Child brain tumors can be classified by advanced imaging and AI

Child brain tumors can be classified by advanced imaging and AI

Diffusion weighted imaging and machine learning can successfully classify the diagnosis and characteristics of common types of pediatric brain tumors a UK-based multi-center study, including WMG at the University of Warwick has found. This means that the tumor can be characterized and treated more efficiently.

The largest cause of death from cancer in children are brain tumors in a particular part of the brain, called the posterior fossa. However, within this area, there are three main types of brain tumor, and being able to characterize them quickly and efficiently can be challenging.

Currently, a qualitative assessment of MRI by radiologists is used; however, overlapping radiological characteristics can make it difficult to distinguish which type of tumor it is, without the confirmation of biopsy. In the paper, “Classification of pediatric brain tumors by diffusion weighted imaging and machine learning,” published in the journal Scientific reports, led by the University of Birmingham including researchers from WMG, University of Warwick. The study found that tumor diagnostic classification can be improved by using non-invasive diffusion weighted imaging, when combined with machine learning (AI).

Diffusion weighted imaging involves the use of specific advanced MRI sequences, as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR image. One can then extract an Apparent Diffusion Coefficient (ADC) map, analyzed values of which can be used to tell you more about the tumor.

The study involved 117 patients from five primary treatment centers across the UK with scans from twelve different hospitals on a total of eighteen different scanners, the images from them were then analyzed and region of interests were drawn by both an experienced radiologist and an expert scientist in pediatric neuroimaging. Values from the analysis of Apparent Diffusion Coeffcient maps from these images’ regions have been fed to AI algorithms to successfully discriminate the three most common types of pediatric posterior fossa brain tumors, non-invasively.

Professor Theo Arvanitis, director of the Institute of Digital Health at WMG, University of Warwick and one of the authors of the study explains:

“Using AI and advance Magnetic Resonance imaging characteristics, such as Apparent Diffusion Coefficient (ADC) values from diffusion weighted images, can potentially help distinguish, in a non-invasive way, between the main three different types of pediatric tumors in the posterior fossa, the area of the brain where such tumors are most commonly found in children.

“If this advanced imaging technique, combined with AI technology, can be routinely enrolled into hospitals it means that childhood brain tumors can be characterized and classified more efficiently, and in turn means that treatments can be pursued in a quicker manner with favorable outcomes for children suffering from the disease.”

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Does your mind feel like it’s moving in slow motion? You could be dealing with brain fog

Written by Lauren Geall

Feeling tired all the time and struggling to concentrate? You could be dealing with ‘brain fog’. Here’s what you can do about it.

The coronavirus pandemic has affected our wellbeing in a variety of ways. From disrupted sleep and screen fatigue to anxiety and loneliness, you’d be hard-pressed to find someone who hadn’t been affected by the stress, isolation and uncertainty of the last year.

For many people, the pressure of the pandemic has also manifested in the form of ‘brain fog’.

Even if you’ve never heard of the term before, chances are you’ve experienced it at some point over the last couple of months – characterised by mental fatigue, confusion and a general struggle to process information, it can make it hard to concentrate and transform the easiest of tasks into a real challenge. You might find it hard to remember simple facts or interpret what people are saying, too.

It’s almost as if your brain is coated in a thick, syrupy liquid – you’re able to go about your daily life, but there’s a palpable disconnect between your body and the world around you.

Experiencing brain fog for the first time can be an overwhelming experience, but it’s important to note that it’s a completely normal thing and can happen for any number of reasons, including stress.

“Although it isn’t a medical condition, brain fog can be a symptom of mental health conditions (like stress, anxiety and depression), or poor lifestyle habits,” explains Caroline Harper, specialist mental health nurse at Bupa UK.  “Not getting enough sleep may cause brain fog throughout the day and a poor diet lacking in vitamins can also leave you feeling foggy, too.”

Harper also points out that brain fog can be a symptom of medical conditions such as coeliac disease, the menopause and lupus. However, if you’ve experienced brain fog for the first-time during lockdown, it’s more likely that stress or lack of sleep is the cause. 

How to prevent brain fog 

On top of identifying and trying to avoid whatever is causing your brain fog, Harper says there are a number of things you can do to prevent it from developing – many of which you can incorporate into your day-to-day routine.

1. Eat the right foods

Your nutrition doesn’t just play an important role in keeping your body healthy – it affects your brain health, which can impact your wellbeing.

“Make sure your diet is full of fresh fruit and vegetables – it’s an easy way to get the right vitamins into your body,” Harper explains. 

“Slow-release energy foods (like pasta, oats and nuts) can keep you energised throughout the day. If you’re not eating enough, you may experience brain fog and feel irritated easy.”

She continues: “Avoid alcohol, smoking and drinking coffee after 3pm, too.” 

