The differences in the passages above are most likely a result of which of the following?

Hydrocephalus is a condition characterized by an abnormal accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain. CSF surrounds the brain and spinal cord. When the circulatory path of the CSF is blocked, fluid begins to accumulate, causing the ventricles to enlarge and the pressure inside the head to increase, resulting in hydrocephalus.

What are the different types of hydrocephalus?

Communicating hydrocephalus occurs when the flow of CSF is blocked after it exits the ventricles. The word “communicating” refers to the fact that CSF can still flow between the ventricles, which remain open.

Non-communicating hydrocephalus - also called obstructive hydrocephalus - occurs when the flow of CSF is blocked along one or more of the narrow passages connecting the ventricles. One of the most common causes is aqueductal stenosis, a narrowing of the aqueduct of Sylvius, a small passage between the third and fourth ventricles in the middle of the brain.

Normal pressure hydrocephalus (NPH) is a form of communicating hydrocephalus that can strike people at any age, but it is most common among the elderly. It may result from a subarachnoid hemorrhage, head trauma, infection, tumor or complications of surgery. However, many people develop normal pressure hydrocephalus even when none of these factors are present for reasons that are unknown. In that case it is called idiopathic normal pressure hydrocephalus.

Hydrocephalus may be also be classified as congenital or acquired. Congenital hydrocephalus is present at birth and may be caused by either events or influences that occur during fetal development, or genetic abnormalities. In rare cases, congenital hydrocephalus may not cause symptoms in childhood but only manifest in adulthood and may be associated with aqueductal stenosis.

Acquired hydrocephalus develops at the time of birth or at some point afterward. This type of hydrocephalus can affect individuals of all ages and may be caused by injury or disease.

Hydrocephalus ex-vacuo is another form of hydrocephalus that does not fit exactly into the categories mentioned above and primarily affects adults. Hydrocephalus ex-vacuo occurs when stroke, degenerative diseases like Alzheimer's disease or other dementias or traumatic injury cause damage to the brain. In these cases, brain tissue may actually shrink.

What are the symptoms of hydrocephalus?

The possible triad of symptoms typically present as follows:

  • gait disturbance and difficulty walking

These symptoms may not occur all at the same time, and sometimes only one or two symptoms are present. The triad of symptoms is often associated with the aging process and a majority of the NPH population is older than 60 years.

How is hydrocephalus diagnosed?

Once a type of hydrocephalus is suspected by a primary physician, one or more of the following tests are usually recommended to confirm the diagnosis and assess the person’s candidacy for shunt treatment. It is important that at this point a neurosurgeon and/or neurologist become part of the medical team. Their involvement is helpful not only in interpreting test results and selecting likely candidates for shunting, but also in discussing the actual surgery and follow-up care as well as expectations and risks of surgery.

  • Clinical Exams – consists of an interview and or a physical/neurologic examination

  • Brain images to detect enlarged ventricles

  • CSF tests to predict shunt responsiveness and/or determine shunt pressure
    • Lumbar or spinal tap – large volume

    • External lumbar drainage

    • Measurement of CSF outflow resistance

What treatment options are available?

The only available treatment for hydrocephalus is the surgical implantation of a shunt, a device that channels CSF sway from the brain to another part of the body where it can be absorbed. Most shunt systems consist of three components:

  • A collection catheter situated within the cerebral ventricles

  • A valve mechanism to control how much CFS flows

  • An exit catheter to drain the CSF to another part of the body

After the surgery, all components of the shunt system are entirely under the skin, and nothing is exposed to the outside. A limited number of individuals can be treated with an alternative procedure called endoscopic third ventriculostomy. In this procedure, a neuroendoscope — a small camera that uses fiber optic technology to visualize small and difficult to reach surgical areas — allows a doctor to view the ventricular surface. Once the scope is guided into position, a small tool makes a tiny hole in the floor of the third ventricle, which allows the CSF to bypass the obstruction and flow toward the site of resorption around the surface of the brain.

Who is a likely candidate for shunting?

No one single factor is reliable in predicting success from implantation of a shunt. The following findings are generally associated with a better outcome following shunt placement:

  • The onset of gait disturbance as the first and most prominent symptom

  • A known cause for NPH, such as a trauma or hemorrhage

  • The scan shows the ventricle size to be disproportionately larger than the CSF in the subarachnoid space

  • Removal of spinal fluid via lumbar puncture or lumbar catheter gives dramatic, temporary relief of symptoms

  • ICP or spinal fluid pressure monitoring shows an abnormal range or pattern of spinal fluid pressure or an elevated CSF outflow resistance

A complete recovery is possible, but it is not often seen. Many individuals and their families are satisfied when shunt surgery results in reduced disability or dependence than he or she had before surgery, or prevention of further neurological deterioration.

Academic writing in English has a distinctive style – it is formal and uses particular language norms that you need to learn.

Academic style is more than just a writing convention; it can also help you to think more logically and clearly as you work on an assignment.

Below are some tips on how to incorporate four key features of academic style into your writing: objectivity, formality, precision and hedging


Academic writing presents and evaluates issues and arrives at an objective position; a position that focuses on and is informed by research and reasoning rather than personal feelings and opinions.

Personal pronouns, especially ‘I’, ‘you’ and ‘we’ are usually avoided, as these are often associated with subjective views that are influenced by personal preferences or biases.

This statement sounds a bit like a personal opinion:

You can demonstrate that climate change is a real phenomenon by studying alterations in Antarctic ice layers.

