Bilateral basal ganglia abnormalities - MRI

Bilateral basal ganglia abnormalities , mri , co poisoning , leighs disease , liver cirrhosis , HIE

1. DIFFERENTIAL DIAGNOSIS FOR BILATERAL ABNORMALITIES OF THE BASAL GANGLIA AND THALAMUS Dr Roshan Valentine PG Resident St Johns Medical College

2. INTRODUCTION Abnormalities of basal ganglia seen in various conditions. MR – IOC CT - emergency situations – altered sensorium / acute seizures. In this article , we review the MRI anatomy of basal ganglia and pathology conditions of these brain structures

3. ANATOMY Deep gray matter include paired BG and thalamus Here we restrict to abnormalities of lentiform nucleus and caudate nucleus Lentiform N : GP(D) + Putamen(I) Caudate N (I) Basal ganglia involved in production of movement and in memory , cognition and emotion.

4. ANATOMY LFN is rich in mitochondria , vascular supply , neurotransmitters – high metabolic activity and oxygen uptake - vulnerable to metabolic abnormalities Thalamus is paired structure on either side of third ventricles. Responsible for relaying sensory and motor signals to and from the cerebral cortex Disorders of thalamus affects consciousness and abnormalities of sensation

5. ANATOMY BLOOD SUPPLY BG : Medial and lateral lenticulostriate arteries Thalamus : PCA and PCOM Venous drainage : deep venous system ; internal cerebral veins - basal vein of Rosenthal - great vein of galen

6. TOXIC POISONING CAUSE : MC - CO , methanol and CN Impairs mitochondrial enzyme in electron transport chain . CLINICAL FEATURES : Acute cognitive impairment /coma , optic neuritis (methanol) DIAGNOSIS Toxicology and Lab tests , imaging ( assess brain damage)

7. TOXIC POISONING IMAGING FINDINGS CO – GP(MC) : T1 & T2 hyperintense + DWI RD , Delayed leukoencephalopathy CN , Meth : Hemorrhagic necrosis of putamen Meth : White matter edema

8. LIVER DISEASE CAUSATIVE AGENT : Due to nitrogenous waste crossing BBB CLINICAL FEATURES : cirrhosis with portal htn /iatrogenic (TIPSS) IMAGING FINDINGS : - GP and SN : hyper on T1( due to Mn deposn ) - Reversible post transplantation. - Acute hyperammonemia : bilaterally symmetric swelling, T2 prolongation restricted diffusion in the basal ganglia , insular cortex, and cingulate gyrus - MRS : Detection of glutamate-glutamine

9. NON KETOTIC HYPERGLYCEMIA CLINICAL FEATURES : poorly controlled diabetes with chorea , hemiballismus +/- altered mental status. Treatable condition which shows resolution of findings when performed 2-12 months later IMAGING FINDINGS CT: B/L or rarely U/L hyperattenuation of GP or CN MR : hyperintensity on T1 and variable intensity in T2

10. HYPOGLYCEMIA CLINICAL FEATURES : Diabetic pts, Seizures , focal neurological deficits and coma. Extent of brain damage depends on severity and duration of hypoglycemia. IMAGING FINDINGS : T2 hyperintensity in cerebral cortex , hippocampi and BG Mild reversible hypoglycemia – transient and isolated WMI with true diff restriction involving splenium , internal capsule and corona radiata . BG INVOLVEMENT : POOR PX

11. HYPOXIC ISCHEMIC ENCEPHALOPATHY CAUSE : Result of cardiac arrest /drowning/asphyxiation IMAGING FINDINGS: Mild HIE : water shed zones Severe HIE : grey matter structures like cerebral cortex , BG and hippocampi. Brainstem and WM are typically spared. CT : Diffuse edema , decreased attenuation of the cortical gray matter with loss of normal gray matter–white matter differentiation, BG and Thalamus WHITE CEREBELLUM SIGN : diffuse cerebral damage results in lower attn. of cerebral parenchyma , compared to cerebellum and BG which are spared – POOR PX

12. HYPOXIC ISCHEMIC ENCEPHALOPATHY Earliest finding(after 2 hrs ) : Increased SI of the affected areas on DW T2W : hyperintensity and swelling of affected areas ( after 24 hrs ) Delayed : T2 hyperintensity in subcortical WM

13. LEIGH DISEASE Subacute necrotizing encephalopathy CAUSE : Disorder in ATP synthesis at ETC CLINICAL FEATURES : Central hypotonia , developmental regression/arrest , ophthalmoplegia , resp and bulbar dysfunction and ataxia. IMAGING FINDINGS: T2 hyperintensity in BG , periaquedeuctal region , cerebral peduncles and putamen. MRS : High lactate levels in BG DIAGNOSIS : Imaging + Elevated serum and CSF lactate levels.