2. Take five

Taking regular breaks throughout the day is crucial because it gives your brain the time it needs to relax and recuperate and ensures you’re not pushing yourself too hard.

“Take regular hourly breaks for five minutes each time – even if you simply look out the window and change your focus,” Harper says. “It will give your brain a break from constantly focusing.” 

Harper also recommends carrying this habit through to your weekend. While it’s easy to assume you don’t need to take breaks when you’re not working, your brain still needs time to stop focusing – even if your ‘focus’ is watching Netflix.

“It can be tempting to scroll endlessly on social media right now, so make sure you take regular breaks away from your digital devices,” Harper suggests. “Remember: if what you are reading or listening to is causing you to feel overwhelmed, it’s time to switch off.” 

3. Prioritise your sleep

Getting a good night’s sleep isn’t always easy, but try to put in place some relaxing activities and habits that increase your chances of nodding off.

“A relaxing activity, such as a hot bath or reading your favourite book, can leave you feeling relaxed and ready to drift off,” Harper explains. 

“Switch off your digital devices at least an hour before bed, too.”

She continues: “If racing thoughts in your mind are keeping you up, try writing down anything that’s on your mind. Not only can this help you to organise your thoughts and leave you feeling calmer, but it can stop any worries or stresses building up inside your head.”

4. Seek support

If your brain fog is getting overwhelming, it’s important to seek extra support.

Harper explains: “If you’re struggling with your health or wellbeing right now, sharing your concerns with someone you trust can really help, even if they can’t change what you’re experiencing.

“Your GP will always be available to discuss support for your mental health, too.” 

How to treat brain fog 

Sometimes it’s not always possible to prevent brain fog from developing – so what can you do to ease symptoms in the meantime?

“If you find yourself feeling fuzzy or you’re struggling to concentrate, take yourself away for a break until your symptoms begin to ease,” Harper explains. 

“It’s your body’s way of saying that you need a break, so listen to it.”

On top of this, Harper recommends moving your body (“exercise or stretching can help to reduce your symptoms”) and giving your brain a boost via snacks.

“Eating high-energy snacks – like nuts, a banana and dried fruit – can reduce your symptoms of brain fog and provide you with a much-needed energy boost.” 

Although brain fog can be frustrating to deal with, taking these steps to prevent and reduce symptoms should help you to feel more in control.

And remember: as much as we hate to be cliché, these are unprecedented times – so don’t be too hard on yourself if your brain isn’t playing along.

If your brain fog persists for a couple of weeks, it’s important to speak to your doctor, as they’ll be able to support you.  

If you, or someone you know, is struggling with anxiety, you can find support and resources on the mental health charity Mind’s website or visit the NHS’ list of mental health helplines and organisations and the NHS Every Mind Matters resource hub.

You can also ask your GP for a referral to NHS Talking Therapies, or you can self-refer.

For confidential support, you can also call the Samaritans in the UK on 116 123 or email [email protected]

Images: Getty

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Evidence for routine brain tumor imaging is murky, but research can shed light

tumor

What is the best way to monitor a brain tumor? This question is at the heart of a new Position Statement published in open-access journal Frontiers in Oncology. The article is the work of a large collaboration of UK experts and stakeholders who met to discuss the value of routinely imaging brain tumor patients to assess their tumor treatment response, which is known as “interval imaging”. Their verdict: there is very limited evidence to support the practice at present. However, the article also discusses how future research could determine and maximize the value of interval imaging by assessing its cost effectiveness and how it affects patient quality of life, treatment and survival.

Medical staff use brain scans at predetermined times to assess if a brain tumor patient is responding to treatment, but scanning frequency can range from every few weeks to every few months. Different countries and hospitals use different approaches, but what is the best approach and is any of this based on science?

Getting things right is important. Not scanning someone enough could mean that doctors miss the signs that a patient requires further treatment. Conversely, scanning someone excessively is inconvenient and impractical for patients and medical staff alike, and can cause patient anxiety, especially if the results of the scan are unclear.

Scanning patients is also expensive, and with limited budgets, healthcare facilities need to use their resources as cost-effectively as possible. Most interval imaging aims to find increases in tumor size, but tumors grow differently in different patients, which sometimes makes it difficult to draw concrete conclusions from interval imaging results. Would patients be better off receiving scans only if they experience new symptoms?

A group of experts and other stakeholders met to discuss these issues in London in 2019. The group was diverse and included numerous people with an interest in these issues. “Charity representatives, neuro-oncologists, neuro-surgeons, neuro-radiologists, neuro-psychologists, trialists, health economists, data scientists, and the imaging industry were all represented,” said Dr. Thomas Booth of King’s College London and the lead author on the article. Their findings are presented in this latest Position Statement.

The group discussed the evidence behind current interval imaging practices in the UK. “We found that there is very little evidence to support the currently used imaging interval schedules and that the status quo is no more than considered opinion,” said Prof. Michael Jenkinson of the University of Liverpool, and senior author on the article.

