amnesia.jpg
Shraddha Ramakrishnan z3254528, Samantha-Joelle Al-Asmar z3296055, Apryll Smith z3216640

Introduction


The media item ‘Clive Wearing, Part 2b: Living without Memory’ is a cut video segment from the BBC documentary entitled ‘The Mind – Second Edition’. This documentary was filmed in 1998 and revisits Clive Wearing, a unique amnesiac, 13 years after the onset of his condition. The video excerpt, following on from Part 2a, documents Clive’s evaluation by a neuropsychologist and presents scans of the damage done to his brain, as well as providing a fascinating insight into Clive's own perception of his illness.
Amnesia refers to the temporary or permanent malfunction of some part of the memory system, which can be caused by head injury, shock, severe illness, trauma or mental disease. Memory loss can manifest itself in two different ways: Retrograde Amnesia, which is characterized by memory loss for events before the trauma, and Anterograde Amnesia, which is the inability to store new memories.
Clive Wearing, an English Conductor and Musicologist, suffers from the most publicised and intriguing case of Amnesia ever known. He has been severely affected by both Retrograde and Anterograde Amnesia since March 1985, after contracting Herpes Encephalitis, a simple virus that normally causes cold-sores. Clive's condition is the most devastating case of Amnesia ever recorded, and as such, it is of particular interest to Neuroscientists and Psychologists alike. His memory span ranges from only 7 - 30 seconds, and as well as being unable to store new information, Clive has absolutely no recollection of past events. He is perpetually stuck in the present moment, with no connection to the past or future.
Clive has been the subject of numerous documentaries that have each taken a different approach to discussing his prominent clinical case. This particular segment was chosen because it provides a reliable in-depth explanation of his unique and debilitating condition, and reflects on the many ways in which it has affected his life over the years.

Media Item









Neuroscientific Context


What is Amnesia?


Amnesia, in simple terms, is forgetfulness or loss of memory. It is a neurological disorder that can be caused by head injury, shock, senility, severe illness or mental disease. Depending on the type of Amnesia, it can be a loss of short term or long term memory, and for severe cases, it is a memory deficit disorder, wherein the absolute retrieval of lost memory is impossible.

The two major forms of Amnesia are Retrograde Amnesia, which is characterised by the loss of memory for the event before and leading up to the trauma, and Anterograde Amnesia, which is the inability to create and store new visual memories. There are also several types of Amnesia and Amnesic diseases, including Transient Global Amnesia, Traumatic Amnesia, Wernicke-Korsakoff’s Psychosis, Hysterical (fugue) Amnesia, Infantile or childhood amnesia, and Posthypnotic Amnesia.

These types are often classified according to their causes, for example, Traumatic Amnesia is caused by a blow to the head (trauma), whereas Wernicke-Korsakoff Syndrome occurs due to alcohol abuse. Other types are defined by their name, for example, Infantile Amnesia refers to the inability to recall events from a person’s childhood, whereas Posthypnotic Amnesia describes the loss of memory post hypnosis.

The chosen video segment features Clive Wearing, who famously suffers from both Retrograde and Anterograde Amnesia, and as such, these two forms of Amnesia will be the main focus of further discussion.

Hippocampus and Memory

hippocampus.png
Memory consists of two major types; Short-Term Memory (STM) and Long-Term Memory (LTM). The latter stores events, facts and procedures in the brain for later retrieval and consolidation. The storage takes place in two independent memory subsystems, each mediated by different neuronal structures and mechanisms. These are the implicit subsystem (unconscious) and the explicit subsystem (conscious), which also comprises two subsystems; episodic, where episodes with spatial temporal context involving detailed re-experience of the initial events are stored, and semantic, in which knowledge lacks spatial temporal context such as facts.

Any impairment of the LTM results in cognitive deficiency such as Amnesia, which is caused by the absence of clear intellectual dysfunction or general knowledge loss, hence, affecting the medial temporal lobe (MTL) structure where the hippocampus is found.

LTM impairment can be either Retrograde and Anterograde, if the medial temporal lobe damage is bilateral, or highly selective for verbal or visual memoranda, if the lesion is unilateral. Consequently, damage to any other related structures such as the basal forebrain can cause Amnesia, as such damage can indirectly interfere with normal hippocampal region processing. This finding is further evidence that the hippocampus is needed to lay down new episodic memories. On the other hand, the brain system damaged in Amnesic patients has a temporary role in memory as time passes after learning, memory is reorganized and consolidated within the neocortex, and hence the TLM structure is not needed for storage and retrieval.

