case files neurology
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case files neurology


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alertness
\u2022 Recurrent visual hallucinations that are typically well formed and detailed
\u2022 Spontaneous features of parkinsonism
3. Suggestive features (one or more of these in the presence of one or more core fea-
tures is sufficient for a diagnosis of probable DLB; in the absence of any core fea-
tures, one or more suggestive features is sufficient for a diagnosis of possible DLB;
probable DLB should not be diagnosed on the basis of suggestive features alone)
\u2022 REM-sleep behavior disorder
\u2022 Severe neuroleptic sensitivity
\u2022 Low dopamine-transporter uptake in basal ganglia demonstrated by SPECT or
PET imaging
4. Supportive features (commonly present but not proven to have diagnostic specificity)
\u2022 Repeated falls and syncope
\u2022 Transient, unexplained loss of consciousness
\u2022 Severe autonomic dysfunction
\u2022 Hallucinations in other modalities
\u2022 Systematized delusions
\u2022 Depression
\u2022 Relative preservation of mesial temporal lobe structures on computed 
tomography/magnetic resonance imaging
\u2022 Reduced occipital activity on SPECT/PET
\u2022 Low uptake MIBG myocardial scintigraphy
\u2022 Prominent slow wave activity on EEG with temporal lobe transient sharp waves
DLB, dementia with Lewy bodies; EEG, electroencephalograph; MIBG, metaiodobenzylguani-
dine; PET, positron emission tomography; REM, rapid eye movement; SPECT, single-photon
emission computed tomography.
Source: McKeith IG, Dickson DW, Lowe J, et al. Diagnosis and management of dementia with
Lewy bodies: third report of the DLB Consortium. Neurology 2005;65:1863\u20131872.
Imaging studies are important to evaluate for other conditions that can
mimic this disorder (vascular dementia, tumor, normal pressure hydrocephalus,
etc). Patients with DLBD usually have less hippocampal atrophy than patients
with AD (but more than control subjects). Whether this difference is clinically
useful is under investigation, as is the diagnostic utility of functional imaging.
Single-photon emission CT scanning or positron emission tomography scanning
can show decreased occipital lobe blood flow or metabolism in DLB but not in
AD. Reduced dopamine transporter activity in the basal ganglia is seen with
positron emission tomography scanning or single-photon emission CT scanning.
Other Tests
In certain circumstances, neuropsychologic testing is helpful to differentiate
DLB from AD and to establish a baseline for future comparison. Patients with
DLB can have changes on electroencephalography earlier than patients with
AD, but whether this difference is diagnostically useful is not clear.
Cerebrospinal fluid (CSF) examination is not required in routine cases, but
patients with AD have higher levels of tau protein in their CSF than patients
with DLB. Patients with both LB variant-AD have intermediate values. CSF
levels of beta-amyloid are lower than normal in DLB, AD, and LBV-AD.
However, CSF beta-amyloid levels in DLB, LBV-AD, and AD do not differ
from each other.
Treatment
There are no medications that have been shown to delay the degeneration of
this disorder. Symptomatically, the anticholinesterase medications (i.e.,
rivastigmine, donepezil, and galanthamine) have been demonstrated to have
186 CASE FILES: NEUROLOGY
Table 21\u20132
CLINICAL PHENOMENOLOGY OF DEMENTIA WITH LEWY BODIES
\u2022 Comparison to PD
\u2013 Less severe parkinsonism
\u2013 Less tremor
\u2013 More postural instability
\u2022 Comparison to AD
\u2013 More visuospatial deficit
\u2013 Less language, memory encoding deficit
\u2022 Comparison to AD & PD
\u2013 More fluctuation and hallucinations
AD, Alzheimer disease; PD, Parkinson disease.
cognitive/behavioral symptom improvement. The cortical cholinergic deple-
tion in DLB is actually much more severe than AD and so appears to be more
responsive to treatment. Cognitive and behavioral symptoms have been shown
to improve with this class of medications, however, not depression.
Neuroleptic agents should be used with extreme caution in these patients.
