decoding the deep gray
DESCRIPTION
jurnal neuroimaging, basal gangliaTRANSCRIPT
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Christie M. Lincoln, MD, Jacqueline A. Bello, MD, and Yvonne W. Lui, MD
Neurographics 2:92102 Sep 2012 www.neurographics.com
Presented by : dr. DILA SITI HAMIDAH
Lecturer : dr. H.FARHAN ANWARY, Sp.Rad(K), MH.Kes
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INTRODUCTIONBASAL GANGLIA
collection of deep gray matter nuclei
play a major role in the extrapyramidal system
contribute to:
higher emotional
sensorimotor
associative
cognitive
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INTRODUCTION
Imaging Anatomy
Neuronal Circuitry
Imaging Appearance of PathologicProcesses
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ANATOMYPaired structures
One set of nuclei within each cerebral hemisphere
and hemi-brain stem
CAUDATE NUCLEUS
LENTIFORM NUCLEUS
PUTAMEN GLOBUS PALLIDUS
SUBTHALAMIC NUCLEUS
SUBSTANTIA NIGRA
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Axial T1-weighted MR image demonstrates the
putamen (short arrow) and globus
pallidus (arrow), collectively referred to as
the lentiform
nucleus. An asterisk is over the caudate
head
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Caudate Nucleus TAILED
Derived from the telencephalon
Composed of : HEAD, BODY, TAIL
Follows the lateral wall of the lateral ventricle with its tail terminating at the amygdala
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Caudate Nucleus Bilateral or unilateral lesions of the caudate :
Abulia
Apathetic affect with loss of:
initiative
spontaneous thought
emotional response
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Lentiform Nucleus Comprises
2 parts :
Putamen
Globuspallidus
lenslike shaped
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The globus palliduscomprises 2 segmentsthat is, internal (black arrow) and external (white arrow) segmentsseparated by the internal medullarylamina
Globus Pallidus
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Subthalamic Nucleus
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Substantia Nigra
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Vascular Supply Rich vascular supply
Primary constributor : the medial and lateral lenticulostriate arteries, and the recurrent artery of Heubner
The medial lenticulostriates
The medial basal ganglia, caudate nucleus, and internal capsule
Arise from the A1 segment of the ACA
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Vascular Supply The recurrent artery of Heubner
The superolateral caudate head, the anterior limb of the internal capsule, and the anterior lentiform nucleus
The largest and longest of the perforating branches, typically arises from the proximal A2 segment of the ACA
The lateral lenticulostriates
The lateral putamen, caudate nucleus, and external capsule
Arise from the M1 segment of the MCA
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Vascular Supply The substantia nigra is supplied by:
Its caudal extent : peduncular branches of the posterior cerebral artery, the medial posterior choroidal artery, and the superior cerebellar artery.
Its rostral region : the premamillary branches of theposterior communicating artery and the peduncular branches of the anterior choroidalartery
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Vascular Supply The subthalamic region is supplied by :
Posteromedial arteries derived from the posterior communicating and posterior cerebral artery
The peduncular branches of the anterior choroidalartery
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Neuronal Circuitry Several different neurotransmitters :
GABA
Dopamine
Acetylcholine
Glutamine
Enable the function of the basal ganglia as an intermediary between the cortex and the thalamus viathe basal gangliathalamocortical circuits
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Neuronal Circuitry Consist of 2 circuits :
Direct
Indirect
Maintain somatotopic organization of movement forfluidity and coordination
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IMAGING Most of the basal ganglia are well-demonstrated on
crosssectional imaging
Noncontrast CT shows the caudate, putamen, and globus pallidus relatively high attenuationcompared with white matter
On MR imaging, the caudate and putamen generallyfollow cortical gray matter signal intensity
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IMAGING In the healthy adult :
The globus pallidus, subthalamic nucleus, and substantia nigra : relatively hypointense to cortical gray matter on T2WI, due to higher iron concentration
In a young patient:
The substantia nigra is hyperintense on T2WI
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IMAGING Imaging is useful in the evaluation of basal ganglia
abnormalities
CT is the most commonly performed brain imagingand demonstrates calcification, acute hemorrhage, prior ischemic injury, and volume loss
MR imaging is advantageous in delineating anatomy and demonstrating signal-intensity alteration
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IMAGING ALGORITHM: CTHYPERDENSE
HEMORRHAGE
CONTRAST POST
ANGIOGRAM
CALSIFICATION AGE RELATED
METABOLISM ABNORMALITY
FAHR DISEASE
HIV
DOWN SYNDROME
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A 70-year-old woman with a history of hypertension presentswith headache. Noncontrast head CT shows acute
hemorrhage in the leftlentiform nucleus
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A 53-year-old man immediately after a conventional cerebral angiography has a noncontrast head CT, demonstrating left lentiform
hyperattenuation, which resolved on follow-up imaging the next day (not shown).