In summary, the form of memory impaired in Amnesic patients is the explicit memory or declarative memory, given that memory is composed of multiple and separated systems. Amnesic patients are adept at a wide variety of tasks that assess priming, skills and habits, as well as being able to complete some tasks that do not require direct recall from the memory, such as word fragment completion.



memo_types.jpg

Causes of Amnesia


The limbic system, which includes the thalamus, hypothalamus and hippocampal regions along with other components such as the entorhinal cortex and parahippocampal gyrus, is responsible for the expression of emotion and behaviour of humans, as well as the storage of long term memory. When this section is damaged via various causes, it results in Amnesia.
Most often, Retrograde amnesia is caused by concussive brain injury, and other diseases that cause seizures, encephalitis, aneurysms and strokes as well as chronic alcoholism. Amnesia can also be induced by other causes that disrupt the brain experimentally in animals as well as humans. These include electroconvulsive shock (ECS) to the brain, disruption of protein synthesis, brain lesions and drugs such as benzodiazepenes.

Clive Wearing's Case


In this case, research findings stated that Clive had acute onset Herpes Simplex Encephalitis (HSE), a viral infection. In comparison with other infectious diseases, encephalitis has a very high mortality rate and very few drugs available for treatment. Yet, miraculously, Clive survived, but is recorded as having the worst case of Amnesia recorded.
As Dr. Erin Bigler suggests from the MRI scan conducted in 1991, Clive has a large area of brain tissue missing and instead the area is filled with cerebrospinal fluid. There is a small remnant of superior temporal gyrus on the left side of his brain. On the right side of his brain, there seems to be a wastage of the temporal lobe with the lateral lobe being better preserved.
As discussed pin previous sections, the memory is composed of various and separated structures. The explicit memory is often impaired in amnesic patients, but Clive's implicit memory remains intact, and as a result, his musical skills and intense love for his wife, whom he remembers perfectly, remain intact. Playing the piano is a skill, and therefore it is a procedural memory in which the person is unable to describe exactly how he does it, but in fact can show us how it is done.

What is Encephalitis?


Encephalitis is an inflammation of the brain resulting from either a viral or bacterial infection. It is a serious medical emergency which affects approximately 1 in 200000 people in the U.S each year, with most cases being fatal. Although it can affect anybody, children and the elderly are prone to encephalitis due to a weaker immune response.
Symptoms of encephalitis can include headaches, nausea, fever, fatigue, muscle weakness, seizures, aversion to light and clumsiness. Encephalitis is diagnosed by taking blood cultures, lumbar samples (spinal taps), and in serious cases, a biopsy may be necessary to determine if there is an infection of a virus.
Encephalitis is treated by the administration of strong narcotics. In the case of a Herpes Simplex virus, as with Clive, an anti-viral drug, Acyclovir is given intravenously. If the inflammation is caused by and enterovirus or an arbovirus, dexamethosone, a steroid injection may be administered in conjunction with narcotics for pain reduction. With the occurance of seizures, the patient also needs to be treated with anticonvulsants.

Symptoms of Amnesia


Major symptoms of Amnesia include difficulty learning new information, difficulty recalling previously learned information, disorientation and confusion.

Diagnosis of Amnesia


A CT Scan and/or MRI (magnetic resonance imaging) must be conducted to determine head injury. If a fever is detected, spinal tap, CBC, urinanalysis and blood cultures should be taken to determine if there is an onset of encephalitis, meningoencephalitis, cerebral abscesses or encephalomyelitis. If there is no fever and the patient appears to have lost memory connecting them with recent events, one must consider other causative diseases such as Alzheimer’s disease, cerebral arterial sclerosis, neurosyphilis, chronic alcoholism, cerebral tumors.

Treatment of Amnesia


Treatment for patients with amnesia has been particularly challenging, since the processing of memory takes place even after the learning process for a while. If this processing is disturbed before it can be “saved”, the person will have no recollection of the memory whatsoever. This learning process also depends on the state during which it takes place. For example, if a patient were to learn something in their amnesic state, it would not be retrieved later in an unaltered state.