So, how can we determine if interval imaging is valuable? The meeting participants also discussed a variety of potential research approaches that could cast light on the most important factors—patient quality of life, patient survival, and cost effectiveness. However, this is not without its challenges.

“The treatment complexity and relative rarity of brain tumors mean that solutions beyond traditional ‘randomized controlled trials’ alone are required to obtain the necessary evidence,” said Booth. “We propose a range of incremental research solutions.”

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Bride-to-be told music in her head was stress actually had a brain tumour

When Emma Bond noticed some music playing while visiting a hospital as part of her job, she thought it was odd they would be playing tunes there.

She had no idea the sounds she was hearing were in her head, and actually a sign of a brain tumour.

The 29-year-old, from Newton-le-Willows, Merseyside, was planning her wedding to fiancé Edd Blake and when she went to the doctor to talk about what she was experiencing, it was put down to stress.

When she eventually had more tests, doctors found the tumour and she had to undergo surgery two days before she was due to get married.

Emma, who works for a health care company which makes respiratory products, first noticed the symptoms in June 2019.

She said: ‘I had just done some training on a device for one ward and I went to introduce myself to another ward and as I went to the desk I started hearing music in my head.

‘I think it was the geriatric ward and I was thinking “why are they playing this music on the ward?”.

‘I was really confused and I had to walk outside. I was thinking “what was that?”‘

Asked to describe what the music was like, Emma said: ‘This is going to sound weird but when it was happening, I knew the song, I could hear it and felt I had heard it before.

‘But I cannot even speak what it was saying – it was very strange.

‘The only thing I really remember was why would they be playing this kind of music on a geriatric ward – I must have been thinking it was like Kanye West or something like that.

‘It would be in my head for about 30 seconds and then it would go.’

Emma started to hear the music again over the next few days so went to A&E but was told she was suffering from stress and the doctor advised her to take some time off work.

Emma said: ‘The first few times it happened were the worst, it was quite scary. I was thinking I’m not stressed, there’s something going on.

‘I could hear music but when people were responding to me I also thought they were also singing the lyrics to the song.’

She continued to hear music several times a day and so her GP booked her in for a scan at Whiston Hospital.

The scans led to a referral to The Walton Centre where they discovered Emma had a grade two brain tumour.

The surgery, two days before her planned wedding date, was a success as surgeons were able to remove 95% of the tumour, and the operation was followed up with radiotherapy and chemotherapy.

Once the tumour was gone, the music in her head stopped.

Despite her experience, Emma wasn’t put off listening to music – something that was helped by her friends and family choosing her Spotify playlist while she was undergoing radiotherapy.

Emma said: ‘The very last songs on the list chosen by my dad was Chumbawamba’s I Get Knocked Down But I Get Up Again [Tubthumping] and You’ll Never Walk Alone.’

The couple decided to dedicate 2020 to raising money for The Walton Centre and Clatterbridge Hospital in Bebington, where she was treated.

Edd said: ‘I was so grateful for all the support both The Walton Centre and Clatterbridge were giving Emma, I just had to do something.

‘So we came up with the crazy idea of me running a mile a day for a year and fundraise as we go.

‘I’ve been overwhelmed with the support we’ve had from friends, family, colleagues and beyond, it’s been amazing.’

Edd completed his challenge on December 31, totalling 366 miles. So far they have raised more than £8,500 and they’re aiming for £10,000 before they close the appeal in March.

You can donate to the fund here.

Do you have a story to share?

Get in touch at [email protected]

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Newly discovered brain pattern has implications for treating paralyzed, Parkinson’s patients

Researchers discover hidden brain pattern

When reaching for a cup of coffee or catching or throwing a ball, our brain manages to coordinate the movement of no less than 27 joint angles in our arms and fingers. Exactly how the brain is able to do this is a topic of much debate among researchers.

Now, led by Maryam Shanechi, USC Viterbi assistant professor of electrical and computer engineering and Andrew and Erna Viterbi Early Career Chair, researchers discovered a signature dynamic brain pattern that predicts naturalistic reach and grasp movements. The discovery, which is now published in Nature Communications, could become a catalyst for the development of better brain-machine interfaces and improving treatment for paralyzed patients.

In this study, the goal was to compare both the small and large spatiotemporal scales of brain activity. Small-scale activity refers to the spiking of individual neurons or brain cells; large-scale activity refers to Local Field Potential (LFP) brain waves that instead measure the aggregate activity of thousands of interacting individual neurons. Both may contribute to performing reach and grasp movements, but how?