14. WILSON DISEASE CAUSE : Accumulation of Cu due to ceruloplasmin deficiency. CLINICAL FEATURES : dysarthria, dystonia, tremors , ataxia, Parkinsonian symptoms, and psychiatric problems. IMAGING FINDINGS: MR : T2 hyperintensity in Putamen(MC) GP , caudate nucleus , thalamus Less common : cortical and subcortical region , mesencephalon , pons , vermis and dentate nuclei DWI restriction in early stages

15. OSMOTIC MYELINOLYSIS CAUSE : electrolyte imbalance, chronically alcoholic pts, chronically debilitated organ transplant pts , rapid overcorrection of hyponatremia. Oligodendroglial cells are more susceptible to osmotic stresses.

16. OSMOTIC MYELINOLYSIS IMAGING FINDINGS: MRI : T1 and T2 hyperintensity in affected areas Central pontine myelinolysis : Symmetric trident shaped / bat wing shaped T2 /FLAIR hyperintensity in central pons Ventrolateral pons and pontine portion of CST are spared Extrapontine myelinolysis : T2 hyperintensity in GP , putamen , thalamus and cerebellum. DWI R in early stages – not typical though DIAGNOSIS : Imaging + serial Na measurement

17. WERNICKE ENCEPHALOPATHY CAUSE : Vit B1 def , Chronic alcoholics , GI or hemat neoplasm , chronic dialysis , prolonged TPN without vit supplementation. CLINICAL FEATURES : altered consciousness, ocular dysfunction, and ataxia IMAGING FINDINGS: MRI : Symmetric T2 hyperintensity in medial thalamus , periaqueductal area , mammillary body and tectal plate. Petechial hemorrhage , diffusion restriction and contrast enhancement of affected areas

18. NEURODEGENERATION WITH BRAIN IRON ACCUMULATION (NBIA) Heterogenous group of disorder with brain degeneration and excessive iron deposition in basal ganglia(PAN K 2 gene mutation.) 2 types Classic early onset , rapidly progressive( halloverden spatz ) Atypical late onset and slowly progressive CLINICAL FEATURES : pyramidal or extrapyramidal signs , dystonia, and dysarthria IMAGING FINDINGS: MR : B/L T2 hypointensity in GP with high signal intensity center -EYE OF THE TIGER appearance

19. Creutzfeldt – jakob Disease Transmissible fatal neurodegenerative disorder caused by prions CLINICAL FEATURES : rapidly progressive dementia, myoclonus, and multifocal neurologic dysfunction . DIAGNOSIS: Brain Biopsy /autopsy, periodic charp wave complexes at EEG IMAGING FINDINGS : MRI : DWI R of cerebral cortex and basal ganglia Variant CJD : Bovine spongiform encephalopathy B/L lesions in pulvinar nuclei of thalamus( pulvinar sign/hockey stick sign)

20. FAHR DISEASE Bilateral striopallidodentate calcinosis B/L symmetric deposition of Ca and other minerals in BG ,Thalamus , Dentate nuclei and centrum semiovale in absence of HYPOPARATHYROIDISM. CLINICAL FEATURES : Headache , vertigo , movt disorders , syncope , seizures , coma, dementia , parkinsonism , chorea, dystonia etc. IMAGING FINDINGS: MRI/CT : B/l symmetric dense calcifications in BG , dentate nuclei , thalamus , subcortical white matter .

21. DEEP CVT CAUSE : hypercoagulable states , OCPS , vasculitis , intracranial / systemic infections IMAGING FINDINGS: Superficial CVT: cerebral edema and venous infraction of cerebral cortex near vertex. Deep CVT: Venous HTN , b/L involvement of thalamus and basal ganglia. MRI/CT: Venous HTN and cerebral edema results in T2 hyperintensity in thalamus , BG , internal capsule and DWM Hemorhhagic transformation common MR venogram : evaluation of thrombus

22. ARTERIAL OCCLUSION CLINICAL FEATURES : Agitation , obtundation , coma , memory dysfunction and various ocular changes IMAGING FINDINGS: Acute infarcts : T2 hyperintensity and DWI R with occlusion seen on MRA based on the artery occluded. Artery of Percheron infarct : B/l symmetric paramedian parts of thalamus and midbrain on both sides.

23. Figure 19. Basilar artery occlusion in a 61-year-old man with ocular signs and severe obtundation . (a) Diffusionweighted MR image shows bilateral hyperintense areas in the paramedian thalamus (arrows). (b) Timeof - flight MR angiogram clearly depicts occlusion of the rostral portion of the basilar artery (arrow). (c, d) Noncontrast CT scans obtained 3 days later show bilateral subacute infarcts of the thalamus (arrows in c) and an infarct in the right cerebellar hemisphere (arrow in d).

