31 Neuropsychiatry – 3
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| 1. Dyslexia is a characteristic feature of Gerstmann syndrome. |  |
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| 2. Difficulty in reading and writing is a feature of Wernicke’s aphasia. |  |
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| 3. Carbon monoxide poisoning can cause amnesic confabulatory syndrome. |  |
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| 4. CJD is associated with triphasic waves on the EEG in 80% of cases. |  |
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| 5. A normal CSF reading includes 5 neutrophils per mL. |  |
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| 6. Barbiturates increase fast activity on the EEG. |  |
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| 7. Epilepsy-related automatisms are a common cause of homicide. |  |
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| 8. Dorsolateral prefrontal cortex lesions cause apathy. |  |
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| 9. Genes code for introns, exons and tRNA. |  |
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| 10. The polymerase used in a polymerase chain reaction (PCR) is heat stable. |  |
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| 11. In post-concussion syndrome the symptoms most rapidly improve after the first 6 months. |  |
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| 12. Schizophreniform psychosis is recognized in HIV. |  |
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| 13. Huntington’s disease is associated with CAG repeats. |  |
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| 14. In Huntington’s disease the unaffected siblings have a higher than average rate of criminal behaviour. |  |
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| 15. Implicit memory is preserved in Korsakoff’s syndrome. |  |
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| 16. Psychotic disorder in the context of multiple sclerosis has a poor outcome. |  |
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| 17. Narcolepsy is associated with loss of muscle tone in clear consciousness. |  |
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| 18. Left–right disorientation is a feature of left parietal lobe lesions. |  |
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| 19. Fluoxetine is effective in the treatment of pathological laughing/crying. |  |
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| 20. Prosopagnosia can result from a penetrating right-sided head injury. |  |
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| 21. Neuropsychiatric symptoms occur in most patients with systemic lupus erythematosis. |  |
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| 22. The treatment of choice for hypersomnia associated with severe apnoea is tracheostomy. |  |
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| 23. Night terror in adults is associated with depression. |  |
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| 24. Depression is rare in hyperthyroidism. |  |
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| 25. Vitamin B12 deficiency commonly causes dementia in the elderly. |  |
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ANSWERS
False: Gerstmann syndrome results from damage to the left angular gyrus or less commonly the dominant parietal lobe. The characteristic features are dysgraphia, dyscalculia, right–left disorientation and finger agnosia (Lishman 1997, p. 65; Mitchell 2004, p. 84; Yudofsky & Hales 2002, p. 573).
True: Fluent or Wernicke’s aphasia is characterized by a fluent verbal output with normal word count, phrase length, effort, articulation and prosody. There is difficulty in repetition and in word finding. The verbal output is often empty of content words. Paraphrasic substitutions and neologisms are common. Extreme and unintelligible fluent aphasia is called jargon aphasia. Reading and writing are usually impaired. Patients produce paraphrasic and disjointed written text (Hodges 1994, p. 57; Mitchell 2004, p. 72; Yudofsky & Hales 2002, p. 568).
True: Amnesia is common. It is often the last symptom to resolve. Delirium is an early symptom and classical Korsakoff syndrome is sometimes seen. Memory and executive problems occur in most patients (Lishman 1997, p. 550; Mitchell 2004, p. 249).
Although the EEG is almost always abnormal, the changes are usually variable and non-specific in the early stages. Moreover, nvCJD does not show these characteristic EEG changes (Lishman 1997, p. 478; Mitchell 2004, p. 180; Sadock & Sadock 2005, p. 469; Wright et al 2005, p. 386).
False: Normal CSF should contain less than 5 white cells per mL, and usually no neutrophils (Lindsay & Bone 2004, p. 56).
True: Barbiturates increase beta (fast) activity, particularly in the frontal regions. This effect is opposite to that of alcohol (Sadock & Sadock 2005, p. 185).
False: Epileptic automatism is an extremely rare cause of serious violence (Gelder et al 2000, p. 2050; Sadock & Sadock 2005, p. 385).
True: Apathy has been associated with damage to the orbitofrontal, dorsomedial and dorsolateral prefrontal cortex, the basal ganglia, the thalamus and the internal capsule (Fitzgerald 1996, p. 237; Hodges 1994, p. 23; Lindsay & Bone 2004, p. 109; Mitchell 2004, p. 442; Sadock & Sadock 2005, p. 325).
True: A gene is that segment of DNA which codes for a single protein or for a single stretch of RNA if it is not one which undergoes translation (e.g. genes for tRNA). This includes coding (exon) and non-coding (intron) segments. The gene is transcripted into mRNA before the non-coding regions are spliced out. The remaining mRNA is then translated into protein. The mRNA is divided into codons, i.e. triplets of nucleotides which code for specific amino acids. This triplet code is ‘read’ by a separate molecule of RNA, the tRNA, which has a single amino acid bound to it. The tRNA also has a triplet code (the anticodon) with which it matches the codon on the mRNA. At the ribosome the tRNA molecules line up on the mRNA by matching their anticodons with the mRNA codons and the amino acids they carry are joined in the correct sequence to form a protein. A separate strech of DNA codes for the tRNA molecules (Alberts et al 2000, p. 6).