To answer this question, Shanechi and Hamidreza Abbaspourazad, a Ph.D. student in electrical engineering, created a new machine-learning algorithm to extract dynamic neural patterns that co-exist in spiking and LFP activity at the same time and to identify how these patterns relate to each other and to movements. The study was done in collaboration with Bijan Pesaran, professor of neural science at NYU, who performed experiments to collect spiking and LFP brain activity during naturalistic reach and grasp movements using neurophysiology techniques in the field.

By applying the new algorithm to the collected data, they identified commonalities and differences between spiking and LFP activities. From there, they were able to ultimately discover a common pattern between them that was highly predictive of movements.

“When looking closer, we discovered that this common multiscale pattern actually happened to dominantly predict movement compared to all other existing patterns,” Shanechi said. In other words, the team identified a previously undetected pattern of brain activity associated with reach and grasp movements which provides a possible neural signature for them.

Shanechi, who recently received the NIH Director’s New Innovator Award and the ASEE Curtis W. McGraw Research Award, focuses on neurotechnology research; she studies the brain through modeling, decoding, and control of neural dynamics. This publication is just one of many recent projects Shanechi has led to better understand complex neural patterns and neural dysfunctions to develop therapies relating to both physical and mental disabilities. In fact, she has been on a bit of a streak lately, with multiple major Nature publications in the last few months.

“Interestingly,” Shanechi explains, “we found that this neural signature pattern was not only shared between spiking and LFP signals, but also between our different subjects who were making movements.”

This means that the shared pattern can help researchers understand how an individual’s brain controls reach and grasp movements. More importantly, it also suggests that different people may have a similar neural signature when making reach and grasp movements.

Of course, understanding what the brain is doing is only half the battle. Translating brain activity into action is another thing altogether. But Shanechi’s model can do just that. She and her team are able to translate brain activity into movement.

Abbaspourazad adds, “Our model not only discovers the signature patterns in neural activity but also predicts arm and finger movements quite accurately from these patterns.” This is especially promising in the development of brain-machine interfaces to restore movement in paralyzed patients.

In addition to helping paralyzed patients, Shanechi hopes this research can also help better understand the neural mechanisms of movement disorders like Parkinson’s disease to guide future therapies.

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What is the Nervous System?

The nervous system is a complex network of nerves and cells that carry messages to and from the brain and spinal cord to various parts of the body.

Image Credit: VectorMine / Shutterstock.com

The nervous system includes both the Central nervous system and Peripheral nervous system. The central nervous system is made up of the brain and spinal cord, and the peripheral nervous system is made up of the Somatic and the Autonomic nervous systems.

The central nervous system (CNS)

The central nervous system is divided into two major parts: the brain and the spinal cord.

The brain

The brain lies within the skull and is shaped like a mushroom.  The brain consists of four principal parts:

  • the brain stem
  • the cerebrum
  • the cerebellum
  • the diencephalon

The brain weighs approximately 1.3 to 1.4 kg. It has nerve cells called the neurons and supporting cells called the glia.

There are two types of matter in the brain:  grey matter and white matter.  Grey matter receives and stores impulses.  Cell bodies of neurons and neuroglia are in the grey matter.  White matter in the brain carries impulses to and from grey matter.  It consists of the nerve fibers (axons).

The brain stem

The brain stem is also known as the Medulla oblongata. It is located between the pons and the spinal cord and is only about one inch long.

The cerebrum

The cerebrum forms the bulk of the brain and is supported on the brain stem.  The cerebrum is divided into two hemispheres.  Each hemisphere controls the activities of the side of the body opposite that hemisphere.

The hemispheres are further divided into four lobes:

  • Frontal lobe
  • Temporal lobes
  • Parietal lobe
  • Occipital lobe

The cerebellum

This is located behind and below the cerebrum.

The diencephalon

The diencephalon includes the thalamus and hypothalamus. The thalamus is where sensory and other impulses go and coalesce.

The hypothalamus is a smaller part of the diencephalon.

Other parts of the brain

Other parts of the brain include the midbrain and the pons:

  • the midbrain provides conduction pathways to and from higher and lower centers
  • the pons acts as a pathway to higher structures;  it contains conduction pathways between the medulla and higher brain centers

The spinal cord

The spinal cord is a long tube-like structure that extends from the brain. The spinal cord is composed of a series of 31 segments.  A pair of spinal nerves come out of each segment.  The spinal cord region from which a pair of spinal nerves originates is called the spinal segment.  Both motor and sensory nerves are located in the spinal cord.

The spinal cord is about 43 cm long in adult women and 45 cm long in adult men and weighs about 35-40 grams. It lies within the vertebral column, the collection of bones (backbone).

Other parts of the central nervous system

The meninges are three layers of membranes that cover the brain and the spinal cord.  The outermost layer is the dura mater.  The middle layer is the arachnoid, and the innermost layer is the pia mater. The meninges offer protection to the brain and the spinal cord by acting as a barrier against bacteria and other microorganisms.

The cerebrospinal fluid (CSF) circulates around the brain and spinal cord. It protects and nourishes the brain and spinal cord.

