Neuro 03

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Neuro 03
2012-02-11 19:07:39
Neuro syndromes

syndromes and NT
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  1. What is Wallenberg syndrome? what are its signs/symptoms?
    • Wallenberg syndrome - (also called Lateral medullary syndrome or posterior inferior cerebellar artery syndrome) is a disease in which the patient has a constellation of neurological symptoms due to injury to the lateral part of the medulla in the brain, resulting in tissue ischemia and necrosis.

    • The lesion is on the dorsal lateral section of the rostoral medulla , usually very high up on the medulla. Usually caused by a bleed or ischemia in the PICA = posterior inferior cerebellar artery (goes to posterior inferior cerebellum) on it way there it winds around and cross the medulla and tributaries come of and supply the medulla.–so what happens is that a big piece of plaque comes up the big pipes (vertebral arteries) but flows into smaller tributaries and get stuck and clogs the little artery going to the medulla and hence causes ischemia in this part of the brain stem.

    This syndrome is characterized by sensory deficits affecting the trunk (torso) and extremities on the opposite side of the infarction and sensory deficits affecting the face and cranial nerves on the same side with the infarct. Specifically, there is a loss of pain and temperature sensation on the contralateral (opposite) side of the body and ipsilateral (same) side of the face. This crossed finding is diagnostic for the syndrome.

    Symptoms: (true of most brain stem issues)

    Another characteristic of this cerebellar damage is hypotonia, were as cerebrum damage causes hypertonia.

    Valgus nerve also starts here so damage can cause ANS issues.

    Also may have nystagmus. Loss of pain and temp in

    ipsilateral face because of the destruction of the trigeminal nuclei (trigeminal nerve , controls chewing muscles and face sensation) contralateral

    body pain and temp loss – due to damage to the lateral spinothalmic tract. (which cross at the segmental level, so if the lesion is above the segmental level it causes this contralteral loss )

    ataxia - The damage to the cerebellum or the inferior cerebellar peduncle can cause ataxia

    Most characteristic signs: contralateral sensation loss and ipsilateral face sensation loss, posterior inferior cerebellar damage and artery damage.
  2. What is a Brown-Séquard syndrome? What are the signs of it?
    • Brown-Séquard syndrome, also known as Brown-Séquard's hemiplegia and Brown-Séquard's
    • paralysis, is a loss of sensation and motor function (paralysis and ataxia) that is caused by the lateral hemisection (cutting) of the spinal cord.

    This is loss of procieption and motor control on side of lesion but pain and temp are unaffected in that limb but on the limb on the other side they would be impaired below the level of the lesion.

    This is a rare injury usually caused by something like a knife wound or gun shot.

    The motor cortex on the right side controls the left side of the body and as the motor pathways descend into the brainstem they cross over and then go on down the cord in a contralateral manner, until they synapse in the ventral grey horn and become lower motor neurons. Sensations such as pain and temperature cross over a the segmental level and then travel up the cord contralaterally. However, proprioception goes up the spine ipsilaterally to the brain stem, so the R leg goes up to the L brain ipsilaterally. So we know this is Brown-seguards syndrome because the lesion or partial cut in the spine must be between T2-L4, because the arms are fine so it has to be below the brachioplexus and hence T1 and due to the issues with the quads we know it above L3-4 sense that the quads nerve roots . We know it is partial because things are still getting through, so it is a half cut of the spine and it must be on the left side of the spine.
  3. What is Myasthenia gravis? what drug is used to treat it and how does it work?
    Myasthenia gravis – (names means grave muscle weakness) is a pathology were antibodies sit on some of the acetylcholine receptors there by blocking them , so that acetylcholine can't act as effectively on the far side of the synaptic junction. This is why we give such a pt neostigmine which will cause the acetylcholine to hang around longer which gives it more of a chance of triggering the few unblocked receptors. The primary symptoms of this disease is muscle weakness. This disease tends to attack cranial nerves first, in particular it effects the fascial nerve first. Most common symptoms in pt developing this disease is tired and weak fascial muscles , this effect is worse at the end of the day. It can also effect swallowing and this can cause choking. This becomes lethal if it effects the vagus. For exterme causes the pt may carry neostigmine.

