Other Less Common Disorders
Wow, it’s Day 10 already! Today is the final lesson in this course. In today’s lesson, I’m going to present a few unusual neuropsychological syndromes, some of these might sound familiar, because I have mentioned them in passing, but others will be completely new.
Patients with anosognosia are unaware of their illness or impairments, and in some instances, might actively deny that something is wrong. For example, after suffering a stroke, patients might lose the ability to move the contralateral arm (i.e, the arm on the opposite side to where the stroke occurred in the brain). If asked to move their arm, these patients might say that they are moving their arm (when they are not) or might deny that their arm belongs to them. Neglect, where patients ignore one side of the world, is considered a type of anosognosia.
Anosognosia means to have no knowledge of a disorder, and comes from Greek: “an” means without, “nosos” means “a disorder”, “gnosis” means “knowledge”, and “ia” means “a condition”.
People with Anton’s syndrome are anosognosic about their blindness. In other words, they are blind but are unaware of this. These patients may behave as though they can see, for example, they might guess the items around them. In other instances, these patients may be in denial of their condition and believe that the lights are off (for example). This condition is very rare.
Alien Hand Syndrome
Also, a rare syndrome, one of the patient’s hands behaves as though it has a mind of its own, or is no longer under the control of the individual. There are reports that this syndrome is a result of the two hemispheres, left and right, no longer communicating with each other because, for example, of the surgical severance of the corpus callosum. In addition to this, the supplementary motor area, which is part of the frontal lobe, has also been injured. Some of the accounts of alien hand syndrome were bizarre, for example:
• One hand throws ingredients in a dish while cooking.
• The one-hand physically stops the other from performing a task.
• One hand is packing a suitcase while the other hand is removing the same items.
Some theories are that the weak impulses to move the impaired hand would be stopped typically by the supplementary motor area. In individuals with damage to the supplementary motor area, those weak impulses aren’t stopped, and instead, they continue to move the hand.
Patients with Gerstmann’s syndrome present with the following four symptoms:
• Finger agnosia. Patients with finger agnosia can’t differentiate between the fingers of their hand. If the clinician touches one of the patient’s fingers, while the patient’s eyes are closed, then the patient is unable to say which finger was touched. The patient might also not be able to tell if the clinician is touching the same finger, but at two different points (e.g., the tip of the finger, and the knuckle).
• Right-left disorientation. Left-right disorientation is not limited to the hands (unlike finger agnosia) but is apparent for all parts of the body. These patients will confuse the left and right part of the body—they move the wrong hand, or report to sense a feeling in the wrong limb.
• Agraphia. Agraphia is a condition where the patient is no longer able to write. Patients with aphasia, such as Broca’s aphasia, often also present with agraphia (because language production is affected for verbal and written mediums). It is rare, but patients can lose the ability to write but are still able to speak.
• Acalculia. Patients with acalculia cannot solve mathematical problems. When testing for acalculia and agraphia, it’s very important to establish the education level of the patient, and whether the patient was able to perform these two tasks before the illness.
Congratulations on completing the course! We’ve covered so much work over the last ten days. We learned about the history of neuropsychology, the structure of the brain, cortical conditions such as amnesia, aphasia, agnosia, and apraxia, neglect, the dementias, epilepsy, and a few other interesting conditions. Hopefully, this course has fostered your interest in neuropsychology and I hope that you will continue your studies further! I’ve made a few recommendations for you if you want to read further on this subject matter.
Thanks again for taking this course, and please let us know if you have any feedback!
Cheers inquisitive minds,
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