Neurons

The neuron is the basic unit in the nervous system. It is a specialized conductor cell that receives and transmits electrochemical nerve impulses. A typical neuron has a cell body and long arms that conduct impulses from one body part to another.

Image Credit: ShadeDesign / Shutterstock.com

There are three different parts of the neuron:

  • Cell body
  • Dendrites
  • Axon

Cell body of a neuron

The cell body is like any other cell with a nucleus or control center.

Dendrites

The cell body has several highly branched, thick extensions that appear like cables and are called dendrites.  The exception is a sensory neuron that has a single, long dendrite instead of many dendrites.  Motor neurons have multiple thick dendrites. The dendrite's function is to carry a nerve impulse into the cell body.

Axon

An axon is a long, thin process that carries impulses away from the cell body to another neuron or tissue.  There is usually only one axon per neuron.

Myelin sheath

The neuron is covered with the Myelin Sheath or Schwann Cells. These are white segmented covering around axons and dendrites of many peripheral neurons. The covering is continuous along the axons or dendrites except at the point of termination and the nodes of Ranvier.

The neurilemma is the layer of Schwann cells with a nucleus. Its function is to allow damaged nerves to regenerate.  Nerves in the brain and spinal cord do not have a neurilemma and cannot recover when damaged.

Types of neuron

Neurons in the body can be classified according to structure and function. According to structure, neurons may be multipolar neurons, bipolar neurons, and unipolar neurons:

  • Multipolar neurons have one axon and several dendrites. These are common in the brain and spinal cord.
  • Bipolar neurons have one axon and one dendrite.  These are seen in the eye's retina, the inner ear, and the olfactory (smell) area.
  • Unipolar neurons have one process extending from the cell body. The one process divides with one part acting as an axon and functioning as a dendrite. These are seen in the spinal cord.

The peripheral nervous system

The Peripheral nervous system is made up of two parts:

  • Somatic nervous system
  • Autonomic nervous system

Somatic nervous system

The somatic nervous system consists of peripheral nerve fibers that pick up sensory information or sensations from the peripheral or distant organs (those away from the brain like limbs) and carry them to the central nervous system.

These also consist of motor nerve fibers that come out of the brain and take the messages for movement and necessary action to the skeletal muscles. For example, on touching a hot object, the sensory nerves carry information about the heat to the brain, which in turn, via the motor nerves, tells the muscles of the hand to withdraw it immediately.

The whole process takes less than a second to happen. The neuron's cell body that carries the information often lies within the brain or spinal cord and projects directly to a skeletal muscle.

Autonomic Nervous System

Another part of the nervous system is the Autonomic Nervous System. It has three parts:

  • The sympathetic nervous system
  • The parasympathetic nervous system
  • The enteric nervous system

This nervous system controls the nerves of the body's inner organs on which humans have no conscious control. This includes the heartbeat, digestion, breathing (except conscious breathing), etc.

The nerves of the autonomic nervous system innervate the smooth involuntary muscles of the (internal organs) and glands and cause them to function and secrete their enzymes.

The enteric nervous system is the third part of the autonomic nervous system. The enteric nervous system is a complex network of nerve fibers that innervate the abdomen's organs like the gastrointestinal tract, pancreas, gall bladder, etc. It contains nearly 100 million nerves.

Image Credit: MattLphotography / Shutterstock.com

Neurons in the peripheral nervous ystem

The smallest worker in the nervous system is the neuron. There is one preganglionic neuron for each of the chain of impulses, or one before the cell body or ganglion, that is like a central controlling body for numerous neurons going out peripherally.

The preganglionic neuron is located in either the brain or the spinal cord. In the autonomic nervous system, this preganglionic neuron projects to an autonomic ganglion. The postganglionic neuron then projects to the target organ.

There is only one neuron between the central nervous system and the target organ in the somatic nervous system while the autonomic nervous system uses two neurons.

References

  • http://www.cse.iitk.ac.in/users/hk/cs781/NervousSystem.pdf/
  • http://classvideos.net/anatomy/pdf/3708091011-pdf.pdf
  • http://www.bio12.com/ch17/Notes.pdf
  • http://highered.mcgraw-hill.com/sites/dl/free/0070960526/323541/mhriib_ch11.pdf
  • http://www.sfn.org/skins/main/pdf/brainfacts/2008/brain_facts.pdf
  • http://www.freeinfosociety.com/media/pdf/4423.pdf

Further Reading

  • All Nervous System Content
  • Function of the Nervous System
  • Development of the Nervous System
  • Pathology of the Nervous System
  • What are Schwann Cells?

Last Updated: Jan 21, 2021

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.

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How is RRMS Different from PPMS and SPMS?

