferent pathway of the hippocampus, projecting chiefly to the hypothalamus.
MORO REFLEX
after a loud noise or abrupt change in an infant’s head position, there is first symmetrical abduction and extension of extremities followed by symmetrical adduction and flexion.
PHOBIA
obsessive, persistent, unrealistic, intense fear of an object or situation
ELECTROCLINICAL SYNDROME
distinctive disorders identifiable on the basis of a typical age onset, specific EEG characteristics, seizure types, and often other features which, when taken together, permit a specific diagnosis.
WILSON’S DISEASE
hepatolenticular disease – a genetic disorder marked by muscular tremors, paresis, cirrhosis of the liver, mental deterioration, and deposition of copper in the cornea (Kayser-Fleischer ring).
PRAXIS
the ideation or execution of complicated movements
DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMOR (DNET)
is a recently described but rare tumor that occurs in children and characterized by long-standing, intractable partial complex seizures.
BRUDZINSKI SIGN
seen with meningitis; flexion of the neck results in flexion of the hip and knee and passive flexion of the lower limb on one side causes a similar movement in the opposite limb
hgECoG
high gamma (70 to 150 Hz) electrocorticography
OHTAHARA SYNDROME
or Early Infantile Epileptic Encephalopathy is a neurological disorder characterized by seizures. The disorder affects newborns, usually within the first three months of life (most often within the first 10 days) in the form of epileptic seizures. Infants have primarily tonic seizures, but may also experience partial seizures, and rarely, myoclonic seizures. Ohtahara syndrome is most commonly caused by metabolic disorders or structural damage in the brain, although the cause or causes for many cases can’t be determined. EEG reveals a characteristic pattern of high voltage spike wave discharge followed by little activity resembling burst suppression.
VESTIGIAL STRUCTURES
a structure or organ is vestigial if it has diminished in size or usefulness in the course of evolution. In human beings, the vermiform appendix (a hollow, worm-shaped organ about the size of a pencil, attached to the beginning of the large intestine) marks descent from mammals that had a much larger sac in this position and used it to digest their high-cellulose diet.
ELECTROCOCHLEOGRAPHY
measurement of electrical potentials (cochlear microphonics, summating potentials, and action potentials of the eighth cranial nerve) in response to acoustic stimuli measured by an electrode in the external acoustic canal on the tympanic membrane or through the typmanic membrane applied to the promontory or round window.
BATTLE SIGN
seen with fracture of the base of the skull; discoloration over the skin of the mastoid region of the skull with the bruising first appearing near the tip of the mastoid process.
BLOOD BRAIN BARRIER (BBB)
intricate network of capillaries within the central nervous system that alters permeability and restricts passage of certain chemicals and organisms from entering the brain tissue.
MYOCLONIC-ASTATIC EPILEPSY (MAE)
or Doose Syndrome, is an epilepsy syndrome of early childhood that is often resistant to medication. Onset of MAE occurs commonly in the first five years of life, with the mean age being three. Statistics show that it usually affects children who have previously developed normally, and boys are twice as likely as girls to develop MAE.
MACROSOMIA
abnormally large size. Neonatal macrosomia is excessive birth weight in a neonate, seen most often in children of diabetic mothers or those with cerebral gigantism.
ALEXITHYMIA
inability to recognize or describe one’s emotions.
EUPHORIA
an exaggerated feeling of physical and emotional well being not consonant with apparent stimuli or events
PHARMACOLOGICAL COMA
a state that lacks both awareness and wakefulness induced by pharmacological agents, i.e., medications, anesthesia used to treat nonconvulsive status epilepticus.
ANERGIA
characterized by abnormal inactivity; extreme passivity
ACQUIRED BRAIN INJURY (ABI)
an insult to the brain causing brain injury that is not hereditary, congenital, or degenerative. Causes of ABI are varied and include traumatic brain injury (TBI), stroke, encephalitis, aneurysms, anoxia, metabolic disorders, meningitis, and brain tumors.
PENUMBRA
in radiography, an area of blurring around the edges of a structure. Ischemic penumbra is an area of moderately ischemic brain tissue surrounding an area of more severe ischemia.
PSEUDOBULBAR AFFECT (PBA)
is a condition characterized by episodes of uncontrollable laughing and/or crying that may be inappropriate, unrelated to the situation at hand, or not expressing the person's mood. The condition is known by other terms, including emotional liability, emotional incontinence, and pathological laughing and crying. PBA is associated with neurologic disorders that may include, but are not limited to multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), dementias including Alzheimer's disease, Parkinson's disease, stroke, and traumatic brain injury.