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Fig 5. A, A 45-year-old woman with Fahr disease manifesting hyperattenuation/calcification of the bilateral lentiform nuclei on noncontrasthead CT. B, A 16-year-old HIV-positive girl also with hyperattenuation/calcification of the bilateral lentiform nuclei on noncontrast head CT. C, A21-year-old man with Down syndrome (trisomy 21) has noncontrast headCT demonstrating bilateral lentiform calcifications.
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IMAGING ALGORITHM: CT
HYPODENSE
EDEMA
INFARK
OLD HEMORRHAGE
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A 29-year-old man with hypoxic brain injury after heroin overdosehas hypoattenuation within the lentiform nucleus and caudate on
noncontrast CT
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A 58-year-old man with left hemineglect has noncontrast
head CT using a narrow window showing subtle
hypoattenuation in the right lentiform nucleus
(A). Gray scale cerebral blood volume perfusion map (B). clearly shows the
perfusion deficit
Noncontrast head CT in a 68-year-old woman with known Huntington disease shows atrophy of the bilateral caudate nuclei resulting in a boxlike configuration to the frontal horns.
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IMAGING ALGORITHM : MRI
T1 HYPERINTENSE
HYPOXIA
HYPERALIMENTATION WILSON DISEASE
CHRONIC LIVER FAILURE
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A T1-weighted MR image in a 56-year-old man with hepatoma and hepatic
encephalopathy shows hyperintensitywithin the bilateral globus pallidi
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IMAGING ALGORITHM: MRI
PUTAMEN
LEIGH DISEASE
METHANOL TOXICITY
PRION DISEASE
WILSON DISEASE
GLOBUS PALLIDUS
HYPOXIA
HYPOGLICEMIA
HALLERVODEN-SPATZ
DISEASE
CO TOXICITY
NF 1
T2 HYPERINTENSE
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HIE in a 38-year-old woman who was resuscitated after being involved in a traffic accident. (a) T2-weighted MR image demonstrates
bilaterally symmetric hyperintense areas in the thalamus (white arrowheads), basal ganglia, and cerebral cortex. Black arrowheads =
caudate nuclei, arrows = lentiform nuclei
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CO poisoning Symmetric CT
hypoattenuationand T2 hyperintensity due to necrosis in the globus pallidus are characteristic of carbon monoxidepoisoning Noncontrast head CT in a 30-year-old man with
carbon monoxide poisoning shows characteristicbilateral globus pallidal necrosis
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Neurofibromatosis type I An autosomal dominant
disorder and one of the most common phakomatoses
T2 prolongation typically affects the globus pallidus and the brain stem, cerebellum, and thalamus
An 18-year-old woman with neurofibromatosis 1 also demonstrating
characteristic irregular hyperintense signal intensity on T2WI in the bilateral globus
pallidi.
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Hallervoden-Spatz (PKAN) MR imaging:An eye of the tiger
appearance, withbilateral central T2 hyperintensityrepresenting gliosis
Surrounded by a rim of T2 hypointensity, representing iron inthe globus palliduson T2-weighted sequences
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Leigh Disease Progressive hereditary neurodegenerative disorder
Involves brain structures highly dependent on glucose metabolism (ie, the lentiform nuclei and caudatenuclei)
Additional areas including the thalamus, periaqueductal gray, tegmentum, red nuclei, anddentate nuclei
Symmetric T2 signa-intensity abnormality
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Toxic and Metabolic Insults The toxin that produces bilateral putaminal lesions is
methanol poisoning
Patients often present with metabolic acidosis
Classic MR imaging findings of bilateral putaminalnecrosis, which may be associated with hemorrhage
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31-year-old woman with known history of Wilson disease presents with characteristic MR imaging findings of lateral putaminal T2 hyperintensity (arrow)
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A 40-year-old woman with progressive multifocal neurologic dysfunction who underwentMR imaging with symmetric T2 signal intensity abnormality in the bilateral caudate heads,bilateral putamina, and bilateral subinsular ribbon and bifrontal cortex, which are imagingfindings shared by all types of prion diseases (A). Diffusion-weighted imaging showsrestricted diffusion in the same areas (B).
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Perivascular Space Dilatation Perivascular spaces or Virchow-Robin spaces
containing perforating lenticulostriate arteries course through the inferior basal ganglia
Generalized cerebral volume loss, metabolic disorders,and central nervous system infection perivascularspaces enlargement
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An MR image of an 87-year-old woman with memory loss who shows prominent perivascular spaces following the CSF on all pulse sequences including T2
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Substantia Nigra and SubthalamicNucleus Nigrostriatal denervation, the hallmark of Parkinson
disease, leads to overactivity of the globus pallidusinterna and the substantia nigra pars reticulata.
The cardinal motor signs found in Parkinson disease, akinesia, rigidity, and resting tremor, are attributed to loss of dopaminergic input to the striatum, which results from degeneration of the substantia nigra pars compacta
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