Multiple sclerosis is a neurodegenerative disorder that damages the nerves in the brain and spinal cord, leading to problems with muscle movement, balance and vision. The illness is an example of a demyelinating disease, where the protective coating called myelin that surrounds nerve fibres becomes damaged.

Multiple sclerosis follows a different course in every individual but there are three main ways in which the disease can progress depending on which form of the illness a patient has.

Relapsing remitting multiple sclerosis

Around 80% of all individuals with multiple sclerosis have the relapsing remitting form of the disease. These individuals have periods where their symptoms are mild or absent (remission), followed by periods of symptom relapse. Symptoms may occur suddenly and in acute bouts or exacerbations.

During these periods of relapse, symptoms may become worse each time and the relapsing remitting form of this condition may eventually progress to secondary progressive multiple sclerosis, where there are few or no periods of remission. Relapsing remitting multiple sclerosis may be diagnosed when two episodes of relapse are separated by more than 30 days or there has only been one relapse but there is MRI evidence of newly scarred or damaged myelin three months later.

Secondary-progressive multiple sclerosis

Patients with this form of multiple sclerosis often experience phases of relapse followed by remission at first, but this later gives way to progressive disease, characterized by worsening symptoms and few or no periods of remission.

Primary-progressive multiple sclerosis

The least common form of multiple sclerosis is the primary progressive form which occurs in about 10% to 15% of all cases and usually in people aged over 40 years. In this form of the condition, symptoms get worse over time rather than occurring in bouts or as sudden attacks.

Primary progressive multiple sclerosis may be diagnosed if there have been no previous symptoms of relapse but the patient has become increasingly disabled over a period of at least one year.

Sources

  1. http://www.nhs.uk/Conditions/Multiple-sclerosis/Pages/Causes.aspx
  2. www.nlm.nih.gov/medlineplus/tutorials/multiplesclerosis/nr229105.pdf
  3. http://www.who.int/mental_health/neurology/Atlas_MS_WEB.pdf
  4. http://mssociety.ca/en/pdf/ms-effects.pdf
  5. http://www.nice.org.uk/nicemedia/live/10930/29202/29202.pdf

Further Reading

  • All Multiple Sclerosis Content
  • Multiple sclerosis (MS)
  • Multiple Sclerosis Symptoms
  • Multiple Sclerosis Diagnosis
  • Multiple Sclerosis Causes
More…

Last Updated: Aug 23, 2018

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.

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Neuronal Migration Disorder

Neuronal migration disorder refers to a group of disorders that arise from the abnormal migration of nerve cells during embryonic development. If the migration of neuroblasts is disturbed during neurogenesis, neural circuits do not form properly in the correct parts of the brain. This is referred to as cerebral dysgenesis.

The migration commonly takes place in the second month of pregnancy. In cases of migration disorder, only some of the neuroblasts reach the cortical layer or neuroblasts overshoot their path and instead reach the subarachnoid space. In addition, the organization of the neuronal layer in the cortex may be disrupted. Abnormal migration of the neuroblasts leads to abnormal formation of the gyri, the ridges of the cerebral cortex in the brain.

Some examples of neuronal migration disorders include lissencephaly, schizencephaly, porenchephaly, pachygyria, agyria, macrogyria, microgyria, neuronal heterotopias, agenesis of corpus callosum, agenesis of cranial nerves and band heterotopias.

Symptoms

Symptoms of neuronal migration disorder vary according to the type and degree of abnormality. The most common symptoms include:

  • Loss of muscle tone
  • Decreased motor function
  • Seizures
  • Developmental delay
  • Mental retardation and failure to thrive and grow
  • Difficulty feeding
  • Smaller than average head size. This is called microcephaly.
  • Some infants have the characteristic facial features of neuronal migration disorder.

Treatment

A diagnosis is made based on clinical investigations and radiological imaging studies. Treatment is symptomatic and includes the use of antiepileptic medications to prevent and correct seizures, along with physical, occupational and speech therapies to support the child with the various problems associated with the disorder.

Sources

  1. http://mcloonlab.neuroscience.umn.edu/8211/papers/Valiente_10.pdf
  2. http://brain.oxfordjournals.org/content/127/6/1458.full
  3. www-cogsci.ucsd.edu/~sereno/201/readings/03.08-NeuralMigration.pdf
  4. http://www.100megspop3.com/chanvinci/01.pdf

Further Reading

  • All Neuronal Migration Disorder Content

Last Updated: Jun 25, 2019

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.

Source: Read Full Article

What Causes Coloboma?

Ocular coloboma is an abnormality of the eye resulting from its defective development. One or both eyes may be affected  by holes or gaps in the cornea, iris, ciliary body, lens, choroidal layer, lens, retina or optic disc. In many patients, a coloboma is accompanied by microphthalmia and anophthalmia, or other defects in various parts of the body.

Colobomas are present in 0.5–7.5 per 10,000 births, and can be caused by a genetic mutation or by toxic environmental factors.