To help establish an objective distance from the topic, instead of using a personal pronoun, you could try:

  1. Using the topic as the subject
    Alterations in Antarctic ice layers demonstrate that climate change is a real phenomenon.
  2. Using a passive verb
    The reality of climate change can be demonstrated by studying alterations in Antarctic ice layers.
  3. Using ‘it’ as an empty subject
    It can be demonstrated that climate change is a real phenomenon by studying alterations in Antarctic ice layers.

Avoiding ‘I’ does not mean you cannot express your own opinion. Your own evaluation of the material is still extremely important; however, you can communicate this by using evidence or logical argumentation.


Academic writing is very explicit and provides the reader with all the information they need to understand your meaning. This is in contrast to written or spoken English in less formal contexts, which often relies on readers or listeners to supply extra information that completes the message.

To make your writing more formal, try to:

  1. Replace informal words that are associated with ‘chatty’ spoken styles ( such as contractions) with more formal vocabulary
  2. Avoid rhetorical questions the reader cannot answer
  3. Use full words instead of contractions
  4. Avoid unspecified categories
  5. Avoid colloquial language

For example, this passage contains some informal words (going, good, tell, though, really), a rhetorical question (How good…?), a contraction (can’t), a vague category (etc.) and a colloquialism (first-class, top notch, check out):

  • The investigation has been going for four years. How good has it been? At this stage, researchers can’t tell, because they still need to check out the data to account for differences in age, gender, socio-economic-status, etc. Once that work is done though, the information will be really first-class.

Using the tips above, you could improve this passage by using more formal vocabulary, removing the rhetorical question, writing words in full, elaborating on the vague category and removing the colloquialism as seen below:

  • The investigation has been underway for four years. Researchers cannot yet determine the effectiveness of the project because it is necessary to first analyse the data to control for age, gender, socio-economic status and other demographic variables. Despite this, the information collected is expected to be highly valuable for future studies.

Online learner’s dictionaries that provide examples of how words are used in context can help you determine the formality of specific words. If a word has many possible meanings, or appears in many idioms, it is more likely to be informal.

To communicate your meaning precisely, you should try to:

Include a sufficient high level of detail and specificity

The amount of detail you provide depends on the purpose of your work, but you should always try to avoid ambiguity.

The following sentence is very broad and general, which makes it sound like a personal opinion.

  • Most people didn’t like changing trains on the way to work, but they still thought it was better than taking a bus.

How many people are ‘most’? How strong is their dislike of changing trains? In what way are trains better than buses?

To make it more precise, the writer could specify exactly which group of people they are referring to, what their preferences were, and the degree of strength of those preferences.

  • While the majority of the survey respondents indicated their dislike of changing trains on their commute to work, they preferred taking two trains to taking one bus, which they perceived would be slower overall and less comfortable, or both.

The additional detail in the sentence above clearly makes the message more precise.

Certain verbs are considered too imprecise for academic writing, in that they do not provide detailed, exact meaning we require. These include verbs that are commonly used in less formal contexts, particularly those with many possible meanings and multi-word verbs.

Verbs with many possible meanings include ‘do’, ‘make’, ‘put’, ‘keep’, ‘have’ and ‘get’. For example, some of the many possible meanings of ‘get’ are:

  • Receive (get an email)
  • Obtain (get a better view)
  • Bring (get a bucket and mop)
  • Buy (get a new shirt)
  • Arrive (get there at 7pm)

If you use the single verb that expresses exactly what you mean by ‘get’, your writing will be more precise.

The researchers got results from a large participant group


The researchers obtained results from a large participant group

Multi-word verbs are verbs that require more than one word to create meaning, including phrasal and prepositional verbs, for example:

Cut off, find out, give up, hand out, let down, pick out.

Again, try to use a single verb with the same meaning instead, such as:

Discontinue, discover, quit, distribute, disappoint, select.

Use a dictionary and/or a thesaurus to find suitable alternatives for imprecise or multi-word verbs.


Hedging language in academic writing is used to express caution and avoid strong, unqualified statements that may be easily disproven.

To avoid generalisations, you can:

  • Use a quantifier (e.g. few, many, some)
  • Use adverbs or adverbial phrases (e.g. occasionally, often, usually)
  • Use modal verbs (e.g. can, may, might, would, could)

The following claim is quite strong:

Leading a sedentary lifestyle causes chronic health conditions.

You could avoid overstating the relationship using the hedging tips above as follows:

Extended physical inactivity can contribute to a range of chronic health conditions and may have a negative effect on mental health.

Cautious but inclusive statements, like the one above, may be challenged but not easily dismissed.

This page outlines some tips to help you incorporate four key features of academic style into your writing. Another way to become familiar with these features is to look for them in the academic texts you are reading in your studies.

  • How do authors express their views objectively?
  • What formal and precise vocabulary is used?
  • How do authors avoid making generalisations?

The more you look for these aspects of writing in academic texts you are reading, the more easily you will be able to incorporate those features into your own writing.

Explore all resources

  • Academic English is a distinct language, and one you’re expected to write in at university. Understand how to identify, create and improve your academic style.

  • Effectively combine your ideas with those of other writers.

  • Academic writing aims to be clear and precise, with a direct style that moves logically from one idea to the next. This page describes how you can structure sentences and paragraphs to achieve clarity and ‘flow’ in your writing.

The differences in the passages above are most likely a result of which of the following?

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