6. 7. 8. 9.
Letters to the Editor Dorr J, Krautwald S, Wildemann B, Jarius S, Ringelstein M, Duning T, et al. Characteristics of Susac syndrome: A review of all reported cases. Nat Rev Neurol 2013;9:307-16. Susac JO, Egan RA, Rennebohm RM, Lubow M. Susac’s syndrome: 1975-2005 microangiopathy / autoimmuneendotheliopathy. J Neurol Sci 2007;257:270-2. Do TH, Fisch C, Evoy F. Susac syndrome: Report of four cases and review of literature. AJNR Am J Neuroradiol 2004;25:382-8. Saenz R, Quan AW, Magalhaes A, Kish K. MRI of Susac’s syndrome. AJR Am J Roentgenol 2005;184:1688-90.
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Website: www.annalsofian.org
DOI: 10.4103/0972-2327.150609
Issues with normative data of hippocampal volumetry in Indian population Sir, We read the paper entitled, “Hippocampal volumetry: Normative data in Indian population[1]” with great interest. The paper has attempted to give the normative data of hippocampal volumes in Indian population. The paper, though written well, could have been better if it clarified some of the issues: a. Paper mixes two issues of medial temporal sclerosis with hippocampal atrophy of Alzheimer’s disease and other dementias. Both however are different issues. Only a very small number of Alzheimer’s disease patients have hippocampal sclerosis. How could the paper extrapolate the data from the adults to elderly? b. Present study has taken adults, and given the normative data using 200 adults. The sample size calculations for the same have not been mentioned. How did the authors arrive at the figure of 200? Sampling method could have been mentioned. c. Implications of volumetry in medial temporal sclerosis (MTS) could have been mentioned apart from lateralization. d. Authors could have discussed more about the difference in the findings of hippocampal volumes e.g. Western data, Asian and their own data. Why is this difference? What do they hypothesize? e. Means of hippocampal volumes have been given, but the paper does not mention standard deviation of the same. Means without standard deviation would not make much sense? How could one deduce limits of “abnormal hippocampal volume/s” when standard deviations have not been given. f. Why was paired t-test used to know intra-rater variability and which 20 patients were chosen for the same? And why only 20? What decided the sample size calculations for the same? Intra-rater reliability coefficient could have been mentioned. g. Authors could specify which protocol of the review paper they have used and how was the calculation of area and volume was done as described by Konard et al.[2] h. Authors somehow attempt to extrapolate the data they obtained in young adults to older adults. This does not seem appropriate as hippocampus is a plastic and
vulnerable structure[3] affected by several stimuli and moreover, medial temporal lobe gets affected by a variety of factors in patients with Dementias.[4] Kuljeet Singh Anand, Vikas Dhikav, Sharmila Doraswamy1, Umesh Chandra Garga1 Departments of Neurology, and 1Radiology, Postgraduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi, India For correspondence: Dr. Vikas Dhikav, Department of Neurology,
Postgraduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi - 110 001, India. E-mail: [email protected]
References 1. 2.
3. 4.
Mohandas AN, Bharath RD, Prathyusha PV, Gupta AK. Hippocampal volumetry: Normative data in the Indian population. Ann Indian Acad Neurol 2015;18:267-71. Konrad C, Ukas T, Nebel C, Arolt V, Toga AW, Narr KL. Defining the human hippocampus in cerebral magnetic resonance images — an overview of current segmentation protocols. Neuroimage 2009;47:1185-95. Anand KS, Dhikav V. Hippocampus in health and disease: An overview. Ann Indian Acad Neurol 2012;15:239-46. Dhikav V, Sethi M, Anand KS. Medial temporal lobe atrophy in Alzheimer’s disease/Mild cognitive impairment with depression. Br J Radiol 2014:20140150.