Coloboma is an eye abnormality that occurs before birth. Colobomas are missing pieces of tissue in structures that form the eye.

What causes a coloboma?

As the baby develops in the womb, a specialized layer of ectoderm (the neuroectoderm), which gives rise to neural cells, comes to the surface to form the optic vesicle. This then invaginates, or curves inwards, to form two parts: the optic fissure in front and the optic cup towards the back. The optic fissure then closes as the two lips grow towards each other. Their fusion leaves only a small gap called the optic disc, through which the hyaloid artery enters the eye.

This fusion process occurs from the fifth to the seventh week of development. Any disruption can result in coloboma formation. The optic fissure is formed at the lower part of the eyeball, which means most colobomas are found there. The segment that remains unfused determines the part of the eye that is affected.

Some colobomas go unnoticed because they are very small and isolated. Others are larger but still isolated. More severe conditions result when a coloboma is associated with other abnormalities of the eye like microphthalmos. The most severe cases are when a coloboma is associated with anomalies of the brain and other systems outside the brain.

The classification of colobomas reflects the groups of coloboma genes involved and the period of development affected. Generally, the earlier in development a defect occurs, the more severe the congenital outcomes. Genes including SHH and SIX3 are involved in defects occurring before the 20th day of fetal development and result in severe anomalies of the eye, brain, and other organ systems. This is also traceable to the fact that SHH is a gene expressed in almost all tissues.

After this period, genes like TCOF1 may cause less severe defects of the brain and organs, whereas PAX6, MAF1, CHX10, or RBP4 can cause isolated colobomas.  MAF1 and similar genes are expressed only in the eye; hence, their expression results in a milder phenotype.

Another factor that comes into play is the presence of genetic redundancy, which means that some gene anomalies can be compensated for by other genes expressed in certain tissues like the brain, but not in the eye, for instance, where the compensatory genes are not expressed.

Genetic causes

Most syndromes associated with coloboma are the result of Mendelian inheritance or chromosomal anomalies. As of now, almost 40 genetic regions linked to coloboma formation have been traced to their chromosomal origins, and many of the genes have been identified as well.

Some known coloboma-associated genes include SHH, CHX10 and MAF. Three coloboma syndromes share the same genetic locus at 22q11, making this a likely location for one or more genes that are crucial to normal development of the eyes.
Autosomal dominant and autosomal recessive inheritance are found equally in 27 coloboma phenotypes which are not yet mapped, whereas three are supposed to be X-linked. For some, the mode of inheritance is not yet clear. Thus colobomas are not caused by any one gene, but are rather a part of a more widespread aberration in development.

Environmental causes

Present research shows at least 39 genes are involved in coloboma syndromes, or isolated coloboma. All these are crucial to early intrauterine development, particularly of the central nervous system. However, these mutations account for only about half of all colobomas, which means many more mutations that could cause this condition remain unknown.

Most sporadic cases of coloboma are unilateral and often due to environmental factors, leading to malformations in multiple systems of the body. One classic example is the CHARGE syndrome, wherein colobomas of the iris or uvea is present in almost 86% of patients. The mechanism by which this occurs is not always clear, but such conditions comprise a good percentage of patients with coloboma.

Some suggested environmental triggers (operating during pregnancy) include:

  • Drugs used in pregnancy, such as thalidomide (4%) and alcohol
  • Vitamin A and vitamin E deficiency
  • Infections with cytomegalovirus (CMV) and toxoplasmosis
  • Ionizing radiation exposure
  • Hyperthermia

Syndromes associated with coloboma

There are several conditions of which a coloboma forms a part, such as:

  • Treacher-Collins syndrome
  • Cat-eye syndrome where the coloboma is a vertical one in the iris, caused by an abnormality of chromosome 22q11
  • Patau syndrome caused by an extra copy of chromosome 13 (trisomy 13)
  • Coloboma with cryptophthalmos where the eyelids are absent
  • CHARGE syndrome which stands for a constellation of Coloboma, Heart defects, Atresia of the nasal choanae, Growth retardation, Genital anomalies and Ear abnormalities, sometimes with microphthalmia
  • Manitoba oculotrichoanal syndrome with multiple physical anomalies of the eyes, hair and anal opening
  • Fraser syndrome with webbing and number abnormalities of the fingers or toes, or both, with renal and genital abnormalities and sometimes cryptophthalmos
  • Goldenhar syndrome with faulty development of the ear, nose, soft palate and jaw
  • Amniotic band syndrome
  • Aicardi syndrome, Noonan syndrome, renal coloboma syndrome and Solomon syndrome

Sources

  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257322/
  • https://www.ncbi.nlm.nih.gov/books/NBK532877/#_article-21509_s6_
  • https://ghr.nlm.nih.gov/condition/coloboma#genes
  • www.ncbi.nlm.nih.gov/pmc/articles/PMC1735648/pdf/v041p00881.pdf

Further Reading

  • All Coloboma Content
  • What is Coloboma?
  • What are the Symptoms Coloboma?
  • Treating and Managing Colobomas

Last Updated: Mar 20, 2019

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.