MASKING
the interference caused to the perception of one sound by the simultaneous presence of another.
DELIRIUM
transient disorder characterized by a disturbance of consciousness and cognition with rapid onset and a fluctuating course.
APOPTOSIS
a morphological pattern of cell death affecting single cells. It is a mechanism for cell deletion in the regulation of cell populations and occurs during formation of the cerebral cortex.
CONTRACTURES
tendon and soft tissue of limbs in a fixed position due to increased muscle tone leading to muscle shortening.
SUBDURAL EMPYEMA
is an abscess of purulent material located between the dura mater and the arachnoid mater most often found in the frontal lobes.
FIFTH DAY SEIZURES
now referred to as Benign Neonatal Convulsions, these seizures occur between the first and seventh day of life in otherwise normal, full-term infants born after an uncomplicated, normal pregnancy and delivery. There is no family history of neonatal seizures.
ACTIGRAPHY
a relatively noninvasive method of monitoring the human rest/active cycles. A small actigraph unit is worn by the patient usually on the wrist of the non-dominant arm. The actigraph is useful for determining sleep patterns and circadian rhythms.
FARBER’S DISEASE
describes a group of inherited metabolic disorders called lipid storage diseases, in which excess amounts of lipids (oils, fatty acids, and related compounds) build up to harmful levels in the joints, tissues, and central nervous system. Most children with the classic form of Farber’s disease die by age 2, usually from lung disease.
APALLIC SYNDROME
now referred to as persistent vegetative state, is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness
INTERNAL CAROTID STUMP PRESSURE
the measure of the back pressure resulting from collateral flow through the Circle of Willis via the contralateral carotid artery and the vertebrobasilar system. The critical stump pressure is unknown. Pressures below 50 mm Hg are thought to be associated with hypoperfusion.
QUASIPERIODIC DISCHARGES
EEG waves or complexes occurring at intervals only approaching regularity.
LOCKED-IN SYNDROME
quadriplegia and mutism with intact consciousness and the preservation of voluntary vertical eye movements and blinking
PLEXUS
a network of lymphatic vessels, nerves, or veins
PAVOR NOCTURNUS
also known as night terrors, sleep terrors, incubus attack, is a parasomnia disorder that occurs predominantly in children in N3 stage of sleep. The patient has feelings of terror or dread and is unable to recall the event.
CEPHALOHEMATOMA
hemorrhage of blood between the skull and periosteum (membrane that lines the outer surface of all bones). It is a complication of childbirth that may occur after a prolonged second stage of labor or instrumental delivery.
GRAPHOELEMENT
specific named components of the EEG; elements within the graph or tracing. These specific elements are identified by visual pattern recognition, e.g., triphasic waves, delta brushes.
SOMATOFORM DISORDERS
a group of mental disorders in which physical symptoms suggest the presence of a medical disorder but are not fully explained by a general medical condition, the direct effects of a psychoactive substance, or another mental disorder. Symptoms are not under voluntary control, unlike those occurring in factitious disorders. The category includes: body dysmorphic disorder, conversion disorder, hypochondriasis, pain disorder, somatization disorder, and undifferentiated somatoform disorder.
ENCEPHALOMYELORADICULOPATHY
a disease involving the brain, spinal cord, and spinal nerve roots.
FESTINATING GAIT
one in which the patient involuntarily moves with short, accelerating steps, often on tiptoe, with the trunk flexed forward and the legs flexed stiffly at the hips and knees. It is seen in Parkinson disease and other neurologic conditions that affect the basal ganglia. Called also festination.
GIANT CELL ARTERITIS
a chronic vascular disease of unknown origin, occurring in the elderly, characterized by severe headache, fever, and accumulation of giant cells in the walls of medium-sized arteries, especially the temporal arteries. Ocular involvement may cause visual impairment or even blindness. Called also cranial, granulomatous, or temporal arteritis and Horton arteritis, disease, or syndrome.
MARCUS GUNN PUPILLARY PHENOMENON
with unilateral optic nerve or retinal disease, a difference between the pupillary reflexes of the two eyes when a light is shone alternately into each one with the other eye covered; on the affected side there is abnormally slight contraction or even dilation of the pupil. Called also Gunn pupillary phenomenon or sign.
TIBIOADDUCTOR REFLEX
tapping of the tibia on the medial side results either in homolateral adduction of the lower limb or crossed adduction from side to side.