24. NEURO – BEHCET DISEASE Behcet syndrome : uveitis , oral ulcers and genital ulcers. CNS involvementin 4-49% CLINICAL FEATURES : Headache , dysarthria , cerebellar signs , sensory signs and personality change. IMAGING FINDINGS: T2 hyperintense and T1 hypointense and CE with vasogenic edema at brainstem, basal ganglia (bilateral involvement in one-third of cases), and thalamus , WM(LC)

25. FLAVI VIRUS ENCEPHALITIS Eg : Japanese encephalitis, West nile fever , Murray valley fever IMAGING FINDINGS: Symmetric involvement of deep grey matter JE : T2 hyperintensity in B/L posteromedial thalamus Intralesional hemorrhages + DWI R Less common sites : basal ganglia, substantia nigra , red nucleus, pons, hippocampi, cerebral cortex , and cerebellum . JE and Murray valley fever involve THALAMUS West nile fever : B/L involvement of thalamus , caudate and lentiform nucleus

26. CEREBRAL TOXOPLASMOSIS CAUSE : Toxoplasma gondii typically in imuncompromised pts MAGING FINDINGS: M ultiple focal lesions in the basal ganglia and lobar gray matter–white matter junctions T2 W : hypo to isointense lesions with prominent mass effect and vasogenic edema +/- hemorrhagic lesions Post Contrast : nodular/ ring enhancement MRS : increased lipid levels without elevated choline levels

27. PRIMARY CNS LYMPHOMA CAUSE : immunocompetent and immunocompromised IMAGING FINDINGS: T2 hypointensity and high attenuation in CT involves deep hemispheric periventricular white matter, corpus callosum, and basal ganglia MRS : Elevated choline levels Immunocompetent : Solid, homogeneously enhancing lesions Immunocompromised : Ring enhancement and central necrosis

28. PRIMARY BILATERAL THALAMIC GLIOMA Thalamus is affected in 1-1.5% of brain tumors / contiguous spread from pineal germ cell tumors. CLINICAL FEATURES : behavioral impairment ranging from personality changes to dementia . IMAGING : T2 hyperintense and T1 isointense B/L symmetric mass with no CE Low grade tumors characterized by absence of tumor progression on serial MR images,

29. NEUROFIBROMATOSIS TYPE I MC neurocutaneous syndrome CLINICAL FEATURES : café-au- lait spots, axillary freckling , Lisch nodules, neurofibromas, plexiform neurofibromas , optic glioma, bone dysplasias , or pseudoarthrosis . IMAGING FINDINGS : Focal T2 hyperintense and TI hypointense in GP > brainstem and cerebellum NO mass effect No surrounding edema No CE MRS : high NAA- Ch , Naa -Cr and Cr- Cho ratios

30. DX

31. LAB EVALUATION Immunoassay Toxoplasmosis and Flavivirus Eeg + CSF analysis CJD Vit B1 assay Wernickes Serum glucose Hypoglycemia/Hyperglycemia Serum Ceruloplasmin Wilsons disease Serum and CSF Lactate Leigh Disease Serum Ca , P and PTH Fahrs DIsease

32. DX

33. CLINICAL HISTORY Suicide attempt cardiac arrest diabetic hypoglycemia hyperglycemia Hiv – AIDS Vit deficiency Electrolyte imbalance

34. DX

35. IMAGING FINDINGS B/L symmetric LN andCN Systemic /metabolic Asymmetric focal/Discrete Infection/neoplasm Thalamus+ BG Hypoxia , osmotic myelinolysis , wilsons disease , Leighs disease , Fahrs disease , CJD , deep CVT, Infection , Primary CNS lymphoma BG w/o Th Systemic disease ( toxic poisoning , hypoglycemia , hyperglycemia , liver disease , huntingtons disease , NF) B/L Th w/o BG Focal ( arterial occlusion , Flavivirus , infection )

36. ASSOCIATED ABNORMALITIES Diffuse or focal cortical involvement Hypoxia , hypoglycemia and CJD Diffuse and bilateral white matter abnormality poisoning , hypoglycemia Brainstem Leigh disease , Myelinolysis , Neuro behcets disease , Basilar artery occlusion Perilesional edema + infiltration outside BG + Th CNS infection + tumors

37. ASSOCIATED ABNORMALITIES T2W HYPERINTENSITY Acute diseases of d eep grey matter nuclei T1W HYPERINTENSITY Hepatic dis , Mn deposition , Hyperglycemia , NF 1 CT Ca – Fahrs disease, Hypoparathyroidism H’age – Poisoning, CNs toxoplasmosis, Venous infarction , JE DWI Acute cytotoxic brain damage in acute infarction, hypoxia, hypoglycemia, CJD, and Wernicke encephalopathy MRS lactate in hypoxia or mitochondrial disease