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Autism Spectrum Disorder & Allergies

Autism spectrum disorder (ASD) is an umbrella term for developmental conditions that affect communication, behaviour and social interaction. Typically, symptoms start to be seen in young children (before 3 years) and persist throughout life. Affected individuals tend to have an altered perception of the world and have key social differences that cause issues with understanding and relating to other people. As ASD is a spectrum, the severity of symptoms or traits can vary tremendously, with some having intellectual disabilities, whereas others are high functioning and may have above normal intelligence (known as Asperger’s).

The exact causes of ASD are still poorly understood, though an atypical brain development is thought to be the cause of many of the symptoms. There is evidence that ASD can run in families and may have a genetic basis in some cases. Other causes are thought to be attributed to the mother’s health during pregnancy e.g. infection, toxic metal poisoning, teratogen/alcohol exposure and usage of SSRIs during pregnancy.  

What are Allergies?

An allergy is an adverse reaction of the body’s immune system to certain substances (allergens), which can be certain types of food (see Food Allergies Explained), dust, latex, mould, pollen and animal dander. Allergies are mediated by immunoglobulins in the body, notably IgE, though other immunoglobulins can also be involved.  

Allergies are common, affecting around a quarter of people in the UK at some point in their lives. Children tend to suffer from more allergies, though they can grow out of them as they age. However, other allergies can be acquired later in life to things that were not previously a cause of allergy.

Image Credit: Jim Vallee / Shutterstock

The key symptoms of an allergic reaction (the body’s response to an allergen) can include the development of a rash, sneezing, runny or blocked nose, wheezing and exacerbation of asthma or eczema. These are usually mild and disappear once the allergen is removed, however, in extreme cases, a more severe reaction known as an anaphylactic shock can occur, which is a medical emergency if not treated urgently.

Allergies can usually be managed by the usage of over the counter medications such as sprays, drops, creams and inhalers. Anti-histamines can minimize the severity of symptoms.

It is important to note the differences between an allergy, sensitivity and intolerances. A sensitivity is an enhanced exaggerative effect of an ordinary substance such as coffee, which can lead to palpitations, for example. An intolerance is where large amounts of a substance, such as milk (lactose intolerance), can lead to diarrhoea or vomiting, but not activate the immune system.

Allergies in People with ASD

Several studies have found a abnormal immune function in individuals with ASD. This is manifested with an increased frequency of recurrent infections and autoimmunity in children with ASD. This is supported by large cohort studies, which have found increased levels of IgE and IgG in children with ASD. Although allergies are common in children, the immune dysfunction seen in some children with ASD may predispose affected children to higher rates of allergies compared to non-ASD children.

A recent study by Guifeng and colleagues (published in JAMA Network in 2018); found a significant positive correlation between allergies and ASD in children. Children with ASD were twice as likely to have a food allergy as children without ASD. This study is purely observational, and causality cannot be determined, though the strong association between ASD and allergy in 200,000 children does provide strong evidence to suggest the two are strongly related.  

As to whether ASD causes allergy (specifically food allergy), or whether allergies cause ASD, or whether both conditions are related to some third factor, is debatable. Some studies have shown that gastrointestinal complaints are higher amongst children with ASD compared to those without. It is therefore speculated that food allergy development may be attributed to gut microbiome alterations and immune activation as a result, which impairs brain development and function through the gut-brain axis (enteric nervous system).

In summary, the rates of allergies; especially food allergies, are much higher in children and individuals with ASD compared to those who do not have ASD. Some hypothesize that an impaired immune system, coupled with alterations in the gut, may affect brain development as well as allergy development. More research is needed to better describe the association between allergies and ASD.

Sources:

  1. NHS.uk, 2019. What is autism? https://www.nhs.uk/conditions/autism/what-is-autism/
  2. NHS.uk, 2019. Allergies. https://www.nhs.uk/conditions/allergies/
  3. Guifeng et al, 2018. Association of Food Allergy and Other Allergic Conditions With Autism Spectrum Disorder in Children. JAMA Netw Open. 1(2):e180279. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6324407/

Further Reading

  • All Allergy Content
  • What are Allergies?
  • Different Types of Allergies
  • Old Friends Hypothesis
  • What is the Microbial Diversity Hypothesis?
More…

Last Updated: Jul 30, 2019

Written by

Osman Shabir

Osman is a Neuroscience PhD Research Student at the University of Sheffield studying the impact of cardiovascular disease and Alzheimer's disease on neurovascular coupling using pre-clinical models and neuroimaging techniques.

Source: Read Full Article