Patients, often treated for behavioral issues with neuroleptics, have been
described to have disastrous responses to this class of medicines, even when
using \u201catypical antipsychotics.\u201d For severe depression, electroconvulsive
therapy has been shown to be effective and safe. In addition, parkinsonian
motor signs have also been shown to improve with ECT.
Comprehension Questions
[21.1] A 68-year-old woman is diagnosed with dementia with Lewy bodies.
Her medications are mixed up with her husband\u2019s medication bottles.
Which of the following is most likely to be her husband\u2019s medication?
A. Rivastigmine
B. Donepezil
C. Haloperidol
D. Galanthamine
[21.2]. A 61-year-old man is brought into the doctor\u2019s office for memory loss
and confusion. Which of the following symptoms are most suggestive
of Alzheimer disease as opposed to dementia with Lewy bodies?
A. Visual hallucinations
B. Dramatic fluctuations in clinical condition
C. Early anterograde memory loss
D. Early shuffling gait
[21.3] A 73-year-old man is noted to have a slow onset of cognitive deficits. The
physical examination reveals no obvious etiology. Which of the follow-
ing imaging findings are most suggestive of dementia with Lewy bodies?
A. Medial temporal lobe atrophy
B. Parietal temporal hypometabolism
C. Atrophy of the midbrain
D. Occipital lobe hypometabolism
Answers
[21.1] C. Haloperidol is a dopamine-receptor blocking agent that can have
severely deleterious consequences in this disorder. The other three are anti-
cholinesterases and have evidence for the use presented in the literature.
[21.2] C. Cognitive impairment in DLB is characterized by more executive
dysfunction and visuospatial impairment more than the anterograde
memory loss of AD.
CLINICAL CASES 187
[21.3] D. Occipital lobe hypometabolism is most typical of DLB. Medial
temporal lobe atrophy and parietal temporal hypometabolism are char-
acteristic of AD. Atrophy of the midbrain is characteristic of progres-
sive supranuclear palsy.
REFERENCES
Ballard C, Grace J, McKeith I, et al. Neuroleptic sensitivity in dementia with Lewy
bodies and Alzheimer\u2019s disease. Lancet 1998;351:1032\u20131033.
Bonner LT, Tsuang DW, Cherrier MM, et al. Familial dementia with Lewy bodies
with an atypical clinical presentation. J Geriatr Psychiatry Neurol
2003;16:59\u201364.
Geser F, Wenning GK, Poewe W, et al. How to diagnose dementia with Lewy bod-
ies: state of the art. Mov Disord 2005 Aug;20(suppl 12):S11\u201320.
Korczyn AD, Reichmann H. Dementia with Lewy bodies. J Neurol Sci
2006;248:3\u20138.
McKeith IG, Dickson DW, Lowe J, et al. Diagnosis and management of dementia
with Lewy bodies: third report of the DLB Consortium. Neurology 2005;65:
1863\u20131872.
Miyasaki JM, Shannon K, Voon V, et al; Quality Standards Subcommittee of the
American Academy of Neurology. Practice parameter: evaluation and treatment
of depression, psychosis, and dementia in Parkinson disease (an evidence-based
review): report of the Quality Standards Subcommittee of the American
Academy of Neurology. Neurology 2006;66:996\u20131002.
188 CASE FILES: NEUROLOGY
CLINICAL PEARLS
\u2756 Lewy bodies are associated with a number of clinical syndromes,
including Alzheimer\u2019s dementia and Parkinson disease.
\u2756 The typical clinical syndrome of DLB is relatively specific for the
Lewy body pathology, but the converse is not necessarily so and
can constitute part of a spectrum of synucleinopathies.
\u2756 Compared to AD, DLB is associated with a greater loss of acetyl-
choline and a smaller loss of acetylcholine (ACh)-receptors
\u2756 Levodopa can be effective for the parkinsonism but is often not very
rewarding for behavioral or cognitive dysfunction.
\u2756 REM-related behavior disorders can be one of the first symptoms
of DLBD, prior to the onset of significant cognitive or motor
disturbance.
\u2756 CASE 22
A 48-year-old man complained of \u201cnumbness and stiffness\u201d in his arms for the
past 4 months. His gait has gradually deteriorated