    Neostigmine (Prostigmin, Vagostigmin) is a parasympathomimetic that acts as a reversible acetylcholinesterase inhibitor. Or in other words it is a drug which inhibits the effects cholinesterase there by keep acetylcholine around longer. This is used to treat diseases such as Myasthenia gravis.
  4. What disease is caused by a loss of dopamine? what drug is used ot treat it and why?
    Parkinson disease – is a disease in which there are issues with dopomaine levels this is treated with L Dopa which is a precursor to dompaomine which is small enough to pass through the mengines into the CNS were it help create higher levels of dopamine. Unfortunatly, after 5-10 years of using L dopa there are side effects that develop that can cause problems. Symptoms include: rolling tremors and gait disturbances – they will shuffle and then freeze and be unable to move during which they will shake. Another symptom is micrograffi or very small handwritting.

    Modern treatments are effective at managing the early motor symptoms of the disease, mainly through the use of levodopa and dopamine agonists. As the disease progresses and dopaminergic neurons continue to be lost, a point eventually arrives at which these drugs become ineffective at treating the symptoms and at the same time produce a complication called dyskinesia, marked by involuntary writhing movements. Diet and some forms of rehabilitation have shown some effectiveness at alleviating symptoms. Surgery and deep brain stimulation have been used to reduce motor symptoms as a last resort in severe cases where drugs are ineffective. Research directions include investigations into new animal models of the disease and of the potential usefulness of gene therapy, stem cell transplants and neuroprotective agents. Medications to treat non-movement-related symptoms of PD, such as sleep disturbances and emotional problems, also exist.

    Dopamine – is an inhibitory neurotransmitter made by the substantia nigra is a brain structure located in the mesencephalon (midbrain) that plays an important role in reward, addiction, and movement. Substantia nigra is Latin for "black substance", reflecting the fact that parts of the substantia nigra appear darker than neighboring areas. This is due to high levels of melanin in dopaminergic neurons. Parkinson's disease is characterized by the death of dopaminergic neurons in the substantia nigra pars compacta. and act on the basil ganglia. Loss of dopamine leads to parkinson.
  5. What is adrenalins other name and what does it do?
    • epinephrine and nor epinephrine – Epinephrine
    • (also known as adrenaline) is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines. It is produced in some neurons of the central nervous system, and in the chromaffin cells of the adrenal medulla from the amino acids phenylalanine and tyrosine.
  6. What is MS and what are some of the symptoms of it?
    The fact that MS is a multifocal lesion is the key to diagnosing it for it is only the fact that a patient will have a number of weird unrelated symptoms such as Tingling in the hand weakness in the legs and blurred vision which indicate that it is caused by multiple unrelated lesions and hence is MS.

    Multiple sclerosis (abbreviated to MS, known as disseminated sclerosis or encephalomyelitis disseminata) is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms

    Most common demylinating disease is MS – which is a problem with attacks on the myelin in the CNS but not in the PNS. This is when the mylein sheath in CNS are destroyed leaving behind plaques (scars) which disrupt nervous functions.

    Symptoms of MS – MS symptoms come and go as the diseases moves in and out of remission (or relapse) slowly growing worse.

    • Ataxia – poor coordination (or poor motor control)
    • Eye issues – common in the early stages – such as blurred vission , due to optic nerve issues , or diplopia = double vision
    • Tingling in extremities (toes in fingers) , common early symptoms
    • Numbness
    • Intention tremor – tremor in limbs when the person is intending to move
    • Fatigue – this can be very bad, during a flare up even putting on a heavy sweat shirt can can make a pt's arm to heavy to lift, another example would be sheets a pt in a flare up might not even be able to turn over with a sheet on them.
    • Dysarthia – (you will find this and not aphasia in MS pt's) this is when there is a mechanical issue with producing speech. Pt's with this tend to speak in a very robotic manner. Example: broken jaw, or nerve issues with tongue.
    • (uncommon symptom) inappropriate laughter
    • Bowel and bladder issues – problems with voiding can lead to infections which can and often does kill the pt. Clinical Note: some patient find that it is sitting (hanging over a toilet) on a toilet which makes it hard to pee, so some pt may find they can only pee if they
    • squat over a bucket.
    • Lhermitte's sign, sometimes called the Barber Chair phenomenon, is an electrical sensation that runs down the back and into the limbs. In many patients, it is elicited by bending the head forward. It can also be evoked when a practitioner pounds on the posterior
    • cervical spine while the neck is flexed; this is caused by
    • involvement of the posterior columns. Lhermitte's
    • sign is named for Jacques Jean Lhermitte, a French neurologist and neuropsychiatrist. Thus it is incorrect to spell the term as "L'hermitte's sign". The sign suggests a lesion of the dorsal columns of the cervical cord or of the caudal medulla. Although often considered a classic finding in multiple sclerosis, it can be caused by a number of conditions, including transverse myelitis, Behçet's disease, trauma, radiation myelopathy, vitamin B12 deficiency (subacute combined degeneration), and compression of the spinal cord in the neck from any cause such as cervical spondylosis, disc herniation, tumor, and Arnold-Chiari malformation. This also happens in spinal menigitis.
  7. What are some of the treatments for MS?
    • Treatments for MS
    • MS pt's are often put on corticosteriods such as prednizone to decrease inflammation and suppress their immune system. This is done because some believe it is an autoimmune disease.