True: PCR is a technique used to amplify DNA. Firstly a mix is prepared containing buffers, nucleotides, short primers and a DNA thermostable polymerase (Taq) isolated from the thermophilic bacterium Thermus aquaticus. This mix is added to the sample DNA. It is then placed in a machine to automate the next part of the process. This first involves heating the sample to separate the two strands of DNA. This allows the primers to attach to the DNA and start a process of localized replication using the nucleotides and the DNA polymerase. The machine lets the sample cool before starting a new cycle. Each cycle doubles the amount of the DNA of interest that is present providing exponential growth. After a few hours this usually results in enough DNA to analyse further – for instance to run on a gel to identify a polymorphism in an individual. The polymerase has to be heat stable to avoid being denatured during the heating process (Alberts et al 2000, p. 508).
False: Post-concussion syndrome presents in some patients after mild traumatic brain injury (post-traumatic amnesia <24 hours, loss of consciousness <20 min). It consists of a number of somatic, perceptual, cognitive and emotional symptoms. Most individuals recover usually within 6 months. In some cases it persists longer, with little improvement over time (Mitchell 2004, p. 138; Yudofsky & Hales 2002, p. 641)
True: Various psychotic disorders, i.e. depressive, manic, paranoid and schizophrenic, may arise in patients who already show physical manifestations of ARC or AIDS or the psychosis may first draw attention to the disease (Lishman 1997, p. 331; Yudofsky & Hales 2002, p. 798). However, others believe that there is no evidence that HIV infection causes schizophrenia (Mitchell 2004, p. 190; Sadock & Sadock 2005, p. 438)
True: Huntington’s disease is an autosomal dominant neurodegenerative disorder with motor, cognitive and psychiatric symptoms. It is caused by a CAG trinucleotide repeat expansion mutation in exon 1 of the Huntington gene on the short arm of chromosome 4. As CAG encodes for glutamine, the mutation results in a protein with excess glutamine residues. Repeats of more than 35 CAGs are associated with disease. The longer the repeat length beyond 35, the earlier the onset of the disease. This at least partially explains the anticipation phenomenon, i.e. the disease becomes manifest at earlier ages in successive generations, as repeats tend to increase in length during parental transmission. This phenomenon may be more common in mutations inherited from the paternal line (Lishman 1997, p. 466; Mitchell 2004, p. 161; Sadock & Sadock 2005, p. 414).
True: Conduct disorder and criminal behaviour are not uncommon in the offspring of Huntington’s disease patients, even in those not carrying the genetic mutation. Environmental factors, limbic-basal-cortex disruptions and being brought up by an affected parent may be contributory (Yudofsky & Hales 2002, p. 930).
In Korsakoff’s syndrome, anterograde memory is most severely affected. New learning is impaired. Disturbance of time sense and confabulation occur. Immediate memory span is well preserved, and beyond a variable retrograde gap remote memories are well preserved. Implicit memory is well preserved. They can learn to mirror write even though they do not remember having been asked to perform the task before (Lishman 1997, p. 30; Mitchell 2004, p. 234).
False: Psychotic disorders in the context of multiple sclerosis are rare, but have a good prognosis with remission rates over 90% (Feinstein 1999, p. 80).
Cataplexy is the temporary loss of muscle tone precipitated by emotions such as anger and laughter while the patient is fully conscious. Cataplexy occurs in 60–70% of those with narcolepsy (Mitchell 2004, p. 224; Yudofsky & Hales 2002, p. 715).
True: Left–right disorientation suggests a dominant parietal lesion. Gerstmann syndrome refers to the presence of dyscalculia, dysgraphia, finger agnosia and left–right confusion (Lindsay & Bone 2004, p. 111; Mitchell 2004, p. 84).
True: Although the evidence is empirical, small doses of fluoxetine have been tried with success. Rapid improvement has been achieved without unpleasant side-effects. Other drugs used with some success are amitriptyline, levodopa, and amantadine. Dopamine agonists should be reserved for cases that have not responded to either fluoxetine or amitriptyline (Feinstein 1999, p. 76; Mitchell 2004, p. 320).
True: Prosopagnosia results from bilateral or non-dominant parieto-occipital lesions (Lishman 1997, p. 18; Mitchell 2004, p. 75).
True: Neuropsychiatric manifestations occur in up to 60% of patients with systemic lupus erythematosis. They include acute and chronic organic reactions, schizophrenic and affective psychoses, changes in personality, neurotic symptoms, seizures, cranial nerve palsies, peripheral neuropathy, movement disorders and intracranial ischaemic events (Lishman 1997, p. 419; Mitchell 2004, p. 219).
False: In sleep apnoea, the treatment of choice is usually nasal continuous positive airway pressure (nCPAP) (Lindsay & Bone 2004, p. 106).
True: Sleep terrors are sudden and brief episodes of panic and confusion with intense autonomic activation. They are most common between ages 5 and 7 years. Thereafter they become increasingly uncommon. They are more common in males. They are often associated with sleepwalking, sleep talking, confusional arousals and Gilles de la Tourette syndrome. Night terror persisting after age 20 years is often associated with anxiety, depression and phobias (Schneerson 2000, p. 142).
False: Up to a third of hyperthyroid patients would meet criteria for major depressive episodes. Moreover, the symptoms of hyperthyroidism such as anxiety, fatigue, insomnia, lability, dysphoria, poor attention span and weight loss overlap with those of depression (Lishman 1997, p. 508; Sadock & Sadock 2005, p. 2154).