TRANSTENTORIAL HERNIATION
herniation of brain structures through the tentorial notch. Called also tentorial herniation. Usually this is descending or caudal transtentorial herniation, with downward displacement of medial brain structures by a supratentorial mass to exert pressure on underlying structures, including the brainstem. This can be a life-threatening situation because of pressure on the third cranial nerve, with symptoms including dilated, nonreactive pupils, ptosis, and decreasing consciousness or coma. Ascending or rostral transtentorial herniation is a much rarer syndrome in which cerebellar structures herniate upward through the notch because of a lesion beneath the notch. This can cause ocular symptoms, hemiparesis, and eventually coma.
OCCULT BLOOD
that present in such small amounts as to be detectable only by chemical tests or by spectroscopic or microscopic examination.
DECORTICATE RIGIDITY
abnormal flexor posturing of the limbs, indicative of a lesion in the cerebral hemispheres or disruption of the corticospinal tracts. The patient exhibits bilateral adduction of the shoulders, pronation and flexion of the elbows and wrists, and extension, internal rotation, and plantar flexion of the lower extremities.
NEONATAL RESPIRATORY DISTRESS SYNDROME
a condition of the newborn marked by dyspnea with cyanosis, preceded by symptoms such as dilatation of the nostrils, grunting on exhalation, and retraction of the suprasternal notch or costal margins. Most affected babies either were born prematurely, have diabetic mothers, or were delivered by cesarean section; sometimes there is no known cause. This is the major cause of death in the newborn, and survivors have a high risk for chronic neurologic complications. Prematurity with interrupted development of the surfactant system is the most common cause.
HEMODYNAMIC MONITORING
continuous monitoring of the movement of blood and the pressures being exerted in the veins, arteries, and chambers of the heart. Current invasive techniques permit monitoring of intra-arterial blood pressure, pulmonary artery pressure, left atrial pressure, and central venous pressure.
Y-LINKED INHERITANCE
the pattern of inheritance shown by genes carried on the Y chromosome (Y-linked genes); only males can be affected, and they always express the phenotype and transmit the gene to all of their sons.
CAFÉ AU LAIT SPOTS
light brown pigmented macules seen in neurofibromatosis and Albright syndrome.
ANTICHOLINERGIC SYNDROME
the central and peripheral effects produced by overdosage or abnormal reaction to clinical dosage of anticholinergic drugs, e.g., atropine, phenothiazines, antihistamines, and tricyclic antidepressants; signs and symptoms include anxiety, delirium, disorientation, hallucinations, seizures, tachycardia, hyperpyrexia, mydriasis, vasodilation, gastric and urinary retention, and decreased salivary, sweat, bronchial, and nasopharyngeal secretions.
INFRATENTORIAL
beneath the tentorium of the cerebellum.
BALLISMUS
violent flinging movements of the limbs; called hemiballismus when it affects only one side of the body.
DIALYSIS DYSEQUILIBRIUM SYNDROME
a condition occasionally seen following overly rapid hemodialysis, characterized by increased intracranial pressure that causes nausea, headache, vomiting, restlessness, and a decreased level of consciousness. The neurological complications may lead to coma and death if not treated. The cause of this syndrome is thought to be the rapid decrease in the blood urea nitrogen that accompanies dialysis. Called also dialysis dysequilibrium.
QUADRANTANOPIA
defective vision or blindness in one fourth of the visual field
KAPOSI SARCOMA
a multicentric, malignant neoplastic vascular condition characterized by blue to red nodules under the skin, usually on the lower limbs, especially the toes or feet; the nodules slowly increase in size and number and spread to more proximal sites. Tumors may remain confined to skin and subcutaneous tissue, or may become more widespread and involve the viscera. The condition occurs endemically in certain parts of Central Africa and Central and Eastern Europe, and a virulent, disseminated form occurs in immunocompromised patients. Human herpesvirus 8 has been implicated as a causative agent.
INCUS
the middle of the three auditory ossicles in the middle ear. Called also anvil.
VENTURI MASK
a type of disposable face mask used to deliver a controlled oxygen concentration to a patient. The flow of 100 percent oxygen through the mask draws in a controlled amount of room air (21 per cent oxygen). Called also venturi.
LEUKOENCEPHALITIS
inflammation of the white substance of the brain
PALEOCORTEX
that portion of the cerebral cortex that, with the archeocortex, develops in association with the olfactory system, and which is phylogenetically older and less stratified than the neocortex. It is composed chiefly of the piriform cortex and the parahippocampal gyrus.
