So I really thought that I’d written a post about Unilateral Neglect before but apparently I’m just imagining that! Perhaps my confusion is because I did write an essay about it for the first course I took last year, and hence forth I’ve become all muddled and confuddled that I can no longer differentiate from the work I ‘have to do’ and the blog posts I enjoy doing…
Anyway, this is the most perfect time for me to write about unilateral (or hemispatial) neglect, as my dog appears to be displaying the symptoms! Brilliant isn’t it? I shouldn’t be this excited but I can’t help it.
Meet Barley: 
She is a 16 year old Whippet x. Lurcher who used to spend her days chasing bunnies and sometimes catching them, but now just potters about the place and would rather just stare at a field of rabbits and keep walking than bother to do anything about them. A few months ago Barley had a stroke, she suffered severe left side weakness and although has gained a lot of mobility back still has a slightly wonkey head. I believe she is still having small strokes and that she must have had one about a fortnight ago that affected her posterior parietal cortex. My reasons for suspecting this are outlined below, after my brief explanation of unilateral neglect symptoms in humans.
Okay, so here goes the ‘science’. Hemispatial neglect can occur following damage to the right or left posterior parietal cortex, most commonly occurring however in the right and usually as a result of a stroke. The form of neglect can be both extrapersonal, representational and/or personal. In right hemispherical damage the effects tend to be longer lasting and more severe, though most patients do recover over time.
Extrapersonal Neglect
In cases of extrapersonal neglect patients fail to be aware of objects on the contralateral side of their lesion, in most cases this means that they neglect objects in the left side of space. For patients to be diagnosed with hemispatial neglect no other explanation such as a motor or sensory deficit can be present (Vallar, 1998). This form of neglect can involve near space (or peripersonal space) or far space, or both. Often patients will recover over time from hemispatial neglect syndrome. It’s common for these patients to fail to draw the left hand side of a picture, as illustrated below, or for them to even eat food only from the right hand side of their plate and not realise that there is still food on the left to be eaten.
Figure illustrates the left side neglect of a patient.
Representational Neglect
In these cases patients neglect the contralesional space in their memories and imagination of places, objects and people. Representational neglect is far more common to right hemispherical damage and is found in conjunction with the extrapersonal visuospatial neglect described above (Bartolomeo, D’Erme, & Gainotti, 1994).
Personal Neglect
Personal neglect differs in that the patient fails to recognise or use parts of their own body that are on contralateral side of their brain damage. Patients are reported to be unaware of their own limbs, claiming for example that the left leg attached to them belongs to somebody else and is not theirs. This form of neglect is less common than that of extrapersonal neglect, and may involve additional regions of damage. Right personal neglect following a left sided lesion is extremely rare although some cases have been reported (see Peru & Pinna, 1997).
Now of these three forms of neglect I believe it is quite likely that my dog Barley is suffering from extrapersonal neglect following some sort of damage to her Posterior Parietal Cortex in her right hemisphere. The photographs below show my reasons for thinking this is likely. (Thanks go to my Mom for taking these photographs and emailing them to me!)
First image
Number One. Bowl still relatively full of food.
Number Two. Barley eating her food.
Number Three. Barley thinks she has finished eating.
It is pretty clear from these images that she’s really neglecting to ‘see’ the food that is in her left visual field! If mom turns the bowl around so that the food is then on the right hand side of the bowl she continues to eat, albeit a little confused as to where this food has magically appeared from but still.
I hope that these images and experiences of Barleymow have helped illustrate this neurological disorder well, and I will keep tracks on how Barley is doing over time and write about anything new or interesting that happens.
statisticallysignificantscience.wordpress.com 
Poor Barley! I hope you’re being nice to her as well as observing her slow decline!
Hey Polly,
My mom’s looking after her for me, so she’s in very good hands! I did go back home after her first stroke and spent a few days hand feeding her toast with jam as that’s all she decided she wanted to eat.. she’s so picky!
Love her to pieces really, just think her recent ‘issues’ are pretty cool. š
O
You need to repurpose an old record player as a dog bowl rotator. Or the motor off one of those rotating ornament displays, that’s probably a better speed!
