Answer for BIR CoW 16 May 2021
Hypoxic ischemic encephalopathy
Findings
1. Bilateral Symmetrical areas of gyriform restricted diffusion noted in the bilateral frontotemporoparietooccipital regions
2. Bilateral symmetric homogenous FLAIR hyperintensities with restricted diffusion noted in bilateral basal ganglia and bilateral posterior thalamus
Discussion
Hypoxic–ischemic brain injury (HIBI) is not uncommon in day to day clinical practice. It occurs in cases of cardiac arrest that are revived by cardiac resuscitation In adults, mild to moderate hypoxic ischemic brain injury leads to water shed infarcts. Severe HIBI affects gray matter of the perirolandic cortical neurons, occipital cortex, medial prefrontal cortex, basal ganglia, thalami, hippocampus and cerebellum. In acute stage (less than 24 h), affected cortex and deep gray matter may show restricted diffusion in the form of bright signal on. Diffusion Weighted Images (DWI) and corresponding low signal on apparent diffusion coefficient (ADC) map due to cytotoxic edema. DWI starts to pseudonormalize after one week. In early subacute stages (24 h–2 weeks). In chronic stages, T2W/FLAIR hyperintensity decreases, but the cortical laminar necrosis seen as gyriform hyperintensity on T1W images starts to become more prominent. Early evidence of cortical laminar necrosis was seen in our case as T1W hyperintensity involving the right occipital and perirolandic cortex. On contrast study gyriform pattern of cortical enhancement was seen which is likely due to breakdown of blood brain barrier and impaired autoregulation. Contrast enhancement is usually seen in such cases after 1–2 weeks, peaks after 1–2 months, and commonly resolves after 6 months. CT scan has a limited role in diagnosing the extent of hypoxic brain injury. CT Signs of global hypoxia : Loss of cortical gray white matter differentiation Reduced delineation of deep gray matter Effacement of cortical sulcal spaces
REFERENCES
1. Norton L., Hutchison R.M., Young G.B., Lee D.H., Sharpe M.D., Mirsattari S.M. Disruptions of functional connectivity in the default mode network of comatose patients. Neurology. 2012;78:175–181. [PubMed] [Google Scholar] 2. Els T., Kassubek J., Kubalek R., Klisch J. Diffusion-weighted MRI during early global cerebral hypoxia: a predictor for clinical outcome? Acta Neurol Scand. 2004;110:361–367. [PubMed] [Google Scholar] 3. Forbes K.P., Pipe J.G., Bird R. Neonatal hypoxic ischemic encephalopathy: detection with diffusion-weighted MR imaging. Am J Neuroradiol. 2000;21:1490–1496. [PMC free article] [PubMed] [Google Scholar] 4. Takahashi S., Higano S., Ishii K. Hypoxic brain damage: cortical laminar necrosis and delayed changes in white matter at sequential MR imaging. Radiology. 1993;189:449–456. [PubMed] [Google Scholar] 5. Siskas N., Lefkopoulos A., Ioannidis I., Charitandi A., Dimitriadis A.S. Cortical laminar necrosis in brain infarcts: serial MRI. Neuroradiology. 2003;45:283–288. [PubMed] [Google Scholar]
Findings
1. Bilateral Symmetrical areas of gyriform restricted diffusion noted in the bilateral frontotemporoparietooccipital regions
2. Bilateral symmetric homogenous FLAIR hyperintensities with restricted diffusion noted in bilateral basal ganglia and bilateral posterior thalamus
Discussion
Hypoxic–ischemic brain injury (HIBI) is not uncommon in day to day clinical practice. It occurs in cases of cardiac arrest that are revived by cardiac resuscitation In adults, mild to moderate hypoxic ischemic brain injury leads to water shed infarcts. Severe HIBI affects gray matter of the perirolandic cortical neurons, occipital cortex, medial prefrontal cortex, basal ganglia, thalami, hippocampus and cerebellum. In acute stage (less than 24 h), affected cortex and deep gray matter may show restricted diffusion in the form of bright signal on. Diffusion Weighted Images (DWI) and corresponding low signal on apparent diffusion coefficient (ADC) map due to cytotoxic edema. DWI starts to pseudonormalize after one week. In early subacute stages (24 h–2 weeks). In chronic stages, T2W/FLAIR hyperintensity decreases, but the cortical laminar necrosis seen as gyriform hyperintensity on T1W images starts to become more prominent. Early evidence of cortical laminar necrosis was seen in our case as T1W hyperintensity involving the right occipital and perirolandic cortex. On contrast study gyriform pattern of cortical enhancement was seen which is likely due to breakdown of blood brain barrier and impaired autoregulation. Contrast enhancement is usually seen in such cases after 1–2 weeks, peaks after 1–2 months, and commonly resolves after 6 months. CT scan has a limited role in diagnosing the extent of hypoxic brain injury. CT Signs of global hypoxia : Loss of cortical gray white matter differentiation Reduced delineation of deep gray matter Effacement of cortical sulcal spaces
REFERENCES
1. Norton L., Hutchison R.M., Young G.B., Lee D.H., Sharpe M.D., Mirsattari S.M. Disruptions of functional connectivity in the default mode network of comatose patients. Neurology. 2012;78:175–181. [PubMed] [Google Scholar] 2. Els T., Kassubek J., Kubalek R., Klisch J. Diffusion-weighted MRI during early global cerebral hypoxia: a predictor for clinical outcome? Acta Neurol Scand. 2004;110:361–367. [PubMed] [Google Scholar] 3. Forbes K.P., Pipe J.G., Bird R. Neonatal hypoxic ischemic encephalopathy: detection with diffusion-weighted MR imaging. Am J Neuroradiol. 2000;21:1490–1496. [PMC free article] [PubMed] [Google Scholar] 4. Takahashi S., Higano S., Ishii K. Hypoxic brain damage: cortical laminar necrosis and delayed changes in white matter at sequential MR imaging. Radiology. 1993;189:449–456. [PubMed] [Google Scholar] 5. Siskas N., Lefkopoulos A., Ioannidis I., Charitandi A., Dimitriadis A.S. Cortical laminar necrosis in brain infarcts: serial MRI. Neuroradiology. 2003;45:283–288. [PubMed] [Google Scholar]
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!