Neuro Block 3-Pt 2

ptheodore's version from 2015-08-03 09:54

Reticular Formation & Limbic System

Question Answer
Maintains consciousness.Ascending Reticular Activating System (ARAS)
Mid brain RF talks to the thalamus through the ______ and ______talks to the cortex intralaminar nuclei
Thalamic lesions can result in _____ if intralaminar nuclei are affected.Coma
Produces coma or slow-wave sleepTransection through midbrain
Constant wakefulness.Transection at midpontine level
Lesion through this structure will not affect the normal function of the ARAS.Transection through lower medulla/uppermost part of spinal cord.
Serotonin depletion in the raphe nuclei produces Insomnia (can’t sleep).
The ARAS projection also inhibits the ____ of the thalamus, for a better night sleepReticular nucleus
Involved in habituation, which is very important for a good night’s sleep, or to be able to study.Reticular formation
Disorientation, ‘not thinking clearly’.Confusion
Semi-consciousness or drowsiness. Stimuli will arouse patient but only for the duration of the stimuli.Somnolence
Patient responds in a limited way to painful, or extremely intense, stimuli.Stupor
No response to painful external stimuli.Coma
Motor neurons located at C3/C4 of the spinal cord innervate the diaphragm as thePhrenic nerve.
Motor neurons from T1-T10 innervate intercostal muscles as theIntercostal nerves.
Respiratory center is located in theVentrolateral medulla
Dorsal respiratory centerInspiration.
Ventral respiratory centerInspiration/Expiration.
Connects mammillary bodies with anterior nucleus of thalamus. This tract continues on to the cingulate gyrus.Mammillothalamic tract
Originates in the medial part of the hippocampus, and becomes the Fornix at the posterior end of hippocampus.Fimbria
From hippocampus to mammillary bodies.Fornix
Hippocampus along with the parahippocampal gyrus & dentate gyrus, are called theHippocampal formation.
Hippocampal formation.Hippocampus along with the parahippocampal gyrus & dentate gyrus
Involved in recent memory functions, particularly consolidation of memory. Damage leads to inablity to form short term memoriesHippocampus
Has a role in the recognition of novelty (new).Hippocampus
Ammon’s HornHippocampus
Involved in determining affective (emotional) perception of sensory stimuli, particularly fearAmygdala
Amygdala is connected to hypothalamus byStria terminalis
The combination of ‘psychic’ and physiological responses to a stimuli is calledEmotion.
Brodmann’s areas 28 and 34.Entorhinal cortex
Helps connect hippocampus and neocortex, thus involved in memory consolidation.Entorhinal cortex
Atrophies before other structures in Alzheimer’s.Entorhinal cortex
Thin sheet of gray matter that separates the lateral ventricles (also does limbic stuff).Septum (septum pellucidum)
Important area for ‘learning how to recognize and avoid negative consequences’.Cingulate Cortex/Gyrus
Ocular palsy, Gait ataxia, Mental confusion Most often results from chronic alcohol consumption.Wernicke’s Encephalopathy
Treatment involves thiamine (B1) administration after which symptoms usually resolve quickly.Wernicke’s Encephalopathy
Subdural hematoma & bariatric surgery (gastric bypass) can cause Wernicke’s Encephalopathy
Results in destruction of mammillary bodies.Korsakoff’s Syndrome
Is caused by chronic alcoholism. Symptoms include anterograde memory deficits, mental confusion, and confabulation*. Since excessive consumption can damage cerebellum, patient may also show cerebellar symptoms.Korsakoff’s Syndrome
Ataxia, Nystagmus, Ptosis, Cardiac defects, ‘Red beefy’ tongueKorsakoff’s Syndrome
Hemorrhages may also occur in diencephalon and brainstem regions, in the gray matter surrounding 3rd and 4th ventricles, and cerebral aqueduct. This can result in opthalmoplegia (weakness/paralysis of eye muscles).Korsakoff’s Syndrome
Visual agnosia, hyperphagia, hypermetamorphosis, hypersexuality,hyperoralityKlüver-Bucy syndrome
Bilateral lesions in the hippocampal formationLoss of short-term memory
A major pathway that travels in close association with the tail and body of the caudate nucleus that conveys information from the amygdala to the hypothalamus?Stria terminalis
Bilateral lesions that involve the amygdaloid nucleusKlüver-Bucy syndrome
Sudden fit or outburst.Paroxysm
Migraines, MS, trigeminal neuralgia , TIA’s, are examples of conditions that could causeParoxysmal Neurobehavioral Disorders: (transient,focal, neurological symptoms)
Auras, blurry vision, nausea, vomiting, photophobia.Migraines
Can be very similar to cluster headaches, but much higher frequency of attacks, shorter duration, and (most important) always responds to the NSAID Indometacin.Paroxysmal Hemicranium (Hemicranium Continua)
‘Lightning-quick’ strike of pain typically in response to non-noxious stimuli.Trigeminal neuralgia
Multiple possible neurologic symptoms.Multiple Sclerosis
Look like seizures but EEG is normal.Pseudo-seizures
Most common type of syncope; Vasovagal Syncope A.K.ACardioneurogenic
Autoimmune disease wherein the immune system attack myelin.Multiple Sclerosis
Period of symptoms (days to months) followed by recovery (usually full). Most common initial type of MS.Relapse-remitting
Occurs in persons after years of relapse-remitting MS. Gradual deterioration on top of relapse-remitting.Secondary progressive
Steady, continuous deterioration from the onset of MS, with relapse/recovery periods.Progressive relapsing MS
Gradual, steady progression with no periods of relapse remission of MS. Later age of onset, equal between sexes.Primary progressive MS
Clinically isolated syndrome may be an indication ofMultiple Sclerosis
Rx for Multiple Sclerosishigh dose steroids, or plasmapheresis or Interferons
Damage to nerves outside the brain or spinal cord.Peripheral neuropathy
Damage/loss of a single nerve or nerve group. (Ex. Carpal tunnel, sciatica).Mononeuropathy
Many peripheral nerves lose function simultaneously (Ex. Guillan Barre, diabetes, kidney failure, Lyme disease, alcoholism, and many others).Polyneuropathy
When the nerve root(s) are the affected area.Radiculopathy
When MULTIPLE nerve root(s) are the affected area.Polyradiculopathy (Cauda equina)

The Glasgow Coma Scale

Question Answer
No eye opening.1
Eye opening to pain.2
Eye opening to verbal command.3
Eyes open spontaneously.4
No verbal response1
Incomprehensible sounds.2
Inappropriate words.3
No motor response.1
Extension to pain.2
Flexion to pain.3
Withdrawal from pain.4
Localising pain.5
Obeys Commands.6

Lesions and Respiration

Question Answer
Bilateral damage to forebrain (or diencephalon) structures results in hyperapnea alternating with apnea. Often seen in terminal care.Cheyne-Stokes respiration
Damage to periaqueductal gray and RF in midbrain or upper pons. Sustained, rapid, deep hyperapnea.Central neurogenic hyperventilation.
Damage to dorsolateral tegmentum of the pons. Prolonged inspiration followed by prolonged expiration.Apneustic breathing.
Midpontine damage resulting in 3-5 rapid, deep breaths followed by periods of apnea.Cluster breathing.
Damage to dorsomedial RF in caudal pons or rostral medulla.Ataxic (Biot's) breathing
Due to damage to ventrolateral medulla respiratory centers, or the descending axons in the caudal medulla.Respiratory arrest



EEG's & Seizures

Question Answer
EEG requires ____ electrodes; _________ on head, _________ on ears.21, 19, 2
Note that the left ear and right ear on the EEG are designated ___ and _________ respectively.A1 & A2
Present in awake, but resting state (eyes closed). Disappear during sleep, and decrease with eye opening or mental exertion.Alpha
Brain wave that occurs during activation of the nervous system (during sensory input and mental activity). Activity decreases during motor movement.Beta
Occurs in children and adults during emotional stress. They also occur during some mental disorders. Interestingly, can also appear during meditative or ‘creative’ states.Theta
Occur during deep sleep in adults, and also in awake infants. If these waves are present in awake adults they likely indicate brain injury.Delta
Waves showing a group of neurons working together for a specific cognitive or motor task.Gamma
Overlaps with other frequencies. Reflects the synchronous activity of motor neurons in the resting state.Mu
Rhythmical cortical activity on an EEG originates fromCortical and thalamic connections.
Generated by cortical nerve cell excitatory and inhibitory postsynaptic potentials.EEG
The EEG is the leading test used to help diagnoseSeizures
Types of seizures that always start in brain.Epileptic Seizures
Seizures not caused by changes in brain electrical activity. Their EEG will look normal.Non-Epileptic Seizures
The actual seizure.Ictis (ictal)
Period immediately following the seizure.Postictis (ictal)
Period between seizures.Interictal
Continuous seizures or clusters of seizures.Status epilepticus
Seizure that affect both hemispheres from the beginning of the seizure. Loss of consciousness occurs for varying periods of time.Generalized seizures
Seizure involve that includes stiffening of the limbs and jerking of the limbs and faceGeneralized tonic clonic ‘Grand Mal’
Seizure involving rapid, brief contraction of body muscles. Usually involves arms or feet/legsMyoclonic
Seizures including periods of lack of awareness, usually lasting less than a minute.Absence ‘Petit Mal’
Seizure involving Abrupt loss of muscle toneAtonic
NORMAL Brief, involuntary twitching of a muscle or a group of muscles.Myoclonus NOT Myoclonic
Area of seizure is limited to one region of the body.Partial seizures
Type of partial seizure that involves no loss of consciousness. Simple Partial
Type of partial seizure which consciousness is lost or impairedComplex partial
One time only seizure (induced by drugs, anesthetics, or unknown).First Seizures
Seizures occurring during high fever in children.Febrile Seizures
Looks like a seizure but no change in EEG. PTSD, panic disorder, are examples, as are factitious (Munchausen’s).Dissociative (Pseudo) Seizures
Seizures due to Diabetes, syncope, migraine, stroke, tumor, etc.Organic causes
High blood pressure and elevated levels of protein in urine in pregnant women.Pre-eclampsia
Tonic-clonic seizures. Leading cause of maternal and peri-natal death, resulting from High blood pressure and elevated levels of protein in urine in pregnant women.Eclampsia
Low level of which Neurotransmitter imbalance can lead to seizuresGABA
Seizures result from over-excitability of a group ofNeurons.
Seizures originating from here are often preceded by auras or hallucinationsTemporal lobe
Point of origin for most seizuresMotor cortex and temporal lobes
Dilantin (phenytoin), Tegretol (carbamazepine)Anticonvulsant (Seizure) meds
Rx for seizure; Device in chest wall, electrode around nerve in neck (when it is large and easily found between carotid and jugular).Location
Rx for seizure; Stimulating electrode ‘wrapped’ around the left vagus nerve (less cardiac effects than the rightVagus nerve stimulation (VNS):
Turns off midbrain (for sleep).Pontine ARAS
Generates REM sleep (and somatic muscle inhibition).Pontine ARAS
Neurotransmitter that causes sleep. When they become activated, midbrain ARAS is turned off, and we sleep.Serotonin (5 H-T)
Loss of consciousness (can’t ‘drive’ cortex).Midbrain lesion
Constant wakefulness (can’t turn off the midbrain).Pons lesions
5-HT depletionInsomnia
Coffee and tea are antagonists of the ______ receptor, which is why they keep us awake Adenosie A1
_____ receptors are located on ACh neurons in the ARAS. ACh neurons are involved in arousal.Adenosine A1
Accumulates during periods of high ATP use. Activation of the receptors results in inhibition of ACh neurons, resulting in sedation/sleep.Adenosine (A1)
Bilateral lesions of the anterior nucleus of the hypothalamusInsomnia
Controls circadian rhythmsHypothalamus
Hypothalamus nuclei that are very active during NREM sleep, inactive during REM.Anterior and Preoptic nucleus
Pathway for circadian rhythmsLight→Optic nerve → Hypothalamus→Suprachiasmatic Nucleus → Brainstem.

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