Pd

Presynaptic dopamine transporter imaging with SPECT and 123I FP-CIT, used to distinguish between disease with and without nigrostriatal deficit. Whereas neurodegenerative parkinsonian syndromes such as PD, MSA, and PSP present with compromised dopamine terminal function, illnesses without involvement of those terminals (e.g., essential tremor ET ) present with normal findings. Images courtesy of Prof. Klaus Tatsch, University of Munich. See color version on Companion CD. Fig. 4....

Energy Metabolism In Pd

Although the etiology of PD is unknown, the possibility of an underlying defect in mitochondrial metabolism has been addressed in several biochemical studies (76). There is evidence of reduced complex I activity in the substantia nigra in PD, and Gu et al. have suggested that a mitochondrial DNA abnormality may underlie this complex I defect in at least a subgroup of PD patients (77). Studies in other tissues, however, have produced conflicting results, perhaps in part because biochemical...

Clinical Aspects

KD is traditionally classified into three major forms on the basis of the age of onset (1) early-infantile, (2) late-infantile or juvenile, and (3) adult form. These forms also differ in their clinical severity, and the late-onset forms are characterized by a milder and more protracted course. The emergence of molecular genetic advances in the metabolic diseases has blurred these discrete boundaries between categories and consolidated the concept of a continuum of disease expression from...

Activation And Regional Cbf Patterns In Normal Individuals And In Pd

The classical view of the basal ganglia function under normal circumstances is that of a structure in which five separate parallel circuits, under dual control by the direct and indirect pathways, subserve specific areas of the neocortex. These segregated pathways thus process cortical information from the supplementary motor area (SMA) and premotor cortex (PMC) dorsolateral prefrontal cortex (DLPFC) lateral orbitofrontal cortex anterior cingulate area and oculomotor cortex. Their role seems to...

References

Thomas P, Hazif-Thomas C, Saccardy F, Vandermarq P. Loss of motivation and frontal dysfunction. Role of the white matter change. Encephale 2004 30 52-59. 2. O'Sullivan M, Morris RG, Huckstep B, Jones DK, Williams SC, Markus HS. Diffusion tensor MRI correlates with executive dysfunction in patients with ischaemic leukoaraiosis J Neurol Neurosurg Psychiatry 2004 75 441-447. 3. van der Knaap MS, Naidu S, et al. New syndrome characterized by hypomyelination with atrophy of the basal ganglia and...

Spect Radioligands

Although 123I-P-CIT is clearly useful in imaging striatal DAT, its pharmacokinetic characteristics delay imaging until the day after radioligand injection (28). It also may be somewhat less specific than desired, having a tendency to accumulate at serotonin transporters (29,30). Thus, N-Q-fluoralkyl analogs 123I-FP-P-CIT 4-iodophenyl -nortropane) and 123I-FE-P-CIT were developed. Both of these compounds bind to live and postmortem striatal DAT within 30 min and wash out of the occipital cortex...

Lysosomal Disorders

Krabbe Disorder Infants

Lysosomal disorders may present as a classic leukodystro-phy or a leukoencephalopathy associated with systemic manifestations. The disorders discussed are not exhaustive of lysosomal disease with white matter disorders and are meant to be representative. Metachromatic leukodystrophy is also known as MLD metachromatic leukoencephalopathy cerebral sclerosis, diffuse, metachromatic form sulfatide lipidosis arylsulfatase A deficiency arylsulfatase A (ARSA) deficiency and cerebro-side sulfatase...

Mitochondrial Cytopathies

Mitochondrial disorders are caused by mutations of nuclear or mitochondrial DNA encoded genes involved in oxidative phosphorylation. Mutations in these critical genes are associated with specific clinical syndromes with diverse presentations (99,100). Because mitochondria are present in many of our organs and play a key role in energy metabolism, mitochondrial encephalomyopathies often present as multisystem disorders that may manifest with neurologic, cardiac, endocrine, gastrointestinal,...

Presynaptic Da Function

18F fluorodopa FDOPA is the radioligand used mostly for quantifying the nigrostriatal dopaminergic dysfunction in PD. This tracer measures the rate of FDOPA decarboxylation and subsequent storage in the dopaminergic nerve terminals. FDOPA uptake is estimated by using a striatal occipital ratio SOR striatal occipital - 1 9,10 or influx constant K computed from dynamic data 11-13 . It has been established that FDOPA uptake is reduced in the posterior putamen but relatively preserved in the...

Summary

Positron emission tomography PET scan with 18F -6-fluoro- dihydroxyphenylalanine FDOPA is currently the imaging gold standard for diagnosing Parkinson's disease PD , but this procedure is available at only a limited number of facilities. PET cameras are expensive, they require proximity to a cyclotron, and tests are nonreimbursable. A less costly and more available test, such as a single photon emission computed tomography SPECT , may thus be helpful in the diagnosis of early or atypical PD, if...