Answers – 86 References – 87
Case 6 Case 6
3.2.3 Sampler CT Scan Cases
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side. The basal ganglia and thalamus are hypoactive on the left, while the right cerebellar hemisphere shows clear hypo- metabolism.
This aspect is characteristic of cases of the nonfluent/
agrammatical variant of primary progressive aphasia. Most cases (again, not all, since predicting pathology in such cases remains notoriously difficult, although their neurodegen- erative nature is obvious) are associated with frontotemporal neurodegenerative type pathology, as this case is likely to be given the absence of anomalies in the posterior parts of the cingulate gyri. Although it has been presented above that variant Alzheimer disease cases can initially present with normal uptake of 18FDG in those regions, here in Case 5, the picture can be entirely explained by frontotemporal lobar degeneration.
This case shows that there is in general a good correlation between clinical primary progressive aphasia cases and their PET pattern although it is not unusual to see PET patterns which do not match the more typical ones for primary pro- gressive aphasia despite typical clinical picture.
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.Fig. 3.10 Typical case of Lewy body disease with cingulate island sign and hyperactivity of the basal ganglia
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.Fig. 3.10 (continued) a–c Transaxial, coronal, and sagittal slices after registration to the MNI_305 template. d Registration along the axis of the temporal lobes
Neuroimaging in Clinical Geriatric Psychiatry
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possible mechanism by which the pathology has occurred in this patient.
Interpretation: There is evidence of fresh bleeding on the left side in prefrontal area in the form of subdural and intraparenchymal hemorrhage. Also there is evidence of sub- arachnoid bleeding. This is almost certainly traumatic. The fact that the patient has fallen before with evidence of previ- ous injury to the brain on the right frontal area, and because of the history of alcohol dependence, this factor (alcohol use disorder) needs to be considered as a possible contributing factor as well.
An 87-year-old female with anxiety, depression, and a recent onset seizure. CT scan in emergency room is shown in .Fig. 3.11b. Please review the image and identify the abnor- mality.
Interpretation: A case of chronic subdural hematoma on the left frontal area is seen on brain CT scan transverse sec- tion. There is a change in the appearance of the blood as it forms clot to less opacity. Some midline shift is noted. This is an example where a T2 MRI would be more helpful because CT scan beyond certain window of time may miss a smaller subdural hematoma that has organized to similar opacity as brain tissue. Patients in this age group are vulnerable to falls and at times can develop subdural hematoma, which may manifest itself in the form of mental status changes and, like in this case, a seizure.
A 47-year-old female with fatigue, sleepiness, cognitive difficulties, and mood lability/irritability. This evolved over a
couple of years. She still works but finds it extremely difficult to maintain her tasks as a single mother who runs home- based advertisement business. She had parkinsonism in the form of slow gait but also had dysarthria and mild ataxia.
A CT scan was ordered and is shown in .Fig. 3.11c. Please review the image and identify the abnormality.
Interpretation: A case of idiopathic calcification (Fahr disease) is seen on CT scan transverse section; notice the bone-like opacity in the basal ganglia and white matter including cerebellar white matter. This is a rare illness. The fact that the patient had movement changes and cerebellar signs is a good indication for brain imaging, in addition to early age of onset of her cognitive changes.
A 78-year-old man presenting with slowly progres- sive cognitive decline with amnesia at onset. CT scan was obtained by the primary care physician to rule out “reversible cause” for the cognitive change and is shown in .Fig. 3.11d. Please review the image and identify the abnormality.
Interpretation: The history and demographic data sug- gested Alzheimer disease. Brain imaging is useful mainly to rule out other causes but is not recommended by all guide- lines. When a recent image is available, the clinician can review to identify pattern of atrophy that may add certainty to the clinical suspicion of Alzheimer disease. This CT scan transverse image shows widening of the sulci including the Sylvian fissure and calcarine sulcus, in addition to widening of the inferior horn due to hippocampal atrophy suggesting Alzheimer disease.
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.Fig. 3.10 (continued) e 3D-SSP decrease map. Please refer to the text for interpretation
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.Fig. 3.11 A sampler of clinical cases where structural CT scan can be helpful. a A case of acute bleeding in subdural, subarach- noid, and intraparenchymal space evident on this transaxial CT scan (blood and bone appear white on the image). The image shows blood in left frontal area in addi- tion to subarachnoid space in the calcarine sulcus in addition to an area of encephalomalacia (brain tissue loss) from previous injury.
b A case of chronic subdural hematoma on the left frontal area seen on head CT scan transverse section; notice the change in the appearance of the blood as it forms clot to less opacity. Some midline shift is noted. This is an example where a T2 MRI would be more helpful because CT scan beyond certain window of time may miss a smaller subdural hematoma that has organized to similar opacity as brain tissue. c A case of idiopathic calcification (Fahr disease) as seen on CT scan transverse section; notice the bone-like opacity in the basal ganglia and white matter. d A CT scan transverse image showing widening of the sulci including the Sylvian fissure and calcarine sulcus in addition to widening of the inferior horn due to hip- pocampal atrophy as a result of Alzheimer disease
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