This idea might not be well received if applied to human sufferers of the same though!
That’s a brilliant idea, I think we may have an old record player in the loft. I bet my brother would be more than happy to sort something out for her š
Will let you know how that goes!
Excellent article, on an interesting area. My best wishes for Barley too, part-Lurcher ignoring rabbits: neurological, clearly š
Wow–this is totally fascinating. Picture and description are pretty suggestive.
I feel your pain. My old friend has been on her way out for a while now. Though she is still convinced she might catch a rabbit.
As for a turn table a record player might be a bit ott. A solar plant rotator might do a better job. Something along these lines? http://www.dealextreme.com/details.dx/sku.6184
That or she’ll just learn that if she walks around the bowl more food magically appears. š
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Ooh how interesting! But just wondering why couldn’t it be a homonymous hemianopia? =)
Ooo interesting thought. Suppose there’s no reason it couldn’t be either explanation. Guess it’d be hard to tell which is more likely. Will look into it though, if I were at home it’d be easier but might get my mom to conduct a few tests.. š
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hi,
that is a very nice description of your dog’s symptoms…
the nice thing about food neglect is that it shows that it is not purely visual, in which case olfaction would help to find the left side of the food…
I am actually studying unilateral neglect: could i use one of your pictures in my teaching?
thank you,
Yves
Hi Yves,
Thanks for your comments, feel free to use any of the pictures for your teaching. The whole point of my blog is to spread news and information to others so please do so! š
I’m working on getting video footage which I’ll upload when my mom gets it and sends it to me. And maybe even a brain scan… but that’s a definite maybe at the moment.
Hi Olana
Many thanks for posting such an interesting video- it’s a very compelling demonstration of the problems of neglect, particularly considering how important food is to dogs! I noticed that one of the other comments suggested that your dog may be hemianopic. However, I think this is unlikley beacuse if his problem was purely visual, Barley could compensate using his olfactory system, but he clearly cannot do so.
You may also be interested to know that neglect in cats has been induced by damaging their right parietal cortex, then ‘cured’ by causing a second lesion in the LEFT superior colliculus (which controls righwards eye-movements) . The explanation is that the parietal lesion creates a bias towards the right side of space, and the collicular lesion lesion creates a bias towards the left side of space, and the two biases cancel each other out (see Sprague, J. M. (1966). Interaction of cortex and superior colliculus in mediation of visually guided behaviour in the cat. Science, 153(3743), 1544). A similar effect has been reported in an unfortunate human patient too (Weddell, R. A. (2004). Subcortical modulation of spatial attention including evidence that the Sprague effect extends to man. Brain and Cognition, 55(3), 497-506.)
I hope your Barleys recovery continues to go well
I wanted to let you know that your photos of Barley are now part of the “Brain and Behavior” curriculum for University of Pennsylvania Medical Students learning about the function of the parietal lobe. Thanks so much for the interesting post!
Thanks for letting me know! I’m so glad Barley’s been of use to people studying. š It’s still a bit of a mystery what actually was going on, though the symptoms of neglect were clearly present. She had advanced cancer, that combined with the stroke she suffered must have caused damage somewhere in the parietal lobe but how specific it was we’ll never know. She was a great pet and I’m glad her memory is being continued in such a positive way! All the best, Olana
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Hello Olana,
I am writing with a request from Worth Publishers to see if we can use one of your photos of Barley’s Unilateral Neglect in an upcoming textbook. I am sorry for your loss. Her memory clearly still lives on in the name of science. Please email me at the address posted below if you are interested. Thank you.
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All very interesting! I had read about this when I was a psych student, and I recently diagnosed my cat with this problem. Today, I finally decided to rotate his food bowls when he ate only half of what was in each bowl (from the same side in both bowls) and was complaining at mid-day about being hungry when both bowls were half full. Since then, he’s eaten the other half in both bowls, and it’s now almost dinner time, and he hasn’t started begging for food yet. This is a first!
I don’t know of any stroke he might have had, because he has no other symptoms. He is about 13 years old, though, so I suppose he could have had one. As long as turning the bowls works, I’ll just do that. Thanks for the ideas!