Neuro Diseases Flashcards
What is Brown-Séquard syndrome?
Brown-Séquard syndrome is an incomplete spinal cord lesion often in the cervical cord region.
Contralateral loss ofpain and temperature and crude touch, Ipsilateralweakness, ipsilateral loss of vibration, proprioception andfine touch. CAUSED BY TRAUMA
What causes Brown-Séquard?
Most of the cases are caused by trauma
If there is no history of trauma, you should consider MS, Stroke, spinal cord compression and spinal tumors
What is Myasthenia gravis?
- Myasthenia gravis is a rare long-term condition that causes muscle weakness that comes and goes.
- It most commonly affects the muscles that control the eyes and eyelids, facial expressions, chewing, swallowing and speaking. But it can affect most parts of the body.
It can cause double vision
What is the science of drooping eyelid?
What is the pathophysiology of Myathenia gravis (85% of them)?
- 85% of Mg people produce Ach receptor antibodies that can bind to the postsynaptic Ach receptors and they block the receptors.
- prevents Ach from stimulating the receptor and trigger muscle contraction.
- more activity means more receptors become blocked and this leads to less effective stimulation of the muscle.
- -Therefore with rest myasthenia gravis can be improved.
What is the pathophysiology of Myathenia gravis (15% of them)?
15% of people with Mg produce 2 different antibodies.
Muscle specific kinase (MuSK) and low density lipoprotein receptor related protein 4 (LRP4).
MUSK and LRP4 are important proteins In the creation and production of Ach receptor. Destruction of these proteins leads to inadequate Ach receptors being created and organised.
What is Parkinsons?
Parkinson’s disease is a condition in which parts of the brain become progressively damaged over many years due to the lack of dopamine being produced
Symptoms of Parkinsons
1) Tremor
2) Slowness of movement
3) Muscle stiffness
How does Parkinsons develop?
- Parkinson’s disease is caused by a loss of nerve cells in the part of the brain called the substantia nigra.
- Nerve cells in this part of the brain are responsible for producing dopamine.
- If these nerve cells die or become damaged, the amount of dopamine in the brain is reduced. This means the part of the brain controlling movement can’t work as well as normal.
- The loss of nerve cells is a slow process. The symptoms of Parkinson’s disease usually only start to develop when around 80% of the nerve cells in the substantia nigra have been lost.
Is Parkinsons Genetic or Environmental?
Parkinson’s disease can run in families as a result of faulty genes being passed to a child by their parents. However, it’s rare for the disease to be inherited this way.
It’s also been suggested that pesticides and herbicides used in farming and traffic or industrial pollution may contribute to the condition.
Pathophysiology of Parkinsons?
- Reduced release of dopamine
- therefore there is an excessive inhibitory input to thalamus due to D1 and D2 receptors not recieving dopmaine.
- as result there is a demyelination of substantia nigra
What is another name for Wallenberg’s syndrome?
PICA/Lateral medullary syndrome
What is Wallenberg’s?
Wallenberg syndrome is a rare condition in which an infarction, or stroke, occurs in the lateral medulla. Specifically at the posterior inferior cerebellar arteries
The lateral medulla is a part of the brain stem. Oxygenated blood doesn’t get to this part of the brain when the arteries that lead to it are blocked.
Causes of Wallenburgs
- The most common underlying cause of Wallenberg syndrome is a brain stem stroke in the vertebral or posterior inferior cerebellar arteries (PICA) of the brain stem
- Mechanical trauma to the vertebral artery in the neck
- Vertebral arteritis
- Metastatic cancer
- Hematoma aneurysm
What tracts/nuclei are affected in Wallenbergs?
What goes wrong in a subdural hematoma?
- Small veins run into the dural venous sinuses from brain tissue
- they tear where they enter the dural sinuses between the dura and arachnoid
- Causing blood to collect between dura and arachnoid
What is an aneurysm?
- An aneurysm is a bulge in a blood vessel caused by a weakness in the blood vessel wall, usually where it branches.
- As blood passes through the weakened blood vessel, the blood pressure causes a small area to bulge outwards like a balloon.
- eventually this can burst and cause a hemorrhage
What is Strabismus?