Access this article online Quick Response Code:
Website: www.annalsofian.org
DOI: 10.4103/0972-2327.150607
Annals of Indian Academy of Neurology, April-June 2015, Vol 18, Issue 2
Copyright of Annals of Indian Academy of Neurology is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Letters to the Editor Dorr J, Krautwald S, Wildemann B, Jarius S, Ringelstein M, Duning T, et al. Characteristics of Susac syndrome: A review of all reported cases. Nat Rev Neurol 2013;9:307-16. Susac JO, Egan RA, Rennebohm RM, Lubow M. Susac’s syndrome: 1975-2005 microangiopathy / autoimmuneendotheliopathy. J Neurol Sci 2007;257:270-2. Do TH, Fisch C, Evoy F. Susac syndrome: Report of four cases and review of literature. AJNR Am J Neuroradiol 2004;25:382-8. Saenz R, Quan AW, Magalhaes A, Kish K. MRI of Susac’s syndrome. AJR Am J Roentgenol 2005;184:1688-90.
259 Access this article online Quick Response Code:
Website: www.annalsofian.org
DOI: 10.4103/0972-2327.150609
Issues with normative data of hippocampal volumetry in Indian population Sir, We read the paper entitled, “Hippocampal volumetry: Normative data in Indian population[1]” with great interest. The paper has attempted to give the normative data of hippocampal volumes in Indian population. The paper, though written well, could have been better if it clarified some of the issues: a. Paper mixes two issues of medial temporal sclerosis with hippocampal atrophy of Alzheimer’s disease and other dementias. Both however are different issues. Only a very small number of Alzheimer’s disease patients have hippocampal sclerosis. How could the paper extrapolate the data from the adults to elderly? b. Present study has taken adults, and given the normative data using 200 adults. The sample size calculations for the same have not been mentioned. How did the authors arrive at the figure of 200? Sampling method could have been mentioned. c. Implications of volumetry in medial temporal sclerosis (MTS) could have been mentioned apart from lateralization. d. Authors could have discussed more about the difference in the findings of hippocampal volumes e.g. Western data, Asian and their own data. Why is this difference? What do they hypothesize? e. Means of hippocampal volumes have been given, but the paper does not mention standard deviation of the same. Means without standard deviation would not make much sense? How could one deduce limits of “abnormal hippocampal volume/s” when standard deviations have not been given. f. Why was paired t-test used to know intra-rater variability and which 20 patients were chosen for the same? And why only 20? What decided the sample size calculations for the same? Intra-rater reliability coefficient could have been mentioned. g. Authors could specify which protocol of the review paper they have used and how was the calculation of area and volume was done as described by Konard et al.[2] h. Authors somehow attempt to extrapolate the data they obtained in young adults to older adults. This does not seem appropriate as hippocampus is a plastic and
vulnerable structure[3] affected by several stimuli and moreover, medial temporal lobe gets affected by a variety of factors in patients with Dementias.[4] Kuljeet Singh Anand, Vikas Dhikav, Sharmila Doraswamy1, Umesh Chandra Garga1 Departments of Neurology, and 1Radiology, Postgraduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi, India For correspondence: Dr. Vikas Dhikav, Department of Neurology,
Postgraduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi - 110 001, India. E-mail: [email protected]
References 1. 2.
3. 4.
Mohandas AN, Bharath RD, Prathyusha PV, Gupta AK. Hippocampal volumetry: Normative data in the Indian population. Ann Indian Acad Neurol 2015;18:267-71. Konrad C, Ukas T, Nebel C, Arolt V, Toga AW, Narr KL. Defining the human hippocampus in cerebral magnetic resonance images — an overview of current segmentation protocols. Neuroimage 2009;47:1185-95. Anand KS, Dhikav V. Hippocampus in health and disease: An overview. Ann Indian Acad Neurol 2012;15:239-46. Dhikav V, Sethi M, Anand KS. Medial temporal lobe atrophy in Alzheimer’s disease/Mild cognitive impairment with depression. Br J Radiol 2014:20140150.
Access this article online Quick Response Code:
Website: www.annalsofian.org
DOI: 10.4103/0972-2327.150607
Annals of Indian Academy of Neurology, April-June 2015, Vol 18, Issue 2
Copyright of Annals of Indian Academy of Neurology is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