CAPNOGRAPH
an instrument used in anesthesia, intensive care, and respiratory therapy to produce a capnogram, a tracing that shows the concentration of carbon dioxide in each exhaled breath. It is used to monitor the adequacy of mechanical ventilation. Also called capnogram.
THROMBOEMBOLISM
a condition in which a blood vessel is blocked by an embolus carried in the bloodstream from the site of formation of the clot. The obstruction of the pulmonary artery or one of its main branches may be fatal.
ACCOMMODATION REFLEX
the coordinated changes that occur when the eye adapts itself for near vision; they are constriction of the pupil, convergence of the eyes, and increased convexity of the lens.
VASOMOTOR RESERVE
the ability of the cerebral vessels to maintain adequate blood perfusion in the brain regardless of changes in pressure gradients, body position, or blood pressure.
OXYCEPHALY
a condition in which the top of the skull is pointed or conical owing to premature closure of the coronal and lambdoid sutures
P300 POTENTIAL
an event related potential elicited by infrequent, task-relevant stimuli. It is considered to be an endogenous potential as its occurrence links not to the physical attributes of a stimulus but to a person's reaction to the stimulus. More specifically, the P300 is thought to reflect processes involved in stimulus evaluation or categorization. It is usually elicited using the oddball paradigm in which low-probability target items are inter-mixed with high-probability non-target (or "standard") items.
TISSUE PLASMINOGEN ACTIVATOR (tPA)
is a protein involved in the breakdown of blood clots. Because tPA works on the clotting system, it is used in clinical medicine to treat only embolic or thrombotic stroke. Use is contraindicated in hemorrhagic stroke and head trauma.
PACHYGYRIA
condition in which the convolutions of the cerebral cortex are abnormally large; there are fewer sulci than normal and in some cases the amount of brain substance is somewhat increased. Also called macrogyria.
VERTEBROBASILAR ARTERY INSUFFICIENCY
a condition characterized by poor blood flow to the posterior portion of the brain, which is fed by two vertebral arteries that join to become the basilar artery. symptoms may include: loss of vision in part or all of both eyes, double vision, vertigo, numbness or tingling, nausea and vomiting, slurred speech, loss of coordination, dizziness, or confusion, trouble swallowing, and a drop attack.
EVENT RELATED POTENTIAL (ERP)
any measured brain response that is directly the result of a thought or perception. An ERP is any stereotyped electrophysiological response to an internal or external stimulus. The event-related potential (ERP) technique in cognitive neuroscience allows scientists to observe human brain activity that reflects specific cognitive processes.
DOUBLE-BLIND STUDY
an experimental procedure in which neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment; a double-blind procedure is used to guard against both experimenter bias and placebo effects.
DEEP BRAIN STIMULATION (DBS)
a surgical treatment involving the implantation of a medical device, which sends electrical impulses to specific parts of the brain. DBS in select brain regions has provided remarkable therapeutic benefits for otherwise treatment-resistant movement and affective disorders such as chronic pain, Parkinson's disease, tremor and dystonia.
HYPOSPADIAS
an abnormal condition in males in which the urethra opens on the under surface of the penis
NEURODEGENERATIVE DISORDER
a chronic progressive neuropathy characterized by selective and generally symmetrical loss of neurons in motor, sensory, or cognitive systems. Include: Alzheimer's disease, Pick's disease, Huntington's disease, Parkinson's disease, Freidreich's ataxia, amyotrophic lateral sclerosis, familial spastic paraparesis, spinal muscular atrophy.
CRANIOSYNOSTOSIS
premature closure of the cranial sutures, resulting in skull deformities such as oxycephaly, plagiocephaly, scaphocephaly, or trigonocephaly.
AMYOTROPHIC LATERAL SCLEROSIS (ALS)
a progressive neurologic disease with degeneration of lower motor neurons in the gray matter of the anterior horns of the spinal cord, some brainstem motor neurons, and the pyramidal tracts. The disease presents in middle age and affects men two to three times more often than women. The first symptom is muscle weakness, especially in the arms and legs. As the disease progresses the patient has difficulty swallowing) and talking, and later breathing difficulties as the disease affects the accessory muscles of respiration. Eventually muscles atrophy and the patient becomes functionally quadriplegic. Mental processes are not affected, so that the patient remains alert and aware. Called also Lou Gehrig disease.
GLASGOW COMA SCALE
a scale that assesses the response to stimuli in patients with craniocerebral injuries. The parameters are eye opening, motor response, and verbal response. A patient is assessed against the criteria of the scale, and the resulting points give a patient score between 3 (indicating deep unconsciousness) and either 14 (origi |