Strabismus, also called crossed eyes/lazy eye, is a condition in which the eyes do not properly align with each other when looking at an object. The eye which is focused on an object can alternate. The condition may be present occasionally or constantly
What are the two types of Strabismus?
- Syndromic strabismus
- Isolated strabismus
What are the causes for Strabismus?
- Genetics is a possible cause for Strabismus,
- inappropriate development of the “fusion center” of the brain
- problems with the controlled centre of the brain,
- injuries to muscles or nerves or other problems involving the muscles or nerves.
- Surprisingly, most cases of strabismus are not a result of a muscle problem, but are due to the brain
What is encephalitis?
Encephalitis is an uncommon but serious condition in which the brain becomes inflamed (swollen).
It can be life-threatening and requires urgent treatment in hospital. Anyone can be affected, but the very young and very old are most at risk
What is the cause of encephalitis?
Viral infections – several common viruses can spread to the brain and cause encephalitis in rare cases, including the herpes simplex virus and the chickenpox virus.
- Problem with the immune system – It mistakenly attacks the brain causing inflammation
- Bacterial or fungal infections - rare
- Encephalitis is not contagious
Examples of Gradual loss of vision?
Glaucoma,
Cataracts,
Diabetic retinopathy,
Macula degeneration
What is Glaucoma?
- High pressure inside eye damaging optic nerve, causes vision loss gradually. Lose peripheral vision but retain central vision.
Outflowof fluid is blocked->buildup ofpressure in the eye-> damage to the optic nerve->gradual loss of visual field and optic nerve change
What is age related macular degeneration?
Degeneration of the macula (dry - common) (haemorrhage/wet - bleed) Lose central vision, but maintain peripheral vision. Usually is more common in women than men
What is cataracts?
- loss of transparency of the lens, removable by operation. Cataracts sometimes start to develop in a person’s lens as they get older, stopping some of the light from reaching the back of the eye.
Accumulation of clumps of protein or yellowpigments-> lens becomes cloudy-> reducestransmission of ligh
What is the diabetic retinopathy?
Diabetic retinopathy is a complication of diabetes, caused by high blood sugar levels damaging the back of the eye (retina). It can cause blindness if left undiagnosed and untreated
1) leaks out of blood vessels interfering with light transmission
2) Ischaemia - reduced circulation
Examples of Rapid loss of vision?
Retinal vein/artery occlusion,
Ischemic optic neuropathy
What is retinal vein occlusion?
- It is a blockage of the small veins that carry blood away from the retina.
What is Retinal artery occlusion
You lose whatever part of the retina that that artery supplies
What is Ischaemic optic neuropathy
- Ischemic optic neuropathy (ION) is when blood does not flow properly to your eye’s optic nerve, eventually causing lasting damage to this nerve. With Ischaemic optic neuropathy, you suddenly lose your vision in one or both of your eyes.
What is Vitreous haemorrhage
Vitreous haemorrhage is bleeding into the jelly-like filling of the back part of your eye. This substance is the vitreous humour
- Vitreous should be clear on a normal day.
What is Retinal detachment
- Retina peels away, Macula still attached so you lose peripheral vision, keep central vision
What is Acute glaucoma
Acute angle-closure glaucoma is a serious eye condition that occurs when the fluid pressure inside your eye rises quickly.
- rapid damage to the optic nerve
What is syringomyelia?
Syringomyelia is a rare disorder in which a cyst/cavity forms within your spinal cord/brainstem. As this fluid-filled cyst, or syrinx, expands and lengthens over time, it compresses and damages part of your spinal cord from its center outward. It also blocks the CSF.
Which tracts are affected in the syringomyelia?
spinothalamic tract neurons decussating in the anterior white commissure
NOT dorsal column/medial leminscus
What are the causes of Syringomyelia
Most cases of syringomyelia are caused by a malformation of the brain known as a Chiari type 1 malformation.
- A CM1 occurs where the brain joins the spinal cord.
- In this malformation, the brainstem lies lower than normal. Located at the back of the brainstem is the cerebellum.
- Often the bases of each lobe of the cerebellum, or the cerebellar tonsils, protrude from the skull and into the spinal canal.
- Syringomyelia can also occur due to trauma, meningitis, hemorrhage, a tumor or arachnoiditis