    Betaseron is a multiple sclerosis (MS) medication that is available by prescription. It comes as an injection and is injected just under the skin every other day. Clinical studies show that people who took the drug experienced fewer MS relapses and had fewer lesions after two years of taking it. While most people tolerate the medication well, potential side effects include weakness, headaches, and flu-like symptoms. It increases/enhances the immune system. Why this works for some pt and immunosupressent work for other is unknown.

    PT treat MS by trying to decrease its signs in symptoms this is done in many ways , including energy concentration, moderate exercise (to much is bad and so is to little so it takes some skill to set this up) or even just by reducing the movements they have to make in ADLS.
  8. What is Syringomyelia?
    Classic lesion – Syringomyelia – literally means it is a tube shaped lesion within the center of something – usually found in the cervical area – usually idiopathic though it can be caused by trauma – often found in the elderly – This destroys the Grey matter right around the central canal and the white commissure (tube like hole) right in front of the Grey commissure. It then goes down a few cervical levels (can occur in the lumbar but much rarer then cervical). If the white commissure is destroyed we lose pain and temperature bilaterally because these signals cross in the white commissure. They say this loss of sensation occurs in a cape like pattern. Because tend to lose a pair like C4-5 bilaterally. This is a early symptom of the disease. In the early stages of the disease there is no motor problems, but if the cavitation gets worse and the whole gets bigger then it will damage the lower motor neurons that start in the effected segments. Which would causes flaccid paralysis in the levels effected, and not really effect motor control in lower levels. Proprioception goes up the dorsal columns so it would also be unaffected. However If the pressure of the CSF in the central canal bulges out it can cause other odder symptoms.
  9. What is Guillain–Barré-Strohl syndrome?
    Guillain–Barré-Strohl syndrome, is an acute polyneuropathy, a disorder affecting the peripheral nervous system. Ascending paralysis, weakness beginning in the feet and hands and migrating towards the trunk, is the most typical symptom, and some subtypes cause change in sensation or pain as well as dysfunction of the autonomic nervous system. It can cause life-threatening complications, in particular if the breathing muscles are affected or if there is autonomic nervous system involvement. The disease is usually triggered by an infection. The diagnosis is usually made by nerve conduction studies and with studies of the cerebrospinal fluid. With prompt treatment by intravenous immunoglobulins or plasmapheresis, together with supportive care, the majority will recover completely. Guillain–Barré syndrome is rare, at 1–2 cases per 100,000 people annually, but is the most common cause of acute non-trauma-related paralysis in the world.

    Guilian-barre – is a lower motor neuron disease and a sensory neuron disease – because it effects all the nerves of the PNS – also called acute ideopathic polyneuropathy – which means come on quickly and goes away quickly , no idea were it comes from and it effects many neurons – also called landry's ascending paralysis – its called this because the problem usually occur in the legs and the move up the body. There is acute inflamation of the PNS and the motor and sensory nerves are eaten just like in MS and you egt focal demyelination in various areas – you find lymphocytes within the nerves. Believed to be an autoimmune disease but not really sure were it comes from. Often occurs a few weeks after a viral infection or in some cases after surgery. The myelin sheaths are ingested by phagocytes but the schwan cells remain – this causes the loss of a nerve signal because it stop salvatory conduction – In severe cases there are wild fluctuations in blood pressure and breathing issues , this loss of respiration can be the cause of death in many pt's. 3-4% mortality this happens when it get into the cranial nerves though in other cases this just causes sever symptoms such as trouble speaking , swallowing and control of fascial muscles. However most people recover , in most people the pattern is symptoms getting worse for 2-3 weeks and then they plateau for a few weeks and then they get better and in most cases they fully recover and its gone for good. This recovery happens because the nerves regrow. In very sever cases the axon itself can die back – so to recover two things have to happen 1. the axon has to grow back and 2. you have to re-myelinate the nerves.

    In early cases of Guilian-barre and especially in MS – the sodium potasium pumps can migrate down into the unmyelinated areas so the signal can get past that area or you get remyelination, either way these symptoms will go away kin a few weeks. However, in 1/3 of people there may be residual symptoms.