Analysis


The media item was broadcasted in 1998 on the BBC, a reputable television channel that screens a number of notable science documentaries, and is therefore a reliable source of information. It features the opinions of leading experts such as Neuropsychologist Dr Barbara A. Wilson, who has evaluated Clive Wearing’s cognitive functions on 15 occasions since 1985; and Dr Erin Bigler, who has recently examined and interpreted Magnetic Resonance Imaging (MRI) scans of Clive’s brain. These experts use everyday language that is easy to understand, but also use appropriate scientific jargon when presenting neuroscientific information, adding credibility to the documentary.
The segment is aimed at a general but educated audience, who have an interest in Neuroscience and Psychology. The use of expert opinions and analysis, along with Neuroscientific jargon, are evidence that this documentary is intended to be informative and intriguing, rather than sensationalised for entertainment purposes. Conversely, Clive’s wife often expresses her subjective view on his condition, and there are many instances where Clive describes his own experience using emotionally loaded language such as "It's just like death...no thoughts of any kind...nothing at all". This creates a tone of empathy, engaging the audience and forging a connection between the viewer and subject.
Neuropsychologist Dr Barbara A. Wilson’s professional evaluations of Clive Wearing have been ongoing since he was diagnosed with Amnesia in 1985, and thus she is a very reliable authority to describe the nature of his condition. Dr Wilson explains that although she has seen over 700 brain injured people, most with memory impairment, Clive's case is very unique. She confirms Clive’s behaviour of being constantly under the impression that he has just emerged from unconsciousness, because he refuses to accept any evidence that he has ever been awake before. He numerously repeats statements such as “I’ve never heard anything, seen anything, touched anything, smelled anything...It’s like death.”
Dr Wilson explains that she “has never seen that in any other amnesiac people, even people with a very dense amnesia”. This finding is supported by Neurologist Dr Oliver Sacks, who notes that Clive is unlike many other Amnesiacs, who are able to make inferences and realistic guesses about their condition. People with Amnesia often notice changes in their environment or the reactions of others. Instead, Clive Wearing always comes to the conclusion that he has just ‘awoken’ for the first time after being ‘dead’.
Another unique aspect of Clive’s condition is that his musical talents have remained intact. Dr Wilson vaguely comments that there has not yet been a formal evaluation conducted, but that “some people that are interested in the neuropsychology of music” have concluded that his musical skills have not been affected. She goes on to give a very simple explanation of why this occurs, saying that “what that tells us about functioning of the brain is that what’s been damaged in Clive are not the areas concerned with music”. It seems that the virus that destroyed much of Clive’s brain, did not affect his procedural memory. This is consistent with Dr Erin Bigler’s evaluation of Clive’s MRI scans. Dr Bigler’s research correlates the scans with Clive’s cognitive abilities and deficits. He compares MRI images of Clive’s brain, with that of a healthy brain, accurately pointing out an extensive area of missing brain tissue.
According to Dr Wilson, what is even more interesting about Clive’s deficits is that he has quite significant semantic memory impairments as well as episodic memory impairments, meaning that he has also lost much of his general knowledge about things. She notes that he has been virtually unable to learn anything since the onset of the illness, which is consistent with other research on similar forms of Amnesia.

Overall, the simplifications of Neuroscientific content that were made in the documentary, in order to present a clear and concise overview to the target audience, have not compromised the accuracy of the information.

Search Strategy


Amnesia, in its different forms and types has always been a mystery and a topic of much discussion in media as well as scientific literature. Upon watching movies such as 50 first dates, momento and several documentaries, along with the popular TV show 'Grey's Anatomy, each of our group members have been quite interested in the topic. The variety of different cases sparked our interest in researching Amnesia.

We did some research on the internet as well as looking for scientific articles in the UNSW Library database 'Sirius' and found a wide variety of cases. Meanwhile, one of the group members heard about Clive Wearing in one of the Psychology lectures as having the most severe and interesting case of Amnesia recorded, and being the most publicized case, it was very easy to find a video of Clive's everyday life on youtube. After watching a few video segments about Clive Wearing, we chose the most interesting and appropriate video.




References



1. David C. Riccio, Paula M. Millin, Pascale Gisquet-Verrier (Apr 2003). Retrograde Amnesia: Forgetting Back, Current directions in Psychological Science, Volume 12, (no.2), 41-44.

2. Larry R. Squire, Stuart M, Zola (2010). Amnesia, Memory and Brain Systems, Biological and Psychological Perspectives on Memory and Memory Disorders, Volume 352, (no.1362). pp. 1663-1673.


3. Amnesia (2009), Better Health Channel, viewed 9 september 2010, < http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Amnesia >


4. Louise France (2005), ‘The Death of Yesterday’, The Observer 23rd Jan.


5. As Seen on Grey’s Anatomy – IL-2 treatment, Anterograde Amnesia (2009), A Disease A Day, viewed 10 July 2010 <http://www.diseaseaday.com/brain/as-seen-on-greys-anatomy-il-2-treatment-anterograde-amnesia>


6. Sederberg Et Al (2009), ‘Hippocampal and Neocortical Gamma Oscillations Predict Memory Formation in Humans’, Cerebral Cortex, vol.17, no. 5, viewed 10 September 2010, <http://cercor.oxfordjournals.org/content/17/5/1190.full >


7. Hassabis et al (2007). ‘Patients with hippocampal amnesia cannot imagine new experiences’. Proceedings of the National Academy of Sciences of the United States of America, vol.104, no.5, 1726-1731

8. R. Douglas Collins (2007). Differential Diagnosis in Primary Care. Lippincott Williams & Wilkins.

9. What is encephalitis? (2010) eHealthMD. Accessed 9 september 2010. <http://www.ehealthmd.com/library/encephalitis/ENC_summary.html>

10. McDonough et al (1995). The deferred imitative task as a measure of nonverbal measure of declarative memory, Psychology, Vol 92, pp 7580-7584

11. Oliver Sacks (2007), 'The Abyss: Music and Amnesia', The New Yorker 24th Sept.