    • 10% of people get a chronic relapsing/remitting form of
    • Guilian-barre. Key to diagnosing Guilian-barre is blood pressure fluctuations, ascending weakness and it occurred after infection.

    Treatment – plasmapheresis – is used to speed recovery which is when they filter the immune cells out of the blood, this is done because they think its an autoimmune disease.
  10. What is webber syndrome , what causes it and what are it symptoms?
    Webber's syndrome – (also called perduncle syndrome – because it effects the cerebral perduncles/columns – which big bulges on the front)– posterior cerebral artery issue – unilateral oculomotor palsy – lateral styagmus due to medial rectus paralysis – corticospinal tracts also get damaged , and these cross in the medulla so sense this happens before this it causes contralateral symptoms. usually caused by a bleed, or ischemia (caused by embolism) in the posterior cerebral artery which goes to the back of the cerebrum but on the way supplies this part of the brain stem – A stroke can cause this, if it does you can see damage to the oculomotor nerve (on the effected side) , which can cause different pupil sizes and a loss of reaction to light because it would be permanently dilated because the oculomotor nerve going to it would be gone. Also controls eyelid. The Medial rectus is innervated by the oculomotor nerve so the eye would go outward (lateral styagmus of one eye or oculomotor palsy), because of the unopposed actions of the abducens which adbucts the eye. You may also see ptosis (dropping eyelid). The corticospinal tract would also be damaged which would cause spastic paralysis , clonus , barbinski, hoffmans and other symptoms of the UML, and this would also cause a contralateral paralysis or hemiplegia. This is because the corticospinaldie before they cross in the medulla and this damage would prevent motor signals form one side from reaching the other.

    • Signs
    • Mydriasis or Dilated pupil
    • ptosis - Dropping eyelid
    • lateral styagmus
    • UML signs – spastic paralysis , clonus, barbinski, hoffmans sign contralateral hemiplegia
  11. What is Benedikt's syndrome , what are it symptom?
    Benedikt's syndrome – Benedikt syndrome is caused byaa lesion ( infarction, hemorrhage, tumor, or tuberculosis) in the tegmentum of the midbrain and cerebellum. Specifically, the median zone is impaired. It can result from occlusion of the posterior cerebral artery.- occulomotor damage so unilateral oculomotor palsy (like webbers syndrome) , but no cortispinal tract involvement so no UML signs. Red nucleus and medial lemniscus (carries all sensory fibers up through the mid brain to the thalamus and out to the somotasensory cortex) are effected by this syndrome – the medial lemniscus carries proprispetive fibers up form the medulla were they fascilicus gracilis and cuntenous ended on there nuclei , also carries all sensation up from medulla as well. So you lose contralateral sensation because the sensation cross at the medulla below this . The red nucleus is the start of the rubriospinal tract which is important in muscle coordination from the cerebellum , because the cerebeullum sends a lot of information out to the red nucleus and down the rubrospinal tract for muscle coordination. A cerbeller perduncle is in here as well so you will see cerebellar symptoms like ataxia do to loss of cerebellar control.

    Signs:ataxia , contalateral propriception and sensation loss, unilateral occulmotor palsy
  12. What is Parinaud's syndrome and what are it signs?
    Parinaud's syndrome - this occurs when the Pineal gland has a tumor within it, so the pinealoma causes the pineal gland to swell up and push down on the four lumps below it which are the superior and inferior colliculli and on the trochlear nerve beneath them, depending on how this swells can be bilaterally or unilaterally (usually bilateral). Which causes issues with the superior oblique muscles. The trochlear nerve controls the superior oblique muscles so damage to it can cause vertical gaze palsy – were the pt can't easily look down with the eye balls, so they bend the head rather then to look down with the eyes, when they have to look down. Also interferes with the coordination of the pathway of the oculomotor nerve which goes through the superior colliculi which tell the oculomotor nerve to shut down the pupil so without this you have an unreactive pupil to light because the visual reflex is disrupted. Also can have auditory reflexes problems due to inferior colliculi issues.
  13. What happens if there is anterior blee din the brain stem?
    Bleeds on the anterior side of the brain stem, a bleed or blockage in the basilar artery can wipe out the whole front side of the brain stem. On the front of the brainstem is all of the corticospinal and corticobulbo tracts which causes locked in syndrome. This is were the pt is stuck unable to move but they fine cognitively. In some cases they can more there eyes because the oculomotor neuron is often high enough to be above the bleed sense it one of the